ENTOMOLOGY

s A N I T A R yENTOMOLOGYTHE ENTOMOLOGY OF DISEASE,HYGIENE AND SANITATIONEDITED BYWII,LIAM DWIGln~ PIERCE, PH.D.Consulting Entomologist, formerly Entomologist Southem Field CropInsect Inv(Stiqations U"it·'d StotfO Departmentof Agriculture, Bureau of EntomologyBOSTONRICHARD G. BADGERTHE GORHAM PHESS

COPYBIGHT, 1921, BY RICHAnD G. BADGERAll Rights ReservedNLVS/IVRI~II mil II ~IIIIIIIIIIIIII01319Made in the United States of AmericaThe Gorhllm Press, Boston. U. S. A.

The house or typhoid fly, Musca domestica. Greatly enlarged. (Howard and Pierce,.~photo by Dovener.)

TODR. LELAND OSSIAN HOWARDCHIEF OF THE BUREAU OF ENTOMOLOGY,THIS BOOK ISDEDICATEDTO HIM, MORE THAN TO ANY ONE ELSE, DO ENTOMOLOGISTS OWETllE PllACTICAL DEVELOPMENT OF THEm SCIENCE, WUICIITOUCHES UPON EVERY HUMAN ACTIVITY. HE STOOD A.MONGTHE FIRST TO EMPHASIZE THE IMPORTANCE OF SANITARYENTOMOLOGY. HE STANDS NOW THE CHIEF EXPONENT OFE.lIqTOMOLOGY THROUGHOUT THE WORLD.

FOREWORDIN May, 1918, a class was formed, among the entomologists of thecountry to study the recent developments in the entomology of disease,hygiene, and sanitation, for the purpose of equipping themselves for anyspecial service which they might be called upon to render during the war.The lectur~s were mimeographed week by week and mailed to the enrolledmembership, which numbered in excess of 500.The war emergency is over and the mimeographed lectures havepractically all been distributed. These lectures, however, dealt as muchwith domestic as with military problems, and they have now been completelyrevised up to date o~March 1, 1919, and are given forth as aseries of lectures dealing with the entomological problems of peace timesfrom the standpoint primarily of municipal, industrial, and householdproblems, and also with the hope that the course will be of assistance toteachers, and will stimulate research among investigators. Manyimportant topics have been omitted, for we cannot hope to present thewhole subject in a book of this size.This phase of entomology is one which is destined to become veryimportant as our knowledge of disease transmission increases. Thereare many unworked and insufficiently worked problems now in sight, andthese lectures will be found to suggest numerous possible lines of research.. I wish at this time to express my appr~ig.tion of the services ofMr. Jacob Kotinsky, who served as Secretary of the Class, and of my .collaborators in this course of leptures.As nearly as possible the International Rules of Nomenclature arefollowed, but in Entomology the practice had not been followed of enclosingthe original author's name in parenthGsis followed by the 'nameof the author responsible for the present combination, and it has beenimpossible in the present volume to obtain all of the necessary information.W. DWIGHT PIERCE.

(,JIA.PTICRCONTENTSPAoaJ. How INSECTS CAN CARRY OR CAUSE DISEASE 19II.CLASSIFICATION OF METHODS BY WHICII INSECTS CAN CARRY OR CAUSEDISEASE. • • • • • • • • • • • • •• • •••WUY IT IS NECESSARY TO KNOW How INSECTS CARRY DISEASESOlliE NECESSARY STEPS IN ANY ATTEMPT TO PROVE INSECT TRANSMISSION ORCAUSATION OF DISEASE • • • • • • • • • • • • • • • • • • • 25I. COOPERATION ••• • • • • • • • . • • • • • • • • 25II. WHERE SUOULD TIlE INVESTIGATIONS OF INSECT TRANSMISSION BEGIN? 26III. PLAN OF OPERATION • • • • • • . • • • • • • • •• 26IV. How SHALL WE RECOltD OUR OBSERVATIOJo."8? • • • • ., 27V. How CA:N AN U,"8ECT BE INVOLVED IN DISEASE TRANSMISSION? 27, 1. What Kind of Organisms Can Insects Carry? . . . .. 272. In Wbat Manner May Insect Toxins Bring About Disease? 278. Can Insects Themselves Cause Disease? ........ 284. 'Vhere May Insects Obtain the Organisms Whieh Cause Disease? !i!S5. How Can the Insect Transmit the Organism? . . . . 286. What is the Course of the Organism in the Insect? . . . 297. What is thl" Course of the Orgenism on Leaving the Insect? 29VI. WHAT IS KNOWJIi ADOUT TUE DISEASE TO DE IJo."'VESTIGATED? .80VII. WIlAT h-SE{,TS SHOULD BE INVESTIGATED? • • • • • . 80VIII. WnAT IS NECESSARY IN TilE TRANS)IISSION EXPERIMENTS? 81IX. How SHOULD EXPERIMENTAL INSECTS DE HANDLED? 822028III. A GENERAL SURVEY OF TIlE NEEDS OF ENTOMOI,OGlCAL SANITATION INAMERICATilE INSANITARY F ARl!.1How TO IMPROVE FAml SANITATIONTilE INSANITARY TOWNHow TO IMPROVE SANITATION • • •SANITARY PROBLEMS OF CITIESF.N'I'OMOLOGICAL REQUIREMENTS OF l\1UNI,CIPAL SANITATIONINDI'STRIAL SANITATION • • • • • • • • • • • • •IV.A GENERAL SURVEY OF TilE SERIOUSNESS OF INSECT BORNE DISEASES TOARMIESV. RELATION OF INSECTS TO THE PARASITIC WORMS'OF VERTEBRATESMODE OF INFECTION OF INSECT HOSTS. • •II l\IODE OF INFECTION OF VERTEBRATE HOSTS.SPECIFS OF 'WORMS l!'OUND IN INSECTS. • •CESTODA OR TAPEWOlUIS. • • • • • • ••Dipylidium caninum (Linnmus. 11M!) Railliet. 1892Hymenolepis diminuta (Hudolphi. 1819) Blanchard. 1891IIymmolepis nana (Siebold. 1852) manehard, 1891 .Choanotmnia infundibulum (Bloch. 1779) Cohn, 1899Othl"r TapewormsTREMATODA OR FLUKES • • • • ~lX8-18586S888S9404148505152525S5S5-1.55565757

CONTENTSNEMATODA OR ROUNDWORMS • • • • • • • • • • • • • • • •1. Parasitic Nematodes Whose Eggs or Larvre Leave the Body of the FinalHost in the Feces. . . . . • . . . . . . . • . . . .Proto8pirU'fa mU1'i8 (GmeIin, 1790) Seurat, 1915 •.. . • .Spirocerca 8angllinolenta (Rudolphi, 1819) RaiIliet & Henry, 1911Spiru'I'a gast'l'ophila (Mueller, 1894) Marotel, 19U. . . • • •Gongylonema scutatum (Mueller, 18(9) RaiIIiet, 1892 . . . . •Gongylonema mU8C1'Onatum Seurat, 1916 • • • • • • • • • •Gongylonema brel1iapiculum Seurat, 1914 . . . . . . . . • .Gongylonema neoplaaticum (Fibiger and DitIevsen, 1914) Ransom andHall, 1916. . • . . • . • . • . . • • . • • •Arduenna atrongylina (Rudolphi, 1819) RailIiet and Henry, 1911Physocephalus se:I:alaius (Molin, 1860) Diesing, 1861 . . . .Habronema mUBCIJI (Carter, 18(1) Diesing, 1861 • . . . . .Habronema microstoma (Schneider, 18(6) Ransom, 1911 . • .Habronema megaatoma (Rudolphi, 1819) Seurat, 1914. . . •Acuaria api1'alill (Molin, 1858) RaiIIiet, Henry and Sisoff, 1912Filaria gaUinarum Theiler, 1919 . • • • . . • • • . .A8cari8lumbricoide8 LinnlllUs, 1758. • . . . . . . . . . •2. Parasitic Nematodes Whose First-Stage Larvre OCCur in tht' Blood OrLymph of the .Final Host and Leave the Body :Through Ingestion byBlood-Sucking Insects . . . . . . • . . . . . . . . . .Filaria baneroJti Cobbold, 1877 • • • • . .Filaria (Loa) loa (Cobbold, 18(4) . • • . •Filaria demarquayi Manson, 1895 . • • . •Filaria philippinensis Ashburn and Craig, 1006 •Filaria tueumana Biglieri and Ar40z, 1917 . •Filaria cypseli Annett, Dutton and Elliott, 1901Filaria martia Gmelin, 1790 .'. . • • . • • • •Dirofilaria immitis (Leidy, 1856) Railliet and Henry, 1911 • .• •Dirofilaria ropens, Railliet and Henry, 1911 . • • • . • . . •Acanthocheilonema per8tans (Manson, 1891) Bailliet, Henry and Langeron,1912 • • • . • " • . • • • . . . . • . . •A.canthocheilonema gra88ii (Noe, 1907) Railliet, Henry and Langeron,1912. • . • • • . . • • . • • • . • • • . . • •A.canthocheilonema reeonditum (Grassi. 1890) RailIiet, Ht'nry and Langeron,1912 • • • • • • • • • • • • • ',' • • • •Setaria labiato-papiUosa (Alessandrini, 1888) Bailliet and Henry, 1911OncocerM • . • • . . . . . . .8. Other Nematodes . • • . . . . . .4. Mermithidre. . . • . . . . . . .GonDIACEA OR HORSE-HAm 'WORMS. • ••ACANTlIOCEPHALA OR 1'IIORN-HEADED W01\MS. '"MacraJJanthorhynchuB/lirudinacoulI (Pallas, 1781) TraV83Sos, 1916Moniliformis moniliJ01'mill (Bremser, 1819) Travassos, 1915 ., .COMPENDlUlf OF PARASITES ARRANGED ACCORDING TO INSECT HOSTSAphaniptera (Siphonaptera)-f1easDiptera-f1ies . . • • . . •Neuroptera . . . . • . . .Trichoptera-hairy-winged insectsLepidoptera-moths. butterflies .Coleoptera-heetles .Mallophaga-bird liceIsoptera-termitesOdona.ta-dragonfliesPlectoptem-mayfliesPlecoptera-stonefiies . .Orthoptera~ockroa

DAPTeBVI.CONTENTSTHE RELATIONS OF CLlMJI.TE A.ND LIFE AND THEIR BI;AHINGS ON 'THE STUDYOF MEDICAL ENTOMOLOGY • • • • • • • • • '" 97VII. DISEASES BORNE BY NON-BITING FLIES • • • • • 105PLANT ORGANISMS CARRIED BY NON-BITING FLIES 107Thallophyta: Fungi: Schizomycetes: Coccacere. 107Thallophyta: Fungi: Schizomycetes: Bacteriacere 109Thallophyta: Fungi: Schizomycetes: Spirillacere 115SUMMARY OF PLANT ORGANISMS • • • • • • • 115DISEASES OF UNSETTLED ORIGIN PROBABLY CAUSED BY MICROORGANISMS 116ANIMAL ORGANISMS CARRIED BY NON-BITING FLIES 116Protozoa • • • • • • • • • • • • • • •Sarcodina: Amcebina: Amcebidre • '. . . .Mastigophora: Protomonadina: Bodonidre . .Mastigophora: Polymastigina: Polymastigidre.Mastigophora: Binucleata: Leptomonidre . .Mastigophora: Binucleata: TrypanosomidreMastigophora: Spirochretacea: Spirochretidre .Neosporidia: Myxosporidia: Nosemidre • . . . ;Protozoa: Neosporidia: Myxosporidia: ThelohanidreHIGHER ORGANISMS CARRIED BY FLIES. • • • • • •Platyhelmia: Cestoidea: Cyclophyllidea: Treniidre . . .Platyhelmia: Cestoidea: Cyclophyllidea: HymenolepididrePlat,helmia: Trematoda: Malacotylea: SchistosomidreNemathelminthes: Nematoda: Spiruridre • • . . .Nemathehninthes: Nematoda: AscaridreNemathelminthes: Nematoda: Oxyuridre '" .Nemathelminthes: Nematoda: AncylostomidreNem!lthelmintbes: Nematoda: TrichosomidteIMPORTANT GENERAL TEXT BOOKS • • • • •SPECIAL REFERENCES • • • • • • • • • •XlPAGB116116117117117119119UOliO1201201201201211211!l1122122U8128VIII. IMPORTANT PHASES IN THE LIFE HISTORY OF THE NON-BITING FLIES U6HOUSE FLY, MUSCA DOMESTICA LINN.a!lUS •••• 127THE BLUE BOTTLE FLIES OF THE GENUS CALLIPHORA 180THE SHEEP MAGGOTS OR GREEN BOTTLE FLIES 181OTIIER SCREW WORMS AND BLOW FLIES 182OrnER EXCREMENT BREEDERS • • • • • • 185REFERENCES187IX.COMMON FLIES AND How TO TELL THEM APARTTABLE TO SEPARATE THE ADULT FLIESThE LAnv.a!l on MAGGOTS • • • • • • • •Descriptions of Larvre or Maggots . . . . . . . .Table to Separate the Larvre (Maggots) . . . . . .Fannia canicularia Linnreus and Fannia 8calaria }o'abriciusMusca dome8tica Linnreus . . .Stomc:rgl colcitrana LinnreusM uacina atabulanB ;Fallen . . .Calliphora erythroctiphola MeigenCalliphora fIOmitoria Linnreus .Lucilia Iwata Meigen . . .Chrysomya macellaria FabriciusSarcophogidm • • • • • .BIDLlOG~PIIY••••••x. 'rilE CONTROL OF TilE BOUSE FLY AND RELATED FLIESREPRESSIVE MEASURESStriking thlJ SourCIJManure ••..188189141141142144014414514061471481481409150151158158158'158

xiiCIIAPTEUCONTENTSGarbageExcretaCarcasses. ., ..Miscellaneous Breeding PlacesPALLIATIVE MEAStmEB : • • •XI. CONTROL OF FLIES IN BARN YARDS. PIG PENS AND ClllCKEN YARDS. 167REPRESSION OF FLIES IN BARN YARD. • • • 167FLY CONTROL IN PIG LOTS AND PENS • 170PREVENTION OF FLY BREEDING IN CmCKEN Housl'ls AND YARDS 178PAOB16016116116~162XII.XIII.XIV.XV.MYIASIs-TyPl'ls OF INJURY AND LIFE' HISTORY. AND HABITS OF SPECII'lSCONCERNI'lDTlssm:-DI'lSTROYING FORMS •SUBDERlfAL, MIGRATORY SPECIESINTESTINAL AND CROGENITAL MYIASISFORMS PRODUCING MYIASIS IN HEAD PASSAGESBLOODSUCKING FORMS • • • • •SOME BIBLIOGRAPHICAL REFERENCESMYIASIs-ITS PRI'lVENTION AND TREATME!I,"TTrssuE-DESTROYING FOR!l.IS • • • • • •SUBDEIUfAL MIGRATORY SPECIESSPECIES CAUSING INTESTINAL AND UROGENITAL MYIASIS•SPECIES INFESTING HEAD PASSAGES • • •BLOODSUCKING SPECIESDISEASES TRANSlIlITTED DY HLOODSUCKING FLIESPLANT ORGANISMS CARRIED BY BLOODSUCKING FLIESThallophyta: Fungi: Schizomycetes:' BacteriacereThallophyta: ]!'ungi: Schizomycetes: Coccacere.DISEASES OF UNKNOWN OR UNCERTAIN ORIGIN.ANIMAL ORGANISMS TRANSMITTED BY BLOODSUCKING FLIESProto30a • . .. . • • •Mastigophora: Binucleata: lIremoproteidreMastigophora: Uinucleata: LeucocytozoidmMas tigophora: Binucleata: TrypanosomidmMastigophora: Binncleata: Leptomonidre .Mastigophora: Spirochretacea: Spirochretidm . .Telosporidia: llremogregal'inida: HmmogregarinidreJIetazoa . . . . . . . . . .Nemathelminthes: Nematoda: Filariidm.BIBLIOGRAPHYBIOLOGICAL NOTES ON THE BLOODSUCKING FLIESFA.ULY CIIIRONOMlDJE •MidgesFAMILY SnlULIIDJE •Buffalo Gnats .FAMILY I'SYCHQDID..EPappataci FliesFAMILY CULIClD..EFA!l.ULY TABANID..E••Horse Flies . . .FAMILY MUSCIDJE . •Jlloodsucking Fly LarymBiting Species of Musca.True Biting Flies . . .Stable Flies .•175176182190• 1981951962002002042052072082092092092102112122122122142U219216219220220.• 220228tiS228224224226226228228228228!l28'/r229229280

{BAPTEBXVI.XVII.XVIIIXIX.Hmn FliesTsetse FliesPUPIPARA- REFERENCESCONTENTSBIOLOGY AND HABITS OF HonsE FLIESEGGS AND EGG LAYINGLAnvdilPt'P./E •LIFE CYCLEHABITS OF ADULTSCONCERNING CONTROL MEASURESBIBLIOGRAPIIYDISEASES TRANs~nTTED BY MOSQUITOESDISEASES OF rNCERTAIN ORIGIN TnANSlIlITTED BY :MOSQUITOESPLANT ORGANISMS TRAlIo'SlIIITTED BY ~IOSQUITOES •Thallophyta: Fungi. . .Thallophyta: Fungi: Schizomycetes: Bacteriaccre.ANIMAL ORGANISlIIS TRANSlIIITTED BY l\IOSQl'ITOESProtozoa .. .•.. . . • .Mastigophora: Binucleata: Hremoproteicire.Mastigophora: Binucleata: LeueoeytozoidreMastigophora: Binueleata: TrypanosomidreMastigophora: Binueleata: Leptomonidlll .Mastigophora: Binueleata: Plasmodidre. .Mastigophora: Spirochretaeea: Spiroeliretidll'Metazoa . . . . • . .Platyhelmia: FasciolidreNemathelminthes: Nematoda: Filariidre. .Nemathelminthes: Nematoda: MermithidreREFERENCESWHAT WE SHOULD KNOW.ABOUT MOSQUITO IhOLOGYOVIPOSITION AND TIlE EGG STAGETHE LAnv.IE AND THEIR HABITSThE PUP..E. • • • • • • • • ~ADULT MOSQUITOES ••••••• , , ,Table of American Disease-Carrying MosquitoesREFERENCESMOSQUITO CoNTHOLPREVENTION OF l'!OSQUITO BREEDINGScouting, , , , , , . , , ,Determination of SOllrre of MosquitoesLeveling and ]

xivCONTENTSCllAPTEBXX. LoUSE BOR.'iE DISEASES • • • • • •I. DIRECT EFFECT OF LOUSE ATTACX1. Types of Pediculosis Corporis2. Types of Pediculosis Capitis8. Types of Phthiriasis .4. Eltects of Attack of Other Lice .II. TRANSMISSION OF DISEASES BY LICE1. ·Diseases of Plant Origin . • . • • . . .Thallophyta: Fungi: Ascomycetes: Gymnoasccre .Thallophyta: Fungi: Hyphomycetes • . . . .Thallophyta: Fungi: Schizomycetes: CoccacereThallophyta: Fungi: Schizomycetes; BacteriacereSummary of Plant-Caused Diseases • . . . .2. Diseases of Unknown or Uncertain Origin • . .8. Diseases of Animal Origin • • • • • . . .Protozoa •• "...........Mastigophora: Binucleata: TrypanosomidreMastigophora: Binucleata: Leptomonidre. .Mastigophora: Spirochretacea: Spirochretidre. .Telosporidia: Hremogregarinida: HremobrregarinidrelJletazoa. • . . • . . • • . . • • . . .Platyhelmia: Cestoda: Cyclophyllidea: TreniidreXXI.XXII.BIBLIOGRAPHY•••••••TIlE LIFE HISTORY OF HUMAN LICEREFERENCES • • • • • •TIlE CONTROL OF HUMAN LICETHE RAVAGES OF LICERESERVOIRS OF LOUSE BREEDINGCONTROL MEASURESCONTROL OF LICE ON THE BODYControl of Crab Louse . . .Control of Head Louse • . .Control of Body Louse • • .CONTROL OF LICE IN CLOTHING1. Laundry. • . .2. Dry Cleaning . .8. Steam Sterilization4. Hot Air Delousing5. Fumigation. . .6. Storage . . . • • . . ••.7. Impromptu Delou3ing ArrangementsCONTROL OF LICE IN LIVING QUARTERSCONTROL OF LICE IN HOSPITALS • • • • • • •Control of Lice in Hospitals . . . . • . . .Louse-Proof Garments for Medical Attendants, etc.BIBLIOGRAPHY••••••••XXIII. LICE WHICH AFFECT DOMESTIC ANIMALSPART 1. CATTLE LICE AND THEIR CONTROLSucking Lice. . : . . . • .Biting Lice . • . . . . . •Methods of Study of Life HistoryCDntrol Measures . . . • • .Ojls ••....•••••Sprays •.....•.•Miscellaneous Remedies .••.•.•Time for the Application of Control MeasuresSkin InjUlies • • • . . . • . • • •I'AO.286286286287287288289289289289289290290291294029402940294295296297297207801S11812S]281SS148168168]6817SII.!819820." 8218248248268268278288288288288S08S0881882888884884885887SSB8S8

CHAPTERCONTENTSPART 2. LICE AFFECTING CHICKENS, HOGS, GOATS, SHEEP, HORSES, ANDOTHER ANIMALS•••••Lice Infesting Domestic FowlsLice Infesting Rabbits. Cats and DogsThe Hog Louse. . . . • • . .Lice Attacking 'Sheep . . . . . .Biting and Sucking Lice of Goats .Lice of the Horse . . . . . . .Important Uibliographical Re,ferencesXXIV. DISEASES CARRIED BY FLEAS • • • •PLANT ORGANISllS TRANSMITTED BY FLEAS • • •Thallophyta: Fungi: Schizomycetes: BacteriacemANIMAL ORGANISMS TRANSMITTED BY FLEAS • •Protozoa • • • . . . . • . . . . . .Mastigophora: Binucleata: TrypanosomidmMastigophora: Binuclcata: Leptomonidm .Mastigophora: Spirochmtacea: SpirochmtidmTelosporidia: Gregarinida: Agrippinidre. • . .TelOSporidia: Hmmogregarinida: HmmogregarinidreMetazoa . . • . • . . . . . . ..••••Platyhelmia: Cestoidea: Cyclophillidea: Tmniidre . .Platyhelmia: Cestoidea: Cyciophillidea: Hymenolcpididre.Nemathelminthes: Nematoda: Spiruridm . . . . . .Nemathelminthes: Nematoda: FilariidmSmlMARYREFERENCESXXV. THE LIFE HISTORY AND CONTROL OF FLEASFACTORS INFLUENCING ABUNDANCE OF FLEASCONTROL OF' FLEAS. • • • • • • • • •LIST OF REFERENCES • • • • • • • • •NOTES ON THE CHIGOE, DERMATOPJIILUS PENETRANS •XXVI. COCKROACHES •••••••••••••••BIOLOGY •••••••••••••••••KEY TO THE FOUR PRINCIPAL HOUSEHOLD COCKROAC'HESBlatta orientalis (Linnreus) ...•..Blatt61la germanica (Linnreus), Caudell .,Periplaneta amerieana (Linnmus) ....Periplaneta austTalasilll (Fabricius) BurmeisterREMEDIES••••••Fumigation. • . . •Hydrocyanic Acid GasCarbon Bisulphide .Pyrethrum Powder.SulphurPoisons ..•..Sodium Fluoride .Borax •••..Pyrethrum Powder "PhosphorusSulphur .Castor Oil.Traps •••ENEMIESXXVII. DISEASES TRANSMITTED BY 'rilE COCKROACHPLANT ORGANISMS • • • • • • •Thallophyta: Fungi: Coccacere. •Thallophyta: Fungi: Bacteriacem.Thallophyta: Fungi: Spirallaeere •..xvPAGE8S98898i884-lr845846840784885085085085285285285-108558558558558558569578573578588603668673718788748758768768778788809808808808808818818818818818828828828828828828888S888S884887

xviCHAPTERANIMAL ORGANISMS. • •CONTENTSProtozoa . • • . • . •Sareodina: Amrebina: Amrebidre . . . .Mastigophora: Polymastigina: TetramitidreMastigophora: Dinucleata: Leptomonidre .Telosporidia: Gregarinida: Gregarinidre .Telosporidia: Coccidiidea: Eimeriidre. .Neosporidia: Myxosporidia: ThelohaniidreCiliata: Heterotricha: Bursarinidre . .Metazoa • . • • • . • • ..• . . . . . . .Platyhelmia: Gestoidea: Hymenolepididre . . . .Nemathelminthes: Acanthocephala: GigantorhynchidreNemathelminthes: Nematoda: SpiruridreNemathelminthes: Nematoda: Oxyuridre, .REFERENCES • • • • • • • • •XXVIII. THE BEDBUG AND OTHER BLOODSUCKING BUGS: DISEASES TRANSMITTED,BIOLOGY AND CONTROL 891PAGJ!I88888888888888888888888888888988988988988989!)DISEASES OF THE PLANT KINGDOM TRANSMITTED BY BUGS 89~Thallophyta: Fungi: Bacteriacere. . . . . . 89~DISEASES OF UNKNOWN ORIGIN • • • • • 898DISEASES OF THE ANIMAL KINGDOM TRANSMITTED BY BUGS 898Protozoa . . • . . . • . . . . . 898Mastigophora: Dinucleata: Trypanosomidre 893Mastigophora: Binucleata: Leptomonidre .Mastigophora: Spirochretacea: Spirochretidre395898LIFE HISTORY NOTES 899TREATMENT OF BITES 401CONTROL MEASURES 401LIST OF REFERENCES 401XXIX. DISEASES CAUSED OR CARRIED BY MITES AND TICKS 408DISEASES CAUSED BY DIRECT ATTACK OF TICKS AND MITES 403DISEASES CARRIED BY MITES AND TICKS 411DISEASES CAUSED BY PLANT ORGANJSMS 411DISEASES OF UNKNOWN OmGIN 41~DISEASES OF ANIMAL ORIGIN 414Protozoa • . • . . • • • • . . . .•. 414Mastigophora: Binucleata: Trypanosomidre 414Mastigophora: Binucleata: Leptomonidre . 414Mastigophora: Spirochretacea: Spirochretidre . . 418Telosporidia: Hremogregarinida: Hremogregarinidre 4~0SUlIWARY • • • • • • • 4~LIST OF REFERENCES • • • • • • 4~7XXX. THE BIOLOGIES AND HABITS OF TICKS 480BIBLIOGRAPHIC REFERENCES 488XXXI. CONTROL OF TICKS 440LIST OF REFERENCES 449XXXII. FLIES AND LICE IN EGYPT 450THE SULTAN'S FuNERAL 452XXXIII. INSECTS IN RELATION TO PACKING HOUSES 458INSECT-BREEDING PLACES AND THEIR ThEATMElll"T 455PROTECTtoN AGAINST INSECTS • .'. • • 458A BIBLIOGRAPHY OF LITERATURE DEALING WITH SANITATION OF MEATPACKING ESTABLISHMENTS 459

CONTENTS BY AUTHORSBy W. DWIGHT PIERcE-Bureau oj EntomologyHow INSECTS CAN CARRY OR CAUSE DISEASE 19SOME NECESSARY STEPS IN ANY ATTEMPT TO PROVE INSECT TRANSMISSION OR CAUSATION OFDISEASEfl5A GENERAL SURVEY OF THE NEEDS OF ENTOMOLOGICAL SANITATION IN AMERICA • 84A GENERAL SURVEY OF THE SERIOUSNESS OF INSECT BORNE DISEASES TO ARMIES 48RELATIONS OF CLIMATE AND LIFE, AND THEIR BEARINGS ON THE STUDY OF MEDICAL ENTO-MOLOGY 97DISEASES BORNE BY NON-BITING FLIES 105IMPORTANT PHASES IN THE LIFE HISTORY OF THE NON-BITING FLIESli6ThE CONTROL OF THE HOUSE FLY AND RELATED FLIES 158DISEASES TRANSMITTED BY BLOODSUCKING FIlIES 209BIOLOGICAL NOTES ON THE BLOODSUCKING FLIES 228DISEASES TRANSMITTED BY MOSQUITOES 247MOSQUITO CONTROL 275LoUSE BORNE DISEASES 286DISEASES CARRIED BY FLEAS • 850DISEASES TRANSMITTED BY THE COCKROACH 888THE BEDBUG AND OTHER BLOODSUCKING BUGS: DISEASES TRANSMITTED, BIOLOGY ANDCO~ROL 891DISEASES CAUSED OR CARRIED BY MITES AND TICKS 408INSECT POISONING AND MISCELLANEOUS NOTES ON THE TRANSMISSION OF DISEASES BYINSECTS • ~IA TABULATION OF DISEASES AND INSECT TRANSMISSION 478By W. DWIGHT PIERCE AND C. T. GREENE, Bureau of EntomologyWHAT WE SHOULD KNOW ABOUT MOSQUITO BIOLOGY 266By W. DWIGHT PIERCE AND RoBERT H. HUTCHISON, M.A., Bureau of Entomolo;yTHE LIFE HISTORY OF HUMAN LICESOlThE CONTROL OF H~AN LICE 812By B. H. RANSqM, PH.D.. Zoologiat, Bureau of Animal InduBtryRELATION OF INSECTS TO THE PARASITIC WORMS OF VERTEBRATES50By F. C. BISHOPP, B.S., Bureau of Entomology, In Charge Animal Inaeet Infl68tigationaCONTROL OF FLIES IN BARN YARDS, PIP PENS AND CHICKEN YARDS. 167MnA8Is. TYPES OF INJURY AND LIFE HISTORY AND HABITS OF SPEc'tES CONCERNED 175xix

xxCONTENTS BY AUTHORSMYIASIS. ITs PUEVENTION AND TnEAT!.1ENTTHE LIFE HISTOUY AND CONTUOL OF FLEASTHE BIOLOGIES AND HABITS OF TICKS .THE CONTROL OF TICKSPMJm!l00860480440By J. L. WEBB, M.S., Bureau of EntomologyBIOLOGY AND HABITS OF HORSE FLIES • !!86By G. II. Lu!:SON, JR:, M.S., EntomologUt StoI'r8 (Conn.) Agricultural EZpeTimentStation .LICE WHICH AFFECT DOMESTIC ANIlI4ALS • 980By A. N. CAUDELL, B.S., Bureau of Enwmology; Curator of Orthoptera, U. S. NationalMuseum• COCKROACHES874By H. A. BALLOU, PH.D., Imperial Entomologist, BarbadosFLIES .AND LICE IN EGYPTBy E. W. LAAI[E, B.S., Bureau of EntomologyINSECTS IN RELATION TO PACKING HOUSES. 450458

xxiiF1GlIBIlILIST OF TEXT FIGURES24. LARVA OF Stomoxys calcitranB: Enlarged Sketch of Right Stigmal Plate. Theseplates are one and one-half times their breadth apart. (GREENE) • • • • • • 14625. LARvA OF Muacina atabllians: a, Side view of head and prothorax; b, anterior orthoradc spiracles; c, side view of terminal segments of abdomen. (GREENE)' 14726. LARVA OF !lfu8Mna 8tabulan8: Enlarged Sketch of Right Stigmal Plate. Theseplates are lcss than their breadth apart. (GREENE) . • • • • . • • • • " 14727. LARVA OF CaUiphora erythrocephala: Side Vicw of Hcad and Prothorax. (GREENE) 14828. LARvA OF CaUiphora erytkrocephala: Enlarged Sketch of LeIt Stigmal Plate. Theseplates are one and one-quarter times their breadth apart. (GJ.lEENE) • • • • • 14829. LARvA OF ChryBOmya macellaria: Enlarged Sketch of Side of Head and Prothorax.(GREENE) • • • • • • • • • • • '.' • • • • • • • • • 14980. LARVA OF ChryBOmya mocel'aria: Enlarged Sketch of Left Stigmal Plate. Theseplates are less than their breadth apart. (GREENE) • • • • • • . • • • • 14981. LARVA OF Lucilia sericata: a, dorsal view of head and prothorax; b, lateral view ofhead and thorax; c, lateral view of last abdominal segments. (GREENE) • • • • 14982. A MAGGOT TRAP FOR ·HOUSEFLY CONTROL. View of the maggot trap, showing thecon('rete basin containing wau-r in which larvlE are drowned, and the wooden platformon which manure is heaped. (HUTCHISON) • • • • • • • • • 155·88. USE OF FLY~P IN CONNECTION WITH l\IANURE BIN: a, Block of wood set inground to which lever raising door is hinged. • • • • • • • • • • • • • 15784. Top OF GARBAGE CAN WITH SMALL BALLOON FLYTRAP ATTACHED • • • • • • 16085. CONICAL Hoop FLYTRAP; SIDE VIEW: a, Hoops forming frame at bottom; b, hoopsforming frame at top; c, top of trap made of barrel head; d. strips around door;e, door frame; f, screen on door; g, buttons holding door; h, screen on outside oftrap; i, strips on side of trap between hoops; j, tips of these strips projecting toform legs; k, cone; I, united edges of screen forming cone; m, aperture at apex ofcone. (BISHOPP) • • • • • • • • • • • • • • • • • • • • • • • 16886. PLANS OF OPEN HOG-FEEDING TROUGH. (DIBHOPP) • • • • • • • • • • • 17187. FULL GROWN LARVA OF TIlE HUMAN BOT, Dermatobia hominu. (DRAWING BY BRAD-FORD.) Actual length 14.5 mm. • • • • • • • • • • • • • • • 18788. FULL GROWN LARVA OF THE Tmmu-FLY, Cordylobia anthropophaga. (GRUNBERG.)Ventral view. x 6. (FROM AUSTEN) • • • • • • • • • • • 18989. TIlE TUMBu-FLY, Cordylobia anthropophoga. (GRi:NBERG) Female. x 6. (FROMAt:'STEN) • " • • • • • • • • • • • • • • • • • • • 18940. NOSE PROTECTION FOR HORSE AGAINST ATTACKS OF THE NOSE FLY, Gaatrophilulhmmorrhoidalill. (DOVE) • • • • • • • • • • • • • • • • • • • • 20541. CHART ILLUSTRATING THE LIFE CYCLE OF Hmmoprot8'UII columbm, THE CAUSE OFPIGEON MALARIA. (PIERCE) •••••••••••••••••• 21842. CHART ILLUSTRATING THE LIFE CYCLE OF TrypanoBOma gambi87Ule, THE CAUSE OFGAMBIAN SLEEPING SICKNESS. (PIERCE) • • • • • • • • • • • • • • • 21548. LARVA OF A BUFFALO GNAT, Simulium. (JOBBINs-POMEROY) • • • • • • • • 22544. EGGS OF TIlE STABLE FLY, SromoX1J8 calcitranll ATTACIIED TO A STRAW. Greatlyenlarged. (AFTER BIBHOPP) • • • • • • • • • '" • • • • • • • • 28045. TIlE STABLE' FLY: LARVA OR l\UGGOT. Greatly enlarged. (AFTER BISHOPP) •• 28046. THE STABLE FLY: ADL'LT FEMALE, SIDE VIEW, ENGORGED WITII BLOOD. Greatlyenlarged. (AFTER BISHOPP) • • • • • • • • • • • • • • • • • . . 28047. LIFE CYCLE OF PLASMODIUM, CAUSE OF PERNICIOUS MALARIA. (PIERCE) 25248. EGGS AYD LARV.II!I OF CULEX. Enlarged. (lIOWARD) • • • • • • • • 26849. EGGS OF MALARIA MOSQUITOES: a, A~opheles pllnctipenniB; b, A. quadrimaculatUII;c, A. crucianB. (AFTER HOWARD, DYAB AND KNAB) • • • • • • • • • • 26850. LARVA OF TIlE YELLOW-FEVER MOSQUITO. Much enlarged. (HOWARD) • • • • 26951. LARVA OF TIlE MALARIA MOSQmTO, Anopheles punctipennu. (AFTER HOWARD,PYAB, AND KNAB) • • • • • • • • • • • • • • • • 27152. PUPA OF CULEX. Greatly enlarged. (lIowARD). • • • • • • 27258. PUPA OF Anopheles quadrimaculat'Ul/. Greatly enlarged. (HOWARD) 272PAGIlI

XXVIPLATI!ILIST OF PLATESXV. PUP.II!I OF Simulium. (AFTER JOBBINs-POMEROY) • . . • • • 227Fig. 1. Respiratory filaments of pupa of Simulium vittatum... 2. Pupa of Simulium lJenustum, in pupal case... 8. Pupa of Simulium bracteatum: A, Side view of filaments... 4. Pupa of Simulium jenningai... IJ. Pupa of Simulium pictipe8, in pupal case. All greatly enlarged.XVI. ThE STABLE FLY, Stomcr.r:y8 calcitrans. (BIBHOPP) • • • • .. " 281Fig. 1. Eggs in straw... 2. PUpal in straw.II 8. Adults on leg of cow.XVII. STIIAW STACK SHOWING PROPER METHOD OF BUILOING STRAW STACK. (BIB-HOPP) • • • • • • • • • • • • • 28iXVIII. THE HORN FLY, Lyperona irritana. (BIBHOPP) • • • . . . . . 288Fi,. 1. Flies on cow., 2. Cow pasture showing droppings improperly left to breed Hies.XIX. TABANID.lI!I ATTACKING CAT1'LE: TabanuB phmnops on cow's jaw, and T.punctiJer on top of shoulder. (BIBHOPP) • • • • • • •XX. Tabanus punctiJer. (WEBB, PHOTOS BY DOVENER)Fig. 1. Egg masses on grass." i. Larva, dorsal view.II 8. Larva, lateral view.II 4. Pupa, lateral view." 5. Pupa, ventral view.XXI. ThE CLOTHING LoUS,E, Pediculua Corpori8. (PIERCE AND HUTCHISON,PHOTOS BY DOVENER) • • . • • • •Fig. l. Female, ventral view." 2. Male, dorsal view.XXII. EGGS OF THE CLOTHING LoUSE, Pediculus corporia. • . • • • . . . • 805Fig. 1. Mass of eggs, slightly reduced, between sea.ms of trousers (PHOTOBY DOVENEB.)" 2. Great enlargement showing eggs hatching. (PHOTO BY PAINE.)" 3. Very great enlargement showing structure of eggs with exuvire within.(PHoro BY PAINE.)XXIII. STEAM STERrLIZER IN DELOUSING STATION OF U. S. ARMY MEDICALCORPS. The carriage is transferred along the rails in the foreground to railsleading into the other room where another carriage is seen. (HUTCHISON)XXIV. SCALY LEG MITE ON CHICKENS. (BISHOPP) • • • • 406Fig.!. Scaly feet of chickens, caused by mite attack .• " 2. Scaly leg mites, greatly enlarged.XXV. DIPPING SCALY LEGS OF CHICKEN IN CRUDE OIL. (BISHOPP) 407XXVI. THE FOWL TrCK, Argaa perncuB. (BISHOPP). • • • • • • 438Fig. 1. Larval under feathers of chicken." 2. Unengorged male, ventral view; much enlarged .." 8. Female with eggs, dursal view; greater enlargement." 4. Unengorged female, ventral view; same enlargement as fig. !l.XXVII. THE CATTLE TICK, Boophilus annulatuB. (BIBHOPP) ••.....• 485Fig. 1. Fully engorged female." 2. Engorged female depositing eggs.XXVUI. SPRAYING CHICKEN HOUSE WITH OIL BY MEANS OF KNAPSACK SPRAY PUMP.(BISHOPP) • • • • • • • • • • • • • • • • • • • • • • 447PAGE286iSS·80i8i3

SANITARY ENTOMOLOGYC~APTER IHow Insects Can Carry or Cause Disease 1W. Dwight PierceOur nation, as well as all our world civilization, is facing the greatestcrisis in its existence in these days of reconstruction. We must conservehuman energy and keep it at its greatest possible point of efficiency.This means ab~ve all that questions of health are foremosttoday.Entomology bears a twofold relationship to health. Adequate foodsupply upon which human and animal health are contingent is dependentto a greater or less degree upon insect depredations. This is the side ofentomology which has in the past received most of the recognition, thatis, agricultural entomology. It has been generally recognized that insectsalso bear a direct relationship to health, but the public has more or lessdiscounted the relationship, with the result that our public appropriationsfor the study of insects affecting crops are approximately thirtytimes as great as the appropriations for the study of insects affectingthe health of man and animals. The present course of lectures aims togive the latest views in this almost unworked field of medical entomology,with a view toward demonstrating the necessity of obtaining a betterbalance in the two great phases of economic entomology.The scope of the course embraces studies of the relationship ofinsects to disease, the life history of the insects which cause disease,and the best methods of prevention of disease cap.sation by insects. Itis intended to be placed in the hands of the men who will conduct workalong these lines:. to show them why insects are dangerous, how they aredangerous, what their habits disclose as weak points subject to attack,and finally, how to go about controlling them.In my opinion the near future will see a group of professional sanitaryentomologists whose services will be available to solve the insect prob-1 This lecture was given on May 20, 1918, and mimeographed copies were distributedMay 22. It has been considerably revised for the present course.19

~o SANITARY ENTOMOLOGYlems of municipalities, communities, and armies, as well as household andcommercial problems. Municipal entomology has already been recognizedin a small way by certain cities. It will become better known only bythe work of entomologists themselves who are men of vision. The problemsinvolved in entomology sanitation demand ali intensive and specializedtraining which few of us received in school. If we would fitourselves for such work it will demand great ,effort on our part.CLASSIFICATION: OF METHODS BY WHICH INSECTS GAN CARRY ORCAUSE DISEASELong before anyone knew of causative organisms in medicine it wasrecognized that insects might be productive of disease. We may thereforeassume as our first category the diseases actually caused by theinsects themselves.(r.) Diseases caused directly by insects.-We must recognize, forthe sake of arrangement, all pathological conditions brought about byinsects whether of 8: serious nature or not.1. Entomoplwbia.-The fear of insects, both harmless and harmful,is a common ailment, amounting in many people to an obsession. I knowof a young lady who became so frantic over the presence of a huge dragonfly in the automobile that the attempt to catch it led to a seriousaccident. Recently a serious automobile accident was caused by a beesting. Many women become frantic at sight of large insects, and Ihave even seen men lose all sense of courage in the presence of anunknown species of insect. Obviously only patient and tactful educationcan ever cure such an obsession.~. A'TIInoyance and worry.-We have all probably experienced asense of annoyance, amounting sometimes to worry, from insects. Itfrequently ·happens that the annoyance increases to the point of causingacute nervous troubles which, it is quite conceivable, might lead toinsanity with certain people. Animals arc frequently driven frantic byinsects such as buffalo gnats, mosquitoes, and horse flies, and lose allcontrol of themselves. We may classify these different ~ases of insectannoyance in accordance with the sense which perceives it and communicatesits .sensations to the brain. In this manner we have annoyanceoriginating through sight, memory and imagination, sound, smell, taste,and feeling.Sight worry is initiated by the occurrence of unwanted insects inhome or garden, or on one's person, or by their constant swarmingabout until patience is exhausted and one loses control of the nerves.A recently recorded case tells of a lady whose house was badly infestedwith book lice and who was fast becoming a nervous wreck when

-HOW INSECTS CAN CARRY OR CAUSE DISEASE ~1entomological service was sought and the house freed of its pests. Theconstant moving of stl-eams of ants across a floor, the sight of bedbugsor fleas, and many other common insect occurrences may cause a nervousperson great perturbation. Recently a young entomologist was nauseatedand made very sick for hours by the sight of a louse infestedman.MemoTY and imagination WOTTY may be exemplified by the personimpressed by anti-house fly propaganda, whose imagination sees on everyfly multitudes of fatal disease germs. A person once injured by aninsect will often experience acute revulsions of feeling on sight of anothersimilar insect. .Sownd WOTTY such as that induced by the singing of mosquitoes orthe buzzing of horse flies will often lead to insomnia and in the cases ofanimals will cause great uneasiness.Smell worry or annoyance from insects often takes the form of greatembarrassment. A few years ago in Dallas, Texas, Calosoma beetles wereso numerous that people walking on the streets frequently would haveone alight on them, and, in brushing the beetle off, would cause it toexpel a sufficient quantity of liquid to make the person's presenceundesirable in polite society. Many people are so sensitive to bedbugodors that when they sleep in infested rooms they are constantly a,vareof the odor and are possessed of a fear that they will be attacked bythe bugs.Taste OITI/TU)yO/Tlce is often caused by eating berries containing bugs,or which bugs or cockroaches have contaminated. This may often causenausea.Finally, there is the worry aroused by conta·ct of insects, the tingli.'gsensation lfrom insects crawling on the body, the peppery sting of gnatsand mosquitoes, the itching sensations from vermin. Insomnia is afrequent result of such attacks.Thus as results of insect annoyance, we may have worry, nervousexhaustion, excitability,. hallucinations, frenzy, insanity, nausea, insomniaand nervous chills.3. Accidental injury to sense oTgans.-There are numerous cases onrecord of insects accidentally obtaining access to the ear or nose andcausing a stoppage of these organs, or of insects flying into the eyescausing severe irritation or even blindness. Certain species of gnatsare especially annoying when there is any kind of catarrhal affectionof these organs. Myriapods have frequently been recorded as enteringthe nose of a sleeping person.4. Poisoning.-Insects and the related arthropods may poison in avariety of ways. The bite of a tick, flea, spider, mosquito, horse fly,etc., may cause a severe local irritation and poisoning. The poisonous

SANITARY ENTOMOLOGYcentipedes have a poison sac opening on the front pair of legs. Thescorpion stings with the tip of its tail. The bee, wasp, and ant stingwith the ovipositor. M~ny of these injuries are very painful., CertainIepidopterous larvre are pro'vided with barbed hairs which containpoisonous secretions, as the brown tail moth larva, and the larvre ofLagoa. H yperchiria io, etc. Some insects emit poisonous secretionswhich blister (Meloid beetles). Some of the South American honey bees(Trigona) store poisonous honey. .5. Paralysia.-The bite of several species of ticks (Dermacentoranders()lfli (V{ffl.uatus), for example, may cause paralysis with sometimesfatal results. Some spiders, ants, bees, wasps, and. caterpillars inflictsuch a poisonous wound that temporary paralysis of the limb follows.6. Dermatosis.-Direct attack upon the ~ody of men and animals,and parasitism thereon, is not unusual. We have as striking examples'the dermatoses caused by lice (pediculosis), by the chigoe, the redbug (chiggers), the Dermatobia hominis, creeping worms, scab anditch mites (acariasis). Many of these attacks have serious after results,as for instance an acute attack by the chigoe may result in ainhum, theloss of a toe or a foot. Many secondary diseases obtain access to thebody through the skin attack of insects.7. Myiasis and similar internal aftacks.-Under'this heading are tobe considered cases in which insects are present in the tissues of internalorgans of the body. The occurrence of insects has been recorded inorgans of the head, in the intestinal canal, the reproductive organs,and the body wall. When the insect is a fly the disease is called Myiasis.When a beetle is the cause, the disease is called Canthariasis, and if alepidopterous larva is responsible it is known as Scholeciasis. Manyspecies of flies have been recorded as occurring in the human body. Thesewill be studied in detail in a later lesson.(II.) Diseases carried by insects.-The ways in which insects maycarry diseases are very diverse, due to the great differences not only inthe habits of the insects, but also of the disease organisms and thehosts.1. Diseases carried by insects to food.-When insects carry diseasegerms to food or water we speak of the transmission as contaminative.Cont~minative transmission of disease organisms to food by insects isnaturally the simplest mann~r of transmission. This is necessarily doneby insects which frequent excretionary substances and also visit foods,such as certain flies, ants, roaches, and beetles. It is obvious that wemust lo.ok upon all insects which breed in fecal matter, sputum, etc., aspotential disease carriers. Considerable research has already been conductedto prove the actual role of many species of coprophagous insects.The role of the carrier may eithE'r be mechanical or biological.

HOW INSECTS CAN CARRY OR CAUSE DISE..~.SE !e8Many disease organisms are transmitted by insects which exerciseapparently only a mechanical role. Principal among these are bacteriaand certain parasitic worms. Many of the bacteria· may be taken up by6y and beetle larvae, and by adult flies, beetles, roaches, and ants, and becarried on the body or ingested and passed through the body and outin the feces without modification or multiplication. A number of speciesof parasitic worms may be taken up in the egg stage by insects anddeposited in the insect's feces. If such infested feces happen to bedeposited on food, contamination and infection may conceivably follow.Certain other organisms which are carried by insects to fo?d passpart of their life history in the insects. Such are some of the nematodesthat may be ingested by coprophagous insects, which in turn 8;.re eatenby the animals that SerVE' as final hosts of the parasites.!e. Diaeases ·carried by insects to wownds.~We can make the samedivision of these diseases into mechanical and biological carriage. Thetransmission of anthrax, leprosy,. ophthalmia, and such diseases, fromsore to sore or from excreta to sore is purely mechanical. When theorganism passes part of its life cycle 'in the insect we might call thetransmission biological. As examples of, such types of transmission wemay cite European relapsing fever and trench fever, louse-borne diseaseswhich gain acc(!ss to the body by the scratching in of fragments of thelice or their excreta.8. Diseases gaining access through direct attack of insect.-Most ofthe protozoal diseases and some of the parasitic worms gain access tothe body of the vertebrate host by direct inoculation, or indirectly, atthe time of feeding. When the organism is taken up by the insectit begins its development in the insect body and finally reappears in thesalivary glands or some other position adjoining the mouth parts, theinoculation occurring during the blood feast. Such is the inoculation ofmalaria, yellow fever, and Rocky Mountain spotted fever. But otherdilSease organisms pass through the intestinal canai of the insect and outin the f~ces and yet obtain access to the wound by being washed into it bybody secretions of the insect, as is the case of the organism of Africanrelapsing fever inoculated by the tick Ornithodoros moubata.WHY IT IS NECESSAltY TO KNOW HOW INSECTS CARRY DISEASEuIn the foregoing discussion I'have attempted to analyze the methocJsby which insects can cause or carry disease. There is also a practicalfiide of the question. We must know the why and the wherefore and thewhat to do. .Without a conception of the role of the insect we cannot give suffi('ientforce to our arguments, or reasons for taking a particular course

SANITARY ENTOMOLOGYof action. For instance, if we were m~rely to go before the inhabitantsof a Montana valley suffering from Rocky Mountain spotted fever andsay: "We are going to Eut down this epidemic, you must dip your h9rses. and trap all the rabbits and rodents on your place," what kind of ananswer would we get? If the Public Health Service had stepped intoNew Orleans on the announcement of a plague case and ordered everybodyto rat-proof their cellars, without further reason, they would havebeen driven away ..If a sanitary officer reports to his superior that a certain thingmust be done, requiring a considerable outlay of money and the use ofa good many men, he must be able to give him a strong, forceful argumentto prove that he is right. Army officers, and in fact most executiveofficers, want brief answers. The subordinate must therefore have hisinformation on the tip of his tongue.We have seen by the above discussion that the bites of insects mustbe avoided. Where disease-carrying insects are present, the greaterthe concentration of human beings or animals, the greater the necessity 01exercising control, whether it be in a municipality, a commercial establishment,an army, a stock yards, or a ranch. It is incumbent upon allmen charged with entomological sanitation to learn the bloodsuckingfauna about them. Without a knowledge of how mosq~itoes, horse flies,bedbugs, lice, stable flies, gnats, and ticks breed, one can scarcely proceedto prevent their breeding and consequently cannot protect men andanimals from their attacks.One must always prevent insects from coming in contact with wounds.This is especially important in hospitals and during times of epidemics.It is at all times imperative to keep food untouch~d by anything in theform of 'insect life. Insects must not be tolerated in dwellings, nomatter whether there is evidence against them or not. There is evidenceagainst most of them.Domestic animals must likewise be kept as free as possible frominsects. Some day we will recognize that stables should be as wellproofed against flies as dwellings are now. There are more inducementsfor flies and other noxious insects around a stable than anywhere else,and the stable is therefore the direct or indirect source of many of ourtroubles. The measures necessary for holding down insect infestationof stable and barn yards are therefore of primary importance. But toemphasize this importance there must be back of every measure taken orrecommended an argument in the form of a proof of danger if the measureis not carried out.

CHAPTER IISome Necessary Steps in Any Attempt to Prove Insect Transmission orCausation of Disease 1W: Dwight PierceThe study of the causation of disease is attracting far more attentiontoday than it ever has in the past, but it is to be regretted that there isnot a larger proportion of this effort being directed toward locatingthe possible intermediate hosts and invertebrate carriers.Many excellent investigations have been carried out with all otherphases complete, but the question of invertebrate carriers is often leftin a very indeterminate stage. The majority of the investigations whichhave been seriously undertaken to determine invertebrate carriers havebeen condu.cted on other continents than ours. There is a great field for.investigation along these lines open to the investigators in America. Inorder to stimulate such research, I have attempted in this paper to setdown some of the necessary steps for successful investigation.I. COOPERATIONI consider essential to a thorough investigation of disease transmission,the establishment of a perfect working agreement and heartycooperation between one or more physicians and diagnosticians, one ormore parasitologists, and one or more entomologists. It is not safe,nor docs the effort bring the proper amount of credence, when one manattempts to do the whole work. Each phase of such an investigation!Should be handled by an expert on that phase. The day of the solitaryinvestigator is past and we are now in an era of group-investigationswhich cart:y with them weight and conviction. Of course certain preliminarysteps may easily be taken by anyone member of a proposedgroup or it may be possible that they may arrive at an advanced stageby independent work, but the time will come in each investigation whenII. cooperation of investigators will attain the most satisfactory results.'This lecture was printed in Science, n. s., vol. 50, No. 1284, pp. 12S-180, August 8,1919.25

26 SANITARY ENTOMOLOGYn. WHERE SHOULD THE INVESTIGATIONS OF INSECT TRANSMISSIONBEGIN?There are two distinct lines of approach to this problem of insecttransmission. The first is to work from the known disease and to ascertainby experimentation what species of insects might be concerned illits transmission. The other line of approach is to make a study of allthe insects which might be involved in disease transmission and to obtain,by cultures and microscopic studies, a· knowledge of the parasitic organismsnormally and occasionally found in these insects. Working on thisline of investigation, one might in time of an epidemic start with insectsvisiting excreta and attempt to ascertain whether the organism of thedisease at that time epidemic occurs in any of these insects.The first line of investigations would arise from public necessity andprobably be initiated by physicians and parasitologists, or by the suggestionof entomologists.The second line of investigations would probably originate as problemsassigned by a professor or head of a laboratory to students or investigatorsunder his direction. It is highly desirable that such studies be commencedin as many institutions as practicable in the near future. Suchinvestigations will include bacteriological studies, protozoological studies,and helminthological studies, as well as in.vestigations of the life historiesof the insects, and the possible connection between them and diseasetransmission.III.PLAN OF OPERATIONBefore starting out on any line of experiment in this subject, thereshould be written down in concise form the facts already gleaned, on thepractical problems and the theories which have occurred to the variousmembers of the group. A clearly outlined course of action should bemade and be carefully discussed and then the various steps in the investigationsthus outlined should be read and modified to meet the changingviews resulting from the experiments. The cours.e of the work shouldalways be kept plainly in view. Each step should be rigorously andskeptically scrutinized for defects.Inasmuch as the investigation from this point will consist of theanswering by observation and experiment of a series of pointed questions,I shall proceed with my discussion in the form of queries. Probablymany other vital queries wiII occur to the reader, but it is morethan possible that he may overlook some of these if not set forth here.When each query is satisfactorily answered the problem is practicallysolved.

STEPS TO PHOVE INSECT CAUSATION OF DISEASE l!7IV.HOW SHALL WE RECORD OUR OBSERVATIONS?Undoubtedly the mof1t satisfactory method of making a large seriesof records is to u,e some type of loose-leaf card or sheet tiling system.By such means one can always keep in an orderly arrangement all thefacts so far obtained. In tHt'case of investigations of the causation ofa givm disease, one of the most satisfactory metho.d,s which has beenused for recording observations is to prepare a little blank booklet, whichwill fit the filing system, in large quantities, each book to represent acase. This book should contain pages for each phase of the question,with blanks covering all kinds of minutire about this phase. The wholeseries of observations can be tabulated for each point.V. HOW CAN AN INSECT BE INVOLVED IN DISEASE TRANSMISSION?Insects ma.y be involved in disease transmission either by the transmissionof an organism or the inoculation of a toxin, or they may be anintermediate host in the life cycle of an organism, but not come directlyin contact with the final host.1. What Kind·of Organisms Ca". Insects Carry'It has been demonstrated that insects can carry bacteria, fungi, manytypes of protozoa, and many species of parasitic worms, and also that('ertain species of insects may be instrumental in carrying eggs of otherspecies of insects which cause disease.!. In What Ma;n;ner May Insect To:cins Bring About Disease'1\Iany species of insects which bite inoculate "at the time of the bite atoxin which may at times cause serious trouble.Some invertebrates inoculate the toxin by means of the mouth, someby means of a cIa,", some by means of a caudal appendage, others bymeans of the ovipositor. In some cases the invertebrate penetrates theskin with its mouth parts and as long as it is adhering, toxins are createdwhich (lmay in certain cases cause severe paralysis or death. The accidentaleating of certain insects in food will cause poisoning because ofthe toxins contained in the bodies of the insects. It is believed, but notyet satisfactorily demonstrated, that the pollution of food by the excretaof ('('rtain insects may cause ~ertain nutritional diseases.The presence of certain insects in the tissues causes severe irritationsand often the formation of toxins.

~8 SANITARY ENTOMOLOGY3. Can Insects Themselves Cause Disease'!Many species of insects are known to live parasitically upon the,bodies of man and animals all:d by their constant sucking of blood orgnawing, cause skin diseases. Other species of insects habitually lay theireggs on or in the flesh and breed commonly or exclusively in living flesh,causing a destruction of the tissues. Many species of insects are dependentupon mammalian blood for the necessary nutriment to bring aboutreproduction. Some insect larv,ae are .bloodsuckers. It is not at alluncommon for insect larvae to be ingested in food and for titem to continuetheir development in the intestines or other organs, often at theexpense of the 'tissues. In some parts of the world insects are eaten asfood by the natives, sometimes in a raw st.ate, and it is not uncommonin such case for the natives to be infected with parasitic worms which'pass their intermediate stages in the bodies of these insects.4. Where May Insects Obtain, the Organisms which Cause J)isease'!Disease organisms may be taken up by insects directly from the bloodof an infected host, or they may be obtained by contact ,vith infectedsurfaces of the body or taken up from the feces or other excretions ofan infected host. The insect may take up the organisms from theseexcretions either in its larval or its adult stage.5. How Can the Insect Transmit the Organism'!The organism may be transmitted by the insect by direct 'inoculationthrough the proboscis, involving the active movement of the parasite, orthe passive transmission of the parasite in the reflex action which takesplace in the sucking of blood. The organism may be externally carriedon the beak of·the insect and mechanically transmitted at the time ofsucking. It may be located in the mouth parts of the insect and burrowthrough at the same time the insect .is feeding. It n;.lay be in a passivestate on the insect and become stimulated to attack the host when itcomes in contact with the warm body. The organism. may be regurgitatedby the insect on the body of its host and obtain entrance by its ownactivity, or by being scratched in or By being licked up by the host.On the other hand, the organism may pass through the insect, andpass out in its feces, or in Malpighian excretions. It may be washed intothe wound made by the sucking of the insect, by fluids excreted at thetime of the feeding. It may remain in the feces on the host and ultimatelybe scratched in or licked up by the host.The organism may be taken up by the insect and never normally passout of the insect, but be inoculated by the crushing of its invertebrate

STEPS TO PROVE INSECT CAUSATION OF DISEASE !9host upon the body, and the scratching of infected portions of theinsect's body into the blood; or may be transmitted only by the ingestionof the insect itself by its vertebrate .host, or accidentally by some grazinganimal. In fact quite a series of disease organisms find their way intotheir hosts because of the habit of the animals of feeding upon insects.6. What Is the Course of the Orglllnis1TL in the Insect'If the organism is taken up by the insect in its larval stage, it maypass directly through the larva and out in its feces and may quite conceivablypass in this manner through insect after insect larva before itfinally finds a vertebrate host. The organism may be taken up by thelarva and remain dormant in some portion of the larva's anatomy, or onthe other hand, it might undergo considerable development and multiplicationin the larva and remain there through all the ll).etamorphosis ofthe insect until the latter arrives at maturity, at which time developmentof the organism may begin or may continue.Upon being taken up in the blood by the bite of the insect, the organismmay lodge in the esophagus and carry out all its metamorphosisthere, or in some of the organs of the head and find its way into thesalivary glands and thr6ugh the salivary secretions into a new host.It may, on the other hand, pass back into the gut, or into the stomach;from the stomach its path may lead in many directions. It may pass onin its course of development into the rectum and out in the feces, or itmay enter the fatty bodies, or pass into the general cavity of theinsect, or it may migrate forward into the esophagus and into the labrum;and it may pass into the :\Ialpighian tubules, or into the ovaries.The organism may enter the eggs and remain therein through theirdevdopment into the larvae, nymphs or adults, and be transmitted atsome stage of the development of the second generation. Some diseasescan pass on even to the third generation.7. What Is the Course of the Organism on Leaving the Insect'The organism may leave the insect in the saliva and immediately enterthe feeding puncture. It may 'bore through the labium of the insect atthe time of feeding and enter the puncture. It may leave the rectum ofthe insect, or the Malpighian glands and be washed into the puncture bymeans of the secretions of the coxal glands, or some other excretionsmade at the time of feeding. It may be excreted in Malpighian secretions,01' rectal feces, or regurgitated in vomit, and may lie dormant onthe skin of the host, or on the food of the host, until it is scratched intothe blood, or is taken into the mouth.

30 SANITARY ENTOMOLOGYOn the other hand, it may be possible that the organism requiresanother host after the insect, and before it reaches its final host. Thereare cases on record of the, insect being the first host, and two or threevertebrates in succession being hosts of later stages.VI.WHAT IS KNOWN ABOUT THE DISEASE TO BE INVESTIGATED?It is a primary essential that all the workers be able to recognizethe disease which they are trying to study 'and that they be fully informedabout it, so that they ma,y be able to grasp possible solutions of theirproblem. They will, therefore, seek first to answer the following questions:1. What is the history of the disease and how long has it beenknown? How serious has it been?~. What is its distribution?3. Does it occur in pandemic, epidemic, endemic or sporadic form?4. In what seasons of the year is it most prevalent?5. Is there any apparent relationship between its distribution andthe physical, biological or climatic features of the countries where itoccurs?6. Does it affect any particular group, occupation, sex, age, raceor nation of people, or any particular species of animal?7. May any wild animal be considered as a reservoir?8. Has immunity or difference of susceptibility been recognized andunder what circumstances?9. What are the symptoms of the disease?10. What is known regarding immuno-chemistry and bacteriologyof the disease?11. What have autopsies shown?1~. What treatment has been designated?13. What is known or suspected about its causation and dissemination?What organisms have been connected with it?14. What possible theories clln be advanced to account for itscausation and dissemination?A little time spent in collecting these facts may save much e:tForllater.VII.WHAT INSECTS SHOULD BE INVESTIGATED?A thorough entomological stujy of this question may prove a valuableshort cut to the investigation. Many insects will be eliminated by theentomologist before he has finished his preliminary work. He will attemptto answer the following and many other questions and will probablyhave to answer them to the satisf~ction of all his fellow workers.

STEPS TO PROVE lNSECT CAUSATION OF DISEASE 311. What insects coincide in distribution with the general distributionof the disease?'!. What insects occur in peculiar habitats of the disease?8. What bloodsucking insects occur in the locality under investigation?4. What is the relative abundance of these insects?5. Is there a coincidence between the Beason of abundance of anyof these insects. and of the disease?6. What insects occur in the homes, nests, or haunts of infectedhosts?7. What insects are found on infected hosts?8. What insects occur in the working quarters of the patients?9. WiIat insects would be most apt to affect the particular ,groupof hosts most susceptible?10. What insects breed in or frequent the excreta of the hosts?11. What insecta are found at the food of the hosts?U. What insects are found at the sources of the food of the hosts,such as the milk?vm. WHAT IS NECESSARY IN THE TRANSMISSION EXPERIMENTS?The investigations which have preceded will have narrowed the questiondown to certain species or groups of insects which need to becritically studied. All of those insects which come in contact with theblood or mucous membranes of the patient, or the food of the patient,or the feces of the patient, must be given special attention. At thispoint the bacteriologist, protozoologist, or the helminthologist finds hisspecial work beginning. There will be many points which must be workedout by cooperatiQn of the parasitologist and entomologist.Considering first the bloodsucking insects, it is necessary to determine:1. Can the particular insect take up the organism with the blood?!. Does the organism pass into the intestinal canal or does it stopat some point en route?3. To what extent is the organism digested by the insect?4. In what organs of the insect can the parasite be demonstratedfrom day to day?5. Are any changes in the organism demonstrable?6. What path does the organism seem to follow in the insect's bodyfrom day to day?'7. Does this movement of the organism suggest whether the transmissionis by inoculation or does it suggest that the organism will passout of the body in some of the excreta?

SANITARY ENTOMOLOGY8. Can the organism be demonstrated in the mouth parts of theinsect at the time of feeding?9. Can the organism be found in any of the excretions of theinsect?10. How long is it before the organism reaches the mouth or therectum?11. What is the, earliest date at which it can be found in thefeces?I!. What is the earliest date at which infectivity of the host canbe obtained by the sucking of the blood?13. What is the earliest date at which infectivity can be obtainedby scratching in of the feces or portions of the insect?14. Can infection be obtained by either natural or a.rtificial inoculationwithout demonstration of the organism?15. Is the infective organism, contagium or virus filterable?16. Can the virus or organism be transmitted hereditarily by theinsect?17. At what stage of development in the second generation doeshereditary transmission become possible?18. Can the organism be taken up by the immature stages, feedingin infected excreta?19. Can the organism be taken up by immature sta~s of an invertebratefeeding on the host?!O. How long can the immature forms of the invertebrate, infectedby whatsoever manner, retain the organism in their system?!1. Does the organism stay in the insect during metamorphosis?!!. Does the organism undergo any changes preceding or followingmetamorphosis of its invertebl'a te host?23. At what stage in the metamorphosis does the insect begin to beinfective after taking up such organisms?!4. How lpng can the insect remain infected and infective?IX.HOW SHOULD EXPERIMENTAL INSECTS BE HANDLED?. A large proportion of the failures in studies of insect transmission inthe past have arisen from improper handling of the insects. The breedingand handling of the insects is an art in itself, just as is the culturing ofbacteria or protozoa. In fact, there are more diverse requireml!ntsfor handling insects of different species than can be found elsewhere in theanimal kingdom.1. What '111JlI,8t be kno'llm about the insect before beginning transmi88ionexperiments'The normal conditions of life of the insect must be ascertained :-its

STEPS TO PROVE INSECT CAUSATION OF DISEASE 33reactions to heat and cold, moisture and dryness, disturbances, color,light, odor; its food, and the proper condition thereof; its methodsof reproduction, and what food is necessary for reproduction; if soilshould be provided, and what conditions it should be in; if water shouldbe provided, and whether this water should be alkaline or acid, clear orcontaining foreign matter, and in such case what type of foreign matter;whether the water should be still o! in motion, warm, moderate or cold.~. What type of breeding cage should be used?A breeding cage must be used which will most nearly enable theexperimenter to keep the insects under control and yet reproduce essentialconditions for maintaining;. normal, healthy life of the insects andnormal reproduction. Much of this information is available in entomologicalliterature. Many insects probably involved in disease transmissionhave not been properly studied and breeding technique is yet to beworked out.3. Water is necessary in some form in practically all insect breeding.There are more failures to properly breed insects traceable to improperhumidity, or to the lack of moisture in the proper form for theinsects to drink. Much detailed observation may be necessary to obtainthis important information in the case of many insects. •4. There is a combination of temperature and humidity most favorablefor life, for each species, and differmg frO'1n one species to another.5. 'The food of an insect must be in a particular condition in order toobtain normal breeding. It may require a certain degree of immaturity,ripeness, or fermentation. It may require a certain degree of desiccation.Many other details must be attended to by each specialist involvedin the investigation, and we probably have yet to see a single diseaseproblem which has been completely rounded out and solved for the futuregenerations.

CHAPTER IIIA General Survey of the Needs of Entomological Sanitation in. America 1w. Dwight PierceNotwithstanding the great amount of publicity which has been giventhe Anti-fly Campaign, one will find throughout our land a rathergeneral disregard of the danger from flies. Certain newspapers kel'pthe subject annually before their readers, but on the whole, public cooperationis slight. A few cities and communities have definitely organizedmosquito control work, and the Public Health Service has done awonderful amount of work in organizing such efforts. From an entomologicalstandpoint our nation is not sanitary. The reason lies in thefact that the public does not yet realize that insects can and do carrydisease. Science has apparently not put forward the idea in such amanner that it has gripped the average person. Until we do this wecannot expect public cooperation in the .attempt to put down insectspreaddiseases.The problems we have to meet may be divided in several differentmanners. We may separate them into problems of municipalities, townsand villages, and rural communities. We may look at them from thestandpoint of the farm, the home, the market, the factory, and theinstitution. They may be sorted out as problems of drainage, wastedisposal, screening, animal control, etc.Of course we have a greater diversity of entomological contrOl problemsin a municipality, but we also have more people who give attentionto matters of health in a city, and who would complain against unhealthfulconditions. On the other hand, while the ,Problems of the ruralcommunity and town are fewer, the insect conditions often become greatlyaggravated because of total carelessness as to sanitation. This carelessnessin small towns and farms is usually due either to ignorance or lackof organized effort for community betterment.The field of the sanitary entomologist who desires to tread virgin soilis therefore to solve the ways and means of obtaining better fly andmosquito conditions in rural communities. Educational work must be11'his lecture was mimeographed and circulated to the class in January and appearedin parts in The American City, for February and March, 1919.34

NEEDS OF ENTOMOLOGICAL SANITATION IN AMERICA 35carried out which will be of such nature that it will bring results. Wehave the theories and the scientific facts but we must give the publicpractical demonstrations that freedom from insect pests means reducedsickness.Any person informed on this subject who has traveled much in ruralsections of this country and seen -the u:t:lobstructed entrance of myriadsof house-flies to the dwellings, especially the kitchens and dining rooms,and then has stepped outside and within a few feet found the open priviesbreeding these flies, cannot help but feel a sickening sensation and arevulsion toward eating anything that the flies could have polluted. Itis not at all uncommon in rural sections to see babies exposed to the unrestrictedvisits of flies, and their milk bottles covered with them. Thewriter has been informed over and over by physicians in small townsthat when infantile diarrhea or any other intestinal complaint visits atown it makes the rounds of every infant in the town, unless perchance,some mother is more advanced in her knowledge of such matters andkeeps her baby constantly screened. When typhoid fever and dysenteryvisit towns with open privies and unscreened houses or hotels only themore cautious and more resistant escape. Such communities offer everyconceivable opportunIty for the spread of diseases by flies.THE INSANITARY FARMFor fifteen years the writer has traveled extensively in rural communities,principally in the Southern States, where insanitary methods, ifexistent, aggravate disease conditions because of the more favorableclimate and greater number of maladies present. We may picture, therefore,a few of the conditions which have been repeatedly seen in thesetravels, in order the better to show the problems to be met. lVe shall notclaim that these pictures represent the predominant. or the usual, or theaverage condition. Let it suffice that they exist sufficiently often to makethem worthy of serious attention.The farm we will describe has been seen countless times. The househas no screens on the windo!",s, in fact, often has no window panes, ormay have wooden windows which are open all day. The house is one~storied with an outside chimney; and an open fireplace. The chimney andfireplace offer excellent day hiding places for mosquitoes, which areabundant if there is a slough or bayou nearby. The house is built onstumps or pillars raised above the ground. The pigs and chickens, dogsand cats, wander freely underneath. The house has a great open hallwaythrough the middle, separating the bedrooms from the living rooms.On account of the numerous flea-breeding animals which pass under thehouse, fleas are not at all uncommon in the house. The well is usually

36 SANITARY ENTOMOLOGYopen and built into the back portion of the porch. Mosquitoes breed init. There is a poorly constructed, dilapidated privy for the women notfar from the house, but t;he men have none, or if they do, it is not fit toenter. They usually defecate in the open, in the fields or draws, or in awoodland patch. The barn is roughly constructed. The manure is piledin a great pile beside the bam, and breeds multitudes of flies. The stablefloor is urine- and manure-soaked and affords excellt'nt fly-breedingquarters. .Naturally, I have described the worst common type of farm, becauseon this must be built the structure for better sanitation in farm life.In many cases a large number of such places may exist on a singlelarge plantation, for the use of the tenants. In such cases a single manis responsible, who himself lives in a house with all modem sanitaryconveniences.The problem of the sanitarian and the sanitary ,entomologist is toprove to the individual farmer and to the planter landlord the financialvalue of better sanitation. The planter must be shown that inasmuchas the efficiency hours of his tenants are increased, in proportion willtheir products be increased, and in like manner his rental, especiallywhere the rental is based on certain proportions of the crop yield. Hemust see that reduction of mosquitoes means reduction of malaria incidence,that reduction of flies reduces the incidence of typhoid, dysentery,diarrhea, and other intestinal complaints, and that as the sickness rate onthe plantation is decreased the labor output is increased.It will do us no good to theorize if we do not set down clearly theways and means of accomplishing this greater farm output by reducingfly and mosquito breeding. In the present course of lectures will befound the proofs which have accumulated against -these various insects,brief ,statements of how these insects live, and detailed plans of theapproved methods of control. Fortified with this ammunition and morewhich he will personally gain, the sanitary entomologist must fight forbetter sanitation.HOW TO IMPROVE FARM SANITATIONAt this time, however, we may in brief state a few measures whichshould be taken on every farm in order to accomplish greater farm laborefficiency and improve the health of the household and of the anjulals.1. The wVndows and doors should be scretmed against flies andmosquitoes. During the months that fires are not used the chimneysshould have a screen over the top and the fireplace screened. If wirescreening cannot be afforded, mosquito bars can be used. In the majorityof cases the expenditure of the n.ecl!l!$ary amount of money to properly

qNEEDS OF ENTOMOLOGICAL SANITATION IN AMERICA 87screen the place will bewoffset by a greater reduction in doctor's bills forthe women and children at le.ast.fl. Where there are many children passing in and out flies will getin. The children should be taught to use fly swatters. No flies shouldever be allowed to remain in the kitchen and dining rooms. Flies whichvisit food will deposit on it any disease organisms they have picked up.If the water is pure, the fly is' about the only common means of conveyingintestinal diseases to the family.8. Unless the babies and small children are kept indoors in screenedrooms, the helpless children should have a mosquito bar over the carriageor basket so as to protect th!'!m from ~ies. This i~ absolutely essentialif there is any sickness in the neighborhood.4. There should be installed sanitary 'Pit or bucket privies such asare recommended by the Public Health Service. Both men and womenshould be provided with such, and it should be a.rule of every farm thatindiscriminate defecation is absolutely forbidden. As many farms arequite large the most feasible plan would be to place at various placesover the farm where they would be most convenient and best protected,some type of latrine, such as is used by armies, or better still a permanentprivy.5. The well should be kept covered to prevent as far as possiblemosquito breeding and contamination.6. The foundations of the house should be boarded up to preventthe access of animals and to eliminate a favorite mosquito hiding place.The ground around the house should be so drained that water will notflow under the house except in case of'heavy rains, and in such cases willquickly drain off from under the house.7. All ditches, ponds, streams, and bayous on the farm should havethe banks kept clear of obstructions to the free flow of the water. Thereshould not be any tree stumps, trees, roots, weeds, or logs in the stream.The banks should not have overhanging ledges, or puddle pits. Permanentponds and lakes might be stocked with mosquito-eating fish.Places which habitually form puddles after rains should be filled anddrained.8. The barns should h,ave hard packed dirt floors or cement floors.All manure should be' removed daily from the barn. If possible themanure l should be spread whil.e fresh on fields lying fallow. Otherwise themanure should be piled in tightly packed stacks or on platforms over aCE'ment basin containing water, in order to drown the fly larvae migratingfor pupation.9. The garbage should be fed to pigs, preferably in sanitary feedingstalls as described by Bishopp in' the lecture on the control of flies inbarn yards, pig pens and chicken yards (Chapter XI).

88 SANITARY ENTOMOLOGY10. State Boards of Health should follow the California plan andforbid the marketing of fruit dried on farms with open sewage, or whereexposed to visits of flies,THE INSANITARY TOWNIn these same travels in which so many insanitary farms were seen,the writer has sojoij.rned in or passed through many towns which mightbe described as follows: The streets are unpaved and are littered fromone end to the other with papers, cans, 'and the accumulation of months ofmanure droppings, and are altogether filthy and unattractive. Theremoval of trash is nobody's business. The grocery stores and meatmarkets are un screened and have open doors. 'rhe food is covered withflies. Farmers drive up and buy a side of salt pork or other meat,throw it into the pit of their wagon, uncovered, and drive down thedusty road, with a swarm of flies hovering over the meat. The smalllunch rooms where the visiting farmer eats his noon or evening repastare dirty and full of flies. The stores have privies in the rear whichare filthy and an offense to any decent person. Flies abound. Chickensand pigs wander unrestricted through the streets and are often foundfeeding under the privies. The hotel dining rooms and kitchens arcalways full of flies and are usually but a short distance from filthyprivies, and flies are constantly passing back and forth. Cockroaches areserved in the food and wander unrestricted everywhere. The bedding isoften unclean and has been slept in by some one else. Bedbugs are notuncommon. The water pitchers contain mosquito wrigglers. The cisternsbehind each house are unscreened, and contain rain water, full ofmosquitoes. The livery stable has great piles of manure in the stableyards and sometimes right out on the sidewalk.Sometimes the town is a little bigger and the people have become morecivilized and installed interior plumbing, which empties the sewage intoa ditch which runs down to a stream from which cattle drink, or quiteoften this sewage empties into the gutter on the street and fills the airwith filthy odors. Such is not an uncommon thing in America. Onlya few years ago we could have pointed out quite 8. number of cities in th~100,000 class with open sewage.These small towns are often rat infested, and one can easily seethe danger should an outbreak of plague, which is transmitted by therat flea, get a start in such a town, by the advent of a plague infestedrat.HOW TO IMPROVE SANITATION1. Organize the community for better sanitation, and call in anexpert of the Public Health Servi~e, which is giving a great deal of

NEEDS OF ENTOMOL9GICAL SANITATION IN AMERICAattention to cooperative health work. In Russia, such organizations werespringing up all over the land before that country became submerged i~its present chaos.~. Conduct a health publicity campaign.S. 'I'each better sanitation in the schools and organize the childrenfor clean-up work.4. Require the screening of all stores selling food, and of all hotelsand restaurants dispensing food. Do not allow food to be handled insuch a way that it will attract great quantities of flies.5. Require private stables to place manure in fly-tight boxes andto have same removed every 7 to 10 days.6. Require livery stables to remove all accumulations of manuredaily from the town limits.7. Require the burning, feeding or removal of all garbage twice aweek from homes and daily from hotels.8. If garbage is hauled away and dumped the town sho1;1ld arrangefor its daily incineration.9. Require throughout the town limits, depending upon conditions,either sanitary plumbing and sewer connection, or sanitary box or pailprIVIes. Do not allow pit privies or insanitary ones of any type. Doaway as soon as possible with open sewer drainage, installing sewer pipe.Install sewage septic tanks of size adequate for the town. If there are nosewers laid it may be possible to arrange for individual installation ofsimple septic tanks.10. Do not allow pigs and chickens to have access to privies.11. Do not permit general roving of pigs, stock, chickens, etc., onthe town streets.l!. Keep all ditches and waterways in the town free of obstruction,~nd if mosquitoes are breeding, have an oiling squad.IS. Fix strict penalties against defecation on streets, alleys, andvacant lots.14. Install a town comfort station for strangers and people fromthe country.SANITARY PROBLEMS OF CITIESThe sanitary entomological problems are multiple in large cities, andsucn that it..would be an excellent practice to employ at.least a consultingentomologist in all large cities. As a matter of fact many citiesshould have quite a corps of practical sanitary entomologists engagedprimarily for this type. of work.City markets where meats, fish and all kinds of vegetables and produceare exposed for sale, are very attractive places for flies, and in manylarge cities there is gross neglect along these lines.,qS9

40 SANITARY ENTOMOLOGYSanitary inspectors need to exercise considerable vigilance in checkingup obedience to ordinances relating to removal of trash, garbage, manure,excreta; installation of sewage or sanitary privies; proper sanitationamong construction gangs; nuisances arising from stables, factories,sewage and garbage disposal plants, packing houses, stock yards, etc.lIany manufacturing plants have waste products which arc very attractiveto insects. Insect conditions in restaurants, boarding houses andhotels should be frequently checked up.Anti-fly and anti-mosquito propaganda should be conducted annuallyin every city until the people are so well educated to the necessity thereofthat propaganda will no longer be necessary.The sanitary department of large cities should directly supervisemosquito suppression within its bounds.ENTOMOLOGICAL REQUIREl.\IENTS OF MUNICIPAL SANITATIONThe following points should be covered by ordinance in all large citiesdesirous of obtaining satisfactory sanitation. Not enough attentionhas been given by city health authorities to the insect side of theirsanitary problems.1. All foodstuffs, which are eaten raw; all raw meats, fish, birds,cooked foods, bread, cheese, dried fruits, etc., must be kept under coverof glass or screen or otherwise protected from insects, in all markets,stores, street stands, hotels, restaurants and boarding houses. Flies mustnot be allowed to congregate around food sta11s. Cockroaches must beeliminated from all hotels, restaurants and boarding houses. Foodsinfested by insects should be subject to condemnation a~d destruction.Insect contamination of food is dangerous.~. Hotels, public institutions, and lodging houses shall be required tokeep their premises free of bedbugs. Bedbugs carry disease. '3. All school children shall be inspected at the beginning of eachnew school year for head lice, and oftener if circumstances warrant. Incase the children are infested they should be isolated and sent to someclinic where they can be freed of' the lice. All prisoners, patients inhospitals, and applicants at mu~icipal lodging houses should be inspectedfor head, body, and crab lice, and if infested should be bathed andtheir clothing condemned or cleaned. Lice carry many diseases and everyopportunity should be taken which will enable the authorities to reducetheir incidence.4. All livery stables shall be required to remove all manure to thecountry daily, unless specified places for dumping are set aside. Allprivate stables should be provided ,vith a fly-proof box or a maggot-

NEEDS OF ENTOMOLOGICAL SANITATION IN AMERICA 41trap platform for the storage of manure and should have the manureremoved at least every 10 days.5. Garbage should be removed daily from all places where it accumulatesin large quantities, and two or three times a week from privateresidences. All garbage awaiting removal should be kept in closedcans. Garbage must not bc dumped within the city limits unless it isdumped on in_cinerators where fires will soon consume it. These requirementsarc necessary to keep down fly breeding.6. Tin cans, bottles, and receptacles which will hold water, mustnot be allowed to accumulate in back yards, alleys or vacant lots, normay they be dumped within the city limits or near residential sectionsin the suburbs, because they furnish excellent breeding quarters formosquitoes.7. The city should be connected for sewers as far into the suburbsas practicable, and all suburban properties not so connected should berequired to install fly-proof cesspools, or septic tanks, or to arrange byneighborhoods for independent sewage with a common septic tank; or inthe absence of water and necessary plumbing, to install sanitary privies,and be required to have all excreta removed once a week to an incineratoror other type of refuse disposal plant. Open vault privies should not bepE'rmitted in the city. Indiscriminate defecation on streets, alleys, vacantlots, etc., should be strictly forbidden and punishable by law.S. Packing houses, candy factories, syrup factories, and all othermanufacturing institutiQns producing food products should be requiredto screen windows and entrances, and to use fly traps in such a way asto minimize to the utmost the access of flies and other insects to the foodproducts. Especial attention should be given to the prevention of insectbreeding on such premises.INDUSTRIAL SANITATIONMany industries have important entomological sanitary problems inthe preservE4tion of their products from insect contamination and in thel'Worts to conform to sanitary regulations. There are many times whenthey \vould be able to use the services of a consulting sCJ.nitary entomologistto advantage.The keynote of industry today is the prevention or utilization ofwaste. Insect depredations On food products cause waste because thepublicdoes not want polluted food, and because sanitary inspectors arebecoming more and more alive to the menace to health from insect pollutedfoods.It is not generally understood that the presence of weevils and wormsin cereal foods may do more than destroy the food. The evidence is.

SANITARY ENTOMOLOGYgrowing against these insects from the sanitary standpoint. Some ofthese insects contain substances in their bodies which are highly toxi(" asfor instance Sitophilua granarius, the granary weevil, contains thepoisonous substance cantharidin. There are numerous instances of thesickening of animals from eating weevily grain. Still more important isthe fact that where grain is accessible both to rodents and insects, certainparasitic worms pass out in the feces of the rodent in the egg stage,are eaten by the insect larvae in the grain, pass part of their life cyclein the insect, and the insect is then pos:;ibly eaten by a rodent, in whichthe worm completes its life cycle; or sometimes in our breakfast foodswe eat these parasitized insects and become infected with the worms. Forexample, the rat tapeworm, Hymenolepis diminuta (Rudolphi) infestsvarious species of rats, but sometimes is found in man. Joyeux hasproved that its commonest intermediate host is the meal moth, A.sopiafarinalis,which becomes infected by eating the tapeworm eggs, in thelarval stage. Grassi and Rovelli found the cysticercoid in the larva andadult of this moth and also in the earwig, A.nisolabis annulipes and thebeetles Akis spinosa and Scaurus striatu8. Joyeux found that the adultsof the granary beetle, Tenebrio molitor, easily took up the eggs. Acysticercoid or larval stage resembling the mouse tapeworm Hymenolepismicro8toma (Dujardin) has been found by Grassi and Rovelli in thebeetle Tenebrio molitor.The whole problem, therefore, of the control of stored food productinsects is of vital importance to the manufacturers of food.Syrup factories, sugar mills and refineries, ice cream factories, creameries,and candy factories offer great attractions to flies which mayalight on the exposed products and deposit with their feet, or in theirvomit or excreta, germs of disease taken up elsewhere, perhaps daysbefore when the fly was a larva breeding in excrement, and these germsmay find the sweets excellent culture media for extensive growth. Extraordinarymeans must be devised to keep flies away from such products.Packinghouses offer abundant attractions to many kinds of insects,many of which are serious disease carriers.Railroad trains are the means of conveying. from place to placedisease-carrying mosquitoes, flies, roaches, fleas, lice, bedbugs, and mites.Fumigation of railway cars is an essential entomological control measure.Dairies are often found to be the foci of the spread of typhoid fever,and knowing the propensity of the house fly we can see how readily itcan carry the organisms from the stools of a siek person to the milkpails in the dairy. There needs to be rigid control of flies in all dairies.These are but examples of many industries which have problems insanitary entomology.

CHAPTER IVA General Survey of the Seriousness of Insect-Borne Diseases to Armies 1W. Dwight PierceAs thi$ course of study is directed primarily toward obtaining athorough knowledge of the relations of insects to diseases of men andthe measures which must be taken to prevent these diseases, it is eminentlyproper for us to make a survey of the insect problems which confront thegreatest aggregations of men, the modern army. From a study of militarysanitation methods we may learn much which we need to know inpractical municipal problems. Military methods are based on the necessityof quick returns and emergency efficiency, from which are built up inpermanent establishments more perfect measures.The discussion of military entomology immediately falls into two verydistinct lines: first, the army training and concentration camps, andsecond, the active service camps and battle conditions.Before the location of the average training camp, we may assumethat it is possible to deliberate more or less on the desirability of one ormore sites and that in a general way drinking water and general healthconditions are considered. Not infrequently some other considerationwill outweigh sanitation, as when it is considered essential to place a campnear a certain city or on a certain ,vaterway or railway. In such casesof expediency, we are quite likely to find sanitation a serious problemfrom the outset.The camp site is selectelio because of some important reason.From an entomologist's viewpoint a number of outstanding questionsimmediately arise as to this site. Is the ground open or wooded, level orsloping and well drained? Are there water holes, running streams, orswamps in the camp area or nearby? Are there farmhouses, stables,or other buildings on the site and what is the entomological situation inthese buildings? What disease-carrying insects are naturally breedingabout the camp site? If th~re has been any contagious disease of manor animals in the community before the camp was located, the entomologist'sconcern is the greater. He should if possible learn the focus of• This lecture was originally presented May 27, 1918, and distributed the same day.It has been revised for the present edition.43

44 SANITARY ENTOMOLOGYthat disease and the insect conditions of that focus. The original healthconditions on the site may have a distinct bearing on later events.Often the first arrivals at the camp site are contractors with multitudesof laborers and animals collected from everywhere, and from everystratum of society. There are few hygienic arrangements for these men.In fact, the contractors are aiming to obtain as large profits as possible,and therefore hold down the expenses for sanitary waste disposal. Someamong these laborers are almost certain to bring lice, bedbugs, fleas, andpossibly also scabies mites, on their bodies and clothes. Thtown togetherindiscriminately in hastily cOQstructed barracks, there is soon a generaldistribution of vermin. Their animals are quite likely to be infected withscabies mites and possibly other mites, and with bots and ticks. Theundisciplined assembling of many animals and carelessness about manuredisposal offers great attractiveness to all flies and insects attracted byanimals. It is probable that many dogs accompany the laborers andcontribute their quota of fleas. It is almost impossible with crude, uneducatedlaboring men to get them to maintain sanitary conditions. Indiscriminatedefecation, the scattering of garbage, the accumulation ofmanure, personal uncleanliness, all contribute to make contractor camps. t Jsamtary sore spo s.Sooner or later the sanitarians arrive on the spot, very likely witha squad or company of raw untrained labor troops, and the clean-upbegins. We can expect a constant lack of coordination between themilitary and the civilian. As for example, at one camp the sanitaryofficers had constructed drainage ditches to carry off surplus standingwater, but the laborers persisted in throwing scraps of wood, underbrushand waste into the ditches so that they were of no avail, or rather so thatthey formed traps for ~ater pools.During the transition period when the camp is part civilian and partmilitary there will be two very different types of conditions existingside by side, one good, one bad. Of course fhe army sanitarians havesupervision over these civilian camps, but they find difficulty in enforcingsanitation.When a camp is placed like Camp Humphreys, Virginia, on a tongueof land between two shallow bays of water that are known to fill up withvegetation, and which furnish breeding places for millions of mosquitoe;,and with typical swamp lands at the heads of these bays, we may readilysee that the task of the sanitary officer is not an easy one. These baysare moreover at tidal level and the daily fluctuations of the water addcomplications to the drainage problem. Each individual camp, whereverlocated, will present its own type of problems, and necessitates an earlyand thorough entomological survey.The tremendous speed of construction· and the rapid arrivals of fresh!

SERIOUSNESS Ol!' INSECT-BORNE DISEASES TO ARMIES 45contingents of troops and animals in a new army camp make the firstmonths of the entomological sanitarian very busy ones. Common senseis one of the primary essentials in meeting the exigencies of the situation.The possibility of moscfuito breeding must be kept at a minimum in spiteof temporary drainage, multitudes of borrow pits, tree stumps, fire-waterbarrels, etc. A system of manure, garbage, refuse, and fecal disposalis of necessity hastily devised and must keep pace with the increasingnumbers of men and animals. This waste disposal is handled by specialunits and thl! sanitarian acts only in an advisory capacity. He needstherefore to be very vigilant in his inspections. Army camps nowadaysgrmv in such marvelous proportions that past experiences are of littleavail. The man on the ground must be well versed in the principles ofentomological sanitation and must use his judgment for all it is worth.The constant accessions in troops and raw recruits call for constantscouting and prophylaxis to prevent admission of vermin. The workagainst vermin almost necessitates a specialist to take care of it alone. Infaet it were best if three entomologists were located in each camp, onelooking after the suppression of water and moist earth breeding insects,one looking after the suppression of fecal, waste, and manure breedinginsects, and the third handling the vermin of the person and the barracks.So serious is the vermin problem in all armies i{jlat elaborate measureshave to be taken to combat it. The Germans developed great vacuumtubes that will contain an entire railroad coach. The Russians, and thenother nations, developed bath trains sufficient to handle the cleansing ofthousands of men a day. The Russians and Roumanians developed sodhouses for heat sterilization of clothing. Heat and steam sterilizing plantsof many types have been devised. A tremendous amount of experimentationhas been directed toward chemical cleansing of the clothing.The destruction of waste is such an acute problem that many types ofincinerators have resulted (see figs. 1, ~, 3), but as a camp becomespE'rmanently organized the, sewage system does away with many of theearly difficulties. Permanent incinerators, well kept drainage systems,organized removal of the manure, and disposal of garbage by the quarterma"ter'sdepartment, systematic inspection of quarters and grounds, and'1ystematic bathing and clean!!ing of clothing, characterize the perfectlyadjusted sanitation of a permanent camIf. Every large army camphas its reIllmnt camp and company stables. The farther these stables areloC'ated from the soldiers' barracks the better will be the fly conditionsin the living quarters of the men.The actively engaged army, however, presents entirely different conditions.There is no possibility of developing sewage systems, but temporarylatrines must be substituted (see figs. 4, 5, 6, 7). Manure andga.rbage cannot be farmed out to contractors, but must be disposed of

46 SANITARY ENTOMOLOGYFIG. l.-Cross section of Mann's hillside incinerator, used at U. S. Marine Camp,Quantico, Va. (Mann).FIG. S.-Modification of Mann's hillside incinerator, adapting it to level ground (Mann).FIG. 3.-Small incinerator of the Ferguson type, for use of small units, and capableof transportation (Mann).

SERIOUSNESS OF INSECT-BORNE DISEASES TO ARMIES 47FIG. ".-straddle trench latrines, 1 foot wide, !iI feet deep, 3 feet long, for field operationsat temporary locations (Mann).Flo. 5.-Covered pit latrine level with ground, a semi-permanent type- (Mann).FIG. 6.-Garbage can with top com'erted into portable urinal for use in company streetat night (Mann).

48 SANITARY ENTOMOLOGYby hastily built incinerators, or the manure stacked and treated to kill:flies. Ditches and standing water cannot be drained. They must betreated to kill insect life in them. Temporary hospitals abound andmust be protected from flies and vermin. The men sleep out of doorsor in scanty shelters, even in pig pens, barns, etc., wherever they ca8find shelter in inclement weather.'Insect infestation in these must be reduced to a minimum. W'hen liceabound, hastily constructed devices must be installed or the clothingtreated by chemicals. The trenches and dugouts have to be sprayed withcreosote oils to keep away flies and kill vermin. Terrible stenches arisefrom dead bodies and these' must be buried or treated to prevent flybreeding. In other words, everything here must be done hastily but.~o~~ :otmOf(FIG. 7.-Urine soakage pit, in cross section (Mann's modification from Lelean).effectively, for tomorrow the work may have to be done all over somewherebeyond or behind. The larger the body of men assembled and thegreater the carnage, the more serious the diseases of all kinds andespecially those carried by insects.In the great European War the greatest diseases were those borneby lice. In fact there is plenty of evidence that lo.use-borne diseaseshave been among the worst in many wars of the past. Three seriousdiseases which ravaged the trenches are carried only by lice,-typhusfever, trench fever, and European relapsing fever. Millions of theSerbian nation were wiped out by typhus fever. The Roumanian nationwas swept by typhus and relapsing fever. Russia, Germany, Austria andFrance suffered terribly from these louse-borne diseases. Trench feverspread back from the trenches into the cities. And yet all of thesediseases can be controlled absolutely by suppressing the lice. It is easyto see how serious it is if a case of any of these diseases enters the

SERIOUSNESS OF INSECT-BORNE DISEASES TO ARMIES 41}trenches. The lice spread from man to man, and they arc noted fol~leaving a man with feverish conditions for a normal man.Another disease which has been especially bothersome in the trenchesis scabies. Both horses and men are seriously afflicted with this mitedisease, and special veterinary hospitals were constructed in France solelyfor handling horse scabies.In malarious countries where mosquitoes are breeding in great numbers,malaria is a very serious camp and army problem. Campaigns intropical countries are endangered often by yellow fever, dengue andfilariasis, which are also mosquito-borne diseases.The troops engaged in Asia and some parts of the Mediterranean littoralhad to contend with the possibilities of plague outbreaks. Troopsengaged in the African campaigns had to deal with trypanosome andspirochrete diseases. Along the Mediterranean littoral pappataci feveris to be seriously considered. For example, a detachment of the BritishArmy in Egypt was suddenly attacked by an outbreak of this disease.We are all familiar with the disaster of our Spanish-American Warin which so many thousands were carried away by typhoid fever, dysenteryand diarrhea, all fly-borne diseases. In the present war, to thesemust be added Asiatic cholera, also borne by the fly.The great q_uantity of carcasses on the battlefield gives rise to myriadsof flesh and carrion flies and as a consequence of the habit of theseflies of attacking wounds of living people, there were many cases ofhuman as well as animal anthrax in the European War.These are only the more important army diseases carried by insects.One of the greatest dangers to troops in active service lies in theirmoving into countries with obscure or little studied diseases, or diseasesagainst which the men have had no chance to develop immunity.

CHAPTER VRelation of Insects to the Parasitic Worms of Vertebrates 1B. H. Ransom·The only important part insects are known to play in the propagation()f parasitic worms that affect human beings and other vertebrates isthat of true intermediate hosts necessary to the existence of the parasitesin some of their stages of development. Observations have been recordedin the literature showing that flies and other insects may swallow theeggs of various parasites of man such as hookworms, whipworms andother nematodes in whose life history no intermediate hosts are required,also the eggs of tapeworms in whose normal life history it is known thatinsects are not concerned, for example, Taema aagino,ta, whose intermediatehost is the ox. It has been supposed that insects may thus actas mechanical carriers for such parasites, but as a matter of fact definite-evidence of the importance of insects as mechanical carriers of the eggsor larvae of parasitic worms has not yet been brought forth. On thecontrary there are reasons to suppose that in some cases at least the'swallowing of the eggs or larvae of parasites by insects that can actonly as mechanical carriers and not as intermediate lj,osts, reduces ratherthan increases the chances of the young parasites continuing theirdevelopment and reaching a host in which they can become mature.Among the parasitic worms affecting man and other vertebrates it isthose forms requiring intermediate hosts, so-called heteroxenous parasites,that are of special interest so far as insect transmission is concerned.The monoxenous parasites, or those requiring no intermediate host, maypractically be left out of consideration, with the admission that themechanical carriage of monoxenous parasitic worms by insects may inthe future be proved to have an importance not yet demonstrated.A complete demonstration of the part played by an insect in the lifehistory of a given species of parasite is often a difficult matter. Theanimal which serves as the final host may be subject to infection notonly with the species of parasite under investigation but also with otherspecies liable to be confused with it in some of its stages. The insect1 This lecture was read to the class on December 16, 1918, and distributed January,1919. It has been revised up to date. The names of insects have been revised bythe editor.50

RELATION OF INSECTS TO THE PARASITIC WORMS 51may likewise harbor parasites other than the one that is being studied.The possibilities of confusion and of the entrance of extraneous factorsinto the problem are so many and so varied that in most cases it isonly after the most rigorously controlled experiments, combined withcareful comparative studies of the successive stages of the parasite, thatconclusions may safely be drawn. Furthermore, in working out the lifehistory of a parasitic worm it is not sufficient to prove that insects of acertain species can act as intermediate hosts under experimental conditions.Some species of parasitic worms are able to develop in more thanone species of insect, and the fact that a certain parasite can develop ina certain insect does not necessarily mean that under natural conditionsthe species of inse~t in question serves as the intermediate host of theparasite. For example, one of the common parasites of sheep and cattleis able to pass through its :rhrval stages in cockroaches. These insectsbecome readily infected if the eggs of the parasite which occur in thefeces of the final host animals are fed to them. Under natural conditions,however, cockroaches do not ingest the feces of sheep and cattle, nor arethey found in places where they are likely to be picked up by sheep andcattle. Besides cockroaches, various species of dung beetles have beenshown to be capable of acting as intermediate hosts of the parasite inquestion, and it is evident that these insects are the natural intermediatehosts. Unlike cockroaches they have plenty of opportunity both ofbecoming infected and of passing on their infection to the final hosts.A more or less intimate environmental relationship between the insecthost and the final host generally exists in the case of parasites transmittedby insects. In a number of cases the insects are coprophagous and alsolikely to be ingested by the final hosts, as in the instance just cited.Another highly interesting group of cases is that in which the insectsare ectoparasites on the final hosts, or bloodsuckers that periodicallyvisit them, and thus have particularly favorable opportunities for becominginfected with parasitic worms harbored by the animals they attackand in turn reinfecting the latter.MODE OF INFEC-TION OF INSECT HOSTSAs already stated the part which insects may take in the propagationof parasitic worms of higher animals is that of intermediate hosts, inwhich certain larval stages of the parasites are passed before they areready to enter the bodies of their final or definitive hosts in which theydevelop to maturity. The way in which the insects become infected varieswith different species of parasites. In the case of some species whichlive in the alimentary tract of the final host the eggs or larvae are dischargedfrom the body of the host in the feces. Coprophagous insects

SANITARY ENTOMOLOGYswallow the eggs and if they are suitable intennediate hosts for theparasites the young worms go through several developmental stages andfinally within the bodies of the insects reach a stage in which they areready to be introduced into tIte body of the final host. Certain parasiteswhose adult stages live in relation with the blood vessels of the final hostdischarge their young into the blood stream whence they may be ingestedby bloodsucking insects in whose bodies they undergo development to astage infective for the final host. Aquatic insects may swallow free-livinglarval stages of parasites, or may be actively attacked by larval parasiteswhich gain entrance to their bodies by penetrating the cuticle.These insects may in turn be eaten by other insects and the infection thuspassed on -to them.In some cases the parasites may be taken up by insects or entertheir bodies during an early stage of development of the insects andpersist in later stages. Infection may thus occur during one stage of theinsect but the development of the parasite to a stage infective for thefinal host may not be completed until after the insect has reached a laterstage. Thus flies become infected with a certain parasite of the horseduring the maggot stage, but the young pa~asites do not become sufficientlydeveloped to be returned to the final host until the flies havereached the pupal or adult stage.MODE OF INFECTION OF VERTEBRATE HOSTSParasitie worms that have insects for intermediate hosts reaehtheir final hosts in various ways. In the case of some species the insecthosts are swallowed either as the habitual food of the final hosts, orincidentally with food or drink. In other instances the young worm mayhave already escaped from its insect host before it is taken in with foodor drink by its final host. The cases of accidental infection with horsehairworms not normally parasites of human beings are likely to havehappened in this way. The parasites of which bloodsucking insects areintennediate hosts may be introduced into their final hosts as a result ofthe escape of the larval parasites from the insects at ,a time when theinsects are drawing blood. Commonly the larvre burst through a lveakspot in the cuticle of the insect and then burrow into the skin of thefinal host.SPECIES OF WORl\IS FOUND IN INSECTSThe parasitic worms of the higher animals in whose life history insectsand insect-like organisms play a part, belong to two large zoologicalgroups, Plathelminthes and Nemathelminthes. The former may be subdividedso far as concerns parasitic forms into Cestoda, or tapewonns,

641 SANITARY ENTOMOLOGYare unable to swallow the eggs of the tapeworm. He finds that larvalfleas readily swallow the eggs; these hatch in the intestine of the insect,and the embryos thus released penetrate into the body cavity. They persistin the hexacanth stage until the transformation of the flea into theadult, after which they proceed with their development and in a shorttime reach the cysticercoid stage. Infection of the dog, cat, or humanbeing occurs naturally as a result of swallowing infested fleas. Fleasare exposed to infection owing to the fact that their larvle live in anenvironment likely to be contaminated by the feces of infested dogs orcats. The eggs of the tapeworm as passed in the feces are grouped incapsules containing about a dozen eggs, so that infection of the insecthost is likely to be multiple. The double-pored tapeworm is relativelyuncommon in man and most of the cases recorded, of which there have beenless than 100 all told, three in the United States, are among youngchildren. Children are more likely than adult human beings to swallowfleas, which would explain the greater frequency of infestation among.children. Another possible explanation of the more common occurrenceof this parasite among children than amo.ng adults is that older personsmay possess a greater immunity to infection. Prophylaxis against thedouble-pored tapeworm consists chiefly in keeping dogs and cats free fromlice and fleas, and so far as human beings are concerned excluding dogsand cats, especially if they are lousy or infested with fleas, from humanhabitations.HY1TUf'nolepis diminuta (Rudolphi, 1819) Blanchard, 1891Hymenolepis diminuta (the yellow-spotted tapeworm) is of frequentoccurrence in the small intestine of rats and mice, particularly the former,and of occasional occurrence in the intestine of man. The adaptabilityof the adult tapeworm to hosts so widely different as rodents and humanbeings is paralleled by the adaptability of the larval stage to variousintermediate hosts. Cysticercoids belonging to this species have beenrecorded in various insects, a Lepidopteron, Asopia farinalis, in bothlarva and imago; a Dermapteron, Anisolabis anlflllllipes; Coleoptera, Akisspinosa, ScauruB striatus, and Tenebrio molitor; and fleas Ceratophyllusfasciatus, Xenopsylla cheopis, Pulex irritans, and Ctenocephalus canis;a.lso in myriapods, Fontaria 'Dirginiensis and JuJus sp. Nicoll andMinchin (1911) found the cysticercoids in about 4 per cent of the ratfleas (8 out of 207) they examined during a period of thirteen months,and they succeeded in infecting rats with the tapeworm by feeding themfleas, as Grassi and Rovelli (1892) had previously done by feeding otherinsects. Joyeux (1916) infected the larvae of Asopia farinalis by feedingthe eggs of H. diminuta and believes the cysticercoids recorded in the

RELATION OF INSECTS TO THE PARASITIC WORMS 55adult moth by Grassi and RoveIIi were carried over from the larval stageof the insect. He failed in his attempts to infect Forficula auricularia,Blatta orientalis, and Blattella germanica. He also failed to infect.beetles belonging to the species Blaps mortisaga, but succeeded easily ininfecting the· adults of Tenebrio molitor. The larvIE of this latter beetleaccording to Joyeux are incapable of acting as intermediate hosts ofH. diminuta. He was able to infect the larvIE of rat fleas and of Pulexirritans and Ctenocephalus canis. In these insects the embryos of H.diminuta begin immediately to develop into cysticercoids and do not waitfor the transformation of the larval fleas into adults, as Joyeux found inthe case of Dipylidiwm canimum, the embryos of which apparently liedormant in the insect until after it transforms into the adult stage. Inthis country Nickerson (1911) has reared the cysticercoid in myriapods,Fontaria 't'irginiensis and Julus sp., fed on the eggs of the tapeworm. Hefailed in his attempts to infect meal worms.It is evident that infection of the definitive host with H. diminutarC'Iults from swallowing infested insects, the latter having become infestedas a result of swallowing the eggs contained in the feces of animals harboringthe tapeworms. As a parasite of man in the United States, so far asavailable statistics show, H. diminuta ranks about third in frequencyamong the tapeworms, the beef tapeworm (Tamia satftnata) being themost common, and the dwarf tapeworm (H. nana) being next. Evidentprophylactic measures are those directed toward the destruction of ratsand mice and the avoidance of the ingestion by human beings of thevariousinsects that may serve as intermediate hosts, especially the protectionof farinaceous foods from insect infestation.Hymenolepis nana (Siebold, 1852) Blanchard, 1891Hymenolepis nana (the dwarf tapeworm) is a very common intestinalparasite of rats and mice and is of rather frequent occurrence in man,especially in children. In the United States it ranks second to the beeftapeworm in the order of frequency among the tapeworms of man. Itslife history has not been fully worked out. Grassi (1887), however, hasfound that cysticercoids develop in the intestinal villi of rats that havebeen fed the eggs of the dwarf tapeworm. According to his view thecysticercoids later break out of the villi into the lumen of the intestineand grow into mature tapeworms. The rat thus acts both as intermediateand definitive host of the dwarf tapeworm, the parasite beingspread from one rat to another 'through the medium of the eggs passedin the feces. The dwarf tapeworm, according to Grassi's version of thelife cycle, is an exception to the rule among tapeworms that the adultstage occurs in one species of animal a,nd the larval stage in another

56 SANITARY ENTOMOLOGYspecies likely to be eaten by animals of the species that harbors theadult tapeworm.Inasmuch as Nicoll.and Minchin (1911) have found cysticercoids ina rat flea (Ceratophyllus fasciatus) that in details of head structure areapparently exactly similar to and specifically identical with the dwarftapeworm, the question arises whether such insects may not act as intermediatehosts, and whether in addition to the life cycle of an exceptionaltype described by Grassi, the dwarf tapeworm also has a life cycle ofthe ordinary type. T. H. Johnston has found cysticercoids similar tothose recorded by Nicoll and Minchin in another species of rat flea(Xenopsylla cheopis) as well as in Ceratophyllus fasciatus.Joyeux (1916) has failed in experiments with fleas belonging to thespecies named and to related species, to infect them with H. nana. Hestates he used both larval and adult fleas. On the other hand he was ableto confirm Grassi's results and succeeded in infecting a large number ofrats and mice by feeding them the eggs of the tapeworm. The experimentalevidence thus far available accordingly favors the view that insectsdo not playa necessary part in the life history of the dwarf tapeworm.Furthermore, considering the frequency of occurrence of H. nana asa parasite of man, and the enormous numbers of the parasite~ sometimespresent, it would seem that infection is more likely to occur in the mannerdescribed by Grassi than as a result of f\lwallowing rat fleas, there beingof course a greater likelihood of human beings swallowing rat feces orfecal matter from other human beings containing large numbers of eggsof the tapeworm than of swallowing rat fleas ~ontaining a sufficient numberof cysticercoids to develop into the large number of tapeworms thathave been found in some cases. .Choanotamia infundibulum (Bloch, 1779) Cohn, 1899Choa'llOtomia infwndibulwm is a common tapeworm of chickens invarious parts of the world. Grassi and Rovelli (1892) in Italy foundcysticercoids in the common house fly (Mu.sca domestica) which onaccount of their morphological similarity to Cho'anotrenia infwndibulumthey inferred belonged to this species. From the results of experimentsconducted in this country by Guberlet (1916) it appears safe to concludethat the common house fly acts as the intermediate host of the tapeworm,Choanotrema infwndibulwm, infection of the fly apparently occurring asa result of swallowing the eggs of the tapeworm, and the chicken in tumacquiring the parasite as a result of swallowing flies infested with thecysticercoid stage. Whether infection of the fly regularly occurs duringthe larval or during the adult stage, or during both stages, has not beendefinitely settled.

RELATION OF INSECTS TO THE PARASITIC WORMS 57Prophylaxis in the case of this tapeworm is obviously largelydependent upon fly control measures.Other TapewormsAccording to Villot (1888) the larval tapeworm observed by Stein(185~) in the larva of Tenebrio molitor belongs· to the tapeworm of themouse, known as Hymenolepis microstoma. The same writer (1878,1888) also associates with certain tapeworms of shrews, two species oflarval tapeworms which he found in myriapods, Glomeris limbata. Furtherinvestigations of these parasites appear necessary to substantiatethe views held by Villot as to their specific identity. Ackert (1918, 1919)has recently recorded some experiments in which chickens were givenhouse flies and became infested with tapeworms (Davaimea cesticillU8 andD. tetragona). The immature stages of these parasites were not, however,seen in the flies and the possibility is not excluded that the chickensbecame infected from some source other than ·the flies, notwithstandingthe precautions taken against extraneous infection. Guberlet (1919)caught stable flies (Stomoxys calcitrans) in poultry yards where thechickens were commonly infested with HymMolepis carioca (Magalhaes,1898) and fed them to young chicks with the result that some of thembf'came infested with this tapeworm. He concludes that the stable flypossibly serves as an intermediate host of this tapeworm.TREMATODA OR FLUKESAll species of flukes whose life history is known depend upon molluscsas hosts for certain larval stages, and they mayor may not require oneor more additional intermediate hosts before they reach the definitive host.n is as intermediate hosts following the first intermediate host, a mollusc,that insects can playa part in the propagation of flukes. As yet it hasnot been shown that insects are concerned in the life history of any ofthe flukes (about 100 known species) that affect human beings or domesticanimals, but as the .life history of all of these parasites has riot beendt'termined it is quite likely that in the case of SOJIle species insects will befound ~~ act as intermediate hosts.' Different species and groups ofspt'cies show various types of life history with reference to the numberof larval stages through whicJI the parasite passes and the number Qfintermediate hosts required. A comparatively simple life cycle is asfollows: The mature fluke in the definitive host produces .eggs which passto the exterior in the feces. Under suitable conditions of moisture andtemperature the egg hatches and a ciliated larva, the miracidiunn, issues.If this miracidiunn finds a suitable mollusc (different species of mollus'

58 SANITA,ltY ENTOMOLOGYattract different species of miracidia) it burrows into the soft tissues ofthe mollusc and reaching the respiratory chamber proceeds to developinto the next stage, the 8porocY8t. Within the sporocyst by a processof internal budding more or less numerous so~called redifE develop. Theredire finally leave the sporocyst and migrate into the liver of the mollusc.In the redia several generations of daughter redire may develop bybudding. The next stage, developed also by internal budding from theredia, is the cercarilf'. The cercaria of some species is p:rovided with atail by means of which it swims about in the water when it finally escapesfrom the mollusc. The cercaria may be swallowed by or actively penetrateinto some animal and become encysted in this animal. Finally whenthe animal harboring encysted immature flukes is swallowed by an animalwhich can serve as a host of the adult fluke, the young flukes thus reachingtheir definitive host develop to maturity and the life cycle is complete:Following is given a partial list of the insects in which young flukeshave been recorded. The species to which the young flukes in questionhave been assigned and the final host animals arc also indicated. Furtherinvestigations are likely to show that some of the flukes from insectshave been misidentified and do not belong to the species to which theyhave been supposed to belong, and the data given in the list shouldnot be accepted as fully proved in any case, though there can be no doubtin some of the cases cited. No distinction has been made between certainand doubtful cases, except that a few that are doubtful are indicated byquestion marks. The determination of species of young flukes found ininsects has generally been made solely upon their morphological similarityto adults occurring in vertebrate hosts and it is quite likely that mistakeshave been made by investigators of these parasites just as mistakes havefrequently been made in the association of immature and adult parasitesbelonging to other groups of worms.NEMATODA OR ROUNDWORMSAmong parasitic worms the species of nematodes are more numerousthan either the species of tapeworms or flukes. N~matodes as a groupare not exclusively parasitic and thousands of free-living species areknown to exist, although comparatively few have been described. Manyspecies of nematodes are parasites of insects only and do not occur inother animals. Insects therefore harbor parasitic nematodes which belongto them exclusively as well as the larval stages of nematodes that occurin higher animals in their adult stage. The ubiquity of free-living nematodesintrodQces a frequently troublesome complication into the studyof the life histories of 1l10noxenous parasitic nematodes of which thereare many species, and the common occurrence of parasitic nematodes

RELATION OF INSECTS TO THE LIFE CYCLE OF FLUKESInsect HostAdult Fluke.Final BonColeopteraIlybius fuliginosus (Fabricius) (adult)Water beetle (larva)c, u: uHaplometra cylindraceaProsotocus confususPleurogene5 medians•• clavigerco,.LepidopteraNymphula nymph_ta (Liunret1s) (larva)DipteraAnopheles maculipennis Meigen (claviger Fabricius)(adult)Anopheles rossi Giles (adult)Chironomus plumosus Linnreus (larva)Culex quinquefasciatus Say (fatigan8 Wiedemann)(adult)TrichopteraAnabolia nervosa (Leach) CurtisAnaboUa nervosa (larva)ChEtopteryx villosa (Fabricius) (larva)Dl'I1sus tri6dus McLachlan (larva)Limnophilus rhombicus (Liunreus) (larva).. griseus (Linnreus) (larva).. lunatus (Curtis) (larva).. flavicornis (Fabricius) (larva)Mystacides nigra (Linnreus) (larva)Notidobia ciliaris (Liunreus) (Io.rva)Phryganea sp.Phryganea grandis (larva)Rhyacophila nubila Zetterstedt (larva)NeuropteraSialis lutaria (LiDDreus) (larva)OdonatalEschna (larva and adult)Agrion (larva)u .,cc'"Calopteryx virgo (LiDDreus).. .. (larva and adult)Coroulia (larva)Epi!;heca ..Unknown..Lecithodendrium ascidiaUnknownAllocreadium isoporumOpisthioglyphe rastellusAllocreo.dium isoporumUnknownOpisthioglyphe rastellus..Unknown....., .... ..Lecithodendrium chilostomumUnknownProsotocus confususGorgodera pagenstecheri.. varsovieusisPleurogenes mediansHalipegus ovocaudatusPneumon

60 SANITARY ENTOMOLOGYamong insects introduces an equally troublesome complication into thestudy of the life histories of the heteroxenous nematodes parasitic inhigher animals, for whi,ch insects may serve as intermediate hosts. About~50 species of nematodes have been recorded as parasites of man anddomestic animals. Many of these require no intermediate hosts, butsome are heteroxenous parasites, and a number of these are known to haveintermediate stages in insects and closely related a'rthropods. In thefollowing discussion, in addition to the nematodes parasitic in man anddomestic animals, certain species parasitic in other animals are also consideredbecause of the part played by insects in their life history. Forconvenience they may be placed in two groups, (1) those in which theeggs or first-stage larvre leave the body of the final host in the feces, and(~) those in which the first-stage larvre occur in the blood or lymph ofthe final host and leave the body through ingestion by bloodsuckinginsects.1. Parasitic Nem.atodes Whose Eggs or Lar'tJa! Leave the Body of theFilnal Host in· the FecesProtoapirura muna (GmeHn, 1790) Seurat, 1915This nematode, parasitic in its adult stage in the stomach of variousspecies of rats and mice, is of special 'nterest historically as being thefirst parasite in whose transmission to its final host.an insect was foundto be concerned. Stein in 185~ recorded the presence of encysted nematodesin the larvre of meal beetles (Tenebrio molitor). Leuckart (1867)and Marchi (1867) fed eggs of Protoapirura muria (Spiroptera obtuaa)to meal beetle larvre and followed the development of the young nematodesup to the encysted stage found by Stein. This development is completedin about six weeks after ingestion of the eggs. The development to theadult stage was also followed in mice fed with the encysted nematodes frommeal worms. Johnston (1913) has recorded encysted nematode larvrewhich appeared to him identical with those of P. muna in the body cavityof a rat flea (Xenopsylla cheop;'s).Spirocerca sanguimoltmta (Rudolphi, 1819) Railliet & Henry, 1911The adults of this nematode live in -tumors of the stomach andesophagus of the dog and the wolf. The eggs ·unhatched pass out of thebody of the dog in the feces. Grassi (1888) found encysted larval n~matodesin cockroaches (Blatta orientalis) which he suspected were thelarvre of S. sanguinwlenta. Dogs fed with these encysted nematodes afterfive days showed the larVal free in the stomach; after ten days the youngworms were further developed and ~ere firmly attached to the mucosa

RELATION OF INSECTS TO THE PARASITIC WORMS 61of the esophagus; and after fifteen days they had sunk themselves intothe wall of the esophagus and had developed still further. Grassi concludedthat cockroaches act as intermediate hosts, swallowing the eggs inthe feces of infested dogs, and·in turn being swallowed by dogs. Seurat(1918), however, believes that Grassi was mistaken as to the identity ofthe encysted nematodes found in the cockroaches, and that they werereally the larvre of Spirora gaatrophila, the adult of which occurs in thestomach of the cat, hedgehog (Erinaceus algiro8), and fox (Vu.lpe8 vUlpesatlantica). Seurat (191~, 1916) finds what he considers to be the llltrvreof S. 8anguinolenta encysted in a great variety of animals includingbeetles, reptiles, birds, and mammals. T4e presence of the encapsulatedlarvre in various vertebrates he explains as the result of the ingestion ofinsects infested with the larvre. If the vertebrate is not a host inwhich the parasites can continue their development as they would intheir normal host the dog, they migrate into the wall of the alimentarytract or mesentery and become reencysted without further development.If, however, the infested insect is swallowed by a dog the larvre, afterthey have been freed by digestion of the cysts surrounding them, continuetheir development and finally reach maturity. Seurat in fact foundthat encysted larvre in insects identified as those of S. aanguinolenta whenfed to mice became reencysted in the manner described. Seurat (1916)records the following insects as hosts of the larvre of S. aanguinolenta, allof them beetles: Scarabo:ua (Ateuchus) aacer, .scarabo:ua (Ateuchetua)varioloaua, Aki8 gorlli, Geotropes douei, Cop ria hispanus, and GlImnopleurossturmi. According to Seurat the life cycle of S. sallgl£inolenta,vould be as follows: The eggs pass out of .nfested dogs in the feces,are ingested by beetles, hatch, and the larvre after a period of growth anddeVelopment become encysted. If infested insects are swallowed by dogsor wolves the larval worms are released from their capsules and develop tomaturity. If the insects are swallowed by other animals, the larvre maybecome freed from their cysts as in the alimentary tract of the dog,but they are unable to develop further and leave the lumen of thealimentary tract and become reencysted in the tissues to which theymigrate. In such a case, of course, there is a possibility of their resumingtheir development if the infested animal should afterwards be devoured bya dog or a wolf, but this possibility apparently has not yet been substantiated.Spirora gaatrophila (Mueller,OS94) Marotel, 191~This nematode in the adult stage occurs in the stomach and the lowercnd of the esophagus of the cat. It has also been recorded by Seurat(1918) from the stomach of a hedgehog (Erinaceu8 algiros) and thestomach and esophagus of a fox (Vulpe8 vUlpe8 atlantica), and by the

6! SANITARY ENTOMOLOGYsame author (1918) in the esophagus of the mongoose (Herpeateaichne'Umon). This author identifies certain encysted larval nematodesfound in a species of Onthoplwg'Ua, in Blatta orientalia, in Blapa atrauchi,and in Blap8 sp. (near appendiculata) as belonging to S. ga8trophila.He thinks the parasites found in the cockroach and called Filaria rytipleurite8by Deslongchamps (1824), and those identified as such by Galeb(1878) who associated them with an insufficiently described adultnematode of the rat, are probably the same as those he identified as thelarvre of S. ga8tropltila. He also dismisses Grassi's experiments as insufficientto show that the nematodes encysted in cockroaches are the larvreof Spirocerca sanguinolent a as Grassi believed, and concludes that Grassiwas mistaken and was really dealing with the larvre of Spirura gaatrophila.Seurat (1919) adds Aki8 goryi to the list of insect hosts of the larvre ofS. ga8trophila. •Gongylonema 8c'Utatwm (Mueller, 1869) Railliet, 1892This nematode in the adqlt stage is a common parasite in the mucousmembrane of the esophagus of cattle, sheep, and other ruminants, andhas also been recorded from the horse. Ransom and Hall (1915, 1916,1917) have shown that various species of dung beetles (Aphodiuafemorali8, A. granariw, A. fimetariw, A. coloradenaia, A. vittatua,Ontltopltagua hecate, and O. pennaylvani'Cus) act as intermediate hosts.Experimentally, cockroaches (Blattella germanica) can also be made toserve as intermediate hosts, a part of course which they do not playunder natural conditions. The eggs of the parasite pass out of the bodyof the definitive host in the feces and are swallowed by dung beetles. Theyhatch in these insects, and the larvre entering the body cavity undergo acertain growth and development, reaching their infective stage in abouta month, meanwhile becoming enveloped in capsules in which they lie ina coiled-up position. Further development waits upon the swallowing ofthe infested insect by a cow, sheep, or other suitable host as may readilyoccur while the animal is grazing, the insect being ingested with the herbageupon which if happens to be. Following their ingestion by the definitivehost, the larvre are released from their capsules and develop to maturity.Seurat (1916) has described some larval nematodes from the abdominalcavity of Blaps strauchi, Blaps appendicmata, and Blaps sp. (nearappendiculata) in Algeria that he identifies as Gongylonema scutatum.As pointed out by Ransom and Hall (1917), however, these evidentlybelong to another species as they do not correspond to the forms shownby these writers to be the larvre of G. acutatum. Seurat (1919) addsBlapa emond' to the list of insects in which he has found the larvrein question.

RELATION OF INSECTS TO THE PARASITIC WORMS 63Gongylonema mucronatum Seurat, 1916,This nematode occurs in the adult stage in the mucosa of the esophagusof the Algerian hedgehog (Erinaceus algirus). According to Seurat(1'916) its larval stage is found encapsuled in the body cavity of variousspecies of coprophagous beetles, Ateuchua aacer, Chironitia irroratu.a,Onthophagua bedeli, GY1Tllnopleurua mopaua, Gymnopleurua aturmi, andGeotrupea douei, but there appea,-s to have been some confusion as tothe identity of the larvre in question, and further investigation of the lifehistory of this species is desirable (Ranso~ and Hall, 1917).Gongylonema breviapiculum Seurat, 1914Seurat (1916), in addition to forms found in different spec~es of Blapathat he considers to be third stage larvre of Gongylonemo, Icutatum, hasdescribed as second stage larvre of G~ acutatum some larval nematodesfound encysted in the abdominal cavity of Blapa sp. and Blapa atraucltiin certain localities in Algeria. In a later paper, however (1919), hehas expressed the opinion, based upon the mo:cphology of the worms anda knowledge of the mammalian fauna in the region in which the parasitesare found, that these larvre are third stage larvre and belong to the speciesG. breviapiculum the adult of which occurs parasitic in the cardiac portionof the stomach of a species of jerboa (Dipodillua campestris).Further investigation seems desirable as to the identity of the supposedlarvre of Gongylonema breviapiculum as well as of the other larvre ofGongylonema ·that have been assigned to various species on a basis ofapparent morphological similarities and general considerations. A continuationof the excellent work already done by Seurat relating to thelarval forms of Gongylonema will no doubt clear up the confusion thatnow exists.Gongylonema neoplaaticum (Fibiger and Ditlevsen, 1914) Ransom andHall,1916This nematode occurs in the adult stage in the mucosa of the stomach,esophagus and mouth of the rat. It has been reared experimentallyin the rabbit and guinea pig as well as in the rat and mouse. It is ofspecial interest from the medical standpoint because it is cQmmonlyassociated with and perhaps stands in etiological relationship to gastriccarcinoma of rats. Fibiger and Ditlevsen (1914) have proved that cockroaches(PeriplOlTlcta americOlTla, Blatta orientalia, and Blattella germOlTlica),and a grain beetle (Tenebrio 7nolitor) can act as intermediate host!$.The eggs are passed in the feces of infested rats ~nd if ingested by one

64 SANITARY ENTOMOLOGYof the insects named will hatch, the larvre within twenty days afteringestion of the eggs developing to the infective stage. In this stage thelarvre are coiled up in cysts in the muscles of the prothorax and legs,differing in location from the larvre of G. scuta tum which in artificiallyinfected cockroaches, as in their normal hosts, dung beetles, are foundencysted in the body cavity •.drduentna strongylina (Rudolphi, 1819) Railliet and Henry, 1911This p.ematode in its adult stage occurs in the stomach of the pig.Seurat (1916) has recorded the presence 'of larval nematodes in thestomach of a pig associated with adults of A. stro'11(Jylina which he considersbelong to this species. He has found morphologically similar larvalnematodes encapsuled in the body cavity of Aplwdius rufus castaneus and·states that they also occur in beetles of the genus Onthophagus. Apparentlyno feeding experiments have been carried out. Presumably thelife history would be similar to that of Gongylonema scutatwm, Protospiruramuns, etc., that is, the eggs of the parasite passed in the feces areswallowed by beetles, the larvre develop in these insects to the infectivestage, and are transferred to the definitive host when the beetles areswallowed by a pig, after which the young worms complete their developmentto maturity. Seurat (1919) records the presence of encysted larvmof .d. strongylina in the stomach wall of the Algerian hedgehog (Erinaceusalgirus). Apparently, therefore, the larvre of this species that occurencysted in insects, like those of Physocephalus se:calatus and Spirocercasan(Juinolenta, if ingested by vertebrates other than the normal hosts ofthe adul"t worms, migrate out of the lumen of the digestive tract andbecome reencysted in the neighboring tissues.Physocephalus sexalatus (Molin, 1860) Diesing, 1861The adults of this nematode live in the stomach of the pig, dromedary,and donkey. Seurat (1913) has found two successive larval stages precedingthe adult in the stomach of the definitive host (donkey) and hasalso (1916) established the common occurrence of the earlier of these twostages in various dung beetles (ScaralJO!us [Ateuchus] sacer, S.[.d teuchetus] variolosus, Geotrupes douei, Onthophagus nebulosU8 andO. bedeli). Pigs of course are commonly known to be coprophagus intheir feeding habits and Seurat states that the donkeys of Algeria, wherehis investigations were made, commonly devour fecal matter swarmingwith dung beetles. The way in which the larvre of P. se.valatus reach theirfinal host is therefore evidently through the ingestion of infested beetlesby pigs, donkeys, or dromedaries. Presumably of course the beetles be-

RELATION OF INSECTS TO THE PARASITIC WORMS 65come infested by eating the eggs of the parasite which are passed in thefeces of infested pi~, donkeys, and dromedaries. As in the case ofSpirocerca 8lJ!nguinolen.ta Seurat finds encysted lai'vre of P. 8c:calatu8 invarious vertebrates in Algeria, particularly reptiles and insectivores.Their presence in these animals he would explain in the same way as heexplains the presence of the encysted larvIE of S. 8anguitnolenta in suchanimals, that is, the larvIE present in insects devoured by the animals inquestion are unable to continue their development as they would in pigsand other suitable hosts. On the other hand they do not succumb in theirstrange environment nor do they pass through the alimentary tract withthe feces but penetrate into the walls of the stomach and into other tissuesand become reencysted, surviving in this condition more or les's indefinitely.They may thus be considered parasites that have gone astray but stillcapable of existence in their abnormal environment. The possibility oftheir developing to maturity after reencystment in a strange host if thisanimal should be eaten by a pig has not been substantiated experimentally.Seurat (1916) has counted 4,880 larvre identified as' P. setcalatua in aHingle beetle, ScarabfEUS .(Ateucll.us) sacer. In addition there were 68larvlE of Spirocerca sanguinolenta in the same. beetle, making a total of4,948 larvIE in the one insect.Habronema mU8ca: (Carter, 1861) Diesing, 1861This nematode in the adult stage occurs in the stomach of hOl'ses andother equines, commonly in association with another closely relatedspecies, H. microstoma. The life history of H. mU8ca: has been shown tobe as follows (Ransom, 1911, HllS; Hill, 1918; Bull, .,1919): The eggsor the larvre pass out 'of the body of the ho~t in the feces. They enterthe bodies of the larvIE of the common house fly, probably being swallowed,though the mode of entrance has not been determined by direct observation.The worm larvIE grow and develop in the developing flies and atabout the time the adult insects emerge from the pupal stage the larvIEreach the infective stage. In this stage they are most commonly foundin the proboscis. The ingestion by horses of flies harboring the larvIEbrings the young parasites into the location where the adult occurs,and presumably this is the t:ommon method by which the larvre reach theirfinal liost. The frequent swallowing of flies by horses is an undoubtedfa('t. The mouths of horses' are very attractive to house flies especiallywhile the horses are eating, as anyone can determine by a few minutes'observatl'ion of the animals during the fly season. There is also anotherpossible and very probable way in which the larvm are transferred tohorses, suggested of course by the habit of the larvre of congregatingin the proboscis of the fly. We may expect that it will be demonstrated

66 SANITARY ENTOMOLOGYin analogy with what has been shown to occur in Filaria transmission bymosquitoes, that the larvre of Y·. muscm can actively leave the proboscisof the fly while the insect is sucking moisture from the mouth or lips ofthe horse. There is already indirect evidence that this does occur.The researches of Descazeaux (1915), Bull (1916), and Van Saceghem(1917) have shown that the nematodes which occur in cutaneous granulomataand so-called summer sores of horses are morphologically similarto the larvre of H a~ronema muscre and in all probability·bl'long to thisor a closely related species. Recently Van Saceghem (1918) from investigationscarried out in Africa has reached the conclusion that thenematode of summer sores is Habronema muscre and that it is introducedby flies. Larvre from infested flies were placed in the eye of a horse keptin an insect-proof enclosure, with the result that conjunctivitis andverminous nodules of the nictitating membrane developed. In anotherexperiment two wounds were made on the skin of a horse, one protectedagainst flies and the other left uncovered. The horse was placed in astable in which l'lO per cent of the flies were infested with Habronema.The unprotected wound became transformed into a typical summer sore.Bull (1919), who has made an extended study of cutaneous granulomataof horses in Australia, believes that the larvre of Habronema megastomaare more often responsible for the production of habronemic granulomatathan either H. muscm or H. microstoma.Whether the Habronema larvlE in summer sores are able to migrateultimately to the stomach and complete their development to maturityremains to be determined. Bull (1919) thinks it unlikely that the larvreof Habronema are able to reach the alimentary canal f~om the submucosaof the external mucous membranes or from the subcutaneous tissues, andHill (1918) also notes that the evidence of the occurrence of such amigration is quite insufficient. .It is of interest to note that Habronema muscm was known as aparasite of the fly long before its relation to the horse was demonstrated.Carter in 1861 was the first to record the presence of the nematodes jnflies, following which they were frequently observed by entomologists andothers who had occasion to examine the proboscis of the fly under themIcroscope.Larval nematodes very similar to H. museu. have been seen in theproboscis of Stomoxys calcitrans by Johnston and others. The researchesof Hill (1918) and Bull (1919) have shown that-as far as their experiencehas gone the larvlE in this species of fly have invariably been Habronemamicrostoma so that the occurrence of H. muscm in S. chlcitrans appearsquestionable.The fact that these more or less injurious parasites of the horsedepend upon flies for their existence is a point which may be added to

.. RELATION OF INSECTS TO THE PARASITIC WORMS 67those ~ommonly used in arguments for the necessity of fly eradication.The possibility is also not excluded that flies may introduce Habronemalarvre into human beings, in whose tissues they may perhaps ~ able to livefor a time and do considerabJe damage. 'l'hough there is no evidencethat this ever occurs, the possibility is one that deserves considerationfrom those who have opportunity to investigate the relation of flies towounds and other lesions of the skin and mucous membranes.Habronema microstoma (Schneider, 1866) Ransom, 1911Hill (1918) and Bull (1919) have shown that Habronema microstoma,which, like H. m'U8ClE, occurs in the adult stage in the stomach of thehorse and other equines, has a life history similar to that of H. m'U8ClE.Both of these writers have occasionally observed the presence of H.microstoma in llf usca domestica under experimental conditions but findthat the usual intermediate host is Stomoxys calcitra'1ls. As theyrepeatedly failed. to infect S. calcitrans with the larvre of H. mUSClE it isprobable that the forms from S. calcitrans reported by Johnston (191~)and othc.rs as H. m'U8cO! ,vere H. microstoma. Bull (1919) is of theopinion that the larvre of H. microstoma may sometimes be conccrned inthe production of cutaneous granulomata of horses and that presumablythey are introduced into the skin by the proboscis of an infested fly.Habronema megastoma (Rudolphi, 1819) Seurat, 1914Habronema megastoma in its adult stage occurs in tumors in theIItomach of horses and other equines. Hill (1918) and Bull (1919) havefound that its life history is similar to that of H. musclZ, the house fly(Jf'U8ca domestica) acting as intermediate host in both cases. Attemptsto infect Stomoxys calcitrans with this species failed. Bull (1919) believesthat the larvre of' H. megastoma introduced by infested flies arethe usual cause of habronemic granuloma of horses. So far as the normallife history of H. megaatoma is concerned he thinks that the presence ofthe larvre in the skin or mucous membranes of horses is to be consideredaccidental and that it is uI,llikely that they can reach the alimentary tractfrom such locations and become n;tature. According to his vie,v, therefore,which is shared by Hill (1918), H. megastoma and also the otherIIpedes· of Habronema reach the stomach of the horse as a result of theanimal's swallowing infested flies.Acuaria apiralis (Molin, 1858) Railliet, Henry and Sisoif, 191~The adults of this nematode have been recorded as parasitic in theesophagus and stomach of the domestic fowl. Insects have not been

68 SANITARY ENTOMOLOGYshown to act as intermediate hosts, but insect-like animals commonlyknown as sow-bugs apparently act as intermediate hosts, Piana (189'1)having found larval nematodes in an isopod (Porcellio l(]!vis) that correspondedin morphology with immature nematodes found in chickensharboring also the adult worms. Furthermore these larval nematodesoccurred in sow-bugs only in the locality where the chickens were foundto be infested. Although Piana identified the parasites that he found inchickens as Displw,ragus nasutus (Rudolphi), it is apparent from hisdescription and figures that they belonged to the species Acuaria spiralis(Molin).Filaria gallinuJ,rum Theiler, 1919Theiler (1919) has recorded the occurrence of larval nematodes in aspecies of termite (H odotermcs pretoricnsis). Among the termites onlythe workers were found to harbor ·these parasites, no infested soldiershaving been discovered. Infested termites can easily be distinguishedby the swollen abdomen whiGh gives the insect a sort of balloon-likeappearance. According to Theiler, on many South African farms thecustom exists of digging up nests of termites and allowing the chickensto feed on the insects, and the droppings of chickens running in fhe fieldsare naturally scattered about and serve as food for the termites. Infestedtermites were fed to young chickens that had been hatched in an incubator.Adult worms that had evidently developed from the larvre parasitic inthe termites were found in the intestine or stomach in Iii out of 16chickens that had been thus fed, but none were found in cont'rol chickens.The proper generic position of this nematode described by Theiler as aFilaria remains to be determined.Ascaris lumbricoides Linnreus, 1'158This common parasite of man has been definitely shown to have adirect life history without intermediate host. The opinion o.f Linstow(1886) that a species of Julus (guttulatus) acts as the intermediate hostis without foundation. The common house fly may swallow eggs of thisparasih as well as those of various other parasites which occur in thefeces of infested human beings. The eggs pass through the intestine ofthe fly unhatched. Flies may thus scatter the eggs of Ascaris but thereis no evidence that mechanical carriage of the eggs in this way assistsmaterially in the spread of the parasite. There arc various other naturalagencies more effective than insects in spreading infection with parasitessuch as Ascaris. Stiles, however (according to Nuttall, 1899), fedfemales of Ascaris lumbricoides containing eggs to fly larvre (Muscadomestica) and afterwards found the eggs in later stages of development

RELATION OF INSECTS TO THE PARASITIC WORMS 69in the pupre and adult flies that developed from the larvre. This suggestedthe possibility that flies having become infested as larvre mightconvey the parasitc to man by falling into or depositing their excretaon food. Apparently these experiments have not been repeated.2. Parasitic Nematodes Whose First-stage Larvae Occur in' the Blood orLymph of the Final Host arid Leave the Body Through I"'f}estionby Bloodsucking InsectsFilaria bancrofti Cobbold, 1877This important parasite of man is widely distributed throughout theworld in tropical and subtropical countries. It occurs in the UnitedStates, though apparently it is by no means common. Historically it is ofspecial interest because of the fact that it is the species which Manson(1878) showed passed through certain metamorphoses in the bodies ofmosquitoes after the larvre had been sucked up by these insects in theblood of human beings affected with filariasis. Manson's researches('oupled with confirmatory work by other investigators established thenovel fact of the trllnsmission of an animal parasite by a bloodsuckinginsect, and may be taken as the starting point in the development of ourknowledge concerning the part played by such insects in the spread ofdisease-causing organisms. Lewis had also observed the passage of thelarvre from the human host into mosquitoes. The first observation ofthese larvre in man was recorded by Demarquay in 1864 in Paris, the adultf{'male was discovered by Bancroft in 1876 in Queensland, and the adultmale by Bourne in 1888.The adults of this species live in the lymphatic system, both vesselsand glands. The first-stage larvre which arc provided with a thin cuticularsheath, apparently the transformed egg shell, are found in the bloodstream, usually periodically as tirst shown by Manson, that is, in considerablenumbers only at night or rather during the hours of sleep, as thep{'riodicity may be reversed by making the patient sleep during the daytime. One of the names of the parasite, Filaria noctuma, is based uponthe periodicity of the appe~rance of the larvre in the blood. Variouspatholowcal conditions have been attributed to Filaria barlcrofti such asadenitis, lymphangitis, abscesses, lymph scrotum, chyluria, and ot4erdisturbances of the lymphatic system. The connection between filariasisand el{'phantiasis is still a matter of argument among pathologists.When taken into the stomach of a mosquito the larvre lose their cuticularsheaths. Within 24 hours they leave the alimentary tract, passinto the body cavity, then into the muscles of the thorax. In the musclesthey become shortened to about half their original length and meanwhile

70 SANITARY ENTOMOLOGYincrease to twice or more than twice their original thickness, developinginto what is known as the sausage stage of general occurrence in thedevelopment of Filaria larvre. Developing beyond this stage they increaserapidly in length, cast their skins at least once, and in one to two weeksafter infection of the mosquito, or longer, according to temperature andthe species of mosquito infected, they complete their larval developmentso 'far as the intermediate host is concerned, reaching a length finallyabout three to five times the length of the first-stage larvre and a thicknessabout three or four times the original thickness. They leave the muscles,enter the body cavity, and migrate into various locations, posterior portionsof the body, legs, palpi, but in greatest numbers into the labium.From the evidence afforded by the experiments of Noe (1900) withDirofilaria immitis and additional experiments by Bancroft (1901),Lebredo (1904-1905), Fiilleborn (1908), and others, it has been concludedby analogy in the case of Filaria bancrofti that when an infectedmosquito bites a human being the filaria larvre bore through a thin portionof the labium known as Dutton's membrane, and more rarely other thinportions of the proboscis, actively penetrate the skin of the individualattacked, and reach the lymphatic system where they complete theirdevelopment to maturity.Both anopheline and culicine mosquitoes can serve as intermediatehosts of Filaria bancrofti including the following species (see alsoChapter XVll) :A'lWpheline mosquitoesAlfWpheles (Myzomyia) rossi Giles." (Pyretophorus) costalis Loew." (Myzorhynchus) sinensis Wiedemann." " "peditamiatus Leicester." "barbirostris Van der Wulp.Culex pipiem Linnaeus"""Aedes argen,teua Poirret (Stegomyiaqalopus Meigen)Aedes gracilis Leicester (Stego-myia)Aedes scutellaris Walker (Culexalbopictus Skuse)M amonioides 'UlTl,iformis TheobaldM anaonioides a'T/lTl,ulipes Theobald8cutomyia albolineata TheobaldTaeniorhynchus domesticus Leiquinquefaaciatus Say (fatigamWiedemann)gelidus Theobaldsitiem WiedemannCuliciM mosquitoes~ester

RELATION OF INSECTS TO THE PARASITIC WORMS 71Besides those named about a dozen other species of mosquitoes havebeen tested as hosts of Filaria bancrofti with negative results, or withresults showing that the parasites would only develop imperfectly. Fleas,lice, and Stomoxys have been tested with negative results.Prophylaxis against Filaria balflcrofti evidently consists in measuressimilar to those employed in malaria eradication with reference to mosquitocontrol.- Filaria (Loa) loa (Cobbold, 1864)This parasite of man is a West African species, It has been broughtto America in the slave trade but never established in the New World.The adults live usually in the subcutaneous connective tissue but havebeen found elsewhere in relation with the serous membranes of the abdominaland thoracic viscera. They move about from place to placeand can change their location rather. rapidly; for example, one of theseworms has been seen to cross the bridge of the nose beneath the skinwithin a period of an hour or two. In their progress beneath the skinin various parts of the body they give rise to transient edematous areasknown as Calabar swellings. The larvae produced by the females enterthe blood stream where they are found in the peripheral vessels duringt,he day time, contrary to the habits of the larvae of Filaria bancrofti.Because of this characteristic periodicity of the larvae, Filaria loa hasbeen also named F. diurna. The larvae of F. loa -are provided with asheath relatively much longer than that of the larvae of F. bancrofti.Experiments with various anopheline and culicine mosquitoes, andGlossina palpalis have given negative results as to the possibility of theseinsects acting as intermediate hosts. From Leiper's (1913) researches,it would appear that a species of Chrysops (probably C. dimidiata orC. longicornis) acts as the intermediate host of Filaria loa, the larvreundergoing their development in the salivary glands of the insect. Accordingto Ringenbach and Guyomarc'h (1914), the intermediate host inthe Congo is Chrysops centunonis. Kleine (1915) in West Africa found3fl out of 600 Chrysops examined. to ,be infested with larval nematodeswhich he took to be the larvae of F. loa though he does not give sufficientevidence to support his claims.Filaria demarquayi Manson, 1895This parasite, generally considered identical with Filaria juncea andF. ozzardi, occurs in man in the West Indies and in British Guiana. Theadult has been found in the mesentery and under the peritoneum of theabdominal wall. The first-stage larvae occur in the blood stream. Theirappearance in the circulation is not periodic. According to Low (190fl)

SANITARY ENTOMOLOGYthe larvae can be developed to the so-called "sausage" stage in Aedesargenteus (Stegomyia calopus). Experiments with Anopheles albimanus( albipes), Culex taeniatus, C. quinque{asciatus (fatigans), and othermosquitoes, fieas, and ticks failed to result in any development of thelarvae. Fiillebom (1908) \vas able to develop the larvae to the sausagestage in Anopheles maculipcnnis and Aedes argenteus (Stegomyia calopus),but no development occurred in the tick, Ornithodoros moubata.Further investigations are necessary to determine what insects serve asintermediate hosts for F. demarquayi.Filaria philippinensis Ashburn and Craig, 1906The adult stage of this parasite of man is unknown. The first-stagelarvae occurring in the blood of man are morphologically identical withthose of Filaria bancrofti. Unlike the latter, however, they show noperiodicity. Ashburn and Craig (1907) have shown that the larvae willundergo development in mosquitoes, Culex quinque{asciatus (fatigans) ,similar to that of the larvae of F. bancrofti. It is questionable whetherF. philippVnensis should be recognized as a distinct species.Filaria tucumana Biglieri and Araoz, 1917This species, the adults of which are unknown, is base~ on microfilarirefound frequently in the blood of human beings in Argentina. It appearsto be comparatively harmless. Biglieri and Araoz (1917) conclude thatmosquitoes act as intermediate hosts and apparently consider Aedesargenteus (Stegomyia calopus) the most important vector" though definiteproof of this has not been. obtained.Filaria cypseli.Annett, Dutton and Elliott, 1901The adult stage of Filaria. cypseli occurs in the subcutaneous tissueof the head of the swift, Cypselus affinis, also beneath the subcranialfascia. The embryos or first-stage larvae occur in the lymph and. rarelyin the peripheral blood of infested birds. Dutton (1905) has describedvarious larval stages of the parasite which he finds in an undeterminedspecies of bird-louse belonging to the subfamily Leiothinae that occurson swifts. The first-stage larva as it is found in the blood of the birdand the stomach of the louse is provided with a sheath as in variousother species of Filaria. This sheath is lost and the larva probably soonpenetrates th~ stomach wall. rl'he next stage of the parasite is foundi~ the fat-body of the louse as are two later stages described by Dutton.The last stage of development seen. by him is found free in the body

RELATION OF INSECTS TO THE PARASITIC WORMS 73cavity and this is probably the stage in which the parasite is transferredto the bird; whether as a result of ingestion of the louse by theswift, or as a result of the active migration of the worm from thelouse while the insect is engaged in biting, has not been determined.Filaria martis Gmelin, 1790Filaria mart'is (or Filaria quadrispina) according to various writersoccurs in its adult stage beneath the .skin and in the abdominal andthoracic cavities of Mustela foina. Baldasseroni (1909) has found filariaembryos in the intestine of ticks 'Ixodes ricinus) taken from a martenharboring the adult nematode, and he suggests that ticks may act asintermediate hosts. As in the case of Acanthocheilonema grassu, furtherevidence is n~cessary before ticks can be considered to playa part in thelife history of Filaria martis.Dirofilaria immitis (Leidy, 1856) Railliet and Henry, 1911This nematode, sometimes erroneously listed as a parasite of man",lives in the right side of the heart and pulmonary artery of the dog.The larvae are found in the circulation, most numerous at night as inthe case of Filaria bancrofti. As would be expected from the locationof the adult parasite it may give rise to serious symptoms, and affecteddogs commonly succumb to the disturbances which it causes. It is atroublesome parasite among hunting dogs in the Southern United States.:Soc (1900) showed that the larvae of this nematode continue their developmentin certain species of mosquitoes when sucked up with theblood of infested dogs. In 24 to 36 hours after reaching the stomachof the mosquito the larvae pass into the Malpighian tubules. Theyundergo a certain growth and development in this location, and 11 or 12days after reaching the mosquito they break out of the tubules, enter'the body cavity, and migrate to the labium. From the labium of tnemosquito they reach their final host, the dog, in the same manner asF. bancrofti reaches its human host, namely, by breaking through thinportions of the cuticle of the labium at the time the mosquito is engagedin biting its victim and then penetrate the skin, finally migrating to theheart. Mosquitoes infested with the larvll! of D. immitis are commonlykilled by the parasites owing to their destructive action on the l\Ialpighiantubules, Noc having observed that only about half the mosquitoes thatbecome infested survive. In Italy the common intermediate hosts appearto be Anopheles maculipennis, A. bifurcatus, A. (Myzorhyncht£s) sinensispseudopictus, and A. (Myzomyia) superpict1.b8 among anophelines; culicines,according to Noc such as Culex penicillaris, C. malariae, and exceptionallyC. pipiens, can also act as interm!!diate hosts.

'74 SANITARY ENTOMOLOGYDirofilaria repens, Railliet Ilnd Henry, 1911In the adult stage this nematode, which is a very similar parasite toD. immitis, occurs in the subcutaneous connective tissue of the dog. Itslarvae enter the blood stream whence they are liable to be ingested byblood-sucking insects. According to Bernard and Bauche (1913) theyellow fever mosquito Aedes argenteua (Stegomyia calopus) acts as theintermediate host. These investigators while admitting that other speciesof mosquitoes might act as intermediate hosts of D. repens, found thatA. argmtcus best fulfilled the natural conditions for the transmissionof the parasite, and their experiments were carried out with this speciesof mosquito. They followed the various stages in the development ofthe larval nematodes in mosquitoes fed experimentally upon infested dogs.About 2 days after the mosquito has been fed the nematode larvae leavethe lumen of the alimentary tract and penetrate into the Malpighiantubules where they undergo mos~ of their growth and development. Bythe eighth day the larvae may be found in some cases to have migratedinto the body cavity and thoracic muscles and the last stage of developmentin mosquitoes may be found in the proboscis as early as the ninthday. Six young dogs (10 days old) were submitted to the bites ofA. argmteua (fed 10 to 15 days previously on infected dogs) every morningfor fifteen days. Six young dogs of the same age were kept as controls,not exposed to mosquito bites. The bitten dogs all died withinthirty days. Ecchymotic spots were found beneath the skin at the pointsof the mosquito bites, but no filarias were discovered. The other dogs allsurvived the experiment. Under natural conditions the youngest dogsfound infested with D. repms by Bernard and Bauche were at least 0.year old, hence the writers conclude that the development of the parasiteis very slow. Although they did not succeed in completing their experimentsby recovering the adult stage of the parasite in dogs, followingbites by infected mosquitoes, it appears safe to conclude that D. repensis transmitted by mosquitoes in a manner similar to that in which D.immitis is transmitted.Acanthocheilonema perstOlns (Manson, 1891) Railliet, Henry andLangeron, 1912This parasite occurs in man in tropical Africa and British Guiana,the adults in the intraperitoneal connective tissue and fatty tissue of theabdominal viscera and pericardium, and the first-stage larvae in theblood stream. The larvae exhibit no periodicity in their appearance inthe circulation, the name perstans having reference to this fact.Christy (1903) has suggested that Ornithodoros moubata may act as

RELATION OF INSECTS TO THE PARASITIC WORMS 75the intennediate host of Acanthocheilonema perstans. Wellman (1907)has reported that the larvae of this parasite are taken up by Ornithodorosmoubata and according to his statements develop very slowly in thistick, advanced stages not being found until more than two months afterinfection of the tick. The suggestion made by Feldmann (1905), influencedby Bastian (1904), that the larvae of A. perstans may pass outof the body of the tick with its eggs into bananas and afterwards beingswallowed with this fruit by human beings is a mode of infection whichrequires no consideration as a possibility without more supporting evidencethan has yet been advanced.Hodges (190!'l) observed Ff,aria larvae in the thoracic muscles ofthe mosquitoes, Panoplites sp. and Aedes argenteus (Stegomyia calopus),three days after they had been fed on perstans blood. Low (1903) wasable in one case to obtain development of perstans larvae to the sausagestage in a mosquito (Chrysoconops fuscopennatus). Fiillebom (1908,1913) obtained a similar development in Anopheles maculipervnis. Fiillebornand Low obtained negative results with various species of mosquitoes,sand fleas, lice and simuliids.Acanthocheilonema grassii (Noe, 1907) Railliet, Henry andLangeron, 191!'lThe adults of this nematode occur in the subcutaneous and intennuscularconnective tissue and peritoneal cavity of the dog. The larvaeproduced by the f~males are unusually large, about twice as· long andthick as the average filaria larva, and according to Noe (1907, 1908)do not pass into the blood stream as is generally the case among thefilarias. N oe assumed that the larvm are restricted to the lymphaticsystem, and accordingly concluded that the intermediate host would mostlikely be a tick or similar slow feeding ectoparasite. In fact he foundnematode larvae corresponding to those of A. grassii in Rhipicephalussanguincus, a tick of common occurrence in regions where the dogs areinfested with the nematode in question. Furthennore he states that allof the ticks attached to dogs infested with t.he nematode become infestedwith the larval worms. Additional evidence that R. sanguineus acts asthe intermediate host is that the la'rvae in the ticks undergo growth anddevelopment, at least one molting period having been observed betweensuccessive stages. As R. sanguincus is a tick which falls to the ground totransfonn from the nymphal to the adult stage, the necessary opportunif'yis afforded for the transmission of A. grassii from one dog to another.Noe remarks that the nymph of this tick ingests large quantities oflymph. The larval nematodes taken in with the ingl'sted lymph penetratethe intestinal wall into the body cavity where they undergo the develop·

"16 SANITARY ENTOMOLOGYment necessary before they are ready to be returned to the definitive 'host,after transformation of the nymphal tick to the adult stage. Noe believesthat the dog becomes infected during the initial phase of attachmentof the adult. He also' suggests that adult males which, unlike adultfemales, may pass from one host to another are capable of acquiringinfection from one dog and transferring it to another. He has foundas many as ~~ larvae of A. grassii in one male tick. Noe is of theopinion that the larvae escape through thin portions of the cuticle ofthe mouth parts of the tick and thus reach. the final host in a way similarto that followed by the larvae of D. immitia and other filarias transmittedby mosquitoes. .It is of interest to note that Grassi and Calandruccio (1890) foundlarval nematodes in Rhipicephalus siculus (=R. sanguineus) which theyidentified as the larval of Filaria recondita (=Acanthocheilonema reconditum).Noe thinks that these larvae may have been A. grassii ratherthan A. reconditum.Evidently further investigations into the life history of A. grassii a.renecessary before ticks can be accepted as the intermediate host of thisparasite.Acanthocheilonema reconditum (Grassi, 1890) Railliet, Henry andLangeron, 191~ .This nematode is a parasite of the dog and in the adult stage has beencollected from adipose tissue in the neighborhood of the kidney. Accordingto Grassi and Calandruccio (1890) the first-stage larvae occur in theblood stream, and are the so-called Haematozoa of Le\vis which havebeen seen by many observers, first by Gruby and Delafond (1843), afterwardsby Lewis and others. Apparently, however, the larvae seen inthe blood of dogs by Grassi and Calandruccio as well as those knownas Lewis's Haematozoa are in reality the larvae of Dirofilaria repens.Grassi and Calandruccio describe various stages of nematode larvaefound in fleas (Ctenocephalus canis, C. felis, and Pulex irritans) and in a.tick (Rhipicephal1L8 sicul1L8=R. sanguineus) as developmental stages inthe life history of A. reconditum. According to Noe (1907, 1908), thelarvae found in R. sanguineus by Grassi and Calandruccio were probablythose of Acanthocheilonema grassii.Owing to the confusion existing with reference to the identity of theparasite that Grassi and Calandruccio studied, the species to which thelarval nematodes observed in fleas belong, is uncertain. Grassi and Calandruccio'sexperiments can not'be considered conclusive so far as concernsthe life history of A. reconditum.

RELATION OF INSECTS TO THE PARASITIC WORMS 77Setaria labiato-papiUosa (Alessandrini, 1838) Railliet and Henry, 1911The adults of this nematode are common parasites in the peritonealcavity of cattle in various parts of the world including the United States.The larvae enter the blood stream, and Noe (1903) identifies certainlarval nematodes found in Stomo:cys calcitrans as belonging to thisspecies. That this fly actually serves as the intermediate host, however,remains to be proved.The possibility is not excluded that Noe mistook Habronema larvmfor the larvIE of S. labiato-papillosa.OncocercaAbout twelve species of this genius have been described. Oncocerca'Vol'V'lllus in the adult stage occurs, in nodular tumors beneath theskin of man in Africa. Oncocerca caecutitmB is found in subcutaneousnodules on the head among natives living at a certain altitude on thewest coast of Guatemala and is the cause of so-called "Coast erysipelas."O. gibsoni causes worm nodules in the brisket and other locations incattle in Australia. Two species occur in cattle in the United States:one undetermined species is found in relation with the ligaments of thelegs and neck, the other (0. lienalis) is found in the gastrosplenic ligament.Oncocerca larvae have not been found in the blood stI:eam butmay be recovered from the lymph spaces in the neighborhood of the adultworms. The intermediate hosts of these nematodes are unknown but bitinginsects have been suspected. The results of experiments have been negative.Brumpt (1903) has suggested the possibility that Glossina palpalisacts as intermediate host of O. 'Volvulus.Robles (1919) suggests that two species of Simulium (close to S.dinelli and S. samboni) may be involved as vectors of O. caecutiens inview of the fact that these flies are most numerous in the places wherethe largest number of cases of Oncocerca occur. Furthermore thesespecies of flies are absent in lower altitudes corresponding with the absenceof Oncocerca.3. Other N ematodcaDifferent investigators have recorded the occurrence of larval nematodesof unknown species in various insects. tJsuaUw these have beenvery poorly described and it is questionable in many cases whetherif found again they could be recognized as the same forms. Some ofthem may be the larval forms of nematodes whose adults are alreadyknown as parasites of higher animals. Among such larvae of uncertainidentity may be mentioned Filaria geotrupis In the abdominal cavity

78 SANITARY ENTOMOLOGYof Geotropes stercorarius (possibly the larva of Physocephalus setralatus),Filaria ephemeridarom in the abdominal cavity of the larvae ofEphemera vUlgata and Oligoneuria rhenana, Filara rytipleuritis (ofMagalhaes, 1900, not Deslongchamps, 18!!4) in the abdominal cavity ofPeriplatneta americana (possibly a Gongylonema according to Seurat),Fila1'ia BtomOll:eos in Stomoxys caZcitrans (possibly the larva of Habronemamicrostoma), MastophoruB echiuruB, and CephalacanthuB monacanthusin Tenebrio molitor (probably larvae of' Protospirora muriB),M astophorus gZobocaudatus and Cephalacan.thus triacanthus inGeotrupes stercorarius (possibly larvae of Physocephalus sexalatus).4. M erm.ithidae. .These worms which resemble the nematodes and are usually groupedwith them are not known to be of importance in medical zoology. Onespecies, of uncertain identity, is of interest, however, as it is the so-called"cabbage snake" whose presence among the leaves of cabbage has alarmedpeople who have encountered it. This worm, like others of the samefamily, undoubtedly passes through a portion of its development in thebody of an insect, probably one of the common caterpillars that attackcabbage. Similar worms have been found in apples.GORDIACEA OR HORSE-HAIR WORMSThe Gordiacea or horse-hair worms (as which they are popularlyknown from the superstitious belid that they fre animated horse hairs)are of medical interest because several species have been recorded asparasites of man. They gain entrance to the alimentary tract by beingswallowed in drinking water. The adults are of not uncommon occurrencein springs and other surface waters. When swallowed by humanbeings they are usually soon vomited up but they have in some casesapparently survived in the intestine for several months before they werefinally expelled. In some species, and probably in all, insects serve ashosts for the larval stages. ' The adults deposit their eggs in the waterin which they live. The larvae hatching from the eggs enter the bodiesof insects such as grasshoppers (as for example, in the case of Gordiusrobustus) or crickets (as for example, in the case of Paragordius varius)or in the case of other species they may enter aquatic insect larvae,which may later be devoured by carnivorous water insects. In the latterthe worms undergo their development until they have reached or approachedmaturity when they burst out of the infested insect and escapeinto the water. The following species of Gordiacea have been recordedas accidental parasites of man: Gordius aquaticus, G. chilensis, Para-

RELATION OF INSECTS TO THE PARASITIC WORMS 79gordius varius (a common American species), Paragordius tf'icuspidatus,Paraclwrdodes tolusanus, Parachordodes violaccus, Parachordodes pustuloaus,and Chordodea alpeatria.ACANTHOCEPHALA OR THORN-HEADED WORMSThis highly specialized group of parasites, commonly classified in theNemathelminthes, with which it has little in common beyond a superficialresemblance in the general shape of the body, has been but little studied.Most of the known species are parasitic in birds.Macracanthorhynchus hirudinaceua (Pallas, 1781) Travassos, 1916This worm in the adult stage (sometimes called the giant thornheadedworm) is a common parasite of the intestine of the pig and is saidto occur as a parasite of man along the River Volga. Its eggs pass outof the body of the host in the feces. Swallowed by certain insects [larvaeof lJfeiolontha melolontha, Cetonia aurata, Phyllophaga arcuata (Lachnoaterna), and Diloboderus abderua] the eggs hatch, and the larvaedevelop into an intermediate stage, which in turn completes its developmentto maturity when the infested grub is eaten by a pig.Moniliformia moniliformia (Bremser, 1819) Travassos, 1915This parasite in its adult stage (sometimes called the beaded thorllheadedworm) is of common occurrence in the intestine of rats and otherrodents in tropical and subtropical regions, and has been found in manin Italy. The life cycle is similar to that of the giant thorn-headed wormexcept for the difference in hosts. According to Grassi and Calandruccio(1888), Blapa mucronata acts as an intermediate host. According tollagalhaes (1898) and Seurat (1912), the usual intermediate host is acockroach (Periplaneta americana).COl\IPENDlUM OF PARASITES ARRANGED ACCORDING TO INSECT HOSTS 2Ceratophyllus fasciatus BosoHymenolepia diminuta? Hymenolepia nanaA ph aniptera. (Siphonaptera )-fleasCtenocephalus canis Curtis? ACOlnthocheilonema reconditumI The scientific names of the insects have been revised by the editor.

gODipylidium caniiwumHymenolepis diminuta'SANITARY ENTOMOLOGYCtenocephalus felis Bouche? Acanthocheilonemd reconditum? Dipylidium caninumPulex irritans Linnaeus? Acanthocheilonema reconditumDipylidium caninumHymerwlepis diminutaXenopsylla cheopis RothschildHymenolepis diminuta? Hymenolepis nan a? Protospirura muriaDiptera-fliesAedes argenteus Poirret (Stegomyia calopus Meigen)Acanthocheilonema perstans (incomplete development)Dirofilaria repensFilaria, bancroftiFilaria demarquayi (incomplete. development)? Filaria tucumanaAedes graci1is Leicester (Stegomyia)Filaria bancroftiAedes seutellnris Walker (Culex albopictus Skuse)Filaria ba'1lcroftiAnopheles barbirostris Van der Wulp (Myzorhynchus)FiZaria bancroftiAnopheles bifurcatus LinnaeusDirofilaria immitisAnopheles costali,:; Loew (Pyretophorus)Filaria bancroftiAnopheles maculipennis Meigen (cIa viger Fabricius)A cant hocheilonema per8tan8 (incomplete development)Dirofilaria immitisFilaria demarquayi (incomplete development)Trematode

RELATION OF INSECTS TO THE PARASITIC WORMS 81Anopheles rossi Giles (Myzomyia)TrematodeFilaria bancroftiAnopheles sinensis Wiedemann (Myzorhynchus)Filaria bancroftiAnopheles sinensis peditaeniatus Leicester (Myzorhynchus)Filaria bancroft;Anopheles sinensis pseudopictus Grassi (Myzorhynchus)Dirofilaria immitisAnopheles supcrpictus Grassi (Myzomyia)Dirofilaria immitisChironomus plumosus LinnaeusLecitlwdendriu.m ascidiaChrysoconops fuscopcnnatus (Theobald) (Taeniorhynchus)A cantlwcheilonema perstans (incomplete development)Chrysops spp.Filaria (Loa) loa? Chrysops ccnturionis AustenFilaria (Loa) loa,? Chrysops dimidiata Van der WulpFilaria (Loa) loa? Chrysops longicornis MacquartFilaria (Loa) loaCulex gclidus TheobaldFilaria bancroftiCulex malariae GrassiDirofilaria immitisCulex penicillaris RondaniDirofilaria immitis

Culex pipiens LinnaeusDirofilaria immitisFilaria bancroftiSANITARY ENTOMOLOGYCulex quinquefasciatus Say (skusei Giles) (Jatigans Wiedemann)Filaria bancroftiCulex sitiens WiedemannFilaria bancroftiMansonioides annuli.pes TheobaldFilaria bancroftiMansonioides uniformis TheobaldFilaria bancroftiMusca domestic a LinnaeusChoanotaenia infundibulumHabronema muscaeHabronema microstomaHabronema megastoma? Davainea cesticillus? Davainea tetragonaPanoplites sp.Acanthocheilonema perstan. (incomplete development)Scutomyia albolineata TheobaldFilaria bancroftiStomoxys calcitrans LinnaeusFilaria stomo:ceosHabronema microstomai Habronema muscae? Setaria labiato-papillosa? Hymmolepia carioca"aeniorhynchus domesticus LeicesterFilaria bancroftiSialis lutaria (Linnaeus)TrematodeNeuroptera

RELATION OF INSECTS TO THE PARASITIC WORMS 88• Trichoptera-hairy~winged insectsAnabolia nervosa (Leach) CurtisAllocreadium isoporumOpisthioglyphe rastellusChaetopteryx villosa (FabriciudAllocreadium isoporumDrusus trifidus McLachlanTrematodeLimnophilus flavicornis (Fabricius)Opisthioglyphe rastellusLimnophilus griseus (Linnaeus)Opisthioglyphe rastellusLimnophilus luna tus (Curtis)Opisthioglyphe rastellusLimnophilus rhombicus (Linnaeus)Opisthioglyphe rastetl~Mystacides nigra (Linnaeus)TrematodeNotidobia ciliaris (Linnaeus)TrematodePhryganea grandisTrematodePhryganea sp.Lecithodendrium chilostomumRhyacophila nubila ZetterstedtTrematodeAsopia farinalis (Linnaeus)Hymenolepis dimiwutaLepidoptera-moths, butterfliesNymphula nymphaeata (Linnaeus) (Hydrocampa)Trematode

84 SANITARY ENTOMOLOGYAkis goryi .( Solier)Spirocerca 8anguinole'[ltaSpirura ga8trophiZaAkis spinosa (Linnaeus)"Hymenolepi8. dimmutaColeoptera-beetlesAphodius rufus (Moll) var. castane'us MarshA rduervna 8trongylinaAphodius coloradensis HornGongylonema scutatumAphodius femoralis SayGongylonema scutatumAphodius fimetarius LinnaeusGongylonema scutatumAphodius granarius LinnaeusGongylonema scutatumAphodius vittatus SayGongylonC'Tlla scutatumBlaps appendiculata.GongyZonema sp. (G. 8cutatum according to SeuTt t)Blaps sp.Gongylonema brevi8piculumBlaps sp. (near append~culata)Spirura ga8trophilaGongylonema sp. (G. 8cutatum according to Seurat)Blaps emondiGongylonema sp. (G. 8cutatum according to Seurat)Blaps mucronata LatreilleMoniliformis moniliformi8Blaps strauchi ReicheSpirura gastrophiZaGongylonema sp. (G. scuta tum according to Seurat)~

RELATiON OF INSECTS TO THE PARASITIC WORMS 85Cetonia aurata (Linnaeus)M acracanthorhynchua hirudinaceU8Copris hispanus (Linnacus)Spirocerca sanguinolentaDiIoboderus abderus SturmM acracantlwrhynchua hirudinaccusGeotrupes douci Gory? Gongylonema mucronatwmSpirocerca sanguinolent aPhysocephalus se:r:alatusGeotrupes stercorarius (Linnacus)Cephalacanthus triacanthusFilaria geotrupisM astophorus globocaudatua? Physocephalus se:r:alatusGymnopleurus mopsus (Pallas)? Gongylonema mucronatwmGymnopleurus sturmi Mac Lcay? Gongylonema mucronatumSpirocerca sanguinolentaIlybius f@iginosus (Fabricius)H aplometra cylindraceaMelolontha melolontha Linnreus (vulgaris Fabricius)M acracanthorhynchua hirudinaceuaChironitis irrora tus Rossi (ODitia)? Gongylonema mucrf)natumOnthophagus spp.A rduervna strongylinaSpirura gastrophilaOnthophagus bedeli N eitt.? Gongylonema mucronatumPhysocephalus se:r:alatus

86 SANITARY ENTOMOLOGYOnthophagus hecate PanzerGongylonema scuta tumOnthophagus nebulosus ReichePhysocephalus sexalatusOnthophagus pennsylvanicus HaroldGongylonem(1. scutatumPhyllophaga arcuata Smith (Lachnosterna)Macracanthorhynchus hirudilnaceus .Scarabaeus (Ateuchus) sacer Linnaeus? Gongylonema mucronatumPhysocephalus sexalatusSpirocerca sanguinolentaScarabaeus (A teuchetus) variolosus FabriciusPhysocephalus sexalatus? Spirocerca sanguinolentaScaurus striatus FabriciusHymenolepis diminutaTenebrio molitor LinnaeusCephalacanthus monacanthU8Gongylonema neoplasticumHymenolepis diminuta? Hymenolepis microstomaM astophonis echiurusProtospirura mumWater beetlesPleurogenes clavigerPleurogenes mediansProsotocus confususLeiothinae ( ? genus ? species)Filaria cypseliMallophaga-bird liceTrichodectes latus Nitzsch (canis DeGeer)Dipylidium caninum

RELATION OF INSECTS TO THE PARASITIC WORMS 87Hodotermes pretoriensis FullerFilaria aallinaromAeschna sp.Pro8otocU8 confUBUBAgrion sp.Gorgodera pagefl,8techeriGorgodera 't}tlr80'tlUmsiaPleurogenesOmedianaCalopteryx virgo (Linnaeus)H alipegus ovocaudatwPnewmonoeces 8imili8Cordulia sp.Pro8otocUB confuswEpitheca spp.Gorgodera cygnoide8Gorgodera pagenstecheriGorgodera varso'tliensia18optera-termitesOdonata-dragonBiesPlectopterar-mayBiesClmon dipterum (Linnaeus) Stephens? Opisthioglyphe rastellus•Ephemera vulgata LinnaeusAllocreadium isoporumFilaria ephemeridarum? Opisthioglyphe rastellu8EphemeridaeLecithodendrium a8cidiaOligoneuria rhenana ImhoffFilaria ephemeridarum

88 SANITARY ENTOMOLOGYPlecoptera-stone1liesPerlidaeLecithodendriwm a8cidiaTrematodeOrthoptera-cockroaches, etc.Blattella germanica (Linnaeus) CaudellGongylonema neopla8ticwmGongylonema 8cutatum (experimental infection)Periplaneta americana (Linnaeus) BurmeisterFilaria rytipleuriti8 of Magalhies, 1900Gongylonema neoplasticwmM oniliformi8 monilifonni8Blatta onentalis LinnaeusGongylonema neoplasticwm? Spirocerca 8anguinolentaSpirura ga8trophilaAnisolabis annulipes LucasHymenolepi8 diminutaDermaptera--earwigsM yriapoda-millipedes, centipedes 8Fontaria virginiensis (Drury)Hymenolepi8 diminutaGlomeris IimbataTapeworm larvaeJulus sp.Hymenolepi8 diminutaJulus guttulatusNematode larvaAcarina-ticks, mites 8Ixodes ricinus (Linnaeus) Latreille? Filaria marti8• Included in list because of their similarity to insecls.

RELATION OF INSECTS TO THE PARASITIC WORMS 89Ornithodoros moubata (Murray)? Acanthocheilonema per8tOln8Rhipicephalus sanguineus (Latreille).? Acanthocheilonema gra88ii? Acanthocheilonema reconditwmPorcellio laevis Latreillli? Acuaria 8piralis18opoda-sowbugs ~LIST OF REFERENCESAckert, James E.1918.-On the life cycle of the fowl cestode, DaTJainea ce8ticillua(Molin). (Preliminary communication.) Jour. Parasit. Urbana,Ill., Vol. 5, No. I, Sept., pp. 41-43, pI. 5, figs. 1-4.1919.-0n the life history of Davamea tetragono, (Molin), a fowltapeworm. Jour. Parasit., Urbana, Ill., Vol. 6, No. I, Sept.,pp.28-34.Ashburn, P. M., and Craig, Charles F.1907.-0bservations upon Filaria philippillZen8i8 and its developmentin the mosquito. Philippine Journ. Sci., vol. 2B, No. I, Mar.,pp. 1-14, pIs. 1-7, figs. 1-26.Baldasseroni, Vincenzo.1909.-"I.xode8 ricinU8" L. infetto da embrioni di Filaria. Bull. Soc.Entom. Ital., vol. 40, Nos. 3-4, pp. 171-174, Dec. 30.Bancroft, Thomas L.1901.-Preliminary notes on the intermediate host· of Filaria immitisLeidy. Journ. Trop. Med. Lond., vol. 4, Octt 15, FP' 347-349.Bastian, H. Charlton.1904.-Note on the probable mode of infection of the so-called Filariaper8tan8, and on the probability that this organism reallybelongs to the genus Tylenchu8 (Bastian). Lancet, vol. 166,No. 4196, vol. I, No.5, Jan. 30, pp. 286-287, figs. 1-3.Bernard, P. Noel, and Bauche, J.1913.-Conditions de propagation. de Iii filariose sous-cutanee du chien.Stegomyia fa8ciata bOte intermediaire de Dirofilaria repens.Bull. Soc. Path. Exot., vol. 6, No. I, Jan. 8, pp. 89-99, figs. 1-9.• Included in list because of their similarity to insects.

90 SANITARY ENTOMOLOGYBiglieri, R., and Araoz, J. M.1917.-Contribuci6n al estudio de una nueva filariosis humana encontradaen la Republica Argentina (Tucuman), ocasionada por la"Filaria t'Ucwmana." 1. Confer. Soc. sud-am. de hig. [etc.],Buenos Aires Sept. 17-24, 1916, pp. 408-42~.Brumpt, Emile.1905.-Sur rale des mouches tse-tse en pathologie exotique. Compt.Rend. Soc. BioI., vol. 55, No. 84, Dec. 4, pp. 1496-1498.Bull, Lionel B.1916.-A granulomatous affection of the horse--Habronemic granulomata(cutaneous habronemiasis of Railliet). J ourn. CompoPath. and Therap., vol. ~9, No.8, Sept. SO, pp. 187-199, figs.1-5.1919.-A contribution to the study of habronemiasis: A clinical,pathological, and e~perimental investigation of a granulomatouscondition of the horse-habronemic granuloma. pp. 85-141,pIs. Is-i5, figs. 1-8. [Reprint from Tr. Roy. Soc. SouthAustralia, v. 48.]Christy, Cuthbert.1908.-The distribution of sleeping sickness, Filaria per8tana, etc.,in East Equatorial Africa. (Preliminary report dated Oct.81, 190~). Roy. Soc. Rep. Sleep.-Sick. Comm., No.2, N.ov.,pp. 8-8, 8 maps.De Magalhiies, Pedro Severiano.1898.-Notes d'helminthologie brcsilienne. [5. note] Arch. Parasitol.,vol. 1, No.8, July, pp. S61-S68, figs. 1-4.1900.-Notes d'helminthologie bresilienne. [8. note] Arch. Parasitol.,vol. 8, No.1, May 15, pp. 84-69, figs. 1-25.Descazeaux, J.1915.-Contribution a l'etude de I' "esponja" ou plaies d'ete desCquides du Bresil. (Rapport de Railliet, 17 juin). Bull. Soc.Centro de Med. Vet., vol. 69, Jan. 80-Sept. 80, pp. 468-486, figs.I-S.Deslongchamps, Eugene Eudes.1824.-Filaire. Fuaira. Encycl. Methodique, vol. 2, pp. 891-89'7:

RELATION OF INS~CTS TO THE PARASITIC WORMS 91Dutton, J. Everett.1905.-The intennediary host of Filaria cypseli (Annett, Dutton, Elliott);tne Filaria of the African swift, Cypselus afJim,s.Thompson Yates & Johnston Lab. Rep., Lond., n. s., vol. 6,No.1, Jan., pp. 137-'147, pI. 5, figs. i-x.Feldmann.1905.-Ueber Filaria perstam im Bezirk Bukoba. Arch. f. Schiffs- u.Tropen-Hyg., vol. 9, No.2, Feb., pp. 62-65,2 pIs.Fibiger, Johannes, and Ditlevsen, Hjalmar.1914.-Contributions to the biology and mOl'phology of Spiroptera(Gongylonema) neoplastica n. s. Mindeskr. J apetus SteenstrupsFodseI, 2. Halvbind, 28 pp., figs. 1-3, pIs. 1-4, figs. 1-32.Fullebom, Friedrich.1908.-Ueber Versuche an Hundefilarien und deren tibertragung durchMucken. Beihefte (8) z. Arch. f. Schilfs- u. Tropen-Hyg.,vol. 12, Nov., pp. 313-351 (43 pp.), figs. 1-6, pIs. 1-4, figs.1-38.1908.-Untersuchungen an menschlichen Filarien und deren tibertragungauf Stechmucken. Beihefte (9) z. Arch. f. Schiffs- u.Tropen-Hygr., vol. 12, Nov., pp. 357-388 (36 pp.), figs. 1-3,pls. 1-7, figs. 1-132.1913.-Die Filarien des Menschen. Handb. d. path. Mikroorganism.(Kolle & Wassermann), Jena, 2. Aufl., vol. 8, pp. 185-344, figs.1-41, pIs. 1-6.Galeb, Osman.1878.-0bservations et experiences sur les migrations du Fil_ariarytipleurites, parasite des blattes et des rats. Compt. Rend.Acad. Sc., vol. 87, No.2, July 8, pp. 75-77.Grassi, Giovanni Battista.1887.-Entwickelungscyklus der Tania nana. Dritte priiliminarnote.Centralbl. f. Bakteriol. (etc.), Jena, 1. Jahr., vol. 2, No. 11,pp. 305-312.1888.-CicIo cvolutivo della Spiroptera (Filaria) sanguinolenta. Gior.di Anat., Fisiol. e Patol. d. Animali, vol. 20, No.2, Mar.-Apr.,pp.99-101.Grassi, Giovanni Battista, and Calandruccio, Salvatore.1888.-Ueber cincn Ecltinorhynchus, welcher auch im Menschen parasitirtund des sen Zwischenwirth cin Blaps ist. Centralbl. f.

9! SANITARY ENTOMOLOGYBakteriol. (etc.), Jena, !. Jahr., vol. 3, No. l'i, pp. 521-5!5,figs. 1-7.1890.-Ueber Haematozoon Lewis. Entwickelungscyklus einer Filaria(Filaria recondita Grassi) des Hundes. Centralbl. f. Bakteriol.(etc.), Jena, vol. 7, No.1, Jan. 2, pp. 18-26, figs. 1-16.Grassi, Giovanni Battista, and Rovelli, Giuseppe.1888.-Intorn9 alIo sviluppo cestodi. Nota preliminare. Atti R.Accad. d. Lincei, Roma, Rendic., an. 285, 4. s., vol. 4, 1.semestre, No. 12, June 3, pp. 700-702.1888.-Bandwiirmerentwickelung. Centralbl. f. Bakteriol. (etc.),Jena, 2. Jahr, vol. 3, No.6, p. 173.1889.-Sviluppo del cisticerco e del cisticercoide. Nota preiiminare.Atti R. Accad. d. Lincei, Roma, Rendic., an. fl86, 4. s., .vol.5, 1. semestre, No.3, Feb. 3, pp. 165-174, figs. 1-4.1892.-Ricerche embriologiche sui cestodi. Atti Accad. Giornia diSc. Nat. in Catania (1891-92), an. 68,4. s., vol. 4,2. mem., 108pp., 4 pIs.Gruby, David, and Delafond, Henri-Mamert-Onesius.1843.-Note sur une alteration vermineuse du sang d'un chien determineepar un grand nombre d'hematozoaires du genre filaire.Compt. Rend. Acad. Sc., vol. 16, No.6, Feb. 6, pp. 325-326.Guberlet, J 0110 E.1916.-Morphology of adult and larval cestodes from poultry. Trans.Am. Micr. Soc., vol. 35, No.1, Jan., pp. 23-44, pIs. 5-8, figs.1-30.1919.-0n the life history of the chicken cestode, Hymenolepi8 carioca(Magalhaes). Joum. Parasit., vol. 6, No.1, Sept., pp.35-38, pI. 4, figs. 1-6.Hill, Gerald F.1918.-Relationship of insects to parasitic diseases in stock. Pp. 11-107, pIs. 2-8, figs. 1-49A. 8°. Melbourne. [Reprint fromProc. Roy. Soc. Victoria, new ser., v. 31, pt. 1.]Hodges, Aubrey.1902.-S1eeping-sickness and Filaria per8tan8 in Busoga and its neighborhood,Uganda Protectorate. Journ. Trop. Med., vol. 5, ;No.19, Oct. 1, pp. 293-300, 1 map, 1 pl., figs. 1-2.Johnston, T. Harvey.1913.-Notes on some Entozoa. Proc. Roy. Soc. Queensland, vol. 24,pp. 63-91, pIs. 2-5, figs. 1-45. (Advance separate issued Nov.1, 191!).

RELATION OF INSECTS TO THE PARASITIC WORMS 98Joyeux, Ch.1916.-Sur Ie cycle evolutif de quelques cestodes. Note preliminaire.Bull. Soc. Path. Exot., vol. 9, No.8, Oct. 11, pp. 578-588.Kleine, F. K.1910.-Die Ubertragung von Filarien durch Chrysops. Zeitschr. f.Hyg. u. Infektionskrankh., vol. 80, No.8, Oct. l!6, pp. 845-349.Lebredo, Mario G.1904.-Filariasis. Nota preliminar deducida de experiencias practicas,que dcmuestran el sitio por donde la Filaria noct,£rna abandonacl Culex pipiens infectado. Rev. Med. 'l'rop., Habana, vol. 5,No. 11, Nov., pp. 171-17l!.1905.-Metamorphosis of Filaria in the body of the mosquito (Culexpipiens). Journ. Infect. Dis., Supple (1), May, pp. 339l-359l, pIs. 1-8, figs. 1-16. .Leiper, Robert T.1913.-[Mctamorphosis of Filaria loa.]Trop. Med., Dec. 9l7, 1912].vol. 1, No.1, Jan. 4, p. 51.[Telegram to London SchoolLancet, No. 4662, vol. 184,Leuckart, Karl Georg Friedrich Rudolph.1867.-Die menschlichen Parasiten und die von ihnen herriihrendenKrankheiten. Ein Hand- und Lehrbuch fiir Naturforscher undAerzte. Vol. l!, 1. Lief., vi.l!56 pp., 158 figs. Leipzig & Heidelberg.Low, George C.1909l.-Notes on Filaria demarq1taii. Brit. Med. Journ., No. 2143,vol. 1, Jan. 9l5, pp. 196-197.1903.-Filaria perstO/1l.8. Brit. Med. Journ., No. 2204, vol. 1, Mar. 28,pp. 79l2-7l!4, figs. 1-9l.l.fanson, (Sir) Patrick.18Z8.-0n the development of Filaria sanguinis hominis, and on themosquito considered as a nurse. J'ourn. Linn. Soc. Lond.,Zool. (75), vol. 14, Aug. 31, pp. 304-311.lla.r('hi, Pietro.1867.-l.fonografia sulla storia genetica e sulla anatomia dellaSpiroptera obtu,sa Rud., 34 pp., l! pIs. fol. Torino. [Advanceseparate from Mem. R. Accad. Sc. Torino, CI. d. Sc. Fis., Mat.e Nat., l!. s., vol. l!5, issued in 1871.]

94 SANITARY ENTOMOLOGYMelnikov, Nicolaus.1869.-Ueber die Jugendzustande der 1l:enia cucunnerina. Arch. f.Naturg., Berl., 35 .. Jahr., vol. 1, No.1, pp. 62-'70, pI. 3, figs.a-c.Nickerson, W. S.1911.-An Amel'ican intermediate host for Hymenolepis dimi11AJ,ta~S.cience, n. s., No. 842, vol .. 33, Feb. 17, p. 2'71.Nicoll, W., and Minchin, E. A.1911.-Two species of cysticercoids from the rat-flea (Ceratophyllusfasciatua). Proc. Zool. Soc. Lond., No.1, Mar., pp. 9-13,figs. 1~2.N o~,Giovanni.1900.-Propagazione delle tilarie del sangue esclusivamente per mezzodella puntura della zanzare. 2. Nota pl'eliminare. Atti R.Accad. d. Lincei, Rendic. Cl. di Sc. Fis., Mat. e Nat., an. 29'7,5. s., vol. 9, 2. semestre, No. 12, Dec. 16, pp. 357-362, figs. 1-3.1903.-Studi suI cicIo evolutivo della Filaria labiato-papillosa, Alessandrini.Nota preliminare. Atti R. Accad. d. Lincei, Rendic.Cl. di Sc. Fis., Mat. e Nat., .an. 300, 5. s., vol. 12, 2 semestre,No.9, Nov. 8, pp. 387-393.190'7.-La Filaria graasii, n. sp. e 180 Filaria reconaita, Grassi. Notapreliminare. Atti R. Accad. d. Lincei, Rendic. Cl. di Sc. Fis.Mat. e Nat., an. 304, 5. s., vol. 16, 2. semestre, No. 12, Dec.15, pp. 806-810.1908.-11 cicIo evolutivo della Filaria grassii, mihi, 190'7. Atti R.Accad. d. Lincei, Rendic. Cl. di Sc. Fis., Mat. e Nat., an. 305,5. s., vol. 17, 1. semestre, No.5, Mar. 1, pp. 282-293, figs. 1-4.Nuttall, George H. F.1899.-0n the role of insects, arachnids, and myriapods as carriersin the spread of bacterial and parasitic diseases of man andanimals. A critical and historical study. Johns HopkinsHosp. Rep., Baltimore, vol. 8, Nos. 1-2, pp. 1-154, pIs. 1-3.Piana, Giovanni Pietro.189'7.-0ssel'Vazioni suI Dispharagus nasutus Rud. dei polli e sullelal'Ve nematoelmintiche delle mosche e dei porcellioni. AttiSoc. Ital. Sc. Nat. (etc.), Milano, vol. 36, No. 3-4. Feb., pp.239-262 t figs, 1~21.

,RELATION OF INSECTS TO THE PARASITIC WORMS 95RansolD, Brayton H.1911.-The life history of a parasitic nematode-Habronema muacae.Science n. s., No. 881, vol. 34, No. 17, pp. 690-692.1913.-The life history of Habronema '1nuacae (Carter), a parasiteof the horse transmitted by the house fly. U. S. Dept. Agric.,Bureau Animal Indust., Bull. 163, Apr. 3, pp. 1-36, figs. 1-41.Ransom, Brayton H., and Hall, Maurice C.1915 __ The life history of Gongylonema scutatum. J ourn. Parasit.,vol. 1, No. S, Mar., p. 154.1916.-The life history of Gongylonema scutatum. J ourn. Parasit.,vol. 2, No.2, Dec., 1915, pp. 80-86.1917.-A further note on the life history of Gongylonema scutatum.Journ. Parasit., vol. S, No.4, June, pp. 177-181.Ringenbach, J., and Guyomarc'h.1914.-La filariose dans le>s regions de la nouvelle frontihe CongoCameroun. Observations sur la transmission de Microfilariadiurna et de Microfilaria perstans. Bull. Soc. Path. Exot.,vol. 7, No.7, July 8, pp. 619-626.Robles, R.1919.-0nchocercose humaine au Guatemala produisant la cecite et"l'erysipele du littoral" (erisipela de la costa). Bull. Soc.Path. Exot., vol. 12, No.7, July 9, pp. 442-460, 2 maps,figs. 1-6.Seurat, L. G.19l!e.-Sur Ie cycle evolutif du spiroptere du chien. Compt. Rend.Acad. Sc., vol. 154, No.2, Jan. 8, pp. 82-84.1912.-La grande blatte, hOte intermediaire de l'echinorhynquemoniliforme en Algerie. Compt. Rend. Soc. BioI., vol. 72, No.2, Jan. 19, pp. 62-6S.1915.-Sur l'evolution du PhY8ocephalu8 8etralatua (Molin). Compt.Rend. Soc. BioI., vol. 75, No. S5, Dec. 1!, pp. 517-520, figs.II. 1-4.1915.-Sur l'evolution du Spirora gastrophila Miill. Compt. Rend.Soc. BioI., vol. 74, No.6, Feb. 14, pp. 286-289, figs. I-S.1916.-Contribution a l'etude des formes larvaires des nematodes. parasites heteroXEmes. Bull. Scient. France et Belg., 7. s.,vol. 49, No.4, July 6, pp. 297-377, figs. 1-14.1918.-Extension de l'habitat du Spirura gastrophila (Mueller).Compt. Rend. Soc. BioI., vol. 81, No., 15, July 27, pp. 789-791.

96 SANITARY ENTOMOLOGY1919.-Contributions nouvelles a l'etude des formes larvaires desnematodes parasites beteroxenes. Bull. BioI. France et Belg.(1918), vol. 5!, No.4, Mar. !5, pp. 344-378, figs. I-XII.Theiler, (Sir) Arnold.1919.-A new nematode in fowls, having a termite as an intermediaryhost. [Filaria gaUinarom (nova species) J. 5. & 6. Rep.Director Vet. Research, Dept. Agric. Union South Africa(1918), Apr., pp. 695-707, 1· pl., fig. 1.Van Saceghem, R.1917.-Contribution 8. l'etude de la dermite granuleuse des equides.Bull. Soc. Path. Exot., vol. 10, No.8, Oct., pp. 7!6-7!9.1918.-Cause etiologique et traitement de la dermite granuleuse:Bull. Soc. Path. Exot., vol. 11, No.7, July 10, pp. 575-578.Villot, Fran~ois Charles Alfred.1878.-Migrations et metamorphoses ,des tenias des musaraignes.Ann. Sc. Nat., Zool., vol. 49, 6. s., vol. 8, Nos. !-3, art. 5, 19pp., pI. 11, figs. 1-14.1883.-Memoire sur les cystiques des tenias. Ann. Sc. Nat., ZooI., 6. s.,vol. 15, art. 4, Oct., 61 pp., pI. 1!, figs. 1·13.Von Linstow, Otto Friedrich Bernhard.1886.-Ueber den Zwischenwirth von Ascaris lumbricoides L. Zool.Anz., No. !31, vol. 9, Aug. 30, pp. 5!5-5!8.Von Stein, Friedrich.185!.-Beitriige zur Entwickelungsgeschichte der Eingeweidewiirmer.Zeitschr. f. Wissensch. Zool., vol. 4, No. !, Sept. !, pp. 196-!14, pI. 10, figs. l-!O.Wellman, Frederick Creighton.1907.-Preliminary note on some bodies found.in ticks Ornithodorosmoubata' (Murray) fed on blood containing embryos of FilariaperstOlTUJ (Manson). Brit. Med. Journ., No. !4!9, vol.!, July !o, pp. 14!-143.

CHAPTER VIThe Relations of Climate and Life and Their Bearings on the Study ofMedical Entomology.lW. Dwight PierceAll animal and plant life has its being and reacts according to defi~'Ilite laws in which we find the climatic factor of primary importance.We cannot go far into a subject with as many inter-relationships asmedical entomology without finding it necessary to know something ofthe climatic laws which govern the lives of the various organisms concerned.In several of the lectures attention is especially called to apparentdiscrepancies in the interpretation of climatic effects on the life of theinsects, and this is particularly true in case of the lice. Throughoutour literature there is to be found a hazy notion of the importance oftemperature and still haz~er notions of humidity. There is a great'deal about these factors which help to govern life, that no one knows,but it will pay us to have a clearly defined statement of some of themost important principles as now understood.On a proper understanding of the relations of temperature andhumidity to the life and development of insects, animals, and diseaseorganisms, depend all transmission experiments, all efforts in keepingalive the various creatures involved, all interpretations of results andmany practical measures of control.This difficult subject will be stated in as simple language as possibleso that all may see the basic principles at least.Everyone of us knows that cold and heat can cause pain. We haveindeed a clear understanding that cold and heat kill. We recognize thefact that we seem to work best under conditions when we are absolutelyoblivious of heat or cold, dryness or moisture. We have felt stupidin murky weather. We have felt parched and dried from extremelydry weather. In other words, we cal). now recognize four conditionswhich may affect our well-being, cold, heat, dryness, moisture. These('an be expressed on two scales-temperature and relative humidity. Inother words, we should be able to chart our own susceptibilities to thesefactors by running, for example, a temperature scale vertically on our1This lecture was read July 1, 1918 and issued the same day.07

98 SANITARY ENTOMOLOGYchart paper and a humidity scale from zero to one hundred per centsaturation horizontally.If we picture our reactions or those of the creature 'being stu 'diedon such a chart (see figs. 8, 9), we ,viII better understand the subject.In the lower part of the chart we will locate certain temperatures whichalways cause death from cold. These may be known as' ABSOLUTEFATAL TEMPERATURES.Now a common failing in the past has been to assume that humidityhad nothing to do with the eft'ect of temperature on life, It does havea very decided bearing; A creature which can stand a certain degree,/AN HI1'OTHCTICAl CHAlT SHawlN' m ZONES OF LIfE WCAWOIiS TOTtNPrIlTUR[ AIID RHATIVE HUMIDITY. Dlm'IN' '(01 EACH SPWES,FIG. 8of cold at a given humidity may be absolutely unable to stand that sametemperature at another degree of saturation or relative humidity.Our absolutely fatal temperatures therefore' will form some sort ofa zone on our chart and this zone will probably be bounded by a curve.We call the temperatures below this curve the LOWER ZONE OFFATAL TEMPERATURES. Death caused by cold is called RHIGOPLEGIA.Slightly above these absolutely fatal temperatures will be a zone oftemperatures which might cause death if experienced sufficiently long,but which at least cause a complete suspension of all activity. Andstill higher will be temperatures which also cause suspension of activity,but which do not cause death even- when experienced for very long pe-

RELATIONS OF CLIMATE AND LIFE 99riods. Formerly, this suspension of activity by animal life on accountof cold was called hibernation, which means winter rest. The writer hasshown (Pierce, W. D., 1916, Journ. Agr. Res., vol. 5, PH. 1183-1191)that this same inactivity may be caused by dryness or heat and possiblyby excessive humidity, and that a creature may remain in the samestate of inactivity from the heat of summer through the cold of winterand be awakened from it only by the addition of a requisite amountof moisture at effective temperatures. We must seek other terms thanhibernation, or winter rest, and aestivation, or summer rest. As thisrest consists essentially of an almost complete cessation of all bodilyfunctions, and is a state of insensibility, we may very properly designatethe so-called hibernation as RHIGANES'l'HESIA, or insensibility dueto cold. This state may be acquir~d naturally as winter sets in, or maybe artificially induced at any time of the year by lowering the temperature.The temperatures inducing RHIGANESTHESIA are groupedinto the LOWER ZONE OF INACTIVITY, or the ZONE OF RHIGANESTHESIA.As the temperatures increase, a creature in the state of rest orrhiganesthesia, commences to show slowo movements of the body fluids,and slight jerky motions, lvhich increase with increase of temperature.This awakening or anastasis, when caused by temperature change, is aTHERMANASTASIS.The approximate point at any given humidity at which thermanastasisbegins is the ZERO OF EFFECTIVE TEMPERATURE. It must befirmly fixed in your minds that there is not a single zero of effectivetemperature, as so often claimed, but a different one for every degree orportion of a degree of relative humidity. In other words, at one humiditythe awakening may occur at one temperature, and under other conditionsof humidity the temperature may be considerably higher or lower. Thesepoints can be connected by a curve which represents the lower limit ofthe ZONE OF ACTIVITY, or the THERMOPRACTIC ZONE, meaninga zone of effective temperatures.Many authors have manifested considerable confusion in their writingsand have «;ven claimed that other authors were incorrect because acertain developmental period or reaction was accomplished in their experynentsat a given temperature in a certain period of time while theother investigators obtained totally different results. A man workingin 0. moist coastal section could not justly compare his results with thoseof a man working in a drier section unless the conditions of humidity wererecorded also. For this reason, the writer has maintained that laboratoriesattempting to correlate temperature with life historY, must at leastbe equipped with maximum and minimum thermometers and a slingpsychrometer for determining humidity, and that accurate results arE

100 SANITARY ENTOMOLOGYbased only on a recording hygrothermograph, checked by the abovementioned instruments.The great bulk of work naturally is upon the reactions which takeplace in the zone of activity.It must not be forgotten, however, that control work depends oftenupon a correct knowledge of the lower zone of fatal temperatures, andthat successful storage of breeding material, until the investigator isready to use it, depend~ often upon a knowledge of the requirements ofrhiganesthesia. .Following the awakening, the body takes up all its natural functionsand we must assume that sustenance is available. The lirst activities,at temperatures just above the zero of activity, are naturally verysluggish and this state of sluggishness may be known as RHIGONOCHELIA, or sluggishness caused by cold.Some creatures are very sensitive to cold, usually when the humidityis high. Pain produced by the application of cold is called CRYALGESIA. An abnormal sensitiveness to cold is known as CRYESTHESIA,and a motbid sensitiveness as HYPERCRYALGESIA. These sensationsare probably only experienced with a descent of temperatures.In the zone of effective temperatures or thermopractic zone thereis a point or a dmall restricted zone of temperatures at which all activitiesare most effective, that is, the greatest amount of work is accomplishedwith the least amount of exertion and the least loss of energy.This is the so-called OPTIMUM, or perhaps better, PRACTICOTATVM,meaning most effective. As temperatures ascend to the practicotatumany given function is performed in proportionately shorter time. Asthe temperatures ascend above the practicotatum a particular functionmay be exercised more rapialy but less accurately or less effectively, asfor instance, more eggs may be laid but fewer hatch: but the activity isfeverish and soon exhaustion takes place, or the individual graduallybecomes more &tupid and sluggish. This heat sluggishness is thereforecalled THERMONOGHELIA.Different reactions to heat may be experienced and these have allreceived .appl'opriate designations. As for example, a stifling sensationis called THERMOPNIGIA; an unusual sensibility to heat THERMALGESIA, and a more intense sensibility HYPERTHERMALGESIA. Theability to recognize changes of temperature is THERMESTHESIA,and its extreme is designat\!d as THERMOHYPERESTHESIA, anabnormal sensitiveness to heat stimuli. A fondness for heat or requiringgreat heat for growth is calle..l THERMOPHILIC, while resistance toheat is called Tf.IERMOPHYLIC. When a stifhng temperature is experiencedrapid breathing or 1 ~IERMOPOLYPNEA is often experienced.Contraction under the a~ ion of heat is designated as 'rHER-

RELATIONS OF CLIMATE AND LIFE 101MOSYSTALTIC. The adaptation of the body temperature to that ofthe environment is PECILOTHERMAL. A morbid dread of heat isTHERMOPHOBIA. The determination of the direction or rate oflocomotion by heat is called THERMOTAXIS and movement broughtabout by heat is THERMOTROPISM.As the temperatures increase sluggishness increases until bleep orinactivity is induced and this condition once known as aestivation orsummer rest may better be known as THERMANESTHESIA or insensibilitycaused by heat.The point at which ant!sthesia begins at any given h:Imidity is theupper boundary of the thermopractic or effective zone. rhose temperaturesat which successful Thermanesthesia may be ~xpel'ienced embracethe UPPER ZONE OF INACTIVITY, or the ZONE OF THERMANESTHESIA. This quickly merges into those high temperatures whichmay with sufficient duration of time cause death, and finally, those temperatureswhich are" absolutely fatal under all conditions. 'The highestzone is therefore the UPPER ZONE OF FATAL TEMPERATURES.Death from heat is known as THERMOPLEGIA, or heat stroke.Most investigators have stopped with a more or less hazy acknowledgmentof the existence of these various zones of reactions on the ascendingscale of the th~rmometer, but the literature contains few referencesto similar zones of reactions on the scale of relative humidity. l-Iowever,if we stop to think we must acknowledge that similar reactions do takeplace.We may have death from absolute dryness at almost any temperature,in other words, we have a condition which is called APOXERAEXOSIS, or drying up. At very low humidities one may become insensibleand thus we have XERANESTHESIA. Likewise, a little higherhumidity induces sluggishness or a state of XERONOCHELIA. Wehave most of us experienced this condition of stupidity in a living roomat normal temperatures in the winter due to lack of sufficient moisture.So also there is the humidity which enables each individual to accomplishthe greatest results in the least time with the least amount oft,xhaustion and this is the PRACTICOTATUM. With increase ofhl·midity the activity lessens until an excessively humid atmospherebrings about HYGRONOCHELrA or sluggishness due to moisture; thenHYGRANESTHESIA may be experienced by some species and finallydE-ath due to excessive moisture or iIYGROPLEGIA.This makes it obvious therefore that when we plot the reactionsof a species to temperature and humidity, we are likely to find a seriesof closed figures delineating concentric zones of fatal, inactive, activeand optimum conditions. Thus it is apparent that Rhigoplegia,Apoxeraenosis, Thermoplegia, and Hygroplegia form ,a single zone of

lO!SANITARY ENTOMOLOGYtemperQ.ture-humidities which cause death-this whole zone is the fatalor OLETHRIC ZONE. All conditions of life lie within it, the next zonebeing that which includes Rhiganesthesia, Xeranesthesia, Thermanesthesia,and Hygranesthesia; the whole zone therefore being the ANESTHETIC ZONE, or zone of rest, which includes the conditions knownas hibernation and aestivation. Within this is the THERMOPRACTICZONE or zone of effective temperatures, which is naturally made up ofsuD-zones representing degrees of activity, as the NOCHELIC SUBZONE of sluggish activities on the outside and the PRACTICOTATUMat the center.Temperature and humidity affect every bodily function of everycreature of the plant and animal kingdom. Some creatures may lovecold, some heat, some dryness, some moisture. The pattern of theirreactions will therefore shift from one place to another on t~e chart.Some creatures may be so resistant to cold that fatal temperatures arenever normally experienced and rarely artificially. Some may be veryresistant to dryness and others capable of standing any degree of humidity.In case of plants the root system receives one set of stimuliand the upper portion another, so that the interpretation is not assimple as with animals.In the different stages of growth a creature may have different abilityto withstand extremes.If the approach to unfavorable or ;r.lone:ff'ective conditions is gradual,

RELATIONS OF CLIMATE AND LIFEthe body gradually adjusts and adapts it~elf for entrance into a dormantstate. We find adaptations against cold, heat and dryness, often incysts or in cases constructed by the creature, and in fact some of theseprotective cases are made of substances impervious to w~ter. In thestate of encystment far greater extremes can be experienced than inthe normal state, because of the impervious nature of the cyst.Successful dormancy often depends upon the rapidity with whichit was brought about. Most creatures practically free the intestinalcanal before entering a resting stage.A sudden lowering or raising of temperature may be fatal at temperatureswhich would norm~lly be easily withstood if approached gradually.Alternation of high and low temperatures, if sudden, is often fatalat normally effective temperatures. A ~reature may become dormantwith descending temperatures at a higher temperature than it wouldawaken with ascending temperatures.A continuous maintenance of an even temperature and .humidity ismore or less enedating. A climate which has sufficient variation toallow certain periods of rest from cold at night and heat in the dayis probably productive of better results. It is possible in a given dayfor a creature to have two active and two dormant periods. As forexample, observations of many insects will show that they sleep duringthe cold parts of a night, are active during the morning, sleep duringthp hottest part of the day, are again active in the evening and earlyparts of the night. It is also noticeable that on humid daYIi many insectsare inactive but as soon as the air dries they again resume activity,and the reverse is found in arid regions.Many investigators have failed in keeping insects alive for experimentbecause of failure to keep sufficient water present for drinkingpurposes and ·maintenanee of proper humidity.As long as any creature is experiencing effective temperatures itmust have food available to take when needed and this food must be inproper condition. Long periods without food at noneffective temperaturescan be experienced, but at effective temperatures the length oflife is relatively short. This is a very important point in control workwith ,,11 insects. If you can deprive them of food for a sufficient periodwhen the climatic conditions enforce activity, then control is easy.There are many very difficult points in this question. Inasmuchas noneffective temperatures and also noneffective humidities may bepxperienced each day, it becomes necessary to make elaborate studiesto ascertain the boundaries of the thermopractic and hygropractic zones,and only a thermo-hygrograph record sheet will enable one to make anykind of a satisfactory study.lOS

104 SANITARY ENTOMOLOGYI:lThere is a rule which receives much support, that a given reactionor stage of development is accomplished at an almost constant totaleffective temperature, which i.s the multiple of time units by temperatureunits accumulated above the zero· of effective temperature. Since thezero varies with t}:te humidity, the total effective temperature obtaInedby this rule does likewise. We must therefore reword the rule to read:A. given reaction or 8tag~ of development is accomplished at any givenmean humidity at a constant total effective temperature, which is themultiple of effective time units by temperature wnits accumulated withinthe zone of effective temperatures at a given· atmospheric pressure.To compute this one must fhost eliminate all time, temperature,and humidity which waS noneffective, whether at the top or bottom of thescale. For instance, if at 60% humidity the temperatures 65° to 85°are effective, and during the day the temperature ranged from '50° to 90°,but only during eight hours at the effective t.emperatures; we mustmultiply the period 8 hours by the mean temperature experienced between65° and 85°, considering 65 as 0 and 85 as ~O. The result isthe total effective temperature of that day. Adding these total effectivetemperatures during the total period of the stage, we obtain the totaleffective temperature necessary to bring about the perfection of thestage. Necessarily this is a very complicated proposition, l"equiringvery careful computations.. Nevertheless, once worked out we can establishlaws of control which are of utmost ~alue.Some of the following lectures will refer to the principles laid downin this lecture and lines of research will be suggested leading towardcontrol measures. The charts (figs. 8, 9) should be studied in connectionwith the lecture.

CHAPTER VIIDiseases Borne by Non-Biting Flies 1W. Dwight PierceIt will be necessary in discussing the role of flies in the transmissionof diseas~ to divide the flies into several categories, because so manyspecies of the order Diptera are involved. The flies can be dividedinto two large groups, those which bite and those which do not bite,but, rather, sip their food. Two excellent monographs on the relationsof flies and disease have been published, that on the non-bloodsuckers byGraham-Smith, and that on the bloodsuckers by Hindle.This lecture deals with the non-biting flies only. Among these fliesare to be found the principal house-visiting flies, foremost among whichis the house or typhoid fly, Musca domestica Linnaeus, followed by theblue bottle blow flies, Calliphora vomitoria Linnaeus and C. erythrocephalaMeigen, the green bottle blow fly Lucilia caesar Linnaeus, andvarious other species. The mouth parts of these flies are constructedonly for sucking or sipping liquid or semi-liquid foods.In this lecture can only be given a very condensed statement of therelationship of these flies to disease. A more extensive study shouldinvolve the reading of the books by Hewitt and Graham-Smith quotl'!din the bibliography. In these volumes the evidence is given in greatdetail.Among the most striking of the investigations into t~e capacity ofnon-biting flies for the carriage of disease germs, are a series of three('xcellent papers by the Italian investigator, Cao, whose work is over·looked by many subsequent writers. In fact, there has been but onegood review of his results in English. And yet his investigations openedup the way for practically all of the work on bacterial transmission byinsects. Working with larvae and adults of Musca domestica Linnaeus~Calliphora vomitoria Linnaeus, Lucilia caesar Linna-eus and Sarcophagacarnaria Linnaeus, he proved that the larvae of these flies could takeup and pass through their intestines any bacteria occurring in theirfood, and that all four species acted exactly alike in this regal"d. Exceptwhere he specifically stated, his results applied to all four species inlThis lecture was presented in two parts on July 8 and 15 and distributed entireon July 15, 1918. It has been revised for this edition.lOiS

106 SANITARY ENTOMOLOGYevery instance. Step by step, he proved that fly-larvO! talCe up bacteriafrom their food, and when breedinlg in flesh may take up disease germs aswell as non-pathogenic germs; that these germs may pass unalteredthrough the insects' intestines and out in their feces; that some of themmay remain for a long period in the intestinal canal, and some even.may multiply therein; that they may be taken up by the larva flInd persistthrough its metamorphosis until it arrives at the adult stage, andfor days thereafter, and may be carried by this adult and depositedwith its feces on food or excrement; and that these bacteria will also befound in the glutVnous sub~tances surroundV'-g the eggs when deposited,and thus contaminlate the substance in which the 'TIewly born larvae wi~lfeed; and of course be taken up by this seco'TId generation and possiblybe distributed farther by it.These facts were worked out by Cao in 1905 and 1906, and yetGraham-Smith credits Faichnie (who worked in India in 1909) with beingthe first one to suggest that bacteria ingested by the larva mightsurvive the pupal stage and be present in the intestine of the adult.Later, Bacot, and also Ledingham in 1911 and Graham-Smith in 191!,corroborated these claims that the bacteria could persist in the body'throughout the metamorphosis.Ledingham (1911), Nicholls (19Hl), and Graham..:Smith (191!)have shown that the fly larvre have great powers of destroying microorganismsdue to the fact that many of these organisms are not adaptedto the conditions prevailing in the interior of the larva and pupa, orperhaps more correctly due to the hostile action of bacteria which morenormally frequent the intestines of the larvre. These normal inhabitantsof the fly intestine are principally non-lactose fermenting organisms.Not only bacteria but also protozoa, such as the amoebae of dysentery,and the eggs of parasitic worms, may be taken up by the fly larvre oradults and deposited in the feces. Roubaud (1918) has brought outthe fact that multitudes of the amoebic dysentery germs taken up byadult flies and deposited in their feces die because of the rapid dryingof the feces, and he credits the fly with being a great agent in the destructionof multitudes of protozoa, while granting' the equally greatopportunity of the fly to contaminate food therewith .... Stiles in 1889 fed larvre of Musca domestica with female Ascan,lumbricoides, which they devoured, together with the eggs they contained.The larvae as well as the adult flies contained the eggs ofAscaris (Nuttall, 1899, p. 39). Nicoll (1911) has very thoroughly investigatedthe -relationships of flies to the possible carriage of eggs ofworms and demonstrated the ability of adult flies to ingest the eggs ofvarious species of 'vo~mJ, provided these are small enough, and to pass

DISEASES BORNE BY NON-BITING FLIESthem out whole in the feces, but in all his experiments with the larvae hefound that the eggs were crushed.In addition fo the ability of flies to carry disease germs in theirbody, there are multitudes of proofs of thcir ability to carry them alsoon their body and to deposit them when they feed.The transmission· of disease by nO'Tlrbloodsucking flies is exclusivelyby contamintation either of food, water or wownds. Most of the flieswhich frequent houses and food or visit man because of attractive secretionsor~' juries also are attracted to and breed in excreta or garbage.Hence t contamination of food by direct transportation from infected-excreta i - ~ery simple matter.This ,ntamination may be by the simple depositing of diseasegerms carried on the body of the flies, or by regurgitation, or thedeposition of feces. Wherever a fly alights and remains a few minutesit deposits either vomit or feces. By the nature of its breeding it ishardly to be expected that these deposits will not contain some kind ofbacteria, and possibly protozoa or worm eggs. If these deposits aremade on the moist media offered by foods the germs may easily retaintheir virulence until eaten.As flies can travel considerable distances, at least thirteen miles,the existence of a single disease case with insanitary conditions in thevicimity enabling fly breedmg, might easily infect an entire city or armycamp if the flies were permitted to reach the food of the inhabitants. Itis because of the total lack of sfl!1litary waste disposal in country districtsthat diseases like typhoid fever and dysentery usually become verywidespread. TVe can not know the source of the flies which enter our1107l,ses. We must not let them visit our food. They must be kept awayfrom the eyes and mouths of babies. Our markets where meats andvegetables are sold must be better protected. Only through influencingpublic opinion will we be able to have the fly nuisance in our own publicmarkets abated. Food offered for sale should be kept under glass orscreen at all times.There are so many organisms transmitted by the non-blood-suckingflies that we shall have to -deal with them rather briefly and preferablyaccording to their classific~tion. A thorough digest of the mass ofmatter submitted below should impress the readers with the necessityof fly prevention.PLANT ORGANISMS CARRIED BY NON-BITING FLIESTllAUophyta: Fungi: Schizomycetes: CoccaceaeStreptococcus equinus Andrewes and Horder, a non-pathogenic organismfound in horse dung, was found by Torrey (191!) in a number ofcases on the surface of city caught flies.lO,,{

108 SANITARY ENTOMOLOGYStreptococCU8 fecali8 Andrewes and Horder, an organism occurringnormally in the human intestine and occasionally pathogenic has beenisolated from city caught MU8ca dome8tica by Scott (1917), Cox, Lewisand Glynn (191!?l) and Torrey (191.!?l).StreptococCU8 pyogene8 Rosenbach, an organism causing ERYSIPELAS, SUPPURATION and SEPTICAEMIA was isolated by Scott(1917) from city caught Musca domestica in Washington.Streptococcus 8alivariU8 Andrewes and Horder, an organism frequentlyfound in the mouth, but rarely pathogenic, has been isolated fromthe intestines of city caught Musca domcstica by. Torrey (191!?l), andwas also found on flies by Cox; Lewis and Glynn (191!?l).Diplococcu8 gonorr7weae N eisser (Gonococcus), the cause of GONORRHOEA, was found by Welander (1896) carried on the feet of a flyfor three hours after they had been soiled with secretion.Diplococcu8 intracellulari8 meningitidi8 Weichselbaum (M eningococCU8), the cause of CEREBROSPINAL MENINGITIS, is thought to bepossibly carried by flies by MacGregor (1917).Micrococcu8 flavu8 was isolated by Torrey (191!?l) from the intestinalcontent as well as the surface of city caught flies.Micrococcus tetragenus Gaffky, commonly found in the human body,sometimes pathogenic, sometimes saprophytic, was isolated from Muscadomc8tica by Scott (1917).Staphylococcu8 pyogenes albus Rosenbach, a cause of SEPTIC1\.EMIA, was isolated by Cao (1906B) from the mucilaginous envelope coveringthe eggs of Musca domestica, Sarcophaga 'Vomitoria, Lucilia caesarand Calliphora 'Vomitoria at the time of deposition. Scott (1917) isolatedit from the bodies of MU8ca domc8tica.Staphylococcus pyogenes aurcus Rosenbach, a frequent cause ofABSCESSES, etc., was shown by Celli (1888) to retain its virulence afterpassing through the flies' intestines. Herms (1915) proved by experimentthat MU8ca domestica can carry great numbers of this organismon ib feet. Torrey (191!?l) and Scott (1917) isolated it from the bodies!)f city caught flies. Cao (1906B) isolated it from the eggs at the timeof deposition of laboratory caught flies of Musca domestica, Calliphoravomitoria, Sarcophaga camano, and Lucilia caesar.Staphylococcus pyogencs citreua Passet, a pathogenic, chromogenic,pus-forming organism, was il!'olated by Scott (1917) from bodies ofhouse flies Musca domestica in VVashington. Cao (1906B) fed larvae ofMusca dome8tica, Sarcophaga carnaria, Calliphora 'Vomitoria, andLucilia caesar on meat polluted with this organism and recovered it fromthe feces of mature .flies bred fron these larvae.Sarcina aurantiaca Lindner and Koch, a zymogenic, chromogenic(orange yellow) organism found in air and water, rarely pathogenic,

DISEASES BORNE BY NON-BITING FLIES 109was found by Cao (1906B) to be capable of passing through the intestinesof larvre of Musca domestica, Calliphora 'Vomitoria, Sarcophaga carnaria,and Lucilia caesar, in all stagellbf larval growth and of remainingin the body through pupation to maturity.Thallophyta: Fwngi: Schizomycete8: BacteriacetEBacillus of Koch-Weeks, the cause of an acute infectious CONJUNCTIVITIS (pink eye), is thought by Castellani and Chalmers (1913, p.700) t

noSANITARY ENTOMOLOGYof animals dead from anthrax. externally sterilized eggs of MU8cadomestica, Calliphora 'tJomitoria, Lucilia ClEsar and Sarcophaga camano.and from day to day dissected the larvre feeding on this flesh, alwaysdemonstrating anthrax germs in their bodies, and he further provedthat these larvre retained the germs in their bodies through pupation tomaturity and for at least nine days after maturity. He fed flies onmeat polluted with anthrax. and demonstrated twenty-four hours laterthe bacilli in the feces' and on the eggs. Graham-Smith (1912) foundthat many blow flies (Calliphora erythrocephala and Lucilia clEsar)which emerged from larvre fed on meat infected with anthrax spores wereinfected and remained so f~r 15 days or more. He also found that a largeproportion of house ~ies (Musca domestica) which develop from larvrefed on spores of B. wnthracis are infected. Because of the habit of blowflies of breeding in and attacking wounds there have been many casesof human anthrax on the battle front in Europe. The ease with whichthis may occur is quite evident in view of the above quoted investigations.BacillU8 cloac1E Jordan has been found in the alimentary canal ofMusca domestica in London by Nicoll (1911).BacillU8 coli Escherich, an organism normally found in the alimentarycanal of man, but often found causing secondary infections, was foundby Cao (1906B) in various strains adhering to the eggs at the time ofoviposition of flies caught in the laboratory (Musca domestica, Sarcophagacarnaria, Lucilia ClEsar, and Calliphora 'Vomitoria).Bacillus coli OInaerogenes was isolated by Scott (1917) from Muscadomestica caught in Washington.Bacillus coli communior Dunham, an abundant inhabitant of thehuman and animal intestine, has been isolated from the body and i'ltestinalcontents of ~Musca domestica in New York and Washington byTorrey (1912) and Scott (1917).Bacillus coli communis Escherich, an organism common in the intestineof man and animals and associated with a large variety of lesions,has been isolated from the body and intestinal contents of Muscadomestica by Torrey (1912), Nicoll (1911), Scott (1917) and Cox,Lewis and Glynn (1912).Bacillus coli mutabilis was found on the body and in the intestinesof Musca domestica in London by Nicoll (1911).Bacillus "colisimile" Cao was fed by Cao (1906B) to larvre of Muscadomestica, Calliphora 'tJomitoria, Lucilia ClEsar and Sarcophaga carnariain flesh and he later demonstrated its abundant presence in the feces ofthe larvre.Bacillus cuniculicida Koch and GafFky, the cause of SEPTIC.lEMIA.in rabbits and guinea pigs, was isolated by Scott (1917) from house flies(Musca domestica) caught in Washin~on, and he looks upon the fly

DISEASES BORNE BY NON-BITING FLIES 111as the carrier of laboratory epidemics of rabbit and guinea pig septicmmia.experienced for several years.Bacillu8 diphtherilE Klebs, the cause of DIPHTHERIA, according toexperiments performed by Graham-Smith (1910) may be taken up by fliesfeeding on infected saliva or sputum and may live in the crop and intestinesof the fly for over ~4 hours, and in fact in one experiment he twicerecovered it from the feces of flies 51 hours after feeding on bacilli emulsifiedin broth.Bacillus dY8enteritz "Y" Hiss and Russell, one of the organisms foundin DYSENTERY and INFANTILE DYSEN'l'ERIC DIARRHEA, wasexperimented with by Tebbutt (1913) who fed it with blood to larvm ofMusca dome8tica. The eggs from which these larvle were hatched werewashed in weak carbolic acid or lysol to disinfect them. Before feedingthe larvm on the organism they were carefully washed in weak lysolsolution. In a limited number of cases the bacillus was recovered fromthe pupm and adults of larvre thus fed.The Shiga bacillus, Flexner bacillus and parabacillus of dysenterywere all isolated on flies in Macedonia and a decided correlation betweenthe incidence of flies and dysentery was established by Col. Dudgeon(1919) and associates. They found the examination of fly feces themost suitable method for the isolation of dysentery bacilli.Bacillu8 enteritidi8 Gaertner, the cause of FOOD POISONING inman, and epizootic diseases among animals, was experimented with byGraham-Smith (191~), who feu it to the larvm of Calliphora erythrocephalaand MlU8ca dome8tica, but did not recover it in the adults maturedfrom these larvm. Cox, Lewis and Glynn (191~) isolated a. similarbacillus from flies caught in Liverpool.Bacillu8 fecalis alkaligenes Petruschky, a not infrequent inhabitantof the human intestine, which has been associated with a case of severegastroenteritis, was isolated by Torrey (191~) from the intestinal contentof city caught flies in two different instances.Bacillus fluorescen8 liquefaciena Fluegge, a common organism foundin watpr and air, was fed by Cao (1906B) to larvle of Musca dome8tica~('.J,U'phora vomitoria, Ludlia ClEsar, and Sarcophaga ca rna ria, on fleshcontaining the organisms, and found among the predominant bacteria inthe feces of the larvre. He' found that this organism taken up by thelarvre clJuld persist through the pupal stage and be obtained from thefeces of flies immediately after their emergence, and when fed to adultsit was demonstrated on their eggs when deposited.Bacillus ftuorcscerns nonliquefaciena Eisenberg and Krueger, found inwater and in butter, was fed by Cao (1'906B) to larvre of Muscadomestica, Calliphora vomitoria, Lucilia ClEsar, and Sarcophaga carnaria.and later demonstrated in the feces of the larvre.

112 SANITARY ENTOMOLOGYBaciUus gasoformans nonliquefaciens was found on the body and inthe alimentary canal of Musca domestica caught in London by Nicoll(1911). 'Bacillus griilnthal w~'S fou~d on the body and in the intestines ofMusca domestica by Nicoll (1911).Bacillus lactis acidi Marpmann, a zymogenic bacillus found in cows'milk, was isolated by Torrey (1912) from the surface of city caught flies.Bacillus lactia aer.ogenes Escherich, which is almost constantly foundin milk and is one of the chief causes of s,ouring 'of milk, was isolated fromflies by Cox, Lewis and Glynn (1912).Bacilluslep1'lZ Hanson, cause of LEPROSY, may be carried by Muscadomestica, according to Leboeuf (1913).Bacillus mallei LofHer and Shutz may be transmitted by flies accordingto Rosenau (1916).Bacillus neapolitam.us has been found on the body of Musca domesticaby Nicoll (1911) and Cox, Lewis and Glynn (1912).Bacillus oxytocus pernic~sus Wyssokowitsch, a pathogenic organismfound in milk, has been iSQlated from the intestines of Musca domesticaby Nicoll (1911).Bacillus paracoli Duval a~d Schorer, a pathogenic organism foundfrequently in the stools of children suffering from summer diarrhea, hasbeen isolated several times by Torpey (1912) in New York, both fromthe surface and intestines of city caught flies.Bacillus paratyphosus "A" Schottmiiller, cause of PARATYPHOIDA fever was isolated from the intestinal contents of city caught flies byTorrey (1912).Bacillus paratyphosus "B" Schottmiiller, cause of PARATYPHOIDB fever, was recovered from the body and intestines of Musca domesticacaught in London by Nicoll (1911), with the evidence that it had beencarried by the flies at least for 11 days.Bacillus pestis Kitasato, the cause of BUBONIC PLAGUE, althoughnormally carried by fleas, has been shown by Yersin (1894) and Nuttall(1897) capable of remaining in the intestines of flies in a virulent conditionfor at least 48 hours after infection. Nuttall's ~xperiments indicatedthat this bacillus is fatal to Musca d'omestica.Bacillus prodigiosus Ehrenberg, a nonpathogenic, zymogenic, andchromogenic organism, was fed by Cao (1906B) to adult flies of Muscadomestica, Calliphora 'lJomito'ria, Lucilia cO!sar, and Sarcophaga carnariaand was demonstrated in their feces and on their eggs 24 hours later.Larvre fed on polluted meat contained the germs in their bodies andcarried them through pupation and they could be demonstrated in theintestines of the adult up to nine days after emergence. Ledingham(1911) corroborated Cao's findings of the persistance of this bacillus

DISEASES BORNE BY NON-BITING FLIES 113throughout the metamorphosis of Musca domestica. Graham-Smith.(1918) found that flies of Musca domestica fed on this bacillus may infectmilk for several days, while Calliphora vomitoria flies when infected constantlyproduced infection in milk up to the eighth day and in syrup upto the twenty-ninth day.Bacillus proteus vulgaris Hauser, B. p. mirabilis Hauser, and B. p.zenkeri were fed by Co.o (1906B) to larvre of Musca domestica, Calliphoravomitoria, Sarcophaga carnaria, and Lucilia casar, and Wf!re foundabundantly in the feces of the larvre so fed. Species of Proteus were 0.150found deposited with the eggs of flies fed on infected flesh. Bacillusproteus vulgaris was isolated by Scott (1917) from Musca domesticacaught in Washington.Bacillus pyocyO/Tleus Gessard associated with SUPPURATINGWOUNDS in which blue-green pus is present was isolated in two strainsfrom flies caught in Liverpool by Cox, Lewis a:p.d Glynn (19Hl)~ Bacotand Ledingham (1911) by carefully controlled experiments have provedthat the larvre of Musca domestica fed on infected food retain this bacillusin the gut through the metamorphosis to the adult stage and may distributeit in their excreta.Bacillus radiciformis Tataroff, a saprophytic organism found inwater, was fed by Cao (1906B) to larvre of Musca domestica, Calliphoravomitoria, Lucilia casar and Sarcophaga carnaria, and recovered fromthe feces of the larvre.Bacillus rube1' kielensis Ureunig, a chromoparous (red) bacillus foundin water at Kiel, was fed by Cao (1906B) to larvre of Musca domestica.Sarcophaga carnaria, Calliphora vomitoria, and Lucilia casar, and hedemonstrated that the laryre could take it up in all stages of growth, andthat the bacilli persisted in their bodies through pupation to maturity.Bacillus schafJeri Freudenreich, a nonpathogenic, zymogenic organism,found in "puffy" and "Nissler" cheese, has been found by Nicoll (1911) inLondon on the body and in the intestines of Musca domestica.Bacillt£8 septict£8 agrigenu.s Nicolaier, a pathogenic organism, was fedby Marpmann (1897) to flies, and U hours later the contents of theflies were inoculated into mice, producing fatal infection in a large percent of the inoculations (Nuttall 1899).Bacillus "similcarbonclUo" Cao, a pathogenic organism similar toBacillus a,nthracis, ,vhich produces CARBUNCLES when inoculated, wasfed by Co.o (1906B) to larvre of Musca domestica, Calliph.ora vomitoria,Lucilia ct1!sar and Sarcophaga carnaria and isolated from the feces otthe larvre in a very virulent strain. In examinations of many flies caught:in the laboratory he occasionally isolated a non-pathogenic, mobile strainof this organism. .Bacillus 8ubtilis Ehrenberg, an organism frequently found in air,

114 SANITARY ENTOMOLOGYwater, and soil, and seldom pathogenic, was fed by Cao (1906B) to larvmof Mmca domestica, Calliphora 'Vomitoria, Lucilia Cf1?sar and Sarcophagacarnaria and was among :the predominant bacteria recovered from thefeces of the larvre.Bacillm suipestifer Salmon and Smith, often found in cases of FOODPOISONING and SUMMER DIARRHEA, is recorded by Scott (1917)from the house fly, Musca domestica.Bacillus "tifosimile" Cao, a pathogenic organism strongly resemblingB. typhosus, was fed by Cao (1906B) ·to larvm of Musca domestica,Calliphora 'Vomitoria, Luc.ilia C(Esar, and Sarcophaga carnaria and laterdemonstrated in the feces of the larvre as among the predominant forms instrains of differing virulence. From flies caught around the laboratoryhe isolated pathogenic strains adhering to the eggs when deposited.Bacillm tuberculosis Koch, the cause of TUBERCULOSIS, was fo\\ndin four out of six flies caught by Hofmann (1888) in the room of a tuberculosispatient, whose sputum had contained many germs. Flies fedarti6cially with sputum died in a few days. Within twenty-four hours oftheir being fed on the sputum, the tubercle bacilli appeared in theirexcreta. A guinea pig inoculated with the intestines of flies developedtuberculosis. Celli (1888) reports Alessi's experiments of inoculatingthe feces of :flies fed on tubercular sput"um, and causing the developmentof tuberculosis in two rabbits. Spillman and Haushalter (1887) were,however, the 6rst to find the tubercle bacilli in the intestines and feces offlies which had fed on sputum.Bacterium tularense McCoy and Chapin, cause of a fatal RODENTPLAGUE of which a few human cases are on record, may be transmittedby Musca domestica. Wayson (1915) inoculated the crushed bodies offlies fed on the viscera of an animal dead 48 hours and obtained fatalresults in three series of experiments with guinea pigs.Bacillus typhosus Eberth, the cause of TYPHOID FEVER, was:6rst shown by Celli (1888) to be capable of passing through the intestinesand into the feces of flies. Many authors have added proofs of the roleof the fly in the transmission of this disease and these are ably summarizedby Graham-Smith (1913) and Hewitt (1914). Faichnie (1909) provedthat flies could carry this bacillus in their intestines for 16 days. Leding~ham has isolated the bacillus from the intestines of Musca domestica whichhad fed on it in the larval stage, but found that the normal bacilli in thelarval intestines usually prevent its successful survival through metamorphosis.Bacillus 'Vcsiculosus, which is -very frequently found in human excrement,was fo~nd on the body of Musca domestica caught in London byNicoll (1911).Bacillus .xerosis Kutschert and N.ei~ser,a presumably nonpathogenic

DISEASES BORNE BY NON-BITING FLIES 115organism, usually fou"nd in the eyes, and often associated with conjunctivitis,was isolated by Torrey (1911e) on the surface of city caught flies.Thallophyta: Fungi: Schizomycetes: 8pirillaceae8pirillum (Vibrio) cholem Koch, the cause of ASIATIC CHOLERA,may be carried by flies. The connection of flies with the prevalence ofcholera was first noted by Nicholas (1873). Maddox (1885) first performedexperiments with Calliphora vomitoria Linnaeus and Er-istalistenax Linnaeus as well as other insects and determined microscopicallythe presence of the motile cholera vibrios in the feces. Tizzoni andCattoni (1886) caught flies in cholera wards and after several hoursobtained characteristic cultures of the organism: Many other authors, asSawtchenko (189!), Simmonds (189!), UfFelmann (189!), Macrae(1894), have furnished proofs of fly dissemination of the cholera vibrio, asummary of which can be found in the books by Graham-Smith andHewitt.SUMMARY OF PLANT ORGANISl\ISA brief survey of the data presented above will perhaps help to imprintthe gravity of the fly menace on all who read this. Sixty-three minuteplant organisms have been shown to be transmissible by domestic flies.Forty-four of these organisms have been found on or in flies caught incities or buildings, in other words, were naturally carried by so-called"wild flies." Among these forty-four organisms naturally carried by flieswere several normal inhabitants of milk, also various normal inhabitantsof the human and of animal intestines, which could only be taken up fromexcrement. Some of these organisms are taken from eyes, some from"'putum, some from decaying vegetable matter, others from dairy products.The fly containing such organisms betrays its habits. We find theorganisms of conjunctivitis, infantile diarrhea, sour milk, gas gangrene,(-" l~"'ritis, guinea pig septicaemia, leprosy, paratyphoid A, and paratypl

116 SANITARY ENTOMOLOGYIt is of interest to note that in n"ineteen species the organism has beenproven to pass freely t:Qrough the intestinal canal of the larvae, in thirty~seven species through the intestines of the adult, and in eleven speciesto be capable of persisting ·in the larvre through metamorphosis to theadult. What greater argument could be found that flies are dangerousnot only because of what they as flies have fed on, but also because offood they took while larvre, possibly a long distance away?We have not, however., gauged the depth of the fly's infamy, as we haveso far only listed the evidence of plant diseases transmitted.DISEASES OF UNSETTLED ORIGIN PROBABLY CAUSED BYMICROORGANISMSPURULENT OPHTHALMIA is said to be carried by flies in Egypt.Brumpt accused MU8ca domcatica of being a carrier of TRACHOMA.Rosenau stated that flies have been found breeding in open lesions ofSMALLPOX, and that flies may transmit MEASLES and SCARLETFEVER. Definite experiments certainly should be carried out with aview to determining the exact relationship of flies to these diseases, seek~ing first the possibility of transmission by fecal contamination.Howard and Clark (1912) found that Muaca domcstica flies canretain the virus of INFANTILE PARALYSIS or POLIOMYELITISeither in or on their bodies for !'l4 and 48 hours. The virus may remainalive in the body of the fly six hours after ingestion. The fly can obtainthe virus from secretions of nose and throat and discharge of intestines.Very recently Dorset (1919) and associates have experimentallytransmitted HOG CHOLERA by inoculating with crushed bodies ofinfected Musca domcatica and Fannia canicularia, and also by bringingsuch flies in contact with abraded surfaces.ANIMAL ORGANISMS CARRIED BY NON-BITING FLIESWe will now consider in a similar manner the evidence of transmissionof animal organisms by these same flies.ProtozoaSarcodina: Amoebina: AmoebiclaeLoachia coli (Losch) (Endamoeba) a supposedly harmless commensalin the alimentary canal of man, where it feeds on the contents of thebowels, may be carried in the encysted form by Musca domestica, accord-

DISEASES " BORNE BY NON-BITING FLIES 117 .ing to Roubaud (1918), who finds that the cysts readily pass through thefly intestines at laboratory temperatures or 15-18° C. (59-65° F.) in ~4hours. It may be carried from infected stools to food but must bedeposited in moist substances, as all cysts dJ,"y rapidly in dry flyfeces.Loschia histolytica (Schaudinn), the cause of AMOEBIC DYSENTERY, may be carried in the encysted form by Musca domestica andCalliphora erythrocephela according to Flu (19]6). Roubaud (1918)has carefully investigated and finds that the free amoeba is quicklydigested by the fly, but the cysts may pass readily through the intestineswithin ~4 hours and may be demonstrated up to 40 hours. The cysts dierapidly in dry fly feces, and therefore to live must be placed on moistsubstances, or on food.Mastigophora: Protomonadina: BodonidaeProwazekia sp. is found in Fa'Tllnia canicmaris (Dunkerly 19U).Mastigophora: Polymastigina: PolymastigidaeGiardia inte8tinalis (Lambl) (Lamblia), the cause of LAMBLIANDYSENTERY of rodents and man, may be carried in the encysted formby Musca domestica, according to Roubaud (1918), but must be depositedin the feces on moist substances, or directly on food.Mastigophora: Bintuclcata: LeptomonidaeCrithidia calliphorae Swellengrebel is described as a parasite ofCalliphora erythrocephala' Meigen.Crithidia mU8cae-domcsticae "Verner is described as a parasite ofMusca domestica Linnaeus.1-. ptomonas calliphorae (Swingle) is a parasite of Calliphora erythro

118 SANITARY ENTOMOLOGYLeptomonas m'U8cae-domesticae . (Burnett) is a parasite of M'U8cadomestica Linnaeus, M. nebwo Fabricius, Fann,ia scalaris Fabriciu!,!,Pollenia nulis Robineau-Desvoidy, Teichomyza f'U8ca Macquart, Luciliasp., Pycnosoma putoriwm Wiedemann, Scatophaga lutaria Fabricius,Neuroctena anilis Fallen, Horno,lomyia coroina Verrall, and Sarcophagamurus, undergoing complete metamorphosis in the bodies of the flies.Patton (1910) has demonstrated that the disease may be transmittedfrom fly to fly as folloW's: the food becomes infected from the feces ofthe infected flies which have fed on it; uninfected flies may become infectedby ingesting either t~e long flagellates, the short encysting forms,or the cysts, in the feces of other flies, or in food contaminated by otherflies.Leptomonas pycnosomae Roubaud is a ,parasite of Pycnosomaputoriwm. 0Leptomonas roubaudi Chatton is a parasite in the Malpighian glandsof Drosophila confusa Staeger.Leptomonas sarcophagae (Prowazek) is a parasite in the gut ofSarcophaga haemorrhoidalis Fuller and another species of Sarcophaga.Leptomonas soudanensis Roubaud is a parasite of Pycnosomaputoriwm.Leptomonas stratiomyiae (Fantham and Porter) is a parasite ofStratiomyia chameleon Linnaeus and S. potamida Meigen. Fantham andPorter (1916) proved it experimentally pathogenic by inoculation toMus m'U8culus.Leishmania tropica (Wright), the cause of ORIENTAL SORE ofman, may be taken up in the crithidial stage by M'U8ca domestica andthe organism demonstrated 48 hours after feeding, according to Carter(1909). According to Wenyon (1911) who investigated BAGDADSORE, M'U8ca domestic a may readily feed on the sores and take upLeishmania, but there is no development of the organism and no parasiteswere found in the feces. On the other hand, Row, working with CAMBA YSORE believed the organism transmissible by M'U8ca domestica up tothree hours after the fly had fed on infected sores. He found the gut contentsof flies infective for a monkey three hours after the fly had taken upLeishmania, but Patton (1912) maintains that Cambay sore never commencesin a cut, scratch or abrasion, and failed to transmit the diseasein this manner in numerous experiments with M'U8ca nebulo and Musca sp.A new investigation, however, is warranted by Row's statement, seekingfecal infection of wounds.Rhynchoidomonas luciliae Patton is parasitic in the Malpighiantubules of Musca nebulo and Lucilia serenissima.

DISEASES BORNE BY NON-BITING FLIES 119·Mastigophora: Binucleata: TrypanosomidaeoCastellanella evansi (Steel) Chalmers (TrYp,.-nosoma) 2, the cause ofSeRRA, an African disease of horses and other mammals, may be carriedby Musca domestica by contact with wounds.Castellan.ella hippicum (Darling) Chalmers (Trypanosomo,),2 thecause of MURRINA, a disease of horses and mull'S in the United States·and Panama, may be carried according to Darling (1911, 191!!) by Muscadomestica, Chrysomya and Sarcophaga, from wounds by mechanicaltransmission. He ascertained that the trypanosomes remained alive inthe proboscis of thti fly at least two hours, and he also successfully inoculateda mouse with the crushed portions of a proboscis of a fly which hadfed on infected blood. Isolation of the animals from fly attack, and bindingup of wounds wiped out the epidemic. He did not ascertain whetherthe trypanosome might pass out of the fly's feces and contaminate lesionsin this manner, which naturally is the normal method of fly transmission.Mastigophora: Spirochaetacea: Spirochaetidae~Treponema pertenue (Ca.- :ani), the cause of YAWS, an infectiousdisease of men, may be transmitted by the house fly, Musca domestica.Castellani in Ceylon (1907) found that fli~s eagerly crowd around theopensores of yaws patients. In the hospitals as soon as the dressingswere removed from the yaws ulcerations, they became covered with flies,.sucking with avidity the secretion, which they may afterward deposit inthe same way on ordinary ulcers on other people. He conducted experimentswhi('h proved that the flies do take up the organism, which he recoveredfrom the dissected mouth parts. He fed flies on the organism, thenremoved their appendages and fastened them over scari6ed areas of skinof l"'onkeys, and obtained in two experiments positive lesions by this.Ol"/r\"(1;lm. Robertson (1908) also definit.ely obtained this spirochaetefrom flies collected on yaws lesions. Nicholls (19Hl) ascribes most of thecases of yaws in the West Indies to inoculation of surface injuries byOscinis pallipes Loew. Sarcophaga is also considered a carrier. None·of the i5xperiments have been directed at obtaining infection through the·deposition of the spirochaetes, taken up by the fly in feeding, in its fec.eson other ulcers or injuries. This would appear to be the most likelymethod of inff'etion.• The classification of the Trypanosomes has recently been modified by Chalmers,.including several genera composed of species with similar morphological and biolo{ricalcharacteristics.

HlOSANITARY ENTOMOLOGYN e08poridia: M y:ro8poridia: N o8emidaN08ema api8 Zander, a bee disease, may be communicated to Calliphora'Vomitoria and other insects th.rough feeding on the bee excreta aroundbeehives.Protozoa: N e08poridia: M y:ro8poridia: ThelohatnidaeOcto8porea mono8pora Cha tton and. Krempf is a parasite of F OIIIInia8calam.Theloholnia ovata Dunkerly is also a parasite of Fannia 8caZari8.HIGHER ORGANISMS CARRIED BY FLIESAs pointed out in the introduction of this lecture, flies can carry theeggs of higher organisms. The evidence is presented below, but referenceshould be made to Dr. Ransom's lecture (Chapter V).Platyhelmia: Ce8toidea: Cyclophyllidea: TaeniidaeTaenia (Taeniarhynchu8) 8aginata Goeze, the FAT-TAPEWORMof cattle and rarely of man, has been commonly found in the egg stage inMusca domestica in British East Africa .according to Shircore (1916).It is necessary that the eggs, passed in human or animal. feces, reach thefood or water of the next host (cattle). This may occur by means ofinsanitary sewage disposal, possibly under exceptional circumstances by. the agency of flies.Platyhelmia: Ce8toidea: Cyclophyllidea: HymenoZepididaeChoanotaenia infwndibulum (Bloch) Cohn, the FOWL TAPEWORM,developed to the cysticercoid stage in Musca dome8tica fed on the eggs,and Guberlet (1916) succeeded in infecting new-born chicks by feedingthem on infected MU8ca domestica.Da'Vainea ce8ticillus Molin, a fowl tapeworm, was tested with negativeresults by Guberlet (1916), using Musca domeBtica and Calliphora 'Vomitonain his search for the intermediate host.Da'Vainea tetragona Molin, another chicken tapeworm, likewise gaveGuberlet (1916) negative results with the same two species of flies.Platyhelmio,: Trema.toda: Malacotylea: Schi8to8omidaeSchi8to8oma mansoni Sambon, the trematode worm causing intestinalSchistomiasis of man or BILHARZIOSIS, may be foul!d in the egg stage

DISEASES~ORNE BY NON-BITING FLIES 1~1in Musca domestica, according to Shircore (1916), who recorded eggs ofthis species in flies in British East Africa. The cercaria stage is passedin a snail.N ematheZminthes : Nematoda: S piruridaeHabronema muscae (Carter) Diesing, a STOMACH WORM OFHORSES, passes its earlier stages in Musca domestica, according to Ransom(1913). Either the egg or first-stage larva is ingested by the flylarva breeding in horse manure. Development goes on within the flylarva and pupa, tJ,f'! Id.st stage being found in the proboscis of the adultfly. It passes tUorses through the swallowing of infested flies andprobably may also leave the proboscis of the fly while the insect is feedingon the mucous membranes of the horse.Van Saceghem (1917, 1918) placed flies bred from larvre feo oninfected manure, on skin lesions of a horse and produced infections ofEQUINE GRANULAR DERMATr.rIS, caused by the presence ofHabronema larvre in the skin.Habronema microstoma (Schneider) Ransom and H. megastoma(Rudolphi) Seurat have also been shown to pass their developmentalstages in Musca domestica. (See Chapter V.)Nemathelminthes: Nematoda: AscaridaeAscaris lumbricoides Linnaeus, the cause of HUMAN ASCARIASIS,does not require an intermediate host. Stiles in 1889 fed Musca domesticalarvre on female Ascaris and later found the eggs in different stages ofdevelopment in both larvre and adult flies (Graham-Smith, 1913). Shir('ore (1916) in British East Africa found the eggs in the intestines of~MU8ca domestica in nature. Nicholls (191~) in St. Lucia found theE'~gs in the abdomens of flies, Borborus punctipennis Macquart (Limo.~jna), taken at fecal matter. (See Chapter V.)N ematheZminthes: Nematoda: OxyuridaeOxyuris Cur'V'llla Rudolphi, the EQUINE PINWORM, is recordedby Patton and Cragg (1913), as probably the species of Oxyuris, whichin Madras is often found in the embryo stag!,! heavily infesting the larvreof Musca nwuZo.Oxyu'f!js vermicularis Linnaeus, the HUMAN PINWORM, can beingested in the egg stage by flies, according to Grassi (1883).

SANITARY ENTOMOLOGYNemathelmimthcs: Nematoda: AncylostomidacAncylostoma duodenale D'ubini, cause of HOOK WORM disease ofman, has been found in the egg stage in house fli(!s, M UIIca domestica, byShircore (1916) in British East Africa, and it is therefore possible thatthe eggs may be placed on food, in which the hook worm larva couldhatch and be directly conveyed into the body with the food. No developmenttakes place in the flies. .Necator american~ Stiles, the American HOOK WORM, was collectedin the egg stage in the intestines of Limosilla punctipenlftis in St. Luciaby Nicholls (191~). Galli-Valerio (1905) found that flies could carryon the surface of their bodies not only the eggs but also the larvreof this worm.•N emathelmintMs : Nematoda: TrichosomidaeTrichiuris trichiura (Linnaeus), the WHIP WORM of man, was collectedin the egg stage by Shircore (1916) in British East Africa in theabdomen of Musca domcstica and by Nicholls (1912) in St. Lucia in theabdomen of Borborus punctipennis (Limosina), and the latter succeededin feeding Musca domest.ica on the eggs. It probably does not requirethe flies as immediate hosts, but is undoubtedly distributed in this manner.Thus to the already long list of serious diseases in whose spread thenon-blood-sucking flies may play some part we may now add ~og cholera,poliomyelitis, amoebic dysentery, Lamblian dysentery, Oriental sore,surra, murrina, yaws, purulent ophthalmia, trachoma, the fat-tapewormof cattle, the fowl tapeworm, bilharziosis of man, the stomach wormof horses, equine granular dermatitis, human ascariasis (not normalmethod), equine pinworm, pin itch, two hook worms, and the whip worm,and possibly also smallpox, measles and scarlet fever.We found that the bacteria were only mechanically carried by theflies, except in the case of Bacillus anthracis. A~ong the protozoa alsothose organisms parasitic in vertebrates all seem to be mechanicallytransmitted. The various parasites mentioned, however, pass completelife cycles in the body of the fly. Among the worms, however, there arecases of external mechanical carriage, transmission of eggs throughthe intestinal canal, retention of the egg from larva to adult fly (Ascarislumbricoides), and also cases of the fly serving as an intermediate host(Choanotaenia infwndibulum, and Habronema spp.). The last namedworms are the only organisms known to be transmitted by the fly whichwork for\vard into the proboscis for transmission at time of feeding.A bibliography of the works cited in the lecture follows:

DISEASES BORNE BY NON-BITING FLIES 123IMPORTANT GENERAL TEXTBOOKSFantham, H. B., Stephens, J. 'V. W., and Theobald, F. V., 1916.-TheAnimal Parasites of Man. Wm. Wood & Co., New York, 900 pp.Graham-Smith, G. S., 1918.-Flies in Relation to Disease. Non-BloodSucking Flies. Cambridge Univ. Press, ~9ft pp.Herms, Wm. B., 1915.-Mcdical and Veterinary Entomology. The MacmillanCompany, New York.Hewitt, C. Gordon, 1914.-The House Fly, Musca domestica Linn. HsStructure, Habits, Development, Relation to Disease and Control.Cambridge Univ. Press, 38ft pp.Hindle, Edward, 1914.-Flies in Relation to Disease. Blood-SuckingFlies. Cambridge Univ. Press, 398 pp.Patton, Walter Scott, and Cragg, Francis William, 1913.-A Textbookof Medical Entomology. Christian Literature Society for India, London,Madras and Calcutta, 764 pp.Riley, W. A., and Johannsen, O. A., 1915.-Handbook of MedicalEntomology. Comstock Publishing Company, Ithaca, N. Y.SPECIAL REFERENCES('ao, G., 1898.-L'U:fIiciale San. Riv. D'Igiene di Med. Patr., vol. 11, pp.337-348, 385-397.C10, G., 1906A.-Annali D'Igiene Sper., vol. 16, n. s., pp. 339-368.('ao, G., 1906B.-Annali D'Igiene Sper., vol. 16, n. s., pp. 645-664.Carter, R. M., 1909.-Brit.Med. Journ., vol. !, pp. 647-650.Castellani, A., 1907.-Journ. Hygiene, vol. 7, p. 567.Castellani, A., and Chalmers, A. J., 1913.-l\fanual of Tropical Medicine,2nd edit., p. 700.Celli, A., 188B.-Bullet. d. Soc. Lancisiana d. Ospedali di Roma, fasc. 1.1" 1.('ux, G. L., Lewis, F. C., and Glynn, E. E., 191ft.-Journ. Hygiene,vol. 1~, No.3, pp. 806-309.Darling, S. T., 1911.-Jo'Qrn. Infect. Diseases, vol. 8, No.4, pp. 467-485.Darling, S. T., 1911.-Para!'iitology, vol. 4, No. ft, pp. B3-86.Darling, S. T., 191ft.-Journ. Exper. Med., vol. 15, No.4, pp. 865-366.Darling, S. T., 19U.-Trans. 15th Internat. Congress Hyg. and Demog.,Washington.Davaine, C., IB70.-Bullet. de I'Acad. de Med., Paris, vol. 35, pp. 471-498.

1~4 SANITARY ENTOMOLOGYDorset, M., McBryde, C. N., Nile, W. B., and Rietz, I. H., 1919.-Amel·.Journ. Vet. Med., vol. 14, No. ~, pp. 55-60.Dudgeon, L. S., 1~19.-Brit. Med. Journ., No. 3041, Aprill~, pp. 448-451.Dunkerly, J. S., 191~.-Central. f. Bakt., Paras. und Jiifekt., vol. 6~,p.138.Faichnie, N., 1909.--Journ. Royal Army Med. Corps, vol. ]3, pp. 580-584, 67~-675.Fantham, H. B., and Porter, A.; 1916.-Journ. Parasit., vol. ~, No.4,pp. 149-166.Flu, P. C., 1916.-Geneesk. Tijdschr. v. Nederl.-Indie, vol. 56, No.6,pp. 9!!8-939.Galli-Vale:r:io, B., 1905.-Centralbl. f. Bakt. Orig., vol. 39, p. ~4fl. •Graham-Smith, G. S., 1910.-Repts. Local Govt. Bd., on Public Healthand Medical Subjects, n. s., No. 40, pp. 1-40.Graham-Smith, G. S., 191~.-Forty-first Ann. Rept. Local Govt. Bd.1911-U, Suppl. Rept. Medic. Off., pp. 304-3!!9, 330-835.Grassi, B., l88S.-Arch. Ital. de Biol, vol. 4, pp. ~05-!!08.Guberlet, J. E., 1916.-Journ. Am. Vet. Med. Assn., vol. 49, pp. !!l8-~B7.Hofmann, E., 1888.-Correspondenzbl. d. arztl. Kreis- und Bezirksvereineim Konigr. Sachsen, vol. 44, No. 1!t, pp. IBO-133.Howard, C. W., and Clark, P. F., i91!!.-Journ. Exper. Med., vol. 16,No.6, pp. 850-859.Leboeuf, A., 1913.-Bull. Soc. Path. Exot., vol. 6, No.8, pp. 551-556.Ledingham, J. C. G., 1911.-Joum. Hygiene, vol. 11, No. S, pp. SSS-340. ~MacGr~gor, M. E., 1917.-Journ. Trap. Med. and Hygiene, vol. ~O. No.18, p. fl07.Macrae, R., 1894.-Indian Med. Gazette, pp. 407-41~.Maddox, R. L., 1885.-Journ. Roy. Microsc. Soc., Ser. ~,VOI. 5, pp. 602-607, 94l-9'5~.Marpmann, G., 1897.-Centralbl. f. Dakteriol., 1 Abt., vol. !!!!, pp. U7-IS2.Morgan, H. deR., and Ledingham, J. C. G., 1909.-Proc. Roy. Soc.Med., vol. fl, pt. fl, pp. 133-149.Nicholas, G. E., 187B.-Lancet, vol. ~, p. 724.Nicoll, W., 1911.-Journ. Hygiene, vol. 11, No. B, pp. 381-S89.Nicholls, L., 1912.-Bull. Ent. Research, vol. 8, No.1, p. 85.Nuttall, G. H. F., 1897.-Centralbl. f. Dakteriol., vol. 22, pp. 87-97.Nuttall, G. H. F., 1899.-Johns Hopkins Hospital Reports, vol. 8, Nos.1-~, pp. 1-154.Patton, W. S., I910.-Bull. Soc.-Path. Exot., vol. B, pp. 264-274.

DISEASES BORNE BY NON-BITING FLIES 12(Patton, W. S., 1912.-Sci. Mem. Officers ~fed. & Sanit. Dept., GovtIndia, No. 50, !l1 pp.Ransom, B. H., 1918.""":'U. S. Dept. Agr., Bur. Anim. Ind., bull. 168,pp.1-86.Robertson, A., 1908.-J ourn. Trop. l\Ied. and Hygiene, vol. 11, p.218.Rosenau, M. J., 1916.-Preventive Medicine and Hygiene, pp. ~06-!l52.Roubaud, E., 1918.-Bull. Soc. Path. Exot., vol. 11, No.8, pp. 166-171.Sawtchenko, J. G., 1892.-Review in Ann. Inst. Pasteur, vol., 7.Scott, J. R., 1917.-Journ. Med. Research, vol. 87, No. 164, pp. 115,l!1-124.Shircore, J. 0., 1916.-Parasitology, vol. 8, No.8, pp. 289-248Simmonds, M., 1892.-De~tsch. med. Wochenschr., No. 41, p. 981.Spillman and HaushaIter, 1887.-Compt. Rend. Acad. Sci., vol. 105, pp.852-358.Tebbutt, H., 1913.-Journ. Hygiene, vol. 12, pp. 516-526.Tizzoni, G., and Cattani, J., 1886.-Centralhl. f. d. med. Wissensch.,Berlin, pp. 769-771.Torrey, J. C., 1912.-Journ. Infect. Diseases, vol. 10, No.2, pp. 169-176.rWelman.n, J., 1892.-Berliner klin. Wochenschr., pp. 121S-U14.Van Saceghem, R., 1917.-Bull. Soc. Path. Exot., vol. 10, p. 726; 1918,vol. 11, p. 575. .'Vayson, N. E., 1915.-U. S. Public Health Sel'vice, Pub. Health Repts.,vol. 29, No. 51, pp. 3S90-~S9S.\Velandcr, 1896.-Wicn. klin. Wochenscllr., No. 52.lVenyon, C. M., 19l1.-Kala Azal' BuI1., vol. 1, No.1, pp. 36-58.Yer:...in, A., 1894.-Ann. Inst. Pasteur, vol. 8, pp. 662-667.

CHAPTER VIIIImportant Phases in the Life History of the Non-Biting Flies 1W. DrDight PierceIn the preceding lecture there was brought together an accumulationof evidence against the common flies that frequent our houses whichshould convince anyone of the absolute necessity of keeping flies fromour food, our houses and our bodies. We can only hope to accomplishthis object by becoming familiar at least with the more important featuresin the life history of the lties. From the study of the transmission ofdiseases we may pick out for example a few points in the biology whichneed to be stressed, such as feeding habits. regurgitation of food, excreta,breeding places, oviposition, flight, attraction to odor.We are dealing in this lecture not only with the common house flybut also with most of the common flies ,yhich frequent our houses and areknown as domestic flies. Of the common household flies, only one, the bitingstable fly, Stomoxys calcitrans, is omitted for future discussion.Students would do well to examine some book in which the differentspecies are illustrated, so as to become familiar with the characteristicmarkings. It will then be a good plan to collect the various flies aroundthe house and determine their species.Fairly good illustrations of common household flies are given byHoward and Hutchinson (1915), and Richardson (1917).The best illustrations of the flies are contained in Patton and Cragg'stextbook (1918). .Tables to species of common flies and also illustrations are presentedby Riley and Johannsen (1915).It is also desirable to know how to identify the fly larvre when found.The best American work on this subject is by Banks (191fl). See alsoRiley and Johannsen, p. 815.For general information on the life history, morphology, and anatomyof the house fly refer to Hewitt (1917).The flies are classified largely on the characters of the proboscis,antennre, wing veins, eyes and the arrangement of hairs., The larVal areclassified on the characters of tne spiracles, the ccphalo-pharyngealskeleton, tubercles, hairs and processes.1 This lecture was read July !ali! and distributed July li!9, 1918.126

PHASES IN THE LIFE HISTORY OF NON-BITING FLIES 1~7HOUSE ~LY,l\IUSCA DOMESTICA LINNAEUS II(See Frontispiece)The commlni'house fly, Muaca domestica. is that insect charged withthe carriage of the greatest number of diseases, and probably justly, becauseof its frequentation of all types of excreta, garbage and waste,its common visitations to places where ·foods are handled, and also itsvisits to the human body. We have shown in the preceding lecture howit and its allies can carry disease and what diseases are charged againsteach. N ow we will take a brief review of its life history in order toarrive at important data for handling its control.The house fly adult is yellowish to dark gray in color, with four('quaUy broad longitudinal stripes on the thorax; first three abdominalsegments yellowish with a central black stripe and with two less distinctdiscal stripes. Thf' males measure 5.8 to 6.5 mm. in length, and thefemales 6.5 to 7.5 mm. The eyes in the male: are nearly contiguous andin the female are widely separated.This fly has been distributed by commerce to almost all parts of thecivilized world.Certain features 'of its anatomy are of interest in the present study.The head is prolonged to form a proboscis which is enlarged at tipinto the haustellum bearing apically the oral lobes or labella. These lobf'sbfoar a large number of channels kept open by incomplete chitinous rings.( .llled pseudotracheae, which are fuUy described by Graham-Smith (1913).Tlu.' proboscis of the house fly is adapted to sucking and the absorptionof liquid or liquefied food. It cannot take up very large particles of solidfood. Nicoll (1911) found that the flies could not ingest particles larger~han .OM mm. This therefore determines the size of worm eggs which('an be ingested by the adult. We must assume therefore that whenlIies contain larger eggs, these were taken in by.the larva. Normally,• rt\ pver, the food must pass between the bifid extremities of the chitinousrlllgs of the pseudotracheal channels and pass along these to the mouth.These openings measure from .003 to .004 mm. in diameter. Solid particles,however, are heape!l up in a slight ridge in the channel between theoral. lobes and are prohably sucked into the oral pit and into themouth.When the fly feeds on dry substances such as sugar, dried specks ofmilk, or "putum, etc., it first liquefies the substance by a salivary secretionwhich flows into the oral pit and onto the substance, being distributedby the pseudotrll.cheal channels. The moistening is also aided• An appeal has been made to the International Commission for Zoological NomendJturefor the retention of Musca in .this sense with d()mesticQ; as type.

.128 SANITARY ENTOMOLOGY.by the regurgitation of food from the crop, as proven by Graham-Smith,who fed flies upon carmine colored food, and found carmine stains onsemi-fluid material upon which these flies later fed, for !2 hours.The intestinal canal is composed of pharynx, esophagus, crop, proventriculus,ventriculus or chyle stomach, proximal and distal intestineand rectum. The esophagus passes from the pharynx through the cervicalregion into the thorax, in the anterior part of which it opens intothe proventriculus, and from this same point a duct which is continuouswith the esophag.us passes back into the abdomen to the crop which is abilobed sac, capable of considerable distention. This crop serves as afood reservoir. The fly feea.s until it has engorged the crop, and oftenwill continue feeding, the food then passing directly into the proventriculus.The opening of t:qe proventriculus into the esophagus is ventral.This organ is circular, flattened dorsoventrally. The ventriculus istubular, narrowest in front and narz:_owing again in passing through thethoraco-abdominal foramen. The proximal intestine is the longest regionof the gut, being considerably coiled. The distal intestine begins at theentrance of the Malpighian tubules, and is _only curved once. It is separatedfrom the rectum by a valve. The rectum is composed of threeparts, the intennediate of which is swollen to form the rectal cavity intowhich the four rectal glands empty. ,Food may remain in the crop (or several days, and even when nofurther food is given, it requires many hours to empty the crop completely.After feeding the fly usually retires to a quiet spot and cleansits head and proboscis. It frequently regurgitates its food from the cropin the fonn of large drops of liquid which are subsequently slowly drawnup again and probably pass into the proventriculus. These drops ofregurgitated food frequently are deposited, often for the purpose ofmoistening sugar and similar dry foods.We may now see how easy it is for a fly which has fed on infectedsubstances to contaminate other substances for days by regurgitationfrom the crop, as well as through fecal deposits. Experimental evidencehas proven contamination by both the feces and the vomit.The fly's body is externally constructed so as to further aid indisease carriage. There are numerous hairs or setre on the body, especiallyon the legs. The last joint of the tarsus of each leg bears twoclaws and a pair of membranous pyrifonn pads or pulviIIi. These pulvilliare covered beneath with innumerable, closely set, secreting hairs bY'meansof which the fly is able to walk in any position on highly polished surfaces.These sucker-like pads or pulvilli and the setre of the legs areexcellent bacteria carriers, and not infrequently larger organisms asmites, wonn eggs, etc., are thus carried.The sexes of the house fly are about equal in number. Copulation

PHASES IN THE LIFE HISTORY OF NON-BITING FLIE~may take place, according to Hutchison (1916), as early as the dayfollowing emergence. Oviposition may begin on the third day.He cites a large series of observations on the preoviposition periodshowing that eggs may be laid from ~1J2 to ~3 days after emergence, andthat the period corresponds to temperature and humidity cha~ )s. AtWashington the shortest period was obtained at 8!"l° to 84° P':'; and ingeneral the length of period increased with the decrease of temperature.Increase in humidity seems to hasten egg laying.The eggs are ,vhite, cylindrically oval, slightly hI'oader at the posteriorend with two distinct curved rib-like thickenings on the dorsalsurface, along one of which the egg splits on hatching. These eggsare laid in masses averaging about 1!"l0, and a female may lay as manyas four such batches, and probably under favorable conditions more. Theeggs usually hatch in less than 24 hours, the time of course dependingupon the climatic conditions. At 10° C. (40° F.) the egg period is twoor three days; at 15 to !"loo C. (59-68° F.) it is 24 hours; at !"l5-35° C.(77-95° F.) only 8 to Hl hours, according to Hewit.t (1917).The larvre are white, smooth, cylindrical maggots, tapering at the headend and considerably enlarged at the tail end. When viewed by transmittedlight a dark chitinous structure can be seen in the anteriorregions. This is called the cephalopharyngeal skeleton and is partiallyextrusible. Each species of fly larva is distinguished by the form of thisskeleton and hence if a slide mount is made of a skin boiled in potash, thespecies can be identified by this and one or more other characters. Thethree larval stages differ somewhat in the form of this skeleton so that itbecomes possible to determine exactly the stage of development. Thebody is composed of fourteen segments of which the second is the prothorax.This segment at its posterior margin bears the anterior spiracleswhich are fan-shaped and have six or seven lobes. This segment is followedby the mesotborax, metathorax, and eight abdominal segments.The ninth and tenth (anal) segments are small and ventral. ThelDterior portion of the venter of each of the first eight abdominal'i£:gmmts bears spiniferous pads which assist in locomotion. The eighth.:n' la~t apparent segment bears the spiracular plates. These spiracularplates afford the best means of identification of fly larvae. In the firsttwo stages each plate consists merely of two oblique slits on a slightprominence. In the third stage they are well defined plates, D-shaped,closer together than their width, with flat faces opposed, each with thre,_;inuous slits.In connection with this larval description, we may call attention toerrors existing in many larval descriptions. The thoracic spiracles belongto mesothorax but often appear to have migrated to the prothorax. Thelarge terminal spiracles of Dipterous larvre are always .o{l the eighth, .Hl9

130 SANITARY ENTOMOLOGYsegment, as in almost all orders of insects. The ninth and tenth segmentsare apt to be small and obscure and center around the anus, whichbelongs to the tenth.'The larval period varies in response to climatic stimuli, but underfavorable conditions is about four days in length. When full grown thelarva varies from 10 to 1~ mm. in length. Pupation takes place withinthe last larval skin which shrinks and hardens to form a reddish case orpuparium. This period lasts from 3 to 10 days. When the fly is readyto emerge it pU!lhes off the cap or head end. The entire developmentalperiod may require from eight to eighteen or ,more days. Kisliuk hasfound pupae of the fly in inanure piles at various times during the winter,which of course indicates that the developmental period may occupyan entire winter if the pupa is caught by cold weather. Bishopp, Doveand Parman found that adults emerged from immature stages which hadbeen in manure for six months. Hutchison's observations at Washington,D. C., confirm these findings.The adult flies are capable of considerable flight. Parker demonstrateda migration of two miles in his M!)ntana studies. Bishopp andLaake (1919) record the flight of marked house flies of thirteen miles.In this connection the most interesting contribution is that of Ball(1918) in which he shows that house flies apparently migrated with thewind from 46 to 95 miles from mainland to a tiny island.The house fly has been found breeding in horse manure, human excrement,and hog manure very freely and to some extent in cow and- chickenmanure. It lays its eggs in a great variety of decaying animal andvegetable materials, such as slops, spent hops, moist bran, ensilage,rotting potatoes, dead animals, excreta-soiled straw, paunch contents ofslaughtered animals, soiled paper and rags, etc.THE BLUE BOTTLE FLIES OF THE GENUS CALUPHORA 8The large blue bottle fly, Calliphora 'tJomitoria Linnaeus (plate I,fig. 1) and its near relative C. erythrocephaZa Meigen are often found inhouses. These flies have also been shown to be dangerous insects becauseof their ability to transmit disease. In faoft they are much more likelyto directly transmit disease organisms than the house fly because oftheir habits of breeding in flesh which gives them also the name blow flies.The adults are grayish on the thorax and dark metallic blue with suggestionsof silver on the abdomen. In 'tJomitoria the genre are black andbeset with golden red hairs, while in erythrocephala the genre are fulvousto golden yellow and beset with black hairs.• An appeal has been made to the International Commission for Zoological Nomenclaturefor the retention of OallipliOra in thi!l sense with 'Vomitoria as type.

PHASES IN THE LIFE HISTORY OF NON-BITING FLIES 131These flies are necrophagous and deposit their eggs upon any fresh,decaying or cooked meat, and upon dead insects; they breed occasionallyin human excrement and sometimes will deposit their eggs in open fleshwounds. On the battle fronts of Europe and Asia where the wounded layfor long periods and whero many dead bodies remained uncared for, theseflies multiplied to tremendous numbers and were largely responsible forthe carrying of infections to wounds. When a fly lays its eggs in livingflesh and the larvre develop therein, the iI\fection is called myiasis. Thissubject is of such importance th!1t two entire lectures is devoted to it(Chapters XII and XIII).Impottant as they are, the blow flies are usually subordinated tothe house fly in the discussion of dangerous flies, but thorough investigationsof these species are more than likely to greatly increase theirstanding as disease carriers.The eggs are deposited in masses of ,as many as 300 and a singletiy may possibly deposit three batches. They hatch in from 10 to ~4hours after deposition.The larvre of C. erythrocephala may be distinguished from the housefly larvre by having usually nine but sometimes up to twelve lobes in theanterior (thoracic) spiracles; an anterior scabrous swollen ring on eachof the first eight segments of the abdomen, and a ventral groove oneach segment beneath; the sJ:igmal field concave, surrounded by threepair of tubercles above, and two large and one small pair below; thestigmal plates about once and a fourth their diameter apart, each withthree straight slits, directed principally toward the opposite p1ate; andalso, by having an anal pair of tubercles. The larval characters areillustrated by Hewitt and also by Banks.The larval period requires seven and a half to eight days at !'l3° C.(73.5° F.) and the pupal period fourteen days, according to Hewitt.Bishopp and Laake found the larvre to attain full growth in three to fourdays and the time from deposition of eggs to emergence of adults was 15to ~o days.THE SHEEP MAGGOTS On GREEN BOTTLE FLIESThe European sheep maggot fly, Lucilia s~ricata Meigen, is primarilyan outdoor fly but occasionally is found indoors, especially in farm andcountry houses. It is more brilliant than the Calliphoras, being of aburnished gold with a shining, bluish-green color. (.

IS!!SANITARY ENTOMOLOGYbreed in the flesh causing external myiasis. This species attacks ulcersand sores of men and animals. Its most common attack on sheep andcalves is made on the soiled rumps of animals suffering from diarrhea.No doubt the flies also serve as distributors of the diarrhea.The larva has eight-lobed ant~rior spiracles. The same number oftubercles margin the stigmal plate behind as in Calliphora, but they aresmaller and sharper. The stigmal plates are about one-half theirdiameter apart, each with three straight slits, directed somewhat towardeach other, but also downward.Undoubtedly under battle front conditions this fly can be expectedto visit human wounds and breed in them even more readily than Calliphora.It has been shown by Cao to transmit anthrax with equalease. .Several other species of LucHia have like habits, and the larvre oftwo of these, L. caesar Linnaeus (not sericata Meigen), and L. sylva rumMeigen have been described and illustrated by Banks.The larvae of L. caesar measure 10 to 11 mm. in l~ngth and have notadequately been separated from Calliphora erythrocephala. The larvalperiod averages about fourteen days and the pupal stage about thesame. Bishopp and Laake state that in Texas, during warm weather,the larval period ranges from three to twelve days, the pupal stage fiveto sixteen days and the total developmental period eleven to twenty-fourdays. This ~y is illustrated in plate I, Fig. 2.OTHER SCREW WORMS AND DLOW FLIESThe question of myiasis, which covers screw worms and blow flies, is tobe considered in separate lectures (Chapters XII and XIII), but mentionmust be made of them at present because undoubtedly many infectiousdiseases are carried by these insects which attack alike live flesh throughwounds, and dead animals. I would hardly hesitate to claim thatprobably all such flies may carry anthrax at least, and probably do carryother diseases.Bishopp, Mitchell, and Parman (1917) describe quite fully the habitsof the common American screw worm, Chrysomya macellaria Linnaeus 4(plate I, fig. S, plate II) which breeds in both carcasses and flesh wounds(plate IV). They also treat the black blow fly Phm·mia regina Meigen(plate I, fig. 4), and other species. The large hairy blow fly, Cynomyiacadaverina, Robineau-Desvoidy, and the gray flesh flies Sarcophagate:cana Aldrich, S. tuberosa var. sarmcenioides Aldrich, S. sarraceniae• An appeal has been made to the International Commission on Zoological Nomenclatureto retain Chrysomya in the sense with macellaria as type.

PHASES IN THE LIFE HISTORY OF NON-BITING FLIES 133PLATE I.-Screw WOrms and blow flies. Fig. 1 (upper left).-The hlue hottle fly, Calliphoravomit01"ia. Fig. g (upper right).-The green bottle fly, Luoilia caesal·. Fig.3 (lower left).-The American SCl'ew worm, Chrysomya macellaria. Fig. 4 (lowerright).-The black blow fly, Phormia regina. (Howard and Pierce, photos byDovener.)•

134 SANITARY ENTOIVIOLOGYPLA'J'En.-Eggs of the American screw worm, Chrysomya macellm'iCt, on meat.(Bishopp.)

PHASES IN THE LIFE HISTORY OF NON-BITING FLIES 135Riley (plate III, fig. 1) and S. robusta Aldrich are also among the mostcommon flesh flies.Froggatt .(1915) has given a very fine treatml:'nt of the most importantsheep maggot flies and has presented colored illustrations of someof them.All of these flies are likely to be found in houses and markets andwhen given the opportunity will lay eggs on meat offered for sale orexposed in kitchens or

136 SANITARY ENTOMOLOGY> IPLATE IlL- Flies with dangerous habits. Fig.] (uppel' [cft) ,~A flesh fly, 8rtl'cophagasarm('en.iae. Fig.:2 (upper ri ght) .- The non-biting stable fly, 1~ftl8cina .~tabltlaJTI,B.Fig. 3 (lower left).-The lesser house fly, Fan.nia canir-ula1>i,~, Fig. 4 (lowerright).-The brilliant green fly. Pseudopyrellia c01'nicina. (Howard and Pierce,photos by Dovener.)

PHASES IN THE LIFE HISTORY OF NON-BITING FLIES lS7readily separated by the large number of processes on all the segments.The posterior spiracles are located on raised processes and arenot plates as in the species mentioned above. In F. canicularis thereare four lobes to the posterior spiracles and six finger-like lobes to theanterior spiracles (see Hewitt, 1917) (see figs. 14 to 19).These flies breed in excrement, and in all kinds of decaying vegetablematter and are often found in cases of intestinal myiasis.REFERENCESBall, S. C., 1918.-Migration of Insects to Rebecca Shoals Light Stationand the Tortugas Islands, with Special Reference to Mosquitoes andFlies. Carnegie Inst., "Vashington, Publ. ~5~.Banks, Nathan, 191~.-The Structure of Certain Dipterous IJarvre withParticular Reference to Those in Human Foods.Bishopp, F. C., 1915.-Flies Which Causc Myiasis in Man and Animals.Some Aspects of the Problem. Journ. Econ. Ent., vol. 8, pp. S17-S~9.Bishopp, P. C., and Laake, E. W., 1919.-The Dispersion of Flies by}'light. (Abstract) J ourn. Econ. Ent., vol. 1~, pp. no-n 1.Bishopp, F. C., Mitchell, J. D., and Parman, D. C., 1917.-U. S. Dept.Agr., Farmers' Bull. 857.Froggatt, W. W., 1915.-Sheep Maggot Flies. Dept. Agr., New South\Vales, Farmers' Bull. 95.Graham-Smith, G. S., 1915.-Flies in Relation to Disease. Non-bloodsuckingI~lies.Cambridge Univ. Press.Hewitt, C. G., 1917.-The House Fly. Cambridge Univ. Press.Howard, L. 0., and Hutchison, n. H., 1915.-Housc Flies, U. S. Dept.Agr., Farmers' Bull. 679.Hutchison, R. II., 1916.-U. S. Dept. Agr. Bull. S45.Nicoll, W., 1911.-Journ. Hygiene, vol. 11, No. S, pp. 381-389.Parker, R. R., 1916.-Dispersion of Musca dornestica under City Conditionsin Montana. Journ. Eeon. Ent., vol. 9, pp. S~5-S54.Patton, W. S., and Cragg, F. W., 1915.-A Textbook of Medical"Entomology.Richardson, C. H., 1917.-The Domestic Flies of New Jersey. New JerseyAgrie. Exp. Sta., Bull. '307.Riley, W. A., and Johannsen, O. A., 1915.-Handbook of MedicalEntomology.

CHAPTER IXCommon ~lies and How to 'l'ell Them Apart 1C. T. GreeneOnly a few of the very 'common flies have been included in this chapter;the flies that are likely to appear near any house or in any camp.All of them may be attracted by the odors of fresh and cooking foods.In the following pages are presented two tables, one to separate the differentspecies of the adult flies, and the other to separate the differentlarvre or maggots of the flies. All the terms for the different parts ofthe flies and maggots have been made as plain as possible so that theSucforia/ Type./V1ourH f'ARr.s.FIG. IO.-Mouth parts of fiies: (1" Suctorial type; b, biting type. (Greene.)tables can be used by a non-entomologist. In the {irst table for the adultflies is given the style of the mouth-parts (see fig. 10), that is, whetherthey are adapted for biting or are simply suctorial, then the commonname is given, and then the scientific name. In the second table the larvreor maggots can be separated into different species. Under the name ofeach species, the larva or maggot is described in further detail and heremention is made as to where the species will breed.1 This lecture was presented September 9, and issued September 11. 1918. It .hasbeen somewhat modified.138

COMMON FLIES AND HOW TO TELL THEM APART 139All the Sarcophagid or "flesh flies" can be readily separated from allthe other flies in the following table because their bodies are entirelygray. The head is rather a bright red, the top of the back has threeparallel dark stripes and the top of the abdomen has lighter reflectingareas, giving it somewhat 'of a checkered appearance.TABLE TO SEPARATE THE ADULT FLIESI. Grayish flies with from two to four longitudinal stripes more or lessindica ted on the thorax.1. Dark gray, medium sized fly; top of thorax with four parallel,black stripes; sides of abdomen with a large yellow area (variablein size and never definitely outlined); mouth-parts of 'the suctorialtype (see fig. lOa), never for biting; variable in size butMU.sCA DOME.JTICA "FIa. n.-Diagrammatic sketch of the house fly, MU8ca domeBtica.(Greene.)average about one-quarter inch in length. The common house fly(Frontispiece, figs. 11, Ua) also called typhoid fly.Musca domestica Linnaeus.~. Brownish-gray fly, slightly larger and broader than the house fly.Top of thorax with two long, parallel, black stripes and on eachside of these is a large black dot, below which is a black stripeabout half as long as the two long stripes. Abdomen with twoor three cone-sha:ped dark brown spots in the center and two 01'three round spots on each side (fig. 12c). Mouth-parts piercingor biting type (fig. lOb). Stable fly, also called biting house fly(fig. 46).Stomoxys calcitrans Linnaeus.3. Very dark gray fly, smaller and more slender than the house fly.Abdomen pointed and more conical in shape. Yellow spots on thesides definitely outlined' (fig. 12b). Mouth-parts are of the suctorialtype (fig. lOa). The small house fly (plate III, fig. 3).F awma camic'Ularis Linnaeus.4. Gray fly, a little larger than the house fly. (About the size ofStomoxys calcitram.) Top of thorax has two short, black

140 SANITARY ENTOMOLOGYstripes. Joints of legs reddish at base. Abdomen is gray andin certain lights there are paler gray areas which look likespots but there are never any definitely outlined spots. Mouthpartssuctorial type (fig. lOa). Another stable fly (plate III,fig. fl). . Muscma stabvlans Linnaeus.II. Bluish, or greenish flies.1. Large blue fly, with grayish thorax (average length three-eighthsto seven-sixteenths of an inch). 'l'his fly is rather broad androbust and in certain lights the abdomen ehows paler, reflectingareas but not definite' spots. Mouth-parts suctorial type (fig.lOa). The common blow fly. Lower part of head (cheeks) reddishand the beard black. Calliphora erythrocephala Meigen.fl. A slightly larger fly than the preceding but more shiny and adeep greenish blue. Abdomen slightly more pointed and of an/'r1tnCA DOME6TleA. L. I'lrNNI/I e"Hir:UI.AItM L. S~()H()1C y,s CALC/TRANS.FIG. Ht-Abdominal markings of three common house flies: a, the house fly, MU8cadomeBticaj b, little house fly, Fannia caniculariBj c, stable fly, Stomoa:yB culcitrO/llJ/l.(Greene.) In these diagrams the relative size of the abdomen Is shown. Thelight areas in a and b represent yellow marldngs and are variable in size. In fig.c the markings of the last segment may be present or absent.even coloration (no reflecting spots). Mouth-parts suctorial type(fig. lOa). Lower part of head black and the beard red. Anotherblow-fly (plate I, fig. 1). Calliphora vomitoria Linnaeus.8. Much smaller fly, shiny green with a decided whitish bloom onthe thorax and abdomen. Mouth-parts suctorial (fig. lOa). Agreen bottle fly.'Lucilia sericata Meigen.4. A slightly smaller fly, shiny, metallic green with a. decided bluishtinge and no white bloom. Mouth-parts suctorial (fig. lOa).Green bottle fly (plate I, fig. fl). Lucilia caesar Linna~us.o. A dark green fly, little larger than the above species. It is shinywith bluish tinge. Top of thorax with three dark longitudinalstripes. Thorax often has a bronze tinge. (Average length fivesixteenthsto three-eighths of an inch.) Mouth-parts of the suctorialtype (fig. lOa). The "screw-worm fly" (pl~te I, fig. 3).Chrysomya macellaria Fabricius.

COMMON FLIES AND HOW TQ TELL THEM APART 1416. Deep, shiny blue fly often with a blackish tinge (about five-sixteenthsof an inch in length). Mouth-parts of the suctorial type(fig. lOa). The black blow fly (plate I, fig. 4).Phormia regina Meigen .III. Ashen gray to deep gray•flies. Top of thorax with three blackish,longitudinal stripes. The abdomen has lighter gray reflectingspots (in certain lights). The difPerent species vary in sizefrom a small fly up to a half inch in length. Mouth-parts areof the suctorial type (fig. lOa). Flesh flies (plate III, fig. 1).Sarcophagidae.THE LARVAE OR MAGGOTSThere is a considerable number of flies whose larvre or maggotseither regularly or occasionally live in substances used by man as food.The great majority pass through the intestinal tract without ourknowledge, for most of them cause little or no trouble. Many dipterouslarvre occur in decaying fruits and vegetables and on fresh and cookedmeats. The blow fly, for example, will deposit on meats in a pantry;while other maggots occur in cheese, etc. Pies and puddings in restaurantsare often accessible and very suitable places for flies to deposittheir eggs and no doubt a great many maggots are swallowed in thisway. The occurrence of dipterous larvae in man is known as "myiasis."Various names or divisions are given, as "myiasis externa" or "myiasisdermatosa" for larvre in the skin or wounds; "myiasis intestinalis" forthose in tlle alimentary canal; and "myiasis narium" for larVal in thenose. The presence of ~arvre in the nose is rather accidental in thiscountry and usually due to the "screw-worm." In tropical countrjes thistype of ,myiasis is quite common.The larvae of the ox-warble or bot-fly (Hypoderma lincata Villers)sometimes occur in man. There are various cases recorded, mostly ofchildren, where, in the winter time, a larva is observed under the skin,usually in the neck or shoulders, and upon removal proves to be thelarva of the heel fly in the second stage. Bot infestation is sometimescalled "creeping worms," and many cases have been recorded by armysurgeons on the Mexican borde:t. These cases are probably contractedby men sleeping in stable yards.Descriptio'fUJ of larvae or maggots 2All the larvre mentioned here are broadest near the tip or tail of thebody, and taper forward to the head.J In the following discussion the visible body segments are numbered from headto anus irrespective of their scientific nomenclature.-W. D. Pierce.

SANITARY ENTOMOLOGYThe larva is divided into fourteen parts, of which eleven are distinct,called segments, and the first segment is the head. The head appears tobe bilobed, or divided into two parts when viewed from above, and eachlobe bears a minute cylindrical tubercle or papilla (fig. 13). Below isthe mouth opening; at one side and above it is the pair of mandibles orgreat hooks (fig. 13). The second segment or prothora:s: bears on eachside, in the full grown larva:, a short fan·shapcd process called the anteriorspiracle. The eleventh body segment which might be taken for thelast is often a fusion of the seventh to tenth abdominal segments. Theeighth abdominal segment c~n ahvays be identified by the stigmal platesSf&tr161 fieltl (cDnf4,n/n$ J"MkrlDr "fljll'M! plm.,)~~ Il~IG. 13.-Characters of It museid fly larva. (Greene.) Segment 1 is the head; 9-4are thoracic segments; 5-11 are abdominal. Segment 11 really contains the seventhto tenth abdominal segments, the spiracles being on the eighth, the anus in the tenth.or lobes. The ninth and tenth are usually small and ventral and enclosethe anus. For further details see fig. 13.Table to Separate the Larvae (Maggots)I. Spiny Iarvre.1. A larva with the body flattened; down the middle of the back aretwo rows of spines or processes, there are also two rows alongthe under side and a single row of spin~s along each side. Thesespines or processes are pointed and covered with many bristles.There are also two stigmal plates on top of the last segment.(Figs. 14-16.)Fawnia canicularia.~. The larva: of Fa1l/Tl,ia s_calans are similar (figs. 17-19), but theprocesses have fewer side branches.II. Smooth larvre.A. With one great mo'Uth.-hook; slits in stigmaZ plate 'WVndw,g.1. Body broadly rounded at rear end, without spin~s. Stigmal platewith three winding_slits (figs. !O to ~~). Musca domestica.

COMMON FLIES AND HOW TO TELL THEM APART 148!. Body same as above species, stigmal plate with three S-shapedslits (figs. !3, !4).Stomo:cys calcitrana.B. Two great mouth-hooks; sUts m stigmal plate not winding.1. Body slightly rounded at rear end, faintly spined and with threeshort, pointed slits in stigmal plate (figs. !5, !6).Muacina stobulana.FIG. 14.-Larva of the little house fly, Fannia canicularill. Greatly enlarged. (Howardand Pierce, drawing by Bradford.)FIG. IS.-Dorsal view of eighth abdominalsegment of th.e larva of Fannia. caniculari8.Very highly magnified. (Drawingby Bradford.)FIG. 16.-Ventral view of terminal segmentsof Fa.nnia caniculariB; the ninthand tenth segments are comprised inthe small zone around the anus. Veryhighly magnified. (Drawing by Bradford.)!. Stigmal plates wide apart, each with three -straight slits nearlytransverse to the body and a distinct button (figs. !7, !8).Calliphora erythrocephala. Calliphora vomitoria.3. Stigmal plates about half their diameter apart, each with threestraight slits directed somewhat downward (fig. 31).Lucilia sericata.4. Stigmal plat.es less than their own diameter apart, each withthree straight slits pointed downward; no button (figs. 29, 30).Chrysomya macellaria.

144 SANITARY ENTOMOLOGY5. Stigmal plates at bottom of a deep pit; each plate has threeslits pointing downward, plates less than their diameter apart; nobutton.Sarcophagidae.F OIIlnia canicularis Linnaeus and Fownia scalaris }"abriciusThese larvre are brownish yellow in color. The body is quite flattened,narrow and pointed in fr~mt. The peculiar spines or projections on thebody will separate them from the other species. The larva averagesnearly three-eighths of an inch in length (figs. 14-19). (See ChapterVIII.)FIG. 1 'T.-Larva of Fannia scalari" the latrine fly, .greatly magnified.Pierce, drawing by Bradford.)(Howard andFIG. IS.-Dorsal view of eighth abdominalsegment of the Fann,ia 8Cala.ri,. Veryhighly magnified. (Drawing by Bradford.)FIG. 19.-Ventral view of terminal segmentsof Fa.7IIIIia sca.laris; the ninthand tenth segments are comprised inthe small zone around the anus. Veryhighly magnified. (Drawing by Brad~ford.)Since the larvre of this genus feed on fruit and vegetables that arejust beginning to decay, one can readily see that they are often swallowedby people. There are many records of the passage of larvre or maggotsof this genus. At least some species of this genus breed in human feces,therefore they may be possible conveyers of disease.Musca domestica LinnaeusThe larva of the house fly is slender and tapering in front and largeand somewhat rounded behind. From above, the head is divided into two

COMMON FI.IES AND HOW TO TELL THEM APART 145parts with a tiny papilla on each side (fig. ~O) and there is but onegreat hook. The anterior spiracles (fig. ~l) show six or seven lobes;on the under side of the sixth and following segments there is a transverse,swollen area, wider in the middle and somewhat pointed towardeach end. These areas are provided with minute teeth.. The area isslig_htly prominent and shows two approximate processes. The stigmalfield is barely if at all conCave and not outlined by tubercles; the posteriorspiracles (fig. ~2) are prominent, less than their own diameter apartand each with three winding slits and a button at the base. In somecases two of the winding slits are apparently connected. The secondstagelarvm has two straight slits in each stigmal plate, while in the firstlarval stage there a.re two sma.ller slits on a tubercle each side of theFIG. gO (left).-Larva of Mlruca domestica; dorsal view of head and porthorax. (Greene.)FIG. 21 (center).-Larva of Mwca dOm6Btica; lateral view of tenninal segments.(Greene.) The spiracles are located on the eighth abdominal segment. The ninthand tenth segments are ventral and not very distinct, enclosing the anus.FIG. 22 (right).-Larva of MUllca dOm6l1tica; enlarged sketch of right stigmal plate.These plates are less than their breadth apart. (Greene.)middle and in this stage there are no anterior spiracles. (See ChapterVIII.)The larva of the house 1Iy is rarely swallowed, but there are recordsto that effect. It sometimes breeds in decaying fruits and vegetables.The principal breeding place is in horse manure. It also breeds in humanexcrement and because of this habit it is very dangerous to humanbeings.StomOITJ'!J8 c;alcitrans LinnreusThe larva of this species is very similar to that of the house 1Iy, witha single great hook; the anterior spiracles have five lobes (fig. ~S); thesixth and following segments have each an area on the under side providedwith tubercles; this area is wider in the middle; anal area has twosubmedian tubercles and three each side of these; above them is a row

146 SANITARY ENTOMOLOGYof minute granules, ending each side in a larger granulate tubercle; thereare no tubercles outlining the stigmal field; the stigmal plates are subtriangular,about one and one-half times their diameter apart, black,and each with three pale areas containing an S-shaped slit (fig. 24).These slits are never near each other like in the house fly, and there is noapparent button.This latva commonly breeds in manure of various kinds, but also inFIG. !i!S.-Larva of Stomo"'!!11 calcitra1lll: enlarged sketch of thoracic spiracles. (Greene.)decaying matter, and is not often passed by people, but there is onerecord. Horse manure, cow manure, and wann, decaying vegetation, likeold straw and grass heaps, are common breeding places.FIG. !i!4.-Larva of StomO"'!!1I calcitranll: enlarged sketch of right stigmal plate. Theseplates are one and one-half times their breadth apart. (Greene.)Muscina stabulans FallenHead of larva (fig. 25) divided into two parts from above, no distinctpapilla; two great hooks close together; anterior spiracles withabout six lobes (fig. 25b). The surface of the segments is mostly smooth.Beginning with the fifth segment, on the under side, there is a basal,transverse, swollen area, furnished on the crest with rows of teeth; eachof these areas is divided on the median line. On the next to the lastsegment there is a similar area at the tip, but not divided. The segmentsbelow also show a transverse line before the middle. The lastsegment has the anal basal area with spines, but not very prominent,,and bears a median and three lateral tu~rcles with spines. The tubercles

COMMON FLIES AND HOW TO TELL THEM APART 147are nearly in a transverse row. The rounded tip of the body (fig. ~5c)shows, across the middle, faint traces of four low cones. The stigmalplates (fig. ~6) are scarcely elevated, black, less than their own diameterapart, and each with three very short slits pointing towards those of theopposite plate. .This larva is common in decaying vegetable matter; and has beenreared from rotten apples, pears, squash, mushrooms and dead insect,FlO. 25.-Larva of MtI8cina ,tabulallll: a, Side view of head and prothorax; b, an·terior or thoracic spiracles; c, side view of terminal segments of abdomen.(Greene.)Iarvre. In one case a considerable number were passed by a child suf·fering with summer complaint. Laboulbene records larvre of this speciesvomited by a person suffering from bronchitis.FlO. i6.-Larva of MtI8cina ,tabula1lB: enlarged sketch of ri~ht stigmal plate. Theseplates are less than their breadth apart. (Greene.)Calliphora erythrocephaZa Meigen'rhe head of this larva is distinctly divided into two parts from above(fig. ~7, side view of head) ; each part or lobe has a tiny papilla. Thereare two well separated mouth hooks. The anterior spiracles have fromniw! to twelve lobes. Beginning with the third, each segment shows anapical swollen ring or girdle, whose surface is scabrous (roughened likea file); these rings are broader below than above, and are here notchedon the posterior middle. Each ventral segment, beginning with the fifth,is divided by a transverse groove near the middle. The anal area showsa smooth median process, divided in the middle, and at each outer corneris a cone. The stigmal field is rather concave, the upper lip with threesmall tubercles on each side, the lower lip with two larger tubercles oneach side, and a median pair smaller and lower down. The stigmalplates are about once and a fourth their diameter apart, each with three

148 SANITARY ENTOMOLOGYsimple straight slits directed slightly downward but mostly toward thoseof the opposite plate; the button is distinct (fig. lil8).The blow-fly deposits eggs on dead animals, and also on fresh an~cooked meats. As such are often accessible to them in pantries, it isreadily seen that many larvre are swallowed by people each year; thereare, however, comparatively few records published, probably because thepolluted food causes no ~rouble.Calliphor.a 'Vomitona LinnaeusThis larva appears to be identical with that of Calliphora erythrocephala.There seem to be no visible characters to separate it from thislatter species (figs. lil7 and lil8). The habits are about the same.FIG. r!7.-Larva of Calliphora erythrocephala: side view of heed and prothorax.(Greene.)Lucilia aencata MeigenBody rather stout, not slender in front. The head is distinctlydivided into two parts or lobes, with distinct papilla(figs. 310., b). The~\g:'FIG. 28.-Larva of Ca.lliphora eryth,'or:ephala: enlarged sketch of left stigmal plate.These plates are one and one-quarter times their breadth apart. (Greene.)two great mouth hooks are well separated. The anterior spiracles areprovided with about eight lobes. the surface of the body is mostlysmooth; the sides of segments 3, 4 and 5 are bilobed; beginning withsegment 6 there is a basal ring girdle, roughened. These girdles on segments6 to 9 are widened on the midOle of the under side of the larva;the sides are also swollen, but not plainly bilobed, except those nearthe tip. The under sides of the segments are transversely divided by, aline or furrow in the middle. The last segment is short, the stigmalfield occupying most of the tip. The stigmal field has a slightly depressed,upper lip with three sha.rp tubercles on each side, the intermediateone hardly smaller than the others; and a lower lip with two large,

COMMON FLIES AND HOW TO TELL THEM AP AR'r 149sharp tubercles on each side, and a median pair more remote from themargin (fig. SIc). The anal area is rather sunken with a small roundedtubercle at each outer corner. The stigmal plates are about one-halftheir diameter apart, each with three straight slits, directed somewhattowards each other, but also downward.jj Ih.IJ1a., IT, C.FIG. :n.-Larva of LuciUa 8ericata: a, dorsal view of head and prothorax; b, lateral viewof head and thorax; c, lateral view of last abdominal segments. (Greene.)This larva is mentioned on account of the adult which is very likelyto be met with. This larva is mostly injurious to sheep. Meinert hasreared another Lucilia (L. nobilia Mc:igen, of Europe) from larval takenfrom the ears of a sailor.FIG. 29.-Larva. of Ohry,omya macellaria: enlarged sketch of side of head and prothorax.(Greene.)Chrysomya macellaria FabriciusThe head from tbove is distinctly bilobed (fig. !9). There are twodistinct hooks. The anterior spiracles are very short, and contain onlyFIG. SO.-Larva of OhryBomya maceZlaria: enlarged SKetch of left stigmal plate. Theseplates are less than their breadth apart. (Greene.)7 lobes (fig. !9). The posterior upper part of segment 1 is swollen andwith many spines (fig. !9). E!ich of the foiIowing segments (except!)has a basal, swollen ring, armed with teeth pointing backward, the teethof the front rows are always larger. Beginning with segment 6 the under

V50SANITARY ENTOMOLOGYpart of each ring is much broadened and divided txansversely by a narrowsmooth space. On segments 5 to 10 there is on each side behind a fusiformswollen area pressing against the swollen ring of the next segment;this area also has spines. The tip of the body shows on the dorsal parta great cavity, in the bottom of which _!..!Le the stigmal plates, each withthree straight slits, those of one sub-parallel to those of the other;there is no button (fig. 30). Behind this cavity is a high, transverse,spiny cre'>t; and the ventral part of the tip shows an area covered withspines bearing two rather widely separated;prominent, smooth tubercles.The upper edge of the tip s.hows four small conical tubercles.PLATE IV.- ~crew worm injury to a yearling calf. (Bishopp.)The larva of this insect is called the "screw-worm," and occurs insores and wounds of domestic animals and also in man. There arevarious records of its presence in the ears and nose, or nasal cavities,of people; in swellings near the nose; in a boil under the arm; under theskin of a child; and in the navel of a child~ It is hardly a possiblefactor in intestinal myiasis of man, and most of such recorded casesprobably belonged to some species of Sarcophaga whose larvre are verysimilar in appearance to those of the screw-worm.SarcophagidaeThe Sarcophagidae have two great hooks, and the posterior stigmalplates have three slits as in Calliphora el'ythrocephala and Lucilia seri-

COMMON FLIES AND HOW TO TELL THEM APART 151cata. However, these slits are not directed toward those of the oppositeplate but are sub-parallel to them. The stigmal field is strongly depressedto form a deep pit, and the stigmal plates are at the bottom of this pit.The segments of the body bear complete rings of spinose areas, and oftensupplementary pads on the sides.Sarcophaga larvre prefer animal matter, breeding extensively in carcasses.They have been found in cheese, oleomargarine, pickled herring,dead insects, and human feces. A species was also reared from decayingvegetables.BIBLIOGRAPHYBanks, N., 191~.-The Structure of Certain Dipterous Larvre with P~rticularReference _to those in Human Foods. U. S. Dept. Agr., Bur.Ent., Tech. Bull. ~~.Hewitt, C. G., 19l0.-The Structure, Development and Bionomics of theHouse Fly, j}/usca domestica Linn.Howard, L. 0., 1910.-A Contribution to the Study of the Insect Faunaof Human Excrement. Proc. Wash. Acad. Sci., vol. ~, pp. 541-604.Howard, L. 0., and ;U:utchison, R. H., 1915.-House Flies. U. S. Dept.Agr., Farmers' Bull. 679.Howard, L 0., and Hutchison, R. H., 1917.-The House Fly. U. S.Dept. Agr., Farmers' Bull. 851.Lallier, P., l897.-Etude sur la Myase du Tube Digestif chez l'Homme.These Faculte de Medecine de Paris, pp. 1~0, 1 pI.Lintner, J. A., 188~.-Injurious Dipterous Insects. 1st Rept. Inj.Ins., New York, pp. 168-~~7, figs. 45-67. (Anthomyiidre.)Lowne, B. T., 189~, 1895.-The Anatomy, Physiology, Morphology,and Development of the Blow-fly (Calliphora erythrocephala). ~voIs., London, 778 pp. 5~ pIs., 108 figs.'\' L'wstclld, R., 1907.-Preliminary Rcport on the Habits, Life-cycle, andBreeding Places of the Common House Fly (Musca domestica), asObserved in the City of Liverpool, with Suggestions as to the BestMeans of Checking Its Increase. Liverpool, ~3 pp., 14 figs.Packard, A. S., 1874.-0n the Transformation· of the Common HouseFly, with Notes on Allied Forms. Proc. Bost. Soc. Nat. Hist., vol. 16,pp. 136-150, 1 pI.Patton, W. S., and Cragg, F. W., 1913.-A Textbook of MedicalEntomology.Perez, C., 1910.--Recherches Histologiques sur la Metamorphose desMuscides (Calliphora erythrocephala). Arch. ZooI. Exp., ~74 pp.,16 pIs. ' .

15~ SANITARY ENTOMOLOGY'Riley, W. A., and Johannsen, O. A., 1915.-Handbook of MedicalEntomology.Walsh, B. D., 1870.-Larv.ae in Human Bowels. Amer. Ent., vol. ~, pp.187-189. (Homalomyia.)

CHAPTER XThe Control of the House Fly and Related Flies 1W. Dwight Pierce.We have now come to one of the greatest problems in SanitaryEntomology; the control of the treacherous flies that visit our homes butto bring sickness and death. The anti-fly measures may be classed asrepressive and palliative, and of course the first are the most important.THE FLY MUST BE FOUGHT WHILE BREEDING AND BEFORE IT HAS A CHANCE TO SPREAD DISEASE. Many persons_object to the anti-fly-breeding measures because of cost, but no cost is toogreat iol thereby we prevent epidemics and the loss of thousands oflives.Inasmuc~ as we are dealing with the fly as a municipal, industrial,rural, home, and army problem, the subject will have to be handledtopically.REPRESSIVE MEASURESStriking the SourceManureThe house fly normally breeds in horse manure, but may also breedin the manure of other domestic animals. It is apparent that this thenis th first and most difficult point to strike.Th. disposal of manure is a matter which must be controlled in all1. 'micipalities and wherever there are large congregations of people.For this reason it is an acute problem of army camps and cantonments.In cities it is most acute in stockyards, sales stables, livery stables, andcontractor camps. It is a problem on every farm and with everyindividual who owns a horse, or hog.Chemical Treatmcnt.-Manure is a valuable product and every effortshould be mad(' to conserve and utilize it, first rendering it unfit forflies. Realizing this, the United States Department of Agriculture had1 This lecture was read August 5, 1918, and has been more or less modified to itsprestmt form.153

154 SANITARY ENTOMOLOGYa long series of careful studies made of many chemicals which might beapplied to manure, in ordcr to determine the effects upon the fly larvre,the bacterial activity of the manure, and the fertilizer value of the manure.The results have been p~blished in various bulletins by Hutchison, Cook,and Scales with the principal recommendation in favor of the daily treatmentof fresh manure with powdered borate at the rate of 1 pound to 16cubic feet, or 0.6~ pound per 8 bushel of manure. This will kill about90 per cent of the laiv8:!, and is harmless to the manure. Larger amounts,however, may have a deleterious effect.They also found that a water extract of hellebore, prepared by adding1h pound of powder of hellebore to 10 gallons of water, which afterstirring is left for ~4 hours, is effective at the rate of 10 gallons to every8 bushels (10 cubic feet). Likewise a mixture of % pound of calciumcyanamid and % pound of acid phosphate to each bushel of manuregives a larvicidal action of 98 per cent. Unfortunately these last tworemedies are not available at the present writing.Creosote has been recommended by British authorities, but the investigatorsmentioned above have found a deleterious effect.upon the manure.If the primary essential is destruction of fly breeding, and the otherchemicals are not available for treatment, creosote treatment is effective,and there will still unquestionably be fertilizing value to the manure.Army sanitarians, especially, can not always usc the most approvedmethods, but must rather obtain immediate results with materials andmeans at hand.Maggot Traps.-Hutchison discovered an application of the habitof the fly maggots of migrating from the manure piles before pupation,when he developed the maggot trap which consists of a slatted platformover a cement or metal water-filled basin (fig. 3~). Such platforms canbe built of sufficient size and number to hold the accumulations ofmanure for a period of about two weeks, after which time it is unfavorablefor house fly development. The larvre migrate from the pile and fallinto the water and drown (plate VIII).Storage in Bins.-The house fly is averse to darkness and variouscontrivances have been devised for the dark storage of manure, in pits,tightly closed boxes, windowless rooms, etc. (see plate V). For smallstable accumulations, especially in cities, perhaps this furnishes one ofthe best means of temporary storage. It is a good plan to use fly trapsin connection with manure bins (see fig. 33).Stacking.-Manure may be stacked in such a way as to greatly minimize,if not entirely prevent fly breeding. A stack built up by the drivingof the wagons over the pile and dumping thereon becomes very compactand the internal heating is quite destructive to the fly larvre. The sidesof such a pile should be compacted and the loose materials on the ground

CONTROL OF THE HOUSE F~Y AND RELATED FLIES 155IG. gg.-A maggot trap for house-fly control. View of the maggot trap, showing theconcrete basin containing water in which larvae are drowned, and the woodenplatform on which manure is heaped. (Hutchison.) From U. S. Dept. Agr. Bull.gOO, plate 1 (larger), or farmer's bull. 851, fig. 14 (as above).PLATE V.-Manure box with fly trap attached.(Bishopp.)

156 SANITARY ENTOMOLOGYthrown onto the pile or raked up and burned. The edges of the pile andthe ground around it may be treated with borax or oiled with creosoteor crude oil.In Panama it is a custom to set fire to the manure pile and burn itdown about a foot, thus cove'ring the entire pile with ash.Broadcasting.-Oftcn on farms it is practicable to take the dailyaccumulation of manure and spread it over the fields. When the weatheris dry, or very hot, or too cold for fly breeding, this method is a verydesirable means of handling the manure problem, but the broadcastingof fresh manure on moi'st ground in cloudy or moist weather may give riseto great quantities of flies unless it is spread very thinly and the larvreare not well matured when the manure is scattered. An illustration of 11manure spreader is give~ in plate VI. An undesirable method of spread.ing manure is shown in plate VIII.Collection of Manure.-It is important that manure be colleded· andremoved from the vicinity of habitations at regular periods, sufficientlyfrequent to remove the possibility of its becoming a source of fly breeding.In army camps it is imperative that manure be daily removed from allstables, picket lines and stable yards. In cities the ordinary accumulationsof private stables should be required to be removed once each week,but in the meanwhile it must be either stored in bins or on maggot traps,or daily treated with borax. The accumulations of large stables, liveryand feed stables, stockyards, etc., should be required to be removed daily.We may obtain some of our best illustrations of the proper handlingof manure from anny practices followed during the Great War. Annydiscipline makes it possible, when the command is properly educated tothe importance of it, to control the manure problem more effectivelythan under any other condition on a large scale. Tremendous quantitiesof manure wcre produced in cantonments and shipped in car or trainloads daily. Most of the larger cantonments that were located in progressiverural sections were able to fann out the manure to individualfarmers or to sell to contractors who shipped it by the carload dailyand distributed it to the rural population. ~en unable to do this thearmy officials were compelled to resort to storage or destruction of themanure as discussed in other paragraphs.Loading platforms for shipment of manure need to be carefullywatched and kept under strict supervision. If these platfonns are looselybuilt of framework elevated above the cars, much of the manure fallsthrough the cracks and over the edges, and great accumulations arise atthe sides 'of the tracks and between the tracks. A properly constructedloading platform should have a cement base with the tracks imbedded-inthe cement and should be daily flooded, the washings being swept intopiles and oiled, and burned when dry enough. The writer has found the

CONTROL OF THE HOUSE FLY AXD RELATED FLIES 157l?w. 33.-Use of fly trap in connectiongwund to which lever raising doorU. S. Dept. Agr., No. 734, fig. 6.• I •: J •" .~./with manure bin. A.is hinged. (Bishopp.)Block of wood set inFrom Farmer's Bull.,PLATE YI.-':'\lanuTc "prcadel' (Bisbopp.)

158 SANITARY ENTOMOLOGYaccumulations under loosely built platforms to be a fertile fly breedingcondition.Shipment of Manure.-When manure is shipped by car, the railroadsshould be required to rcmovc it promptly and the contractors should berequircd to unload promptly and distribute it in such a manner that itwill not be a sourcc of flies to thc community wherc it is unloadcd. Ifunavoidable q,elays do not permit prompt handling of this manurc, itshould bc trcatcd with borax watcr.Cleaning Up.-Wcll drain cd ccmcnt floors in stablcs are by all meansthe most sanitarv and lcnd themselvcs best to cleanlincss. If it isimpracticable to havc c~mcnt floors, the dirt floors should bc sloped todrain wcll and should bc madc hard by saturation with oil or mixingwith other s·oils which pack bettcr, as certain types of clay. The floorsshould be swept daily after removal of the manure, and sprinklcd with'borax watcr, or limcd. Frequcnt trcatment with a creosotc compoundis of valuc. Thc ground around hitching posts and pickct lincs becomessoggy with urine and manure, unless treated by digging up the soil forsevcral inches and saturating it with oil, and then tamping it hard.Stable yards should not be allowed to bccomc filled with manure. Theyshould be swept, or rakcd or scraped up daily and the manure removed(sec plate VII). A filthy stable yard may be thc sourcc of scourges offlies.Indneration.-When manure cannot be sold, chemically trcatcd,farmed out, or stacked to prevcnt fly brecding, it must be burned. Thisis often a neccssity in army cncampmcnts. In dry sections the windrowincineration may be practiced. The teams drop their loads in great,long windrows, the horses straddling thc rows. Thesc are spotted withoil and set afire. The wooden chim.ney windrow which was practiced atEdgewood Arscnal consists of a windrow of logs piled to form a horizontalchimney ovcr which thc manurc is piled and then fire is set to the wood.The hillside incilierator dcvised by Dr. Mann at Quantico, Virginia,consisting principally of iron rails and chicken wire screen or gratingsunder which a fire is burning, is practical for small camps. The hammockincinerator, a woven wire hammock or two suspc~ded ovcr a fire, willdo as a temporary cxpedient for a small detachment on temporary duty,or for field parties of hunters or investigators. Furnace incinerators canreduce the manure to an ash and save whatever is of value in the ash.Need of Rigid Inspecti(.Jn.-It is not only army camps that needto have a rigid inspcction system as regards manure disposal. Every citywhich has any regard for the public hcalth should insist on properinspection and regulation of stablcs and places whcre manure accumulates.It is not uncommon in many cities to sce boxes of manure in allcys swarm-

CONTROL OF THE HOUSE FLY AND RELATED FLIES 159PLATE VII.-Road dra,g in use scraping manure in a cow lot on a Tennessee farm.(Bishopp.)PI. ATE VIII.-Undesirable conditions which are overcome by use of the maggot trap.A manure pile covering a large area and having little depth. Illustrating theconditions which favor the greatest loss of nitrogen, and at the same time offerthe best breeding ground for flies. (Hutchison.) From U. S. Dept. Agr. Bull.BOO, Plate III.'

160 SANITARY ENTOMOLOGYing with fly larvre, or to find piles of manure standing for weeks in frontof livery stables, even on the sidewalks.In one small city, the' writer, in passing by a side track where certaingrain companies unloaded straw and feed, using horse drawn wagons~noticed that the ground along these tracks was a thick mixture ofrotting straw, grain, .and horse droppings. This was across the streetfrom the eity market where flies were swarming in the fish stalls especially.Only a personal tour of inspection by a trained observer would turnup many of the most imllortant sources of fly breeding.GarbageNeedless to say it is necessary that garbage be kept in fly-tight canltand that it be removed daily, or every third day when the amount issmall. The army method of building a screened box for holding theFlO. 84.-Top of garbage can with small balloon fly-trap attached.(Bishopp.)garbage cans is very good, and would be an excellent plan for hotels andrestaurants especially. A fly trap on a garbage can will catch manyflies (fig. 34). Empty garbage cans are very attractive to flies. Thewriter has seen many wagons full of cmpty cans which had been washedin lye water, swa,rming with flies, returning to camp. It is, necessary towash the cans in a creosote compound. Householders are very carelessof the cleanliness of their garbage cans. If thcy ~an not wash them theycan rinse them with a hose and treat with a creosote compound or lyewater. When garbage is farmed out for feeding to pigs the farmersshould be bound by contract not to take more than their pigs can consumein a day. The feeding pen should have a cement foundation so that itcan easily be cleaned. The remains of the day's feeding should be burned.Many municipalities, as well as army camps, dispose of the garbage byincineration. Others sell to contractors for reclamation. Some parts ofthe garbage are not of value for feeding or reclamation and the writerhas seen instances where such material was thrown on dumps with tincans and trash and not burned. Great vigjlance is necessary at aU waste

CONTROL OF THE HOUSE FLY AND RELATED FLIES 161dumps to see that no fly-breeding material is dumped anywhere except oninciilera tors.Grease traps at kitchens of mess halls, and at garbage can washingplatformsare attractive places for fly breeding and should be kept cleanand treated with creosote compounds.ExcretaThe disposal of human etccreta is a great problem in all communities,but becomes acute in army and construction camps and at campingresorts. In temporary army camps where latrines are necessary, theexcreta must be disposed of daily. The excreta may be saturated withoil, covered with straw and burned daily. They may be treated withlime or borax or creosote, and buried, gradually mling the latrine. Theymay be removed daily, hauled to an incinerator and burned. Private andpublic camping grounds should be as carefully protected in this manneras an army encampment. Probably much education is necessary toaccomplish this practice. When a sewage system is available, the diffi··culties are less, but care must be exercised to maintain the sewers in goodrepair. If a manhole does not operate properly and sewage accumulateson the walls, flies will breed there. If the main leaks and washes awaythe covering soil, flies will breed in the seepage. The writer has personalknowledge of just such insanitary conditionfj. At some point in thesystem, unless septic tanks are installed, the J!ew'age will empty into astream. The stream bed must be kept free of obstructions, with straightbanks. Notrees, shrubs, grass or other obstacles must interfere withthe steady flow of the sewage, for behind every branch, or roof, or weedsolid excreta will accumulate and flies will breed. In case excrementaccumulates in spite of all vigilance, it should be oiled, burned off andmoved on with all expedition, immediately upon discovery. The mostrevolting sight the writer has ever experienced was caused by the dammingun nf a sewage-carrying stream, causing a tremendous accumulation ofsolid excreta which was. fairly alive with wriggling maggots and blackwith swarms of flies, and this was but a scant quarter mile from aa great army camp, and typhoid fever was present. Only quick measuresaverted an epidemic.CarcassesBodies of animals offer grent opportunities for the breeding of llJ.anyspecies of flies and especially for the spread of disease. Carcasses shouldbe removed as soon as possible after discovery. The best way to disposeof them is to burn them. If they cannot be burned they should be treatedwith quicklime and buried. On the battlefield it is often impossible to

162 SANITARY ENTOMOLOGYbum or bury. Foreman and Graham-Smith have ably shown the valueof coal tar creosote oil as a deodorizer, preventive of decomposition, andBy destroyer in carCaSses. This subject is fully treated by Mr. Bishoppin the chapter on myiasis (Chapt~r XIII).Miscellaneous breeding placesFactory waste, rotting vegetable matter, the accumulation of debrisalong shore line!!, chicken yards, pig pens, alleys, streets which are notswept, gutters, etc., furnish fly-breeding places (see Chapter XI). Mr.Laake's able presentation Of packing-house problems in another lecturecovers that subject sufficiently (see Chapter XXXIII).PALLIATIVE MEASURESIn view of the fact that flies can come great distances, possibly evenover 50 miles as indicated by Ball at Rebecca Shoal, the sanitarian is notalways responsible for all the flies that visit the locality under his ju.risdiction.There is therefore always the necessity of taking measuresagainst the flies themselves, although this is entirely sec,?ndary to theprevention of breeding.Screening.-All foods must be protected from flies because many ofthe flies which visit foods lay eggs therein.· This is especially true ofmeats which are attacked by blow flies, and cheeses which are attackedby skippers. City markets should not expose meats for sale uncovered, asthe attraction to flies is too great. ' A well-screened house will have theleast trouble from flies. In army camps anywhere in the United Statesall sleeping quarters, kitchens, and mess halls should be well screenedagainst flies. All hotels throughout the country, especially in rural communities,should be required to screen all windows and doors.The fly situation around small country hotels is by far the mostrepulsive that can c,rdinarily be found in any community. Very little,if any, care is taken of the privies and the flies come directly from thereto the kitchen and dining rooms. .Screening of garbage cans has been mentioned and is an admirableprocedure. A screened enclosure around privies and latrines would assistin keeping flies away.Fly Traps.-Fly traps of many different designs have been devised.The most efficient is the cone and cylinder type devised by Bishopp (fig.35). The Hodge window trap is good. A small cone and cylinder trapmay be inserted in the lid of garbage cans (fig. 34). The principle of alldifferent traps is the attraction of the flies by a good bait, and thearrangement of the trap so that once there the fly can' not get away. At

CONTROL OF THE HOUSE FLY AND RELATED FLIES 163all places where flies congregate, as markets, eating places, packinghouses, etc., the liberal usc of good fly traps is a very good measure. Asbaits for such traps the following suggestions have been made.1. Milk.!!. Overripe or fermenting bananas, crushed and placed in the baitpan.3. Bananas and milk are better than either separately.4. A mixture of S parts water, 1 part molasses, is good after it hasfermented for a day or two.FIG. S5.-Conical hoop fly trap; side view. A, Hoops forming frame at bottom. B,Hoops forming frame at top. 0, 'rop of trap made of barrel head. D, Stripsaround door. E, Door frame. F, Screen on door. 0, Buttons holding door. H,Screen on outside of trap. I, Strips on side of trap between hoops. J, Tips ofthese strips projecting to form legs. K, Cone. L, United edges of screen formingcone. M, Aperture at apex of cone. (Bishopp.) From Farmer's Bull, U. S.Dept. Agr., No. 784, flgs. 5, 1.5. A mixture of equal parts brown sugar and cheese or curd of sourmilk, thoroughly moistened, is good after it has been allowedto stand three or four days.6. Mucous membrane from the lining of hogs' intestines is attractiveto blow-flies and other meat-infesting flies, as well as the housefly. This is available for fly traps at packing houses.7. Ordinary fish and meat scraps.S. Moistened garbage.These baits are of little value if allowed to dry out. It is not uncommonto sec fly traps standing out in the sun near garbage cans, with noflies within but plenty of flies around, and the bait dried out by thesun. The fly trap must be more attractive than its surroundings. Whenbaits are used which will permit of the development of maggots in them,

164 SANITARY ENTOMOLOGYthe pans should be scalded and then emptied, and rebaited, every threedays.Fly ·Paper.-Sticky fly' paper has distinct merits and in the presenceof abundance of flies should be· used. The hanging pyramid strips areconsidered better by some saniturians than the fiat papers.Poisoned Baits.-Many fly poisons are on the market. Any kind ofpoisoned bait is dangerous in the presence of children or ignorant personsas there arc many reco'rded fatalities to children from drinking fly liquidsor licking poisoned papers. .Phelps and Stevenson,,1917,2 have given a very thorough presentationof the question of fly poisons. Their bulletin should be consulted by anyone desiring to go very far into this phase of the subject.The most efficient strength of formaldehyde is 0.5 to 1 per cent, whichis equivalent to 1.~5 to ~.5 per cent of the 40 per cent solution sold asfonnalin.A muscicide considered by them as even superior.to formaldehyde inmany ways is an aqueous solution of 1 per cent sodium salicylate plus 10. per cent brown sugar.They used sodium arsenite as the basis for their experiments. Thiswas made up in stock solution as follows:• Dissolvr 4.95 gra"!s pure sublimed arsenious oxide AS 2 0 3and ~ograms prl~e sodium carbonate in about 300 cc. of distilled water by heating.When the solution is complete the' liquid is cooled to ~oo C.and the '!"'olume made up to 1,000 cc. with distilled water. Ten cc. of thestock solHion are diluted to 1,000 cc. with distilled water and this iscalled by h 'II the standard arsenite solution, or one-thousandth normalsolution.Sodium flu,nide solution, 1 per cent, gave a mortality equal to thatof the standard trsenite solution.An interesting feature of their investigation Was the reduced effectivenessof these poisolls with lowered temperatures.Fly Sprays.-In .:'he armies flies often congregate in tremendousnumbers and some ki. -I of spray is necessary to kill them.Lefroy handed me the following formula:1 tablespoon formaldehyde.1h pint lime water.1h pint water.MaxwellKirk recommends as a spray in latrines and tents a light oil mixedwith three or four parts of water well shaken. Rubber tubing should.not be used in the spray. A coarse atomizer such as is used in greenhousesis serviceable.• Experimental Studies with Muscicides and Other Fly Destroying Agencies, HygienicLab., Bull. 108.

•CONTROL OF THE HOUSE FLY AND RELATED FLIES 165Bacot recommends a kerosene emulsion of 3 parts soft soap completelymelted by heat in 15 parts of water and the addition up to 100parts of kerosene or other light burning oil, and churning up to anemulsion. This may be kept indefinitely and diluted with water to about1 part emulsion to 10 parts water content.Protection of Animals.-Animals are seriously bothered by the pesteringof flies. Any kind of netting that the animal can shake to disturb theflies is of some value. The question of repellents is one upon which manyinvestigators have labored. Graybill, 1914,8 summarizes the results ofthese investigations. Those formulae most in use all contain crudepetroleum oil and usually soap.A good stock emulsion recommended by Graybill is made of:Hard soap, 1 pound,Soft water, 1 gallon,Beaumont crude petroleum, 4 gallons,Dilute to 1 part emulsion to 3 parts water.Bishopp's fly repellent consists of:Fish oil, 1 gallon,Oil of tar, ~ ounces,Oil of pennyroyal, ~ ounces,Kerosene, 1/2 pint.For dairy cattle, Jensen makes a stock solution of crude ~ etroleumwith the addition of 4 ounces powdered napthalin, and applies with abrush once or twice a week.Jensen has also given three formulm of repellents for ,J?l1"otectingwounds from flies.Formula No.1:Oil of tar, 8 ounces,Cotton seed oil to make 3~ ounces.Formula No. ~:Powdered napthalin, ~ ounces,Hydrous wool fat, 14 ounces,Mix into an ointment.Formula No.3:Coal tar, 1~ ounces,Carbon disulphid, 4 ounces,Mix; keep in a well stoppered bottle and apply with a brush.It is of the utmost importance that flies be kept at a minimum in armycamps. We can do no better than cite a few authorities of the variousarmies in support of this. Ainsworth considers the presence of the housefly the greatest danger signal to an Ilrmy in the field. Savas has cal,led• Repellents for Protecting Animals from the Attacks of Flies, U. S. Dept.Agr. Bul. lSI.

166 SANITARY ENTOMOLOGYattention ·to the connection of flies with the great cholera outbreak in theGreek anny. At Gallipoli the flies were in amazing numbers, the food \vasblack with them as soon as it was set on the table. They filled the tentsand shelters, settled on the refuse of the camp, and on the unburied dead,and by their annoyance multiplied the sufferings of the wounded andspoiled the tempers of the hale. The flies have been very bad in France.Kirschner states that in the hospitals near the front the enormous numberof flies presented a serious danger. Maxwell-I.efroy says that in Mesopotamiathe tents and trenches were full of flies. 'rhe troops at Salonikasuffered greatly from diarrhea and dysentery which coincided in appearancewith the abundance of flies. Wenyon and O'Connor found flies illEgypt largely responsible for outbreaks of amoebic dysentery among thetroops. In this connection Dr. Ballou's lecture on flies and lice in Egypt(Chapter XXXII) will give an excellent first-hand view of conditionsin that country.

CHAPTER XIControl of Flies in Barn Yards, Pig Pens and Chicken Yards 1F. C. BilhoppThe question of the control of flies in their various breeding media orplaces of breeding can not be well divided in the discussion. Attentionhas been given in a previous lecture (Chapter X) to the general aspectsof house fly control and the most favorable breeding media and methodsof handling them have been discussed in a general way. Therefore 'I shalltake up the special prob1ems under the three situations listed in thetitle. Adequate care of the manure and other refuse in these situationswill not only result in the prevention of breeding of house flies in thembut will also reduce the number of certain other flies which playa part indisease dissemination among man and anima1s, notab1y the horn fly, stablefly, l\iuscina spp., Fannia spp., certain Sarcophagids and lesser number&of Muscidae known as blow flies, which occasionally breed in hog manureand freely in unconsumed animal matter in garbage.REPRESSION OF FLIES IN DARN YARDThe discussion of this problem is bound up closely with that of thecontrol of the house fly through the care of horse manure, etc. Ifmanure is promptly disposed. of as removed from the barn the yards arekept in better condition and th

168 SANITARY ENTOMOLOGYdifficulty has been that stock are often kept in a single pen for feedingfor some time and during this time it has been the rule not to clean up thepen. The provision of ample room sp that stock may be removed from onepen to another to permit cleaning is important. This also applies tohorse and mule sales stables. The restrictions placed on the horse andmule dealers who handle stock for the army have tended to greatly improvefly breeding conditions in these stables and yards. I have frequentlyobserved these sales stables to be filled with tightly packed manure fromeighteen inches to three feet deep. In the case of an East St. Louismule sales stable where one' company has thirty-five acres under cover,the removal of all this manure was an enormous task. Yet it was accomplishedso that the company might continue handling stock for governmentuse. The manure was hauled several miles to a fertilizer plant wherethe well decayed part was piled and subsequently dried, ground and soldas sheep manure for lawn dressings, \.-hile the parts with considerablestraw were thrown from cars onto rail incinerators and burned, the ashbeing used in fertilizer mixtures. The entire barns and fences were thengone over with a sand blast machine which cleaned them of all accumulationof dust and saliva which had in some cases become quite thick andhighly glazed. An effort is being made by the authorities in charge tohave the manure fr!>m these stables throughout the country moved atweekly intervals.The drying of manure and its sale in powdered condition for lawndressings, etc., has attained rather large proportions as a commercialenterprise in some of the large cities. This is a satisfactory means ofdisposal of manure and there are good reasons 'why the practise shouldbe extended.It appears that where shavings are used for bedding less troublearises from fly breeding than where straw is utilized. This wouldundoubtedly favor reduction in the breeding of Stomoxys also.Returning to the question of handling manure in cow lots and smallbam lots, it is advisable when labor is at hand, especially in dairy yards,to J-ick up the droppings daily or even twice a day. This is greatlyfacilitated by having the yard where cattle congregate in greatest numbersconcreted. In large dairy lots it has been found feasible to bringthe manure together by means of an iron road drag ( see plate VII). Thisleaves the manure in windrows so it can be easily shoveled into a wagon.For the disposal of manure from dairies and even on the fann nomethod is better than the use of a manure spreader (see plate VI) andthe scattering of the material thinly on open fields. Of course in caseswhere all land is cropped it is not convenient to employ this method duringcertain parts of the year, although it is usually possible to have oneportion of the farm ~vJljlable for manurIng at all times.

CONTROL OF FLIES IN BARN YARDS AND PIG PENS 169The use of manure pits and boxes has been mentioned in a previouslecture, as has also the Hutchison maggot trap. It appears to thewriter that any attempt to construct pits or boxes which are so tightas to prevent the escape of newly emerged flies is likely to meet withfailure. In practically all instances the manure is infested more orl.ess when placed in the box or pit, and following this suggestion thewriter has been advocating the placing of the manure in boxes and pitswhich will not allow flies to gain entrance from the outside and which.are provided with a cone or tent trap to capture the flies which breed out(see plate V). In the absence of the trap feature these would almostsurely escape to the light from the most ti~htly constructed box or pitwhich it is feasible to build and maintain. A manure box of Jhistype has been tried by the Dallas laboratory and found to work admirably.The number of flies caught is often surprisingly large.For small pastures and meadows it is sometimes feasible to utilize abrush drag to break up the cow droppings. This serves three purposespreventingthe breeding of the horn fly, scattering the manure evenlyover the ground, and permitting the grass to grow where it would otherwisebe prevented by the piles.While the house fly does not breed readily in pure cow manure thewriter has reared the species from this substance and has also foundthat where cow manure is mixed with a certain amount of straw it is afairly good breeding medium for this species. The horn fly, Lyperosia.irritans (Haematobia) Linnaeus, breeds exclusively in cow droppingseither in large piles or individual droppings. Blow flies are not known tobreed in cow manure, but a number of species of Sarcophagids, most ofwhich, however, do not have scavenger habits, breed in considerable numbers.The brilliant green fly, Pseudopyrellia comicina Fabricius (plateIII, fig. 4), is very commonly seen on fresh cow droppings; in fact this isusually the most abundant species in this situation in the country. Itmay ·be readily mistaken for Lucilia when not examined carefully. Thisspecies is of no importance as a human disease carrier as it does notenter '}lOuses or visit food. 2In preventing flies breeding in yards it is very essential that watertroughs be kept from running over and whenever overflows or leaks dooccur they should be fixed promptly and the moistened manure and earthcleaned up and hauled away immediately. Special attention should begiven to accumulations of horse manure in yards along feeding racks.Here the mixture of horse manure, waste hay and urine forms a satisfactorymi~ture for fly production.I Unquestionably its larvae must have an important rlile as regards organisms takenup from the manure and passed through their bodies, but whether this rlile is to destroythe organisms or to propagate and distribute is yet to ·be learned.-W. D. Pierce.

170 SANITARY ENTOMOLOGYThe use of larvicides and other chemical compounds in barn yards isusually inadvisable. Thorough cleaning ordinarily will ha,ndle the situation.Crudc oil has been used in yards where considerable numbers ofhorses are kept to pElrmit firm pa,cking of the ground and keep downdust in dry weather. Borax, either dry or in solution, may be used inbreeding places which can not be cleaned thoroughly. Poultry and hogsconsume large numbers of larvre and pupre and scatter the manure so itwill dry out rapidly. These agencies should not be depended upon, however,to effect control.The employment of conical fly traps about st,ables and dairy barns,if they are kept properly baited, will aid in reducing the number of houseflies. Cheap molasses and water (1 to 3), or milk curd, brown sugar andwater in equal parts form good baits. The latter, if kept moist, willremain attractive for two or three weeks. It is comparatively unattractivefor the first few days. Hodge type window traps aid in reducing thehouse fly and stable fly troubles within barns if the barns are closelybuilt and the other windows ,darkeIJed or screened.FLY CONTROL IN PIG LOTS AND PENSThe hog has been looked upon from time immemorial as a filthy animaland he is usually compelled to live in surroundings which would neverbe tolerated for any other beast. .One of the special problems which confronts the municipal and thearmy sanitarian is the utilization on a large scale of .city and campgarbage by hog feeders. There appears to be no more economical way'of disposing of garbage than by this method, but the conditions underwhich the feeding is to be done must be given strict attention by sanitarians.In the vicinity of nearly every city and large army camp islocated one or more of these garbage feeding plants, the number of hogsranging from a few hundred to several thousand. For the most part thegarbage is sold to feeders under annual contract. Army garbage atleast is supposed to be free from glass, cans, coffee grounds, and liquids.The contractors furnish the garbage cans, remove the garbage daily andreturn empty cans which are supposed to be thoroughly cleaned. If theorange, grapefruit, and lemon peels could be eliminated from the garbage,the mass of material not eaten by the hogs would be materially reduced.Garbage feeding plants should be operated under approximately thefollowing set of rules:1. Location of Feeding Stations.-Station should be located as farfrom habitations as possible and also well 'removed, two miles or more, fromthe city limits or the precincts of an army camp. Our recent experimentsshow that flies of various species, including the house fly, travel thirteen

CONTROL OF FLIES IN BARN YARDS AND PIG PENS 171mjIes or more under rural conditions, but that there is a rapid declinein the number of flies which reach points two miles or more from thesource of production. It is also desirable that the pens be located aconsiderable distance from main highways, as passing vehicles h~lp todisseminate the flies.~. DraVnage.-Adequate drainage is essential. It is preferable tohave hog-feeding stations located on hilly ground Ilnd never on flat areas.3. Adequate Room.-In feeding garbage it is essential in order tomaintain sanitary conditions that the hogs be given a considerableacreage. I would place this at a minimum of 2~5 sq. ft. per hog, orapproximately 190 hogs to the acre. Of course as a general principle infattening hogs it is considered necessary to reduce activity by closepenning. It has been proven, however, that hogs make satisfactory gainwhen heavily fed if kept in large pastures .•FlO. S6.-Plans of open hog-feeding trough.(Bishopp.)4. Feeding Troughs and Platforms.-Concrete feeding troughs andplatforms are essential under present inadequate labor conditions. Anumber of forms of troughs and platforms may prove satisfactory froma sanitary standpoint. In some cases feeding floors are used without anytroughs but this necessitates daily cleaning. Under outdoor conditionssuch as exist in the South, it is advisable to locate the feeding troughs onland with pronounced slope. A simple form of construction consists of aconcrete platform about 15 feet wide, length in proportion to number ofhogs (fig. 36). This should have a backward slope of about 10 inches.The trough can be formed by setting a plank on edge in the concret;eabout three feet from the upper side and parallel with it or by a concreteridge several inches high to f6rm the lower edge of the trough. Theupper edge of the platform should be raised so as to prevent water fromwashing into the trough and the feed racks to receive the garbage shouldbe constructed over the front edge of the trough in such a way as to

l7~ SANITARY ENTOMOLOGYreceive all drip. The lower side should be provided with a concrete ridgeprojecting about five inches. This edge along the back will hold mostof the unconsumed garbage, bones, e~c., as they are worked backward, andfacilitates thorough cleaning which should be done at not to exceed threedayintervals.5. Shade.-If location with plenty of trees can be chosen, this ispreferable to sheds for protection from the sun. Where sheds are neededfor protection either from sun or rain, they sh,ould be built on well drainedland and never placed over the feeding troughs. They should be sevenfeet above the ground so as to permit of easy cleaning. Temporary~shade can be constructed extending a few feet over the trougha if desired.6. Contracts.-Annual or longer contracts with thE!' Army or with-eml1icipalities are far more desirable than monthly contracts as they enablethe contractor to put up proper feeding facilities which he would notdo under short contracts. Contract!! should specify the character of feedingarrangements and penalize failure to keep the premises in satisfactorysan~tary co~~ition. The pens should be given frequent inspection bysamtary .officers.7. CleOlTliJn{J of Yards.-In addition to the cleaning of the ~:tteOnsumedgarbage from feeding platform the manure should be scraped upand disposed of, especially during rainy weather. During h9t dr~weather where ample pasturage is used manure is the source of verylittle fly trouble.8. Disposal of Bones.-Bones which are not retained on the feedingplatform and thos'e which are mixed with uneaten garbage pT')uld becollected at four-day ·intervals and placed in fly-proof bone rac~'. .Thesecan be built of lumber and screened on the outside and proyided withny-proof cover. It is desirable that the bones be removed entirely fromthe premises at frequent inte_-vals.9. Avoidance of Transporting Flies on Vehicles.-If garbage cansare properly cleaned there is less tendency for,flies"to follow them than ifleft dirty. Washing in a modera.tely weak solution of cresol tends torepel flies from them. The trucks should ~ washed off' occasionally.There is less danger of flies .following trucks back to camps when they areprovided with covers.,10. Q'lbOITbtity Fed.-Feeding so much ga;:.bage to hogs that it willnot be cleaned up should be discouraged.11. Final Disposal of Hog Manure and Unconsumed Garbage.-Thismaterial may be scattered thinly over cultivated ground and exposedto the sun or promptly plowed under. Where material is found to beheavily infested with maggots, it is advisable to dump it in piles some distancefrom the feeding plant and treat it with borax solution. About onepound of borax should be used to each 8 bushels. If the mass is very wet

!CONTROL OF FLIES IN BARN YARDS AND PIG PENS 178the borax may be applied dry, but if the material will absorb liquid theborax should be dissolved in water at the rate of one pound to fivegallons and sprinkled over i~.U. Del],d Hogs.-Dead hogs should be promptly disposed of either~ burning on the ground or by hauling to rendering plants.\13. Treatment of Hog PooS Where Flies Are Breeding.-All manureshould be scraped up thoroughly, holes cleaned out and the groundsprinkled with borax solution made as above. The holes should thenbe filled and packed; crude oil will assist in this. Lime has little value indestroying fly maggots but will tend to dry up moist areas and reduceodor. Ringing the hogs' noses reduces the number of holes formed andis said to help keep them quiet in fattening.Fly Traps.-Each hog-feeding establishment should be provided witha number of well constructed fly traps, preferably of the conical type,and k~pt well baited. Black strap molasses and water at the rate of 1part molasses to three parts water may be used as bait, or 1 part darkbrown sugar to 1 part vinegar and 8 parts water may be used. The trapsshould be set in situations where flies fend to congregate and away fromdanger of being disturbed.Hogs should not be tolerated in towns or cities. On farms the samegeneral rules for elimination of fly troubles should be followed as appliedto garbage-feeding stations. Fo"!; brood sows, good, dry, clean housing isessential from both the fly control standpoint and that of successfulbreeding.PREVENTION OF FLY BREEDING IN CHICKEN HOUSES AND YARDSComparatively little attention has been given to control of flies inpoultry houses 'and yards. This source of fly breeding is one which shouldnot be ignored as it is present even in far more premises than are manurepiles from horses and cattle. Several species of flies breed in chickenmanure, but the house fly, stable fly and lesser house fly seem to predominate.The writer has found many cases in the South in which thesespecies oI!!eemed to be passing the winter in chicken manure. This appe'lPto .be a favorable place for the larvre to pass the winter as littleheat is; generated to hasten transformation and sufficient protection isaffordet; to prevent the destruction of the immature stages by cold.With small flocks of poultry in the back yard the prevention of flybreeding l~ not difficult but is very likely to be neglected. We have foundthat flies w;ll breed in rather small accumulations of chicken manure ondropping bd'.uds but are produced in greatest numbers if the accumulationsare on ~he soil itself. The weekly cleaning of all excrement fromthe dropping hoards and floor is sufficient to prevent fly breeding. Usually

174 SANITARY ENTOMOLOGYit requires more than a few days' droppin_gs to produce a very favorablebreeding situation. The cleaning of houses is of course facilitated byhaving the dropping board~ readily removable or the roosts hinged so asto give free access to the boards. In the South, dropping boards are notbeing advocated and very few places are provided with them. In suchhouses a concrete floor is very desirable to make cleaning easy, but seldomfound. Sprinkling the aropping boards or floors with air-slaked lime ordry sand helps to take up the moisture from the manure and reduce theattraction for flies.In small places where gardens are available chicken manure can beused to advantage as fertilizer. Where it cannot be disposed of in thisway promptly it should be placed in a box under cover from rain andtreated with borax as previously recommended.Dead fowls breed many dangerous species of flies and they s_hould bedi~'osed of promptly either by a scavenger wagon in a city, or by burningin rura.l districts.The care of yards and houses on large poultry farms shoulq behandled in practically the same way as the small one just discussed ..There is usually less trouble, however, from tbese large plants as theyreceive more constant attention than the small ones. Pigconries are alsoa source of some fly breeding as the pigeon co,?ps usually are placed in aninaccessible place and become very filthy. The houses should be madereadily accessible and cleaned occasionally. Pigeons should be kept undercontrol, and porcelain dishes provided for nests will facilitate cleaning.The frequent and thorough cleaning up of the manure from all domesticanimals and fowls tend to reduce the troubles among them from intestinalparasites. Spraying with standard disinfecting solutions has theeffect of reducing the attractiveness for flies, of excrement, soiled floors,etc., in addition to the germicidal action. Cleanliness;;;,nd spraying ofpremises also increase the efficiency of fly traps.

CHAPTER XIIMyiasis-..-Types of Injury and Life History, and Habits of Species.... Concerned 1F. C. BishoppMyiasis is a term applied to·the attack of living man or animals hy flylarvre. The medical profession usually assigns specific names to theinfestations according to their locatitvt-as dermal (in or under theskin), nasal (nose infestation), aurichlar or otomyiasis (ear attack),intestinal, etc. These names are not entirely satisfactory as often oneform will develop into another or one species of larvre may be concernedin attacks in many different regions. And again several species mayattack the same region but produce different types of iitjury, or thepoint of attack may vary with the stage of the larvre.Any attempt to classify the different types of myiasis according tocharacter or place of attack or species of fly concerned seems to haveits objections and difficulties. For convenience in discussion an attemptis made to divide the subject from the standpoint of method of attackinto the following groups: .First, TISSUE-DESTROYING • FORMS, including those specieswhich are ravenous feeders and destroy living tissues. For example thescrew-worm, Chrysomya macellaria Linnaeus. The species which areincluded in this group with the exception of W olUfahrtia magnificaSchiner attack living animals secondarily, the main source of breedingbeing in dead animal matter.Second, SUBDERMAL MIGRATORY FORMS which are parasiticin animalS' or man and occur during the major part of their lives be~eaththe skin. For example, the ox warble, Dermatobia or "torcel," inman, etc.Third, LARV.tE INFESTING THE INTESTINAL OR UROGENITAL TRACTS. These usually feed to a lesser or greater degree on foodor excrementitious matter within the body. For example the larvre ofthe latrine flies of the genus Fannia and of certain flesh flies of the familySarcophagidae. Infestati9ns largely accidental, except horse bots andrelated species in animals which are truly parasitic.Fourth, FORMS INFESTING HEAD PASSAGES. True parasites1This lecture was presented November 18 and distributed December 20, 1918.175

176 SANITARY ENTOMOLOGYof animals or man occurring in the head sinuses, throat, or occasionallythe eye. For example, the she~p bot, Oestrus avis Linnaeus, and the deerbots, Cephe'llomyia spp.Fifth, BLOOD-SUCKING SPECIES. Highly specialized forms withblood sucking as a normal habit, exclusi,·cly parasites of mnn or animals,such as the Congo floor maggot attacking man, and larvre of the genusProtocalliphora attacking birds.Myiasis is caused by many species in several families. 'rhe habits,in regard to myiasis, of ~he species of any single family vary widely asmight be expected in groups which have become more or less specialized.For instance, the family Oestridae, which is the only family having all itsspecies concerned in myiasis, has members which infetlt the stomach, ot.herswhich develop in the nasal passages and still others which produce •cutancous myiasis. The family ~Iuscidae also exhibits very diverse habitsin this regard, some members being concerned in destructive myiasis,others in specialized dermal cases and still others arc blood suckers.Myiasis in animals is not generally considered in connection withhuman cases. There exists, however, a very intimate interrelationship;in fact, the prevention of myiasis in man is largely dependent upon thecontrol of the trouble in animals. Entomologists- engaged in sanitarywork must be prepared to handle insect attack on animals as well as onmM.iOwing to the need for careful determination of the exact species coneernedin cases of myiasis, both for the immediate needs of the cnse and forthe benefit of science, it is highly desirable that the larvre concerned bebred to adults whenever possible. Specific determination of the larvre,especially when small, is, to say the least, very difficult, but a few shouldbe preserved in alcohol for record and future identi6cation when larvalcharacters are better understood. Some suggestions as to breedingmethods arc apropos. There is no u!>c endeavoring to rear Oestrids afterextraction unless well matured. Most of the larvre from wounds willusually develop on beef. Care must be exercised in rearing the flies toavoid infestation of the material by other species, especially Sarcophagidswhich will drop larvre through screen wire onto meat or excrement. Adouble cage is best to' avoid this; one of these should have a: solid top.Good ventilation is important and sand slightly moist but not wet shouldbe provided beneath the meat. The meat may be partially buried toretain moisture and reduce odor. It should be remembered, that the'larvre have It strong tendency to migrate when ready to pupate.TISSUE-DESTROYING FORMSIt should be said that most forms of larvre attacking man or animalsmay destroy body cells to some extent but not in the sense of the rapid. -.... ~ -_

}

178 SANITARY ENTOMOLOGYtories. All of the species, except Wohlfahrtia magnifica Schiner, arecarrion breeders although the adult flies are attracted to various kindsof food, especially those with strong pungent odors as come from the.cooking of cabbage or turnips. . A few develop occasionally in humanexcrement; normally, however, the decomposition of animal matter hasthe strongest attraction for them and in many regions it is with greatdifficulty that animals can be slaughtered without having the meatcontaminated by their presence in large numbers (see plate II). Garbagecontaining meat and bone will attract and breed them.AMERlcA.-The screw-worm fly occurs throq.ghout the United States,but is of little importance as a pest except in the Southwest where insome sections it is a veritable scourge to the raisers of livestock.The life history of this species will serve as an illustration for thisgroup of flies in the United States. The eggs are deposited on carrion,especially on animals which have died recently. These hatch in a fewhours into maggots which enter the tissues rapidly and become mature inabout six to twenty days. In living animals development seems to berather more rapid. Pupation takes place in the soil from the surface tothree or four inches deep and the flies emerge in from three to fourteendays. The total development period from attack to adult has been foundto vary from seven to thirty-nine days. The activity of this species isconfined to the warmer part of the year, usually from about April firstto November first in the Southern States. The black blow fly, Phormiaregina, on the other hand, appears Jl}ore resistant to cool weather andbecomes most numerous in the southern region during early spring andlate fall. This is ,also true to a large extent with the large hairy blow-flies. These latter entirely disappear during the summer months in thesouthern latitudes.Infestations of screw-worms in animals occur on any portion of thebody where there is broken skin or even on sound skin where blood spotsoccur. For the most part, however, the infestations follow mechanicalinjury or where ticks have been crushed on the host. In man practicallyany part of the body may be attacked, but the most commontype of myiasis is nasal. This is especially true in .Central and SouthAmerica. Such infestations are usual~y associated with malignantcatarrh or bleeding from the nose, and practically always with careles~modes of living. The larvre enter the nose and penetrate the tissue,rapidly producing extensive cellulitis and usually accompanied by considerableserous or bloody discharge. If not detected for two days theinjury is likely to ·be very serious. The frontal and ethmoid sinuses maybe entered and the cartilage and even the bone attacked. Often thetissues of the nose and beneath the eyes begin to collapse and sometimesexcavation reaches to the surface, giving permanent disfiguration. This

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS 179extensive destruction of tissues often results in septicaemia or meningitis.Infestation of wounds on the battlefield or even in hospitals is not at allinfrequent, but such cases are much more easily treated than nasal infestations. ..oorThe black blow fly, Phormia regina Meigen, usually infests only oldsuppurating wounds. In livestock it is commonly found following dehorningand has also bt:J'!n proved to be a common source of wool infestationof sheep in the Southwest. In the latter case the soiled wool followinglambing attracts flies and the maggots feed on this for some time butlater may enter the sheep itself and cause its destruction.The green bottle flies, Lucilia sericata Meigen and L. c(J!sar Linnaeus,which are commonly known as the wool maggots in the British Isles,occur throughout the United States. They have been known to infestwounds in man and animals but the main source of trouble has been theinfestation of soiled wool on sheep. The method of attack in wounds issimilar to that of screw-worms, but the tissue destruction is less rapidalthough this depends largely in either case upon the number of larva!present. They are more abundant in towns than in open country.In South and Central America and the West Indies, Chrysomyamacellaria abounds and gives similar troubles to those in the UnitedStates. In Brazil, Sarcophaga lambcns Wiedemann and S. pyophila N.& F. have been reported by Neiva and De Faria to infest wounds. InHawaii Calliphora dux (Thompson) has caused considerable loss byattacking soiled wool !lond scabs on sheep.EURoPE.-=-In Europe the principal trouble from myiasis occurs insouthern Russia. A considerable number of cases occur in the Mediterraneanregion and SODie farther horth in Australia and Germany. Insoutheastern Russia, according to Portchinsky, the vast majority of casesof this tjpe are caused by the flesh fly, Wohlfahrtia magnifica Schiner,which appears to have habits of attack on man and animals very similarto that of the screw-worm fly in America. He speaks of its attack usuallyfollowing wounds on the bodies of cattle, horses, pigs, dogs, and poultry.It also commonly infests the feet of animals suffering from foot-andmouthdisease. The cases in man occur most commonly in the nose, ears,and eyes. The injury is often serious, resulting in deafness, blindness,or facial disfiguration, and not infrequently in death. This fly depositsliving larvre, and infestations in man are usually the result of sleepingoutdoors during the warm part of the day. The fly is most abundantin iields and woods rather than in towns. It is said to breed in livinganimals only, thus differing in ~n important respect from the screwwormfly.While ~!J.is species is not commonly spoken of as a pest in westernEurope, Liitje reports considerable trouble from it in the western war

180 SANITARY ENTOMOLOGYtheater, especially during 1915. It infested wounds and interfered withtheir proper treatment and also was responsible for many infestationsof the genitalia of cows in that region.Next in importance comes the flesh fly, Sarcophaga camaria L~nnaeu'3.This form does not seem so prone to attack living animals as Wohlfahrtiamagnifica Schiner, but there are numerous cases of myiasis in old suppuratingsores. These may occur in any part of animals or man. In thePetro grad district Lucilz'a caesar Linnaeus is responsible for some cases ofmyiasis, while in Denmark, Holland, and parts of Germany and France,L. sericata Meigen is conce~ned in the iil.festation of wounds. Calliphoraerythrocephala Meigen, Musca domestica Linnaeus and Muscma stabulanaFallen (plate III, fig. 2) are said to oviposit on corpses on the battlefieldsoon after death but before putrefaction sets in.The larvIE of Anthomyia pluvialis Linnaeus has been reported as beingconcerned in auricular myiasis. Probably this species should be consideredas a feeder on excreta rather than placed with tissue-destroyingforms.AFRICA.-Wohlfahrtia magnifica Schiner is reported by Gough inEgypt as being taken from ulcers behind the ears and from orbits ofpatients in the ophthalmic hospitals. In tropical Africa Lucilia argyrocephalaWiedemann commonly attacks mammals, man, and birds. Membersof the genus Pycnosoma, which halL...been included with Chrysomyaby some authors, cause myiasis in numerous caases. Pycnosoma megacephalaand P. bezziana Vin. arc frequently mentioned in literature in connectionwith cases of myiasis in cattle, horses, camels, and other animals,as well as man. P. putorium Wiedemann, P. margin ale Wiedemann, andChrysomya chloropyga (Wiedemann) Townsend are also concerned.Sarcophagids have been recorded as infesting wounds; S. haemorrhoidalisFuller and S. regularis Wiedemann being mentioned in particular.ASIA.-While there are numerous references to myiasis cases in Asia,our knowledge of the species concerned is limited. Members of the genusPycnosoma, particularly P. flaviceps Walker, are concerned with cases inIndia. This species and Lucilia serenissima Fabricius have been mentionedparticularly as being troublesome by attacking cattle after outbreaksof foot-and-mouth disease. It is possible that they may be concernedwith the spread of this disease in addition to the injury wroughtby their burrowing into the tissues. The cosmopqlitan Lucilia COJ8arLinnaeus is responsible for some cases of myiasis. Several Sarcophagidaehave been reported as causing nasal myiasis of man in parts of India, butmost of these have not been specifically determined. S. ruficornisFabricius seems to be among those most frequently concerned.A USTRALIA.-While reports of destructive myiasis in man are comparativelyfew from Australia~ c;eri;l1iJl parts are subjected to veritable

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS 181plague of myiasis among sheep. The center of the region where thi~scourge occurs is in New South Wales, where work for the commonwealth -government has been carried on by Professor W. W. Froggatt for severalyears. Only a brief mention of the species concerned and the characterof attack can be given.The loss is brought about through the blowing of the soiled wool,particularly around the vents of the ewes. The infestation, if notpromptly treated, spreads forward in the wool, resulting in a large loss inthe clip and often the larvre gRin entrance to the bodi~s of sheep andcause their death. Even though penetration does not occur, the skin isacutely inflamed and gives rise to fever, loss of appetite, and sometimesdeath. Froggatt states that he has bred 1,050 flies from the maggots inone pound of wool.Froggatt holds that the blowing of wool is largely Rn acquired habiton the part of Australian flies, as practically no cases of this kind werenoted up to 1908 or 1904. He attributes the acquisition of this habit tothe extended drought which destroyed large numbers of animals of allkinds and resulted. in the production of myriads of flies. He thinks thatduring this period several species of flies acquired the habit of depositingin "smelly" wool. He also considers the more extensive breeding of heavywooled sheep to be a contributory factor. It is certain that injury fromblow-flies has developed from an' almost unnoticed trouble to a problemof first magnitude within the space of a few years. During the firstfew years of the acute trouble the small yellow house fly, Anastellorhinaaugur Linnreus, and the golden hair blow-fly, Neopollenia stygia(Fabricius) Townsend (Pollenia villoso, Robineau-Desvoid'y) appearedto be the principal culprits. In 1918, when the work was taken up moreextensively it was found that the "green and blue" sheep maggot fly,Chrysomya rufifacies Macquart (Pycnosoma), was assuming first importancein connt!ction with the infestation of sheep. The difference inapparent injuriousness is probably governed largely by the seasonalconditions as in the case of species in our own country, C. rufifacics apparwtlybeing concerned largely with cases of myiasis in summer and A.augur during the cool weather. The life histories of these flies do notdiffer materially from tllat of the screw-worm fly, the life cycle beingcompleted in about two weeks under favorable conditions. Other specieswhich have been bred from wool in Australia are Microcalliphora varipes(l\!acquart) Townsend, the Anthomyid, Ophyra nigra Wiedemann,Sarcophaga aurifrons Macquart, and the cosmopolitan Lucilia sericataand L. CfEso,r, and possibly L. tasmanien8i8.

181 SANITARY ENTOMOLOGYSUBDERl\IAL MIGRATORY SPECIESThe species concerned in this form of myiasis arc truly parasitic.In the cases of man they can not be considered as especially dangerous,but in animals they assume first rank as destructive parasites.The type of myiasis produced by these larvre is described undervarious names in medical literature but especially mentioned as creepingdisease. This is owing to the movement of the larvre in the subcutaneoustissues. In the United States we have little cGl"cern for cases of myiasisin man produced by this group of flies as they arc comparatively infrequent.The species concerned arc Hypoderma, probably mostly lineataDeVillcrs and Gastrophilus, probably mostly intestinalis DeGcer (platesX, XII). Unfortunately the larvm concerned usually have not beenpreserved, and in a very few cases have any larvre from man been rearedto maturity.The sanitary entomologist is not particularly concerned with theOestrids infesting cattle, but on account of their importance to theveterinary entomologist they are here briefly discussed (see plates XI.XIII). There are two species in this country, H. lineata Dc Villers andH. bO'lJis DeGeer. The former is the predominant form in the UnitedStates, especially in the southern three-fourths of the country, while thelatter is more restricted to the northern tier of States, New England andCanada. The adults are known as heel flies and oviposit on the hairs, principallyon the legs of cattle. These eggs hatch in three or four days andthe larvre penetrate the skin at the point of attachment or in someinstances may be taken in by licking. After several months spent in thebody of the animal they appear during the late fall and winter monthsunder the hide along the back, forming subcutaneous tumors. When fullgrown these grubs emerge from the host, drop to the ground and afterabout twenty-five to thirty-five days spent in the pupal stage produce:flies which are ready to attack cattle the first warm days during spring.Several cases have recently come under the observation of Mr. E. W.Laake and the writer of the occurrence of this species in the backs ofhorses. These arc responsible for the production of lesions which practicallyrender the use of the infested animals as saddle horses impossiblefor a few weeks.There are a number of records of the occurrence of the young larvreof these :flies in man, especially children. Attention is usually first calledto them on account of pain, soreness or itching in the region of theshoulders or face. The irritation is sometimes rather acute and itslocation moves with the burrowing of the larvre. Before becoming maturethe grubs appear near the surface under the skin or beneath the mucousmembranes of the mouth and can there be extracted with easp

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS18SLPLATE X.-Horse bot flies. Fig. 1 (upper).-Gasl1·olJhilus intestinalis, the commonbot. Fig.!i3 (lower).-Gastrophilus haemorrhoidalis, the nose fly. (Dove.)

184 SANITARY ENTOMOLOGYPLATE XL-Phases of the lifc cycle of bot flies. Fig. 1 (upper right).-Empty eggsof the cattle bot, Hypode1'ma lineata. Fig. g (upper left).-Eggs of the commonhorse bot, Gasll'ophihlS intestina.lis. Fig. 3 (center).-Full grown larva of Hypodermalineata. Fig. 4. (lower right).-Empty puparium of Hypode1'ma lineata.Fig. 5 (lower Jeft).--Empty puparium of Gastrophil11s intestinalis. (Bishopp.)

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS 185PLATE XII.-Method of attack by t he common horse bot, Gastrophiltts intestinalis.Fig. 1 (upper).-Eggs on horse's legs. Fig. 2 (lower).-Larvae attached to wallsof stomach, showing lesions caused by removed bats in center. (Bishopp.)

186 SANITARY ENTOl\lOLOGYPLATE XIII.-Method of attack by the cattle bot, or heel fly, Hypoderma lineata. Fig.1 (upper right) .-Fly ovipositing on cow's leg. Fig.:i! (upper left) .-Portion ofcow's back showing larvae, empty holes and pus exudate ~ Fig. 3 (lower).-Heavilyinfested cow. (Bishopp.)

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS 187These infestations probably come about through the accidentaldepositions of eggs on the bodies or clothing of man, especially children.The possibility of this method of infestation is emphasized through theexperience of Dr. Glaser, who while studying ox warbles in Germany had afly deposit an egg on his trousers which in due time hatched and theyoung larva penetrated the skin of his leg. Later its presence in theoesophageal region was detected by an uncomfortable feeling. The larvaapparently passed up the oesophagus and later was extracted at thebase of one of the molar t~eth.In instances where the Oestrid fly of the genus Gastrophilus attacksman the conditions surrounding the infestation as well as the exactidentity of the larva arc less well understood. It is supposed that theyopng larvle are in some way brought in contact with the mucous mem-FIG. ST.-Full grown larva of the human bot, Dtwmatobia hominiB.Bradford.) Actual length 14.5 mm.(Drawing bybranes of the lips, mouth or eyes and penetrate them, later appeari~gunder the skin: and moving about in a manner somewhat similar toHypoderma. The life history of the species of this genus will be discussedunder intestinal myiasis.AMERlCA.-In America in addition to the Hypodermas we have amongthe lower mammals dermal myiasis produced by several different speciesof Oestrids in the genus Cuterebra. These are most commonly met within rabbits, squirrels and certain field mice. Usually they appear to causeno serious injury except in the case of one form, which is prone toattack the testicles of squirrels and was given the name of Cuterebraemasculator Fitch (equals C. fontilnella Clark).In South America a very interesting and more important form ofmYIasIs In man occurs. This is produced by the Oestrid, Dermatobiahominis (Carl Linne, Jr.) (noxialis Goudot, cyaniventris, Macquart)(fig. 37). This form appears to be normally the parasite of cattle, horses,donkeys and certain wild animals. It is reported as being a serious pest

188 SANITARY ENTOMOLOGYof cattle, in some cases causing the death of many calves, especially whenthe cutaneous tumors become infested with larvre of Chrysomya.The life history and habit~ of the species have not been fully elucidated,although a number of important contributions have been made.It is generally concluded that the infestation of man is brought about inthe following indirect but very interesting manner: The eggs of the :flyare deposited on the bodies of certain bloodsucking insects, especially themosquito known as Paorophora lutzi Theobald (J anthinoaoma) , orattached to leaves frequented by these insects whence they adhereto them. The eggs are att~ched vertically on the under side of theabdomen or the legs. The embryos appear to remain dormant thoughfully developed within the egg and when the bloodsucking dipteronfinds a host, the heat of the animal or the blood taken up stimulates thelarvre to break from the shell and penetrate the skin of the host. Dermaltumors are formed by the larvre, a well-marked hole opening to the outsideas in the case of the ox warble. When the grubs become full grown theyleave the host, drop to the ground and transform to adults. The periodin the host ranges from two to six months. During this time there ismore or less inflammation and sometimes acute pain. This form is widelydistributed through tropical America. Lieut. L. H. Dunn has recordedcases of apparent transmission of the eggs by ticks.In South America Dr. J. C. Nielson has reported the occurrence of theAnthomyid flies (Mydaea anomala and M. torquena) as producing subcutaneoustumors in various birds in parts of Argentina, and Dr. C. H. T.Townsend records M. apermophilae as parasitic on nestlings in Jamaica.EURoPE.-Several cases of dermal myiasis have been reported, especiallyfrom Russia. These are attributed to infestations of larvle ofHypoderma and Gastrophilus.The infestation of reindeer in Lapland and farther south in Norwayby larvre of the Oestrid fly, Oedemagena tarandi Linnaeus, should bementioned. The infestations are almost analogous to those in cattlecaused by Hypoderma. The eggs are laid on the hair during the springand later the larvre appear in the submucous tissues of the back. Asmany as 300 have been reported as occurring in a single animal. Thissame species no doubt infests the reindeer in Alaska and Canada.AFRICA.-In Africa the outstanding form of dermal myiasis is producedby the Muscid fly, Cordylobia anthropophaga Griinberg, commonlyspoken of as the Tumbu fly (figs. 38, 39). The larvre are kuown as "Vcrdu Cay or." These develop in the skin of man and various other hostsincluding dogs (probably the preferred host), cats, horses, and otherdomestic and wild animals. The attack is painful but not serious, thoughno doubt when numerous specimens are present unpleasant symptoms follow.The life history of this form has not been entirely elucidated, but

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS 189it is generally believed that the eggs are deposited on the ground in placesfrequented by hosts and the larvre hatch and penetrate directly throughthe skin. In some cases it appears that eggs have been deposited onclothing, especially if moist with perspiration. They appear in March• (oJ'"~FIG. S8.-Full-grown larva of the Tumbu-fty (Oordylobia anthropophaga, GrUnberg).Ventral view. X 6. (From Austen.)FIG. S9.-The Tumbu-Fly (Oordylob,ia anthropophaga, GrUnberg). Female. X 6.(From Austen.)and diminish until some time in September when they entirely disappear_Experiments conducted by Roubaud indicate that the choice of hostdepends mainly on body temperature, the high temperature of hogs andfowls being fatal to the larvre.Cordylobia rodkainti Gedoelst is the cause of cutaneous myiasis in the

190 SANITARY ENTOMOLOGYforest regions of Africa. Man is an accidental host, the species nonnallyinfesting thin skinned wild mammals. According to Rodhain andBequaert, who have given much attention to the biologies of this andrelated species, the eggs are deposited on the ground in the burrows frequentedby the animals, the larvre hatch out and penetrate the skin whenthe hosts are lying upon them. The larvre develop within the host intwelve to fifteen days. The pupal stage, which is passed in the ground,ranges from twenty-three ·to twenty-six days, the life cycle being aboutforty days. Another Muscid genus, Bengalia (especially B. depressaWalker), causes cutaneous myiasis in man in Rhodesia and other parts ofAfrica. The eggs are deposited on the clothing or person of man andon the hair of animals.Another interesting form is N eocuterebra squamosa Griinberg, whichdevelops in the adipose tissues in the soles of the feet of the Africanelephant.INTESTINAL AND UROGENITAL MYIASISThere is every reason to believe that myiasis of the intestinal tractand urogenital openings results largely from careless modes of living.The types of myiasis included in this group should not be confused withurogenital myiasis caused by Chrysomya and related fonns. A large percentageof these cases is purely accidental and there is no doubt that agreat many larvre are ingested with food which never produce symptomsto attract attention to their presence. Several different families of flieshave been recorded as causing intestinal myiasis, one of the most commonbeing the rat-taillarvre of the family Syrphidae. Records of intestinalmyiasis due to Sarcophagidae are also numerous, but it should beborne in mind, especially with this fly, that there arc many opportunitiesfor mistakes. With little doubt, in many instances, the larvre are notpassed, but are deposited in the excrement by flies which have the habit ofvisiting and depositing larvre almost instantly after defecation.The whole group may be subdivided into those forms which are directlyparasitic, such as horse bots, and others which are more or less accidental.AMERlcA.-The importance of the horse bots in infesting equines issuch that brief discussion is necessary. In this country there are threespecies, all of which are of considerable economic importance. These arethe common horse bot, Gastrophilu.s intestmalis DeGcer, the chin fly orthroat bot fly, G. nasalis Linnaeus and the nose fly, G. haemorrhoidalisLinnaeus (plates X, XII). These three species are widely distributedthroughout the world and were met with as pests in many of the recentwar theaters. Certain other species are also present in European andAsiatic countries but these are of less importance.

MYIASIS-TYPES OF INJURY, LIFE HIS'l't"';lY, HABITS 191The life history of the common bot fly is about as follows: The eggsare attached to the hairs of the host, mainly on the legs, but frequentlyon other parts. These are ready to hatch in from nine to forty days.The larvre are removed from the eggs by the biting and licking of thehost. They take up their abode in the stomach, remaining attached to themucous coatings of the pyloric end of this organ until fully grown severalmonths later. They then detach and pass out with the manure,pupate ncar the surface of the ground and produce the so-called bot fliesthree to six weeks later. The cycle is completed in about a year. Thelife histories of the nose fly and throat bot are similar but differ especiallyin the method of oviposition. The former deposits its eggs, which arenearly black, on the very minute hairs around the lips. The young larvregain access to the mouth and develop as in the common bot fly, but beforepassing out they usually catch hold of the mucous membrane of therectum and are often seen protruding from the anus a few days beforedropping. The annoyance produced by the oviposition of this fly isvery severe. The throat bot deposits its eggs mainly under the jaws andthe larvre are often found in the duodenum and also attach in the stomach.In addition to the annoyance produced at the time eggs are deposited,heavy infestations in the stomach interfere with digestiun and cases arerecorded where the larvre caused death by stopping the pyloric opening.The irritation of hots, which may be present in numbers exceeding 1,000,must be detrimental to the host. The throat bot also attaches in thepharynx in its early stages and is accredited with causing the death ofanimals from this habit.Cases of dermal myiasis in man attributable to these species havealready been mentioned. European writers Jlave also reported the occurrenceof larvre of Gastrophilus in the eye of man.Passing to those forms which arc more or less accidental, the Sarcophagidaedemand first attention. Hasseman has reported a case inwhich an entire family was infested with the larvre gf Sarcophaga lzaemorrhoidalis,the maggots being passed in considerable numbers during warmweather. Numerous other similar instances have occurred and in practicallyevery instance they are traceable to leaving foods exposed to fliesbetween meals. Since the Sarcophagids deposit living larvre on meats,etc., they may be easily overlooked.Cases of intestinal myiasis due to Eristalis larvre are common in thiscountry. A good summary of these cases has been made by Hall & Muir.It appears that they sometimes give rise to acute colicky pains but noserious symptoms. As is well known, the rat-tail larvre are to be foundin decaying vegetation and in water, and the source of infestation mustbe through the swallowing of uncooked and poorly cleaned food such aswatercress and lettuce, a.nd the drinking of unclean water. The follow-

19~ SANITARY ENTOMOLOGYing species have been recorded in this connection: Eristalis tenax Linnaeus,E. arbuatorum Fabricius, E. dimidiatua Wiedemann, and Helopkiluapendulinua Meigen.The cheese maggot or skipper Piopkila casei Linnaeus, is referredto in a number of instances as the cause of intestinal myiasis, often producingintense colic, and this form has also been recorded from the nose.On account of the conunon habit of this fly of depolliting its eggs incheese and smoked meat, it is no doubt often eaten in considerable num

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS 193The Anthomyid flies of the genus Fannia have been recorded as causingserious gastric disorders. Among the symptoms are abdominal pains,nausea, and 'V'tlmiting, and sometimes vertigo, headache, and bloody diarrhea.Fannia canicularis (plate VII, fig. 3; text figs. 14-16), commonlycalled the lesser house fly, and Fanmia scalaris (text figs. 17-19) arewidely distributed and breed in various types of decaying vegetable matterand excrement. We find that the larvre will feed upon and penetratemeat, and they may attack the living tissues to some extent.In the urogenital infesting group the above-mentioned species ofFannia, which are also known as the latrine flies, figure most prominently.These species are rather strongly attracted to human excrement, especiallyurine. This habit is undoubtedly responsible for the infestationof the genitalia. Such infestations must ~ertainly be attrib~ted to theexposure of the genitals in sleep by drunken or careless persons, or occasiOl('Jlyinfants. Robineau-Desvoidy has re.ported a case in which anOestrid larva was passed ftom the bladder by a woman. Kollar has reportedthe occurrence of a large number of larvre of the common housefly in the vagina of a diseased woman. Chevral has brought togethera number of records of" cases of myiasis of the genitalia.EURoPE.-Nearly all the above-mentioned forms are to be encounteredin r_~ts of Europe. In the ¥editerranean countries one wouldexpect to ]Yhd a greater number of forms leading to tllese types ofmyiasis.AFRIcA.-Several of the previously mentioned forms occur in Africa.The Oestrid larva, Pharllngobolus africanus Brauer, commonly attachesto the walls of the esophagus of the African elephant, and an Oestrid00 the genus Cobboldia (C. loxodontis Brauer and C. chrllsidiformisRodhain and Bequaert) are found in the stomach of the African elephant,and C. elephant is (Steel) Cobbold, attacks the Indian elephant ina similar way. Species -of Girostigma in the same family infest thestomach of the Rhinoceros. Anthomyia disgordiensis is said to be notinfrequently passed from the intestines of man in Angola.FORMS PRODUCING MYIASIS IN HEAD PASSAGESAll of the species included in this group are normally parasitic onanimals, and infestation of man, although not uncommon, must be consideredaccidental. In the lower animals the attack of these larvre isoften quite injurious though not usually fatal in itself. In man theprincipal injury sustained is in the effects on the eye when it happens tobe attacked.AMERICA.-In the United States as well as in all parts of the world,the sheep head maggot, Oestrus ovis Linnaeus, is the most important

194~~SANITARY ENTOMOLOGYfonn in this group. The fly deposits living larvle on the nose of thesqeep and the young maggots work upward through the nasal passage,later ente~ the head sinuses. The maggots are quite spiny and hencemust produce much irritation .. They appear to subsist upon the mucoussecretions of the head cavity. Several months are passed in the hostand the larvle drop out and pupate in protected places on the ground,producing flies a few weeks later.I know of no record 0'£ the attack of man by this species in theUnited States, but in other countries it frequently attacks the eyes,nose, mouth, and ears. The fly deposits the l~rvle so quickly that thereis little opportunity to protect one's self. The most serious symptomsdevelop from infestation of the eye where larvle produce severe conjunctivitisand in some cases, if not promptly removed, cause the loss ofsight.In this country the Cervidae (deer, elk, etc.) are attacked by Oestridsof the genus Cephenomyia (C. pratti Hunter, and C. phobifer Clark).The larvre of these flies are found in the head passages, pharynx, andeven in the lungs. ..EURoPE.-The sheep head bot has a wide distribution in Europeand is responsible for loss among sheep and infestation of man as abovedescribed.Probably the most important species in this group is Rhinoest1"U8purpureus Brauer, which is a very common parasite of the horse inRussia, Hungary, and' Italy. This fonn is also responsible for casesof myiasis in the eyes of man, the attack apparently being similar to thatof Oestrus ovis. Horses are infested by the flies which deposit larvlein the nose or eyes. They are much annoyed by the deposition of theinsect and the larvle give rise to fits and other symptoms, mistaken forstrangles, sometimes resulting in death. The species is also known toattack the zebra. Cases of the occurrence of this species in the eyes ofman have been reported from Jerusalem, and are nol infrequent insouthern Russia.The reindeer in Europe are subject to the attack of Cephenomyiatrompe Linnaeus in a way similar to the infestation of sheep by Oestrusovis. Nativig reports the finding of as many as 100 lan-Ie in the nasalcavity and larynx of a young reindeer.AFRICA.-In Algiers, especially, Oestrus ovis is very destructive tosheep and many

MYIASIS-TYPES OF INJURY, LIF~ HISTORY, HABITS 195Many species of Oestrids occur in the head passages of Africananimals. Rhinoe8tru8 hippopotami Grunberg occurs in.tthe skulls ofhippopotami and apparently this sp('cies attacks hogs. The ~neraGedoelstia and Kirkioestrus each contain species which infest t!l.e neadsinuses of African wild mammals.:_-'""BLOODSUCKING FORMSThi~ mode of attack is not generally considered myiasis but it seemsto have a logical place in this discussion. All of the species havingbloodsucking habits ._a-~lopcd among their larvre are to be found inthe family Muscida~Vp to the present time there seems to be comparativelylittle importance attached to them, although such forms as theCongo floor maggot may be responsible for the introduction of diseasegerms into man.AMERICA.-The only representatives of this group found in NorthAmerica are Phormia azurea (Fallen) Villeneuve and P. chryaorrhcea(l\feigen) Rodhain and Bequaert. The first mentioned species is foundcommonly in Europe whcre it was first recorded as feeding in the larvalstage on nestlings of the sparrow and other birds. This same habithas been observed in the United States. The second form, which is quitecommon in the nests of larks and other birds in the southwestern states,appears to cause a definite dermal myiasis as the larvre are frequentlyfound partially imbedded in the wings, legs and body tissues of fledglings.The fly, Mydaea pici Macquart, is reported as infesting young birds in asimilar way in Brazi1. 2EUROPE.-Phormia azurea (above mentioned) is quite common in thenests of birds in France and P. aordida (Zctterstcdt) Roubaud has similarhabits.AFRLCA.-The form which is especially interesting and importantin this group is the African floor maggot, AucJt'lneromyia luteola (Fabricius).This fly appears to be very closely associated with man. Theadults are found in the dwellings and about latrines in tropical andsub-tropical Africa. The eggs are deposited on tbe dry soil of the floorsof native huts, especially un'der sleeping mats. The larvre come out atnight and attack the sleepers, filling with blood in a very short time.The adult. is also a blood-sucker. The larval ~tage occupies about fifteendays and the pupal stage about eleven days. The larvre do notburrow into the tissues but simply attack the skin with the mouth hooksand suck tire blood.• Plath has reported recently on the occurrence in the nest of a robin la.·vae of anew species, Phormia metallica Townsend. He also discovl'red in birds' nests, larvaeof a new species of Anthomyidae, HlIlemyia nidicola Aldrich. The latter probablyfeeds on dead birds only.

196 SANITA:ij.Y ENTOMOLOGYThe related genus Choeromyia contains three or four species includingC. choerophaga Roubaud and C. boueti Roubaud which occasionallybite man but normally live in .the burrows of such hairless animals asthe warthog and ant bear. The habits are similar to the floor maggot.Certain birds are attacked by the larvm of Passeromyia heterochaetaVilleneuve in a way similar to that reported for Phormia. This formoccurs in Central Africa and also in China.SOME BIBLIOGRAPHICAL REFERENCESAusten, E. E., 1912.-British flies which cause myiasis in man. Repts.Local Govt. Bd. on Pub. Heal~h, and Med., n. s., No. 66, pp. 5-15.Bishopp, F. C., 1916.-Flies which cause myiasis in man and animals.Some aspects of the problem. Journ. Econ. Ent., vol. 8, No. S,pp. SI7-329.Bishopp, F. C., and Laake, E. W., 1915.-A preliminary statemen,t regardingwool maggots of sheep in the United .st~ J\tU!~. Econ.Ent., vol. 8, No.5, pp. 466-474. ;-Bishopp, F. C., Mitchell, J. D., and Parman, D. C., 1917.-Screw-wormsand other maggots afF~cting animals. U. S. Dept. Agr., Farmers'Bull. 857. ,,__,..n.. It .....Carpenter, G. H., and...Rewitt,tT.••R., 't'915._:_The.warble flies. FourthRept., Journ. Dept. Agric. & T~ch. Instr. for Ireland, vol. 1 1 5,Ch evra 30 PI ,ene, P'R 1909 .-S,; ur I a 1\6 :.Lyase. ""'-;:._. • •• A h dqJ!S VOles urmalres. rc. eParasit., vol. 12, pp. 369-41j0. \~.Cooper, W. F., and Walling, fW. A:- B., 1915.-The efFect of variouschemicals on blow-fly. Annals of Applied Biology, vol. 2, Nos. 2 andS, pp. 166-182. July. ...Coutant, A. F., 1916.-The habits, life-history, and structure of a bloodsuckingMuscid larva. Journ. Parasit., vol. 1, pp. 135-150, 7figs.De Stefani, T., 1915.-N otes on myiasis in animals and man. II RinnovamentoEconomico-Agrario, Trapani, vol. 9, Nos. 5 and 6, MayJune, pp. 89-92, 110-113.Dove, W. E., 1918.-Some biological and control studies of GastrophilushaemorrhoidaUs and other bots of horses. U. S. Dept. Agr., Bull.597.Dunn, L. R., 1918.~Studies of the screw-worm fly, Chrysomyia macelZaria F., in Panama. Journ. Parasit., vol. 4, No.3, pp. 111-121.Foreman, F. W., and Graham-Smith, G. S., 1917.-Investigations onthe prevention of nuisances arising from flies and putrefaction.Journ. Hyg., vol. 16, No.2, pp. 109-226.

l\IYIASIS-TYPES OF INJUR~~IF.E HISTORY, HABITS 197Froggatt, W. W., 1915.-Sheep-maggot flies. Dept. Agric. New SouthWales, Fanners' Bull. 95, 52 pp.Froggatt, W. W., and Froggatt, J. L., 1917.-Sheep-maggot flies, No.3. Dept. Agr. New South Wales, Fanners' Dull. 113, 37 pp.}'roggatt, W. W., and Froggatt, J. L., 1918.-Sheep-maggot flies, No.4.Dept. Agr. New South Wales, Fanners' Dull. 122,24 pp.Fuller, C., 1914.-The skin maggot of man. Agric. Journ. Union S.Africa, vol. 7, No.6, pp. 866-874.Glaser, Hans, 1912-1S.-Uber Dasselfliegen mit des ausschusses zurBekampfung der Dasselfliege. Nos. 3, 4, 5.Hadwen, S., 1915.-A further contribution on the biology of Hypodermalineatum and Hypoderma boms. .farasit., vol. 7, pp. 3S1-33S.Hadwen, S., and Bruce, E. A., 1916.-0bservations on the migration ofwarble larvle through the tissues. Health of Animals Branch, Dept.Agr. Canada, Sci. Ser., Bull. 22, pp. 1-14.Hall, C. M., and Muir, J. T., 1913.-A critical study of a case of myiasisdue to .Eristalis. Arch. Internat. Med., vol. 11, No.2, pp. 193-203. •Hewitt, C. Gordon, 1912.-An account of the bionomics and the larvleof the flies Fannia canicularis L. and F. scalaris Fab., and their relationto myiasis of the intestinal and urinary tracts. Repts. LocalGovt. Rd. on Pub. Health and Med. Subjects, n. s., No. 66, pp.15-22.Keilin, D., 1917.-Recherches sur les Anthomyides a larves carnivores.Parasit., vol. 9, 125 pp., 11 pl., 41 figs., May.Knab, F., 1916.-Egg disposal in JJermatobia hominis. Proc. Ent. Soc.Wash., vol. IS, pp. 179-1S3.Lallier, P., IS97.-Etude sur la myase du tube digestif chez l'homme.These Faculte de Medecine de Pariilf"iillO pp., 1 pl.Lefroy, H. M., 1916.-The control of flies and vermin in Mesopotamia.Agric. Journ. of India, vol. 11, pt. 4, pp. 323-331.Lutze, I910.-Diseases caused by flies and their larvre. Deutsch.Tierarzt. Wochenschr. Hanover, vol. 23, No. 46, pp. 395-397, 7figs., Nov.Marlatt, C. L., IS97.-The ox warble. U. S. Dept. Agric., Bur. Entom.,n. s., Cir. 25, 10 pp.Neiva, Dr. A., and De Faria, G., 1913.-Notes on a case of humanmyiasis caused by larVa! of Sarcophaga pyophila, sp. n. Mem. Inst.Oswaldo Cruz, vol. 5, No.1, pp. 16-23.Nielson, J. C., 1913.-0n some South American species of the genusMydaea, parasitic on birds. Vidensk. Meddell. fra Dansk naturh.Foren., vol. 65, pp. 251-256, 4 figs., May.Palazzolo, G., 1916.-Hypoderma bovis and the fly Dermatobia noxiaZis

198 SANITARY ENTOMOLOGYor cyaniventris of Brazil. Nuovo Ercolani, Turin, vol. 21, Nos. 26-27, pp. 433-437, Sept.Patton, W. S., and Cragg, F. W., 1913.-A Textbook of MedicalEntomology. . .Phelen, J. M., 1917.-U. S. Army Methods of disposal of camp refuse.. Amer. Journ. Pub. Health, vol. 7, No. '5, pp. 481-484, May.Portchinsky, I. A., 1913.-0e8tru.s ovis L.; its life history and habits,the methods of combating it and its relation to human beings. Mem.Bur. Ent. Sci. Comm. Cent. Bd. Land Admin. and Agric., St. Petersburg,vol. 10, No.3, 63 pp., 28 figs.Portchinsky, I. A., 1914.-..4. review of the spread of the chief injuriousanimal pests in Russia in 1913. Yearb. Dept. Agric. for 1913,Petrograd, 14 pp., 4 figs.Portchinsky, I. A., 1915.-Rhinoestrus purpureu.8 Br., a parasite of thehorse, injecting its larvre into the eyes of men. Bur. Ent. Sci. Comm.Central Bd. Land Admin. and Agric., Petrograd, vol. 6, No.6, 42 pp.,9 figs., 1 pt.Portchinsky, I. A., 1916.-1Vohlfahrtia magnifica Schin., llnd allied Russianspecies. The biology of this fly llnd its importance to man anddomestic animals. l\fem. Bur. Ent. Sci. Comm. Agric., Petrograd,vol. 11, No.9, 108 pp., 39 figs., 2 pl.Rodhain, M. J., 1915.-0n the biology of Cordylobia rodhaini G~oelst.C. R. Hebdom. Ac .. Sci., Paris, vol. 161. No. 11, pp. 323-325.Rodhain, J., and Bequaert, J .• 1915.-0n some Congo Oestrids. Bull.Soc. Path. Exot., Paris, vol. 8, No.9, pp. 687-695.Rodhain, J., and Bequaert, J., 1916.-Materials for a monograph onthe parasitic Diptera of Africa. Bull. Sci. France et Belgique, Ser. 7,vol. 49, No.3, pp. 236-289, 14 figs., April 29.Rodhain, J., and Bequaert, J., 1916.-Materials for a monograph onthe parasitic Diptera of Africa. Second Part. A revision of theOestrinae of the African Continent. Bull. Sci. France et Belgique,Ser. 7, vol. 50, Nos. 1-2, pp. 53-165, 29 6gs., 1 pl., November25.Rodhain, J., and Bequaert, J., 1919.-Materials for a monograph on thef parasitic Diptera of Africa. Third Part. Bull. Sci. France etBelgique, vol. 52, No.4, pp. 379-465, 21 figs., 3 pIs.Roubaud, E., 1913.-Researches on Auchmeromyia, Calliphorine flieswith blood-sucking larvre from tropical Africa. Bull. Sci. Franceet Belgique, Ser. 7, vol. 47, fasc. 3, pp. 105-202, 2 pIs., 32 figs.,June 24.Roubaud, E., 1914.-Stomach- and sinus-inhabiting Oestrids of FrenchWest Africa. Bull. Soc. Path. Exot., vol. 7, No.3, pp. 212-215,March n.

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS 199Roubaud, E., 1914.-Studies of the parasitic fauna of French WestAfrica. Part 1. The producers of myiasis and similar disorders inman and animals. Paris: Masson & Co., !e51 pp., 4 col. pIs., 70figs.Roubaud, E., 1915.-Muscids, the larvre of which bite and suck blood.C. R. Soc. BioI., Paris, vol. 78, No.5, pp. 92-97, 2 figs., March19.Sambon, L. W., 1915.-0bservations on the life history of Dermatobiahominia. Rept. Adv. ('om., Trop. Diseases Research Fund for 1914,London, pp. 119-150.Sergent, Ed., and Sergent, Et., 1913.-"Tamne"-the "Thimni" of theKabyles-the human myiasis of the Taureg Mountains in the Sahara,caused by Oestrus ovis. Bull. Soc. Path. Exot., No. ,7, pp. 487-488,July 9.Ward, Henry B., 1903.-0n the development of Dermatobia hominis.Rep. from the Mark Anniversary Volume, Article XXV, pp. 483-512,plates 35-36.

CHAPTER XIIIMyiasis-Its Prevention and Treatment 1F. C. BislwppIn the preceding lecture the habits and biologies of the various speciesconcerned in myiasis in man and animals have been briefly outlined.An accurate knowledge of the species concerned and a good general ideaof its biology and habits are essential to the proper handling of myiasis.especially when the cases arc numerous.In discussing control of the flies concerned and the treatment of casesthe same general grouping as made in the previous lecture will be followed.Where various species of bIlow flies and related forms arenumerous, immediate steps should be taken to determine the source ofsupply and energetic measures applied to prevent it without waiting forthe appearance of cases of myiasis in man or animals.TISSUE-DESTROYING FORMSPrevention of Breeding.-Since practically all species concerned inthe production of this form of myiasis develop within decaying animalmatter, first attention must be given to this point.Burning of Carcasses.-The carcasses of large animals are sourcesof tremendous numbers of flies. We have estimated that over a millionspecimens may be produced in the body of one cow. Nothing is as satisfactoryas complete destruction of carcasses by burning. This not onlyprevents fly breeding but reduces the chances of the propagation ofsuch diseases as black-leg, anthrax and tuberculosis. Carcass burningcan be carried out under practically any condition with which the sanitaryentomologist will have to deal and the process 'is by no meansdifficult nor expensive. Various methods have been advocated but we hav~found nothing equal to the following: Dig a trench about eighteeninches wide, twelve or fourteen inches deep and equal to the length ofthe carcass to be burned (plate XIV). This trench should be dug withthe direction of the prevailing wind and along the back of the carcass;fill the trench with wood and then turn the animal over on top ofit. Start the fire in the windward end of the trench and no further1 This lecture wall presented November 18, 1918, and distributed January SIO, 1919.200

::\lYIASIS-ITS PREYENTION AND TREATMENTattention is necessary for several hours, when the extremities may be piledin the center to complete burning. The placing of wood on top of thecarcass and addition of wood after the fire has started are unnecessary_About one-quarter of a cord of wood is adequate, and where wood isscarce, burning may be accomplished by using crude oil. Of course afew sticks of wood beneath the carcass will help hold the heat butthis is not necessary. Ten to twenty-five gallons of crude petroleum aresufficient. The odor from carcass burning is not very objectionable,especially if the animal is destroyed soon after death.In cities it is usually feasible to have all large carcasses promptly~OlPLATE XIV.-Trench prepared for burning carcass.(Bishopp.)removed and effectually destroyed by commercial rendering and fertilizerplants. These establishments should be subject to sanitary inspection.Carcass Burial.-Burial is generally unsatisfactory, especially ifbodies are well infested with maggots. We have found that at leasttwenty-four inches of finely packed earth are necessary to prevent theirescape. The free usc of quicklime on the body after it has been pl,acedin the grave helps to destroy the maggots and reduce chances of diseasespread. We have not yet undertaken experiments with the treatment ofcarcasses before burial with creosote oil, but judging by results obtainedfrom treating those on the surface, this should be a good method ofdestroying larvre, reducing odor and killing disease orgamsms.

SANITARY ENTOMOLOGYTreating 'With Chemicals.-Nearly all maggots of this class of fliesare exceptionally resistant to the action of chemicals. We have foundsome to survive submergence· in v~ry destructive insecticides. Foremanand Graham-Smith, working in England, have found that creosote oil,which is one of the higher distillates from coal tar, is quite efficacious inthe treatment of carcasses. Two things are accomplished-the majorityof the larvre are actually Jlit by the spray and destroyed and decompositionis practically stopped with correspon!ling reduction in odor. Inrecent experiments conducted at the Dallas Laboratory, we have foundthat several American makes ·of creosote oil are excellent for this purpose.Small carcasses thoroughly sprayed before infestation takes place willremain free from infestation, the flies being repelled by the substanceand odor practically prevented. The carcass usually shrinks and assumesa mummified condition. Such creosote oils are manufactured bya number of concerns and usually sold at prices ranging from sixtyfivecents to one dollar per gallon, according to the per cent of coaltar acids contained. Rather high percentage of these ingredients (atleast l!'l per cent) is best.Since direct sunlight is a powerful destructive agent in the semiaridand arid regions, if burning cannot be accomplished, the carcasses shouldbe left in the most exposed place possible--not in a gully under shade asis usual. This will often result in about 85 per cent control.Disposition of Garbage.-The question of garbage disposal has beendiscussed briefly in other .lectures (Chapters X, XI). Nearly all garbageis attractive to blow flies as well as other forms and the bone andmeat scraps become infested. Where incineration is practicable it is·most !lesirable. When fed to hogs the bones should be picked out andplaced in a screened compartment or treated with borax or creosoteoil.Destruction of Flies.-In general the destruction of flies should beconsidered as secondary to the elimination of breeding places, but undercertain conditions this method of attack has its place.Traps.-Various types of traps have been devised f~r destruction offlies but a careful comparison of many different forms in experiments carriedout at the Dallas Laboratory shows that there is much differencein their efficiency and also that some minor changes in the constructionof a trap may greatly improve the size of the catch. As a result ofthese experiments the fly trap described in Farmers' Bulletin No. 784is being recommended by the Bureau. This trap appears to be the bestall round form for catching both house flies and blow flies. Of coursethe framework of the trap need not be made of hoops and barrelheads, as suggested in that bulletin, although those prove very satisfactory.The essential principles are to ,have· the high cone, comparatively

MYIASIS-ITS PRE\'ENTION AND TREATMENT 203large opening at the top of the cone, screened area over the cone to admitlight from above, screened sides so as not to cast shadow around thebait, and legs about one inch high. The tent traps are not as efficientas the cone traps and this inefficiency is especially marked in somemakes of traps now being furnished the Army, which arc built with abroad bottom on either side of the tent. This repels the flies to such anextent as to make the traps almost worthless. For blow flies this darkenedarea is not so objectionable as for the house fly. While not strictlya trap, the method of covering carcasses with burlap as recently suggestedby Froggatt in Australia may be of value. Four stakes are driveninto the ground around the carcass, and the tops of these are connectedwith a heavy wire. A canopy is then put over the stakes, brought tothe ground and dirt piled on the edges. When the flies emerge they areimprisoned and soon die. If the canopy is not sufficiently large, thereis danger of many escaping through the migratory habit of the Iarvre.Kind of Bait to Use.-This point has been discussed in a previouslecture. Animal matter is best for blmv flies, and the packing-house refuseknown as "gut slime" is best of all. It is removed from intestineswhen sausage casings are made. Good baits and proper attention to killingand rebaiting are essential to best results.Poiso"",.-It is possible to destroy large numbers of flies by meansof poisoned baits. Arsenic solution (made by boiling arsenic in water)mixed with defibrinated blood, gut slime, or some other attractive baitwiII kill large numbers. This bait may be placed in covered containersto prevent dilution by rain. Cobalt may be substituted for arsenic.When carcasses can not be burned, Frogga tt has advocated slashingthem and spraying with arsenic solution. This poisons large numbersof flies and maggots and reduces the attractiveness of the carcass; somuch so, in fact, that birds and animals will not touch it.Avoidance of Attack on lIfan.-To prevent fly attack it is necessaryto have wounds promptly and properly dressed. Man should avoidexposure by sleeping in the open during hot weather, especially if thereis any trouble from catarrh or nose bleeding. Properly screened hospitalsare of much importance and individual blow flies found withinshould be promptly killed ..Avoidance of Attack to Animals.-In preventing screw-worm attackin cattle and other livestock, there are several important points to beconsidered. Breeding should be done so as to have calves come duringfall, winter or early spring months. Branding and surgical operationsshould also be done out of screw-worm season.. Care should be takento avoid mechanical injury to stock. As the screw-worm flies are worstin brushy pastures, clearing out all underbrush will be found beneficial.Since many cases develop from infestation of ticks and mange, the de-

~04 SANITARY ENTOMOLOGYstruction of ticks and mange mites on animals is important. Careshould be taken to guard against extensive saddle or harness sores onarmy animals.Methods of preventing blowing oi wool on sheep hardly need to bediscussed fully here. Shearing early in the spring, avoiding the soilingof wool, raising hornless breeds and the crutching, that is clipping thewool at the vent and behind the hind legs greatly reduces infestation.Treatment of Infesta.tions 1m, Man.-Nasal myiasis is the most difficultto handle. The larvIE should be removed mechanically as far aspossible. A number of different treatments have been resorted to, theadministra tion of chlorofornl into the nose being the most used. Afteralllarvre have been taken away, it is usually necessary to exercise care toprevent breaking of blood vessels which are frequently greatly exposedby destruction of the surrounding flesh. In most wounds the larvIE arequite easily removed. Of course the details of the care of the patientare to be determined by the physician in charge.Treatment of W ownds in Animals.-Chloroform is the most generallyused of all reagents and is usually satisfactory. The chloroform ispoured directly into the holes and the wounds closed up. This benumbsthe larvIE so that they can be taken out with a forceps. Carbon tetrachlorideis also satisfactory for this use and considerably cheaper.After the larvre have been taken out antiseptic astringent dressing shouldbe applied and pine tar or pine oil and vaseline applied to the outsideto repel flies. Oil of camphor is an excellent fly repellent and aids in thehealing process. Bleeding wounds should be dusted with tannic acidbefore applying the repellent.SUBDERMAL MIGRATORY SPECIESThe reduction of the number of ox warbles in cattle is importantfrom the standpoint of the raiser as well as to lessen the chances ofinfestation of man and horses. The most feasible method yet devisedconsists in the squeezing out of the larvIE from the backs of the animalsafter they have formed the subcutaneous tumors. This should be doneat intervals of about three weeks, all animals being gone over carefully.The period for beginning extraction varies according to latitude fromOctober 15 to March 1.The question of controlling Dermatobia hominis in tropical America,and also its African analogue, Cordylobia anthropophaga, has not beensufficiently worked out to make satisfactory recommendations. No doubtwhere livestock are under control, systematic extraction will reduce thenumber of these, both in animals and man. When humans become infestedit is usually advisable to allow the larva to become stationary and

MYIASIS-ITS PREVENTION AND TREATMENT ~05then remove it through the hole in the skin. It may be necessary to enlargethe hole to get it out more easily. In the case of the Americanforms the bite from various bloodsucking Diptera should be prevented asfar as possible. Having the body well protected with clothing will alsoprobably reduce injury from both of these species. On account of theprobability that some of the African parasites of this class deposit eggson exposed clothing, especially if wet with perspiration, this should beguarded against.SPECIES CAUSING INTESTINAL AND UROGENITAl. MYlAsISCONTROL OF TRULY PARASITIC SPECIEs.-In Animals.-There arethree principal methods of attack against the bots of horses. The de-FIG. 40.-Nose protection for horse against attacks of the nose fly, Gastrophilushaemorrhoidalis. (Dove.)struction of eggs will accomplish much good in the case of Gastrophilusintestinalis and is applicable to some extent to G. nasalis, but apparentlycan not be practiced in G. haemorrhoidalis. Dove has found that thecommon practice of washing the legs of horses with kerosene oil hus butlittle beneficial effect. The creosote derivatives containing about twoper cent phenols destroyed the eggs readily. A miscible creosote compoundreduced with water to this strength and applied with a rag orbrush at the time the horses are groomed will destroy practically alleggs present. Such treatment repeated weekly should accomplish ulmostcomplete control. In this way horses and mules may be kept practicallyfree from infestation. Of course the grooming itself will tend to hatch

206 SANITARY ENTOMOLOGYeggs and get rid of larvre. Clipping of the hair on the legs has alsobeen recommended but is not entirely satisfactory. Dove has experimentedwith certain ·halter devices for the protection of horses in pasturesand also with various types of guards to be used on horses illharness to prevent the attack of the nose fly (fig. 40). In the first casehe used a halter, from which is suspended a box-like arrangement thatcovers the nose when the horse has its head up, but permits of grazingand drinking. A canvass extends back under the jaw to prevent depositionof eggs by the throat bot, and of course the covering of the mouthprevents the ingestion of eggs of the common bot. The main difficultyhas been the production of a durable device of this kind. The nose flyattack is best prevented by a rectangular piece of belting being suspendedfrom the bit rings immediately below the lips, when horses are,at work.The internal treatment of infested animals with carbon disulphidehas heen found to be very efFective if properly done. Three three-dramdo~s at hourly intervals are given in capsules succeeding a period ofstarvation and followed by a purgative.Pretention of Attack in Man.-The reduction of the number of batsby treatment of the lower animals will greatly reduce the chances of infestationin man. Care should be taken not to ingest eggs or larvre,,"hen infested horses are being clipped or groomed.PREVENTION OF ATTACK BY OTHER FORMs.-This group includesthose species accidentally infesting man such as the IHuscids MWlcadomestica, and Muscma spp., Fannia, and Syrphus flies.Destruction of Breeding PlaceB.-Since most of these forms arebreeders in excrementitious matter and decaying vegetation, the propercare of manure of all kinds is important. This has been discussed in otherlectures. Since some of the species, especially }

MYIASIS-ITS PREVENTION AND TREATMENT 207producing pure water. Where it is essential that water must be takenfrom streams care should be exercised not to drink near vegetation.Use of Screena.-Proper screening of houses will do much to protectfoods after prcparation from infestation, although some of the smallforms can not be kept out in this way. A coarser mesh than 16 per inchshould not be used. The use of screened toilets of course can not be toostrongly emphasized.Clea'1llmess and CarefUl Habits.-Many infestations of thc digestivesystem and genitalia could be avoided by not sleeping in unscreened placesin an exposed condition. Prompt attention to infants is important.SPECIES INFESTING HEAD PASSAGESInfestations in A'1limals.-The parasitic forms are very difficult tocontrol and no very satisfactory control measures have been devised.Nearly all of the recommendations made are of little value. Some ofthese consist of the use of repellents in the case of sheep to protectthem from infestation by Oestrus ovis. Pine tar is most frequently usedand this is applied by the sheep themselves. Holes in logs are used forsalting and the sides are smeared with tar. The provision of plowedfurrows where the sheep can protect their noses probably gives somerelief. For very valuable animals screened pens are no doubt warranted,the animals being placed in these during the portion of the day whenthe flies are most active. There seems to be considerable difference ineffect of attacks on breeds. Attempts to remove the larvre from the noseby causing sneezing or with fum~gants arc more likely to drive the larvredeeply into the head than to remove them. Trephining the skull andremoving the larvre in that way may give some relief but is usually notadvisable as other infestations are likely to follow and all the grubscan not be reached. Destruction of adults has been advocated and is.especially applicable to plains areas, as in such places flies are inclinedto congregate on any objects which extend well above the ground. Theflies assemble on such objects and remain there except during the wannerpart of the day and many can be killed.Many of the control measures suggested for the control of the sheepbot can be used against the horse infesting species, Rlzinoestrua purpureua.It might also be possible to utilize muzzles similar to those advocatedfor the horse bots to protect against infestations from this species.Infestations in i1Ian.-lnfestations of man arc so infrequent that preventivemeasures need receive little attention. "Yhere such infestationseither by the sheep head maggot or horse head maggot are commonthe use of nets on the hats similar to those used by apiarists wouldgive protection. Medical attention should be given promptly for re-~ moval of larvre, especially if in the eye.

~08 SANITARY ENTOMOLOGYBLOODSUCKING SPECIESIn Birds.-Since these dipterous parasites are often highly injuriousto birds, and especially to certain beneficial varieties, control measuresshould be considered although nothing has been done along this line. Inthe Southwest it is stated that the mortality among birds is very highowing to these parasites.Possibly trapping of the adults in connection with the control ofother destructive species would be feasible. .In Man.-The Congo floor maggot is the only species in this grouprequiring special attention.' The use of beds instead of sleeping matslaid directly on the floor will give immediate relief. Where beds are notat hand hammocks may be u_sed. The avoidance of sleeping in hutsis advisable. Thorough cleansing and disinfection of the floor shoulddestroy many maggots and the elimination of cracks in the dirt willcheck their breeding. Where sleeping mats are used by the nativesthey should be sunned and aired frequently. It is said that the maggotsare carried from one hut to another in these mats, so that moving theplace of abode does not eliminate the trouble.

CHAPTER XIVDiseases Transmitted by Bloodsucking Flies 1W. Dwight PierceAs stated before it was necessary to discuss the transmission ofdiseases by flies in three lectures, non-bloodsucking flies, mosquitoes andother bloodsucking flies. This is therefore the second lecture on flybornediseases, and embraces quite a different category of diseases. Forconvenience of reference and study it will be likewise handled from thestandpoint of the organism transmitted. The most important volume onthe subject of this lecture is by Hindle.PLANT ORGANISMS CARRIED BY :BLOODSUCKING FLIESThallophyta: Fungi: Schizomycetes: BacteriaceaeBacterium tularense McCoy and Chapin, the causative organism of aRODENT PLAGUE, is probably normally carried by fleas, but Wayson'records some interesting experiments with the stable fly, Stomo:r:ys calcitransLinnaeus. He found that a fly after biting an acutely diseasedguinea pig eight times, if applied to a healthy animal within an hour, willeffectively transmit the disease to the healthy animal and cause its deathin five to nine days. Washings of the flies in normal salt solution, andalso washings of the flies slightly crushed, when injected subcutaneouslywill produce similar results. The transmission by bites occurs only fromthose animals having an advanced stage of the bacteremia, as indicatedby their death within 24 to 48 hours after the fly feeding. The flies havenot been proven infective as long as 24 hours. This same organism hasbeen isolated from cases of DEER FLY FEVER or PAHVANT VALLEY PLAGUE in Utah by Francis (1919). The disease is local and onecase in 1919 was fatal. The fever, lasting from S to 6 weeks, is said tobe initiated by the bite of deer flies (Chrysops).Bacterium anthracis Davaine, the causative organism of ANTHRAXor charbon, can be earned by bloodsucking flies. Nuttall (1899) citesmany early references to the role of bloodsucking flies in the transmis-• This lecture was presented October 7, 1918, and distributed October 19. It hasbeen somewhat modified for the present edition.209

.!e10SANITARY ENTOMOLOGYsion of anthrax, the earliest being by Montfils in 1776. Hintermayer(1846) studied an epidemic which raged among the deer in the Park ofDuttstein. The horse flies; Tabanus bovVnus Loew, Haemotopota plu'Vialis (Linnaeus), and Chrysops coecutiens (Linnaeus) assembled usuallyin thousands on the carcasses of the fallen animals and sucked the profluviawhich escaped from the mouth, nose, and vent. Leaving the bodiesthey immediately sought the healthy animals, thrust their proboscidessoiled with the virus into the skin and in ~his way inoculated the poisonof the disease. Mitzmain (1914) proved that Tabanus striatus Fabriciusand the stable fly, Stomoxys calcitrans Linnaeus, can transmit the diseaseby their bites. Schuberg and Kuhn (1912) transferred anthrax infectionfrom a cadaver to a living animal through the bite of Stomoxys calcitrana.Morris (1918) working on anthrax in Louisiana proved that thehorn fly Lyperosia irritans Linnaeus (H aematobia) when biting an infectedguinea pig four hours or less before its death and up to fifteenminutes after death can transmit infection. One hundred and eightyfourexperiments on different guinea pigs' were made during these timelimits and infection was conveyed in 34 per cent of the cases. Forly.experiments outside of these time limits were unsuccessful. One out oftwo tests with the flies feeding on an infected sheep thirty minutes beforedeath yielded infection in a guinea pig, and all tests of biting in the quarterhours before and after death of the sheep yielded infection in guineapIgS.He also tested a species of Tabanus and proved transmission in 40per cent of 70 cases in which the flies bit between four hours before deathand five minutes after death. Virulent cultures of anthrax were obtainediII nature by Morris from Tabanus atratus Fabricius caught feeding ona carcass. This species will feed on a carcass tJIirty minutes or moreafter death.He likewis~ determined the spores in the feces of the Lyperosia up tosix hours after feeding, of the Tabanus one to twelve hours afterfeeding, and of mosquitoes 48 to 72 hours after feeding.The above cited evidence should be sufficient to emphasize the absolutenecessity of isolating and protecting from bloodsucking insects, animalssick with anthrax. Valuable animals should likewise be kept in screenedbuildings during outbreaks of the disease.Thallophyta: Fungi: Schizomycetes: CoccaceaeStaphylococcus pyogenes albus and a1breUS Rosenbach, the causative'Organisms of various types of SEPTICAEMIA, were obtained by J oly{1898) from a Tabanus on a heifer near a municipal vaccine station.

DISEASES TRANSMITTED BY BLOODSUCKING FLIES 211StreptocOCC'U8 sp., causative organism of SEPTICAEMIA, was recordedfrom Stomoxys calcitra;n.s Linnaeus bv Schuberg and Baing(1914).DISEASES OF UNKNOWN OR UNCERTAIN ORIGINPAPPATACI FEVER, also known as Three-day and Phlebotomusfever, a disease of the Mediterranean regions, which has caused considerabledisability to the troops, especially in Egypt and Greece, is transmittedby the bite of the sand fly, Phlebotom'U8 papatasii Scopoli, andpossibly other species in the genus. This disease is considered very closelyrelated to dengue, if not identical, by Megaw (1919) and others. Itstransmission has been clearly demonstrated by Doer, Franz and Taussig(1909). The blood is infective for only about 24 hours. During thisperiod the flies become infected by feeding on the patient. After ingestingthe virus, there is an incubation period of seven to ten aays before theinsects become infective, and beyond this after an indeterminate periodthey may again become non-infective. Following the bite of an infectedfly, there is an incubation period in man of from SY::l to 7 days, duringwhich time the patient is non-infective. The virus is filterable. Lizardsand ~eptiles are the wild reservoirs of the disease.VERRUGA PERUVIANA, or Carrion's disease, a Peruvian disease,thought to be caused by Bartonella bacilliformis Strong, Tyzzer, Brues,and Sellards is claimed by Townsend (1916) to be carried by Phlebotom'U8verrucarwm Townsend, and he advances evidence to support his claim.EQUINE INFECTIOUS ANEMIA, or swamp fever of horses, adisease caused by a filterable virus jn Japan, was thought to be carriedby Chrysops japonic'U8 Wiedemann, Chrysozona pluviatilis Linnaeus(Haemotopota tristis Bigot), Taban'U8 chrysurus Loew, T. trigon'U8Coquillett, T. trigemimus Coquillett, and Atylot'U8 rufidens Bigot, accordingto the Horse Administration Bureau (1914); and in Americawas claimed by Scott (1915) to be carried by Stomoxys calcitransLinnaeus .. Howard (1917) conducted an experiment with Stomoxys calcitranswhich indicated the probability that this fly transmitted thedisease.HOG CHOLERA, a disease caused by a filterable virus, has recentlybeen transmitted by inoculating animals with infected Stomoxys calcitra;n.s(Dorset, et aI., 1919).GLANDERS is associated by Fuller (191S) with Stomoxys calcitransoutbreaks.POLIOMYELITIS, or infantile paralysis, a disease of unknownorigin, has been suspected by various authors of being transmitted bybiting insects, especially Stomoxys calcitrans and Tabanids. Rosenau

· SANITARY ENTOMOLOGYand Brues (1912) conducted experiments with this fly and reported successfulinoculations of six monkeys by bites of the flies. Anderson andFrost (1912) repeated these experiments and as a result three monkeysexposed daily to the bites ·of seyeral hundred Stomoxys, which at thesame time were allowed daily to bite two intracerebrally inoculated monkeys,developed quite typical symptoms of poliomyelitis eight, seven, andnine days, respectively, from the date of their first exposure. Autopsyof all proved the presence of typical poliomyelitis lesions. On the otherhand these same authors in further experiments (1913) and Sawyer andHerms (1913) record negative results with this fly. Fuller (1913) reportsthat it has been shown that epidemics of infantile paralysis usuallyoccur with an abundance of the stable fly.PELLAGRA, a disease of unknown origin, introduced from Europeto America, was for a long time thought to be caused by eating spoiledcorn. At present sentiment seems to favor considering that it is causedby lack of vitamines. However, it is important that we discuss in thislecture rather briefly the theories propounded regarding bloodsuckingflies as possible transmitters of the disease.Sambon (1910) brought forward the theory that the disease is carriedby the buffalo gnats Simulium spp. Jennings and King (1913b)and Jennings (1914) are inclined to believe that the incidence of thisgenus and of pellagra affords sufficient evidence to exclude Simulium fromthe consideration. On the other hand Jennings and King in their threepapers point out very strongly the possibility of Stomoxys calcitranabeing concerned in the transmission of the disease.RICKETTSIA MELOPHAGI Noller, a body similar to those foundin typhus, trench fever, etc., is found in the bodies of Melophagus ovinus,the sheep tick, but is not known to be associated with any disease.ANIMAL ORGANISMS TRANSMITTED BY BLOODSUCKING FLIESProtozoaMastigophora: Binucleata: HaemoproteidaeHaemoproteus columbae Celli and San Felice, the cause of PIGEONMALARIA or haemoproteasis of Columba livia, is transmitted by thepigeon flies Lynchia maura Bigot in Algeria and India, and L. brwneaOlivier in Brazil. Mrs. Adie (1915) worked out the complete life cyclein the fly, and Acton and Knowles (1914) in the pigeon. Mrs. Adiesucceeded in transmitting the disease to uninfected pigeons by the bitesof Lynchia flies. The flies used were dissected and found to contain

DISEASES TRANSMITTED BY BLOODSUCKING FLIES :!13zygotes and sporozoites. Parasites were found in the blood of thepigeons !e8 days after the flies were first put on them.In the pigeon the asexual cycle is passed. The sporozoites are inoculatedby the bite of the fly. They enter the red blood corpuscles in thelung capillaries where they develop into trophozoites and schizonts anddivide into merozoites, which may continue the asexual cycle by enteringother corpuscles and becoming trophozoites. On the other hand theymay remain in peripheral circulation and develop into the sexual forms,the macro- and microgametocytes. These forms may persist in thepigeon's blood over winter. They are ultimately taken up from theCYCLE OFSCHIZOGONY INCO~UMB" llv,,, ~IG£Jl~.ICYCLE orSPOROGONY INl YNGHIA M"URA, (FLY).LIFE CYCLE OF HAEMOPROTEUS COLUMBAEFIG. 41.(l>ierce.)pigeon's blood by the fly and pass from its proboscis into the gut. Theydevelop into gametes which conjugate to form zygotes in the lower portionof the mid-gut. These become ookinetes and develop into oocystsin the gut wall. The oocysts divide into a multitude of sporozoites whichfind their way through the body cavity into the salivary glands and areready for inoculation.The life cycle is graphically shown in the chart (fig. 41) whichshould be compared with that of Plasmodium (fig. 47) in the lectureon mosquito-borne diseases.H aemoprotcus mansoni Sambon, the cause of HAEMOPROTEASISOF THE RED GROUSE, is transmitted by the grouse fly, Ornithomyialagopodia Sharp in which Sam bon found ookinetes in the stomach.

~14 SANITARY ENTOMOLOGYCertain species of Haemoproteus are mentioned In another lectureas transmitted by mosquitoes (see Chapter XVII).Mastigophora: Binucleata: LeucocytozoidaeLeucocytozoon lovati Sambon and Seligman, the cause of LEUCOCYTOZOASIS OF THE RED GROUSE, Lagopus scoticus, is supposedby Fantham to be likewise transmitted by the grouse fly, Ornithomyialagopodis Sharp, in which he found vermicules.Mastigophora: Binucleata.' TrypanosomidaeAs has been mentioned before, Chalmers' new classification of Trypanosomegenera is used in this volume, although criticizea ·by Mesnil. Thevalue of this classification can be seen in the various lectures in that itgroups together species with similar host relationships. The two generainvolved definitely in biting fly transmission are Castellanella and Duttonella.In the former the final stage in the insect takes place in thesalivary glands, al),d'in the latter, elsewhere in the anterior portions of theinsects. Those species which can not be definitely assigned to a genusare left in Trypanosoma ·(sens. lat.).Castellanella OITIITWme?Ule (Laveran), cause of an EQUINE TRYPANOSOMIASIS in Annam, is believed to be carried by Tabanidae andHippoboscidae according to Castellani and Chalmers.Castellanella bruce? (Plimmer and Bradford) Chalmers, cause ofNAGANA, an African disease affecting many wild and domestic animals,is transmitted normally by bites of the tsetse flies, Glossina morsitansWestwood, G. brevipalpis Newstead, G. pallidipes Austen, G. tachinoidesWestwood, and G. fusca Walker, and may also be transmitted by thehorse flies Atylotus nemoralis Meigen, and a Tabanus, and by the stableflies Stomoxys calcitran.s Linnaeus, and S. glauca. The organism mustundergo part of its development in the alimentary canal of the fly. Whenfully developed it is found in the proboscis and is then capable of beinginoculated into animals by the bite of the fly. Trypanosoma sp., cause ofAINO,. an African disease of cattle probably identical with C. brucei, issuspected by Brumpt to be carried by Glossilna longipenm,is Corti.Castellanella dimorplwn (Laveran and Mesnil) Chalmers, cause of anAfrican ANIMAL TRYPANOSOMIASIS, is carried by the tsetse flies,Glossina palpalis Robineau-Desvoidy, G. tachinoides Westwood, G. morsitansWestwood, and G. longipalpis Wiedemann, and possibly byLyperosia. The trypanosomes upon being taken up by the fly becomeestablished in the hind intestine and gradually extend forward until theyreach the proboscis, when they become fixed and assume the leptomc;mador crithidial form.

DISEASES TRANS~lITTED BY BLOODSUCIHNG FLIES 215Castellanella equtperdum (Doflein) Chalmers, cause of DOURINE ofhorses, has been experimentally transmitted by interrupted feedings ofthe stable fly, Stomoxys calcitrans Linnaeus and Atylotua tomenlosuaMacquart by Sergent and Sergent (1906).CasteUanella evansi (Steel) Chalmers, cause of SURRA of cattle amIhorses, has been experimentally transmitted by bites of Stomoxys calcitransLinnaeus, S. geniculatua Bigot and S. nigra l\Iacquart. Eithel'experimental evidence or strong suspicion points to transmission by thehorse flies, TabOlTtus tropicua Linnaeus, T. striatua Fabr.icius, T. lineolaFabricius, T. atratus Fabricius, T. fumifer Walker, T. partitus Walker,•H_I(A_ ... ~)WII.D R,K,.,VO'"LIrE CYCLE Of TRYPANOSOMA MMBIENSE.THSCAUS .. Of"GAMBIIINSLlZPfNG Slcll .. ",o..MANH.,' TMKLAI'fIU' .P&IIEI ~lM£).HClP' .. m.GutUl~"" AALM.L.lS (.,..en ......... ).ii_ m. H.yo SAPICNS (MAo").FIG. 49.(Pierce.)T. vagus Walker, T. minimus Van der Wulp, and other species of Tabanusand Haematopota. Certain writers have also suspected Lyperosia minutaBezzi, Philaematomyia crassirostris Stein and Lyperosia etEigua l\leigen(Haematobia). The parasite has also been found in the stomach ofStomo:cys geniculatua.Castellanella evans;' mborii (Laveran), cause of MBORI, a cameltrypanosomiasis of Africa, is believed to be carried by Tabanus tacniatuaMacquart and T. biguttatua Wiedemann.Castellanella gambiense (Dutton) Chalmers (nigene'1lo8e Macfie),cause of GAMBIAN AND NIGERIAN SLEEPING SICKNESS of man,has wild animals for its reservoir, and is principally transmitted by Glossina.palpalis Robineau-Desvoidy and its variety fuacipes. Experimental

216 SANITARY ENTOMOLOGYevidence indicates that it can be carried by Glossina morsit0/n8 Westwood,G. fusca Walker, G. long..,ipennis Corti, G. pallidipes Austen, G.brevipalpis Newstead, G. tachittoides "Vestwood, as well as Stomoxyscalcitrans Linnaeu~, and the mosquitoes mentioned in another lecture.After the trypanosomes are ingested in the blood of the fly, multiplicationbegins, usually in the midgut (fig. 42). After the tenth or twelfth day,many long, slender trypanosomes are found which gradually move forwardinto the proventriculus. Such long, slender forms represent the limitof deyelopment in the lumen of the main gut. The proventriculus type,developed about the eighth to the eighteenth or twentieth day, is notinfective; it may occur in the crop, but is not to be found permanentlythere. Between the tenth and fifteenth days multinucleate forms oftrypanosomes are found, and may be styled multiple forms. Some ofthese latter may be degenerative. Long slender forms from the proventriculuspass forward into the hypopharynx. They then pass backalong the salivary ducts, about sixteen to thirty days after the fly'sfeed. In the salivary glands they become shorter and broader, attachthemselves to the surrounding structures and assume the crithidial facies.They remain attached to the wall and multiply. These crithidial stagesdifferentiate into the short, broad trypanosome forms, capable of swimmingfreely. These forms only are infective.After inoculation into the vertebrate these forms multiply by longitudinal'division.Repeated division occurs until the blood ~warms withparasites. They then disappear from the blood and become latent nonflagellatebodies in the intestinal organs. These latent bodies againbecome flagellate and enter the general circulation, and may be taken upby a bloodsucking fly. The above life cycle was worked out by MissRobertson as well as other workers and briefed by Fantham, Stephensand Theobald.Castellam.ella pecaudi (Laveran), cause of BALERI, a fatal equinetrypanosomiasis of Africa, is usually spread by Glossina longipalpisWiedemann and G. morsitans Westwood, but G. tachinoides Westwoodand exceptionally G. palpalis Robineau-Desvoidy may be infected.Stomoxys calcitrans Linnaeus and S. nigra Macquart are recorded aspossible carriers. The incubation period in G. longipalpis is 28 days.The trypanosomes multiply in the fly intestine up to 43 hours afteringestion in a modified form, called by Roubaud the "intestinal trypanosomeform." Under favorable conditions these multiply very rapidlyand in seven to nine days invade the whole of the intestine as far as thepharynx. These flies are not infective until the parasites have invadedthe proboscis and passed through the crithidial and leptomonad phases.These proboscis forms multiply and some reach the hypopharynx, where

DISEASES TRANSMITTED BY BLOODSUCKING FLIES !!17they assume the "salivary trypanosome form" and are then capable ofinfecting any susceptible animal (Hindle).CasteUanella rhodesienae (Stephens and Fantham) Chalmers, causeof RHODESIAN SLEEPING SICKNESS of man, is carried by GlossinamorsitOlTUl Westwood, G. palpalis Robineau-Desvoidy, and G. brevipalpisN ewstead. The insect becomes infective after an incubation period ofabout 14 days and is infective throughout the remainder of its life. Thelife cycle is not completely worked out, but it is known that the trypanosomesfirst become established in the intestines and later invade thesalivary' glands (Hindle).Castellanella soudam.ense (Laveran) Chalmers, cause of TAHAGA ofdromedaries in Sudan, EL DE DAB of dromedaries in Algeria, andZOUSF AN A of horses in Sud Oranais, has been experimentally transmittedby Stomoxys calcitrOlTUl Linnaeu~ S. nigra Macquart, Atylotusnemoralis Meigen, and A. tomrmtosus Macquart ..Duttonella caprae (Kleine) Chalmers, cause of an African goat Trypanosomiasis,is transmitted by Glossina brevipalpis Newstead and G.morsitOlTUl Westwood.Dutt"onella cazalboui (Laveran) Chalmers, cause of SOUMA, anAfrican anim~l trypanosomiasis, is principally carried by the tsetse fliesGlossina palpalis Robineau-Desvoidy, G. longipalpis Wiedemann, G. morsitansWestwood, and G. tachinoides Westwood, but may also be transmittedby. Stomoxys calcitrans Linnaeus, Tabanus biguttatus Wiedemann,and T. taeniatU8' Macquart, apd ·possibly Stomoxys nigra Macquart.Development of the organism is restricted to the proboscis ofthe tsetse fly, the flagellates never multiplying in any other part ofthe alimentary canal. They may change in the proboscis into leptomonador crithidial forms, attach'to the walls of the labrum and undergorapid multiplication. Under the influence of the salivary secretionsome of these fixed flagellates develop into small, actively motile trypanosomesclosely resembling the blood forms. This becomes infectivefrom six to ten or more days after ingestion of the parasites.Duttonella cazalboui pigritia (Van Saceghem), cause of ZAMBIANSOUMA of cattle, is carried by Haematopota perturbans according toYan Saceghem who' found the organ~sm in the intestinal tract of fliestaken on infected animals.Duttonella congolense (Broden) Chalmers, cause of GAMBIANHORSE SICKNESS, is carried by Glossina morsitans and possibly byG. palpalis and species of Glossina, Tabanus and Stomoxys. The variousforms of the parasite have been demonstrated in the alimentary canalof G. morsitfll1l,8 !!3 days after ingestion.Duttonella nanum (Laveran) Chalmers, cause of a fatal BOVINETRYPANOSOMIASIS of Africa, is carried by Glossina palpalis, and

fl18SANITARY ENTOMOLOGYpossibly G. mor8itana. The development in the gut of palpali8 is similarto that described above for T. gambieme. Multiplication begins in thehind intestine and by the tenth day numerous parasites are found in thehind and middle intestine. The slender forms begin to be produced fromthe tenth to the fourteenth day' onward, and the proventriculus isusually invaded about the twentieth day. About the 25th day they invadethe proboscis, where they may be found attached to the labrum, oftenlying in clusters. They tl~en pass through the crithidial phase, many ofthem being extremely long and slender. Subsequently trypanosome formsare produced which may be found free, sometimes in the hypopharynx andat other times in the labrum ... The salivary glands never become infected.(Taken from Hindle who summarizes the work of Duke and others.)DuttoneUa pecorum (Bruce, Hamerton, Bateman and Mackie), causeof a WILD ANIMAL TRYPANOSOMIASIS, is carried by Glo88inamor8itana, G. tachinoide8, G. palpalia, and G. brC'Oipalpis, in the alimentarycanal of which it undergoes its cyclical development.Duttonella aimiae (Bruce, Harvey, Hamerton, Da.vey and LadyBruce), cause of SIMIAN TRYPANOSOMIASIS, is carried by Glossinamor8itans and G. brC'Oipalpis.tDuttonella uniforme ,(Bruce, Hamerton and Mackie), a fatal TRYPANOSOMIASIS of cattle, with wild animal reservoirs, is naturallycarried by Glossina palpalis, which becomes infective in from 27 to 87days. The infection of the fly is always limited to the proboscis.Duttonella vivax (Ziemann) Chalmers, cause of a bovine and ovineTRYPANOSOMIASIS, is carried by Glo88ina tacltinoide8, and probablyby G. palpalis and G. mor8itana. Stomoxys and Lyperosia are suspectedcarriers. The incubation period of the fly is from five to eight days.Trypano8oma franki Frosch, cause of a TRYPANOSOMIASIS OFWILD GAME in Europe, is believed to be transmitted by Hippobo8cidaeand Tabanidae.Trypanosoma gallinarwm, cause of FOWL TRYPANOSOMIASISof the domestic fowl, is carried by Glo88ina palpalia, according to Duke(191fl).Trypanosoma grayi Novy, cause of CROCODILE TRYPANOSOMI:ASIS in Africa, is carried by Glo88ina palpali8 and G. brevipalpia.Trypano8oma theileri Laveran, thought to cause GALL SICKNESSof cattle by some authors, was experimentally transmitted by Theiler inSouth Africa by bite of Hippobo8ca rujipe8 Von OIfers and H. maculataLeach.Trypano8oma tullochi Minchin is native to Gl088ina palpalk inAfrica, and no vertebrate host is as yet known.

DISEASES TRANSMITTED BY BLOODSUCKING FLIES ~19lJlastigoplJora: Binucleata: LeptomonidaeCrithidia melophagia Flu is normally a parasite of the sheep tickfly, Melophagus omnus Linnaeus, and has been experimentally transmittedto rats and mice. Flu (1908) describes in the fly an asexual and sexualreproduction. The latter is characterized by a process of reduction,followed by conjugation with the formation of an ookinete and the infectionof the eggs of the insect, which may cause a second generation of fliesto carry the organism.Crithidia nycteribiae Chatton is found in the parasite fly, Cyclopodiasykesi Westwood.Crithidia pangoniae Rodhain, Vandenbranden, Bequaert and Ponsoccurs naturally in Tabanus hilans Walker, T. 8triatU8 Fabricius, and aTabanu.s sp.Crithidia tenuis Rodhain, Pons, Vandenbranden and Bequaert isnative to Haematopota duttoni Newstead, and H. 'llandenbrandeni Rodhain,Pons, Vandenbranden and Bequaert in Belgian Congo.Leishmania brasiliensis Vianna, cause of nOUBA or oral leishmaniasisof Brazil and Paraguay, is believed by Brumpt and Pedroso to be carriedby bloodsucking flies, either Tabanidae or Culicidae.Leishmania tropica (Wright), cause of BISKRA SORE in Algeria,and BAGDAD SORE in Bagdad, is believed by Wenyon (1911) andSergent and Sergent (1914) to be transmitted by Phlebotomus mmutwafricanus Newstead.Leishmania uta Escomel, cause of UTA, a dermal lesion peculiar tothe western face of the Andes in Peru, is believed by Townsend to becarried "by Forcipomyia utae Knab and F. townsendi Knab.Leptomonas minuta (Leger) occurs naturally in the intestine andMalpighian tubules of Tabanu8 tergestinus Egg.LeptomO'Tlas phlebotomi (Mackie) occurs in nature in Phlebotomusminutus Rondani in India._Leptomonas simuliae (Georgewitch) occurs in nature in Simuliumcolumbaczense Schonberg in Europe.Leptomonas 8ubulata (Leger) attacks Haematopota italica Meigenin Southern France.lJl astigophora: Spirochaetacea: SpirochaetidaeSpiroschaudimtia glossinae (Novy and Knapp) occurs in the stomachof Glossina.Telosporidia: H aemogregarimMla: "H aemogregarilnidaeHaemogregarina francae De Mello, a parasite of t}le dove, Columbalima, i$ suspected of being carried by Lynchia maura Bigot.

SANITARY ENTOMOLOGYH aemogregarilna sp. passes its sporogony in Glossina palpalis butits vertebrate host is unknown.MetazoaNemathelminthes: Nematoda: FilariidaeFilaria (Loa) loa (.Guiyot), cause of a human filariasis, was found byRingenbach and Guyomarc'h in the Congo to pass part of its life cycle inChrysops centurionis Austen, and by Leiper in West Africa in Chrysopsdimidiata Van der Wulp, and C. silacea Austen. Leiper obtained a slightdegree of infection but development was unequal and slow in Haematopotacordigera Bigot and Hippocentrwm trimaculat1lm N ewstead. Heobtained only n~gative results with Stomoxys nigra l\facquart, S. calcitrO/lt8Linnaeus, Glossma palpalis Robineau-Desvoidy, Tabanus parWalker, T. socialis Walker, T. fasciatus Fabricius, and T. secedensWalker. ...Thus it will be seen th~t many of the most dangerous diseases ofanimals and some of the most dreaded human diseases are carried bybloodsucking flies, and furthermore, that the transmission is principallybiological, that is, the insect is a necessary intermediate host. In thiscase the parasite invariably passes its cycle of sporogony in the invertebrateand its cycle of schizogony in the vertebrate, if it passes throughsuch a cycle.A number of organisms found only in the insects are recorded. It isquite possible that some of these will ultimately be linked up withpathological species. Anyone studying disease transmission must knowin advance what organisms he might encounter in the insects he isstudying.BIBLIOGRAPHYAnderson, J. F., and Frost, W. H., 1912.-U. S. Treas. Dept., PublicHealth Report, vol. 27 , No. 48, Reprint No. 99, 5 pp.Anderson, J. F., and Frost, W. H., 1918.-U. S. 'freas. Dept., PublioHealth Report, vol. 28, p. 833.Brumpt, E., 1902.-Arch. de Parasit., vol. 5, p. 158.Castellani, A., and Chalmers, A. J., 1913.-Manual of Tropical Medicine,2nd edit.Doer, Franz, and Taussig, 1909.-Das Pappatacifieber. Franz Deuticke,Leipzig and Wfen.Dorset, M., McBryde, C. M., Nile, W. B., and Rietz, I. H., 1919.-Amer.Journ. Vet. Med., vol. 14, No.2, pp. 55-60.Duke, H. L., 1912.-Proc. Roy. SO«l; 'Vol. B 85, No. B 580, pp. 378-884.

DISEASES TRANS~IITTED BY BLOODSUCKING FLIES fl~1Fantham, H. B., Stephens, J. W. W., and Theobald, F. V., 1916.-TheAnimal Parasites of Man. William Wood & Co.Flu, P. C., 1908.-Arch. f. Protistenk, vol. Ifl, pp. 147-158.Francis, Edward, 1919.-U. S. Treas. Dept., Public Health Reports, vol.34, No. 37, pp. fl061, 2062.Fuller, C., 1918.-Fly Plagues. An unusual outbreak of Stomo:cys calcitransfollowing floods. Union of South Africa, Dept. Agr., eire. 3~,1913.Hindle, E., 1914.-Flies in Relation to Disease. Blood-Sucking Flies.Cambridge Univ. Press., 398 pp.Hintermayer, 1846.-Centralarchiv. f. d. gesamte Staatsarzneikunde,Band 3, pp. 437, 441.Horse Administration Bureau, 1914.-Tokyo. Reviewed in Bull. Inst.Pasteur, vol. 12, No. 14, p. 634.Howard, C. W., 1917.-Journ. Parasit., vol. 4, pp. 70-79 .• Jennings, A. H., 1914.-Journ. Parasit., vol. 1, pp. 10-21.Jennings, A. H., and King, W. V., 1913.-(1) Journ. Amer. Med. Assoc.,vol. 65, pp. fl71-274; (fl) Amer. Journ. Med. Sci., vol. 146, pp.411-440.Joly, P. R., 1898.-Importance du role des insectes dans la transmissiondes maladies infectieuses et parasitaires.-Du fonnol comme insecticide.Bordeaux. Imprimerie du Midi. 90 pp. Thesis.Leiper, R. T., 1914.-Rept. Advis. Comm. Tropical Research Fund for1913, London, p. 86.Mcgaw, J. W. D., 1919.-Indian Med. Gaz., vol. 54, No.7, pp. 241-U7.Mitzmain, M. B., 1914.-U. S. Treas. Dept., Hygienic Laboratory, Bull.94, 53 pp.Morris, Harvey, 1918.-Blood-Sucking Insects as transmitters ofAnthrax or Charbon. La. Agr. Exp. Sta., Bull. 163, 15 pp.Nuttall, G. H. F., 1899.-0n the Role of Insects, Arachnids and Myriapodsas carriers in the spread of bacterial and parasitic diseases ofman and animals. A critical and historical study. Johns HopkinsHospital Reports, vol. 8, Nos. 1,2, pp. 1, 152.Ringenbach, J., and Guyomarc'h, 1914.-Bull. Soc. Path. Exot., vol. 7,pp. 619-626.Rosenau, M. J., and Brues, C. T., 1912.-·Mo. Bull. State Bd. HealthMassachusetts, vol. 7, No.9, pp. 314-317.Sambon, L. W., 1910.-Journ. Trop. Med. and Hyg., vol. 13, No. 19.Sawyer, W. A., and Herms, W. B., 1913.-Journ. Amer. Med. Assoc., vol.61, pp. 461-465.Schuberg, A., and Boing, W., 1914.-Arb. Kais. Gesundheitsamte, Band47, Heft. 3, pp. 491-512.

SANITARY ~TOMOLOGYSchubel'g and Khan, 1912.-Arb. Kais. Gesundheitsamte, Band 40, Heft~, pp. 209-~34.Scott, J. W., 1915.-Scienc~, vol. 42, No. 1088, p. 659.Sergent, Ed., and Sergent, Et., 1900.-Ann. Inst. Pasteur, vol. 20, pp.666-681.Sergent, Ed., and Sergent, Et., 1914.-Bull. Soc. Path. Exot., vol. 7, pp.67'7-679.Townsend, C. H. T., 191~.-Joum. Parasit., vol. ~, pp. 67-'73.Townsend, C. H. T., 1916.-Bull. Ent. Res:, vol. 6, pt. 4, pp. 409-411.Wayson, N. E., 19Io.-U. S. Public Health Service, Public HealthReports, vol. 29, No. 51, pp. 3390-3893. Reprint No. 242.Wenyon, C. M., 1911.-Kala Azar Bull., vol. I, pp. 86-'58.

CHAPTER XVBiological Notes on the Bloodsucking Flies 1W. Dwight PierceMr. Webb, in his lecture which follows (Chapter XVI), has given usa very comprehensive vie\v of the life history and habits of the horse:flies of the genus Tabanus. In another lecture we presented the data ontransmission of diseases by the bloodsucking flies and by reference tothis (see Chapter XIV) it will be seen that quite a number of genera belongingto several families of flies are concerned in disease transmission. Itwill be the aim of this lecture to present some of the salient biological factsconcerning these genera so as to prepare the sanitarian for controllingthose species in his territory, which might cause disease.The insects we have especially to deal with in this lecture are thesand flies of the genus Phlebotomus, in the family Psychodidae; the horseflies of the genera Tabanus, Atylotus, Haematopota, Chrysops, andChrysozona, of the family Tabanidae; the biting flies of the generaStomoxys, Lyperosia, Haematobia, and Glossina, of the family Muscidae;and the parasitic flies of the genera Melophagus, Lynchia, Hippobosca,and Ornithomyia, of the family Hippoboscidae.There are of course many other genera of bloodsucking flies whichmay contain potential disease car~ers. Interesting discussions of theseflies are to be found in the books by Hindle, and Patton and Cragg.FAMILY CHIRONOMIDAEMidge8The little midges of this family are often mistaker. for mosquitoes, towhich they are somewhat related. Their young are the well-knownblood worms in streams and stagnant pools. Of the five subfamiliesonly one, the Ceratopogoninae, contains bloodsucking forms. The eggsof Chironomidae are small and ovoid, or long and pointed at their extremities,and are laid either in a gelatinous string of mucus or separately.The larva consists of thirteen segments, with head directed downwards,and mandibles well developed. On the ventral surface of the eleventh• This lecture was presented October 14, and issued October 22. 1918.223

SANITARY ENTOMOLOGY.!legment and the extremity of the twelfth, there are delicate finger-likeprocesses, usually four in number, which serve as tracheal gills. Thepupa is free and either lives floating in water without any movement orrests on the bottom of the pool. It has a tuft of delicate white threadson the dorsum of the thorax, which serve as breathing tubes; or it mayhave a pair of respiratory trumpets.Ter8e8the8 torren8 Townsend, a mountain form in North America, isa voracious bloodsucker, a.ttacking man and animals, usually on the head,ears, and eyes. Its life history is unknown. .Mycterotypu8 bezzii and M. irritan8 of Southern Europe are voraciousbloodsuckers, biting human beings, as well as animals, and causinginflammatory swellings.Ceratopogon is a large genus containing a number of bloodsuckinggnats called "punkies," found in various parts of the world. Some of theAsiatic species attack bloodsucking mosquitoes and draw blood fromthem. It is therefore possible that these insects may playa role in diseasetransmission. They are very small, measuring Jess than S mm. in length.Only the females are bloodsuckers. They bury themselves often amongthe hairs of the host and are not recognized until they become repletewith blood. They often cause great distress on account of their numbersand the irritation produced by their bites. The different specieschoose different parts of the host for '!,ttack, as for example, some selectthe face, especially the margins of the ears and eyes, while others mayattack the arms or legs.Forcipomyia utae Knab is thought by Townsend to cause the SouthAmerican disease, uta. Forcipomyia is c(:>Dsidered to be a subgenus ofCeratopogon. Larva: have been found in crab holes and below the algalcrust on the sand along the seashore in South America.Culicoides is another large genus of midges very similar to Ceratopogon,and contains many bloodsuckers. Only the females bite. Thelarva: are found in water under various conditions. When searching forlarva: where the adults are abundant, they may be found by gatheringin a white tray some of the green vegetable matter found at the edges ofstreams. The flies can be bred by placing the pupre on moist filter paperin tubes closed with moist cotton.The genera Johannseniella and Haematomyidium also contain bloodsuckingmidges.FAMILY SIMULIIDAEBuffalo GnatsThe buffalo gnats of the genus Simulium are sometimes also calledsand flies and turkey flies. This is a large genus of voracious flies whichoften are so numerous as to cause great distress and even death to men

BIOLOGICAL NOTES ON BLOODSUCKING FLIES 9l9l5and animals. Sambon considered Simulium as the carrier of pellagra,but his theory has not been substantiated. Jobbins-Pomeroy has givenquite a full treatment of the life history of several species of this genus,and Malloch has presented a classification of our American forms. ThelarVa! breed usually in swift-flowing water.The eggs are small, r ather triangular or ovoid objects, and somewhat:.vellowi h in color after a few days. They are laid in masses on grassblades, or leaves, or on stones and other forms of debris at the surfaceof the water or under the surface. The egg stage varies in each speciesaccording to the temperature, but m Jobbins-Pomeroy's studies of fiveFIG. 43. Larva of a buffalo gnat, Simulium.(Jobbins-Pomeroy.)species, the incubation period ranged from 7 to 13 days. A single femalemay lay f~om 500 to 1500 egg according to published claims.The larVa! are invariably aquatic, and are quite characteristicallymarked by the possession of two large appendages on the head in frontof the antennae, which are provided with f an of long hairs. The e fansserve to brush food particles into the mouth of the larva (fig. 43).The meso thorax is provided with a single retractile proleg armed atits apex by a circular row of short hooklets or spines. This pseudopodwith its sucker is used by the larva in attaching itself to objects. A similarbut larger sucker-like disk is situated on the caudal extremity of thelarvre. Respiration takes place through rectal gills located dorsally tothe caudal sucker. These gins are retractile into the rectum, but are

!26 SANITARY ENTOMOLOGYusually extended in running water. They function both as blood gillsand tracheal gills. The structure of these gills affords characters ofvalue for the identification of the species.The larvIE attach themselves by the caudal suckers and float in thestream, catching their food by means of the fan-like processes on thehead. When disturbed, or if the stream diminishes, the larVa! let themselvesfloat down the stream attached by a silken thread to a permanentobject, by which they can regain their former position. "Then about topupate the larva spins over itself a pocket-shaped pupal case. Thepupre are provided with respiratory organs on each side of the thorax.These are composed of long chitinous tubes with a single main stalk andfour or more divisions. Good specific characters for identification arefound in the structure of , these respiratory organs (plate XV).The development period of Simulium in South Carolina is about 7days for the egg, 17 days for the larvre, and 4 days for the pupre. Thenumber of generations depends upon the species and the season and mayrange from one to six or more generations.FAMILY PSYCHODIDAEPappataci FliesThe owl midges are small moth-like flies. Only the genus Phlebotomuscontains bloodsucking flies, Which are orten called sand flies. Thepappataci fly, Phlebotomus papatasii Scopoli, cause of pappataei fever;P. minutuB Rondani, a possible carrier of Bagdad sore, and P. verrucarumTownsend, supposed carrier of verruga, are the only speciesdefinitely charged with carriage of disease. Only the females suckblood. They deposit their eggs in damp, dark places, in clusters orsingly, to the number of from 30 to 80. The eggs are covered with athin coating of a sticky substance which causes them to adhere to anysurface. They are very elongate, dark brown, with longitudinal, black,wavy lines. The incubation period is from six to nine days. The larvIElive in damp earth. They are very peculiar, having large, well markedheads with big jaws, which have four distinct teeth. The body is coveredwith toothed spines and the posterior end bears two pairs of very blackcaudal bristles, one pair of which are as long as the body. The larvafeeds on semi-decaying vegetable matter. The pupa is remarkable for thelarge ridges and excrescences on its thorax. The larval skin usuallyremains adhering to the caudal extremity.These flies breed in crevices of stone walls and fissures between rocksin caves, in dirty, damp cellars, and on the damp walls of latrines andcesspools, and wherever there is damp ground in dark places. Lizards fre-

BIOLOGICAL NOTES ON BLOODSDCl{ING FLIES ~~7-- - -~PLATE XV.-Pupae of Simulium. Fig. I.-Respiratory filaments of pupa of Simuliumvittat1tm. Fig. 5!.-Pupa of Simulium venus tum, in pupal case. Fig. 3.- Pupa ofSimulium bracteatum: A, side view of fiJaments. Fig. 4.-Pupa of Simttlium jen-ningsi. Fig. 5.-Pupa of Simulium pictipes, in pupal case. An greatly enlarged.(After Jobbins-Pomeroy.) From U. S. Dept. Agr. Bu]]. 329, Plate V.

SANITARY ENTOMOLOGYquently serve as blood hosts and are considered the reservoirs of the feverscarried, especially pappataci fever.FA'l\IILY .CULICIDAEThe mosquitoes which in an orderly arrangement would be treatedhere have been considered in other lectures (Chapters XVII to XIX). ..The families so far discussed belong to the Nematocera; the nextfamily belongs in the Brachycera.FAl\IILY TABANIDAEHorse FliesThe family Tabanidae contains the horse flies, gad flies, deer :flies,many genera and species of bloodsuckers. The males throughout thefamily are flower feeders or feed on vegetable juices, and so likewise arethe females in many genera. 'The eggs of Tabanidae are commonly laidin large, shapely masses on the leaves and stems of plants growing inmarshy ground, or «a'erhanging water. In some species they are depositedon stones or rocks above the water of streams, and are very difficult todiscover.Mr. Webb has discussed for us the habits of Tabanus (ChapterXVI). We have seen also that species of Tabanus can carry the animaldiseases anthrax, nagana, souma, surra, and mbori. The genus Atylotuscan carry nagana and dourine; Haematopota, surra and equine infectiousanemia; Chrysops and Chrysozona are probable carriers of equine infectiousanemia. Various other genera are bad bloodsuckers, especiallyPangonia.Tabanid larva! grow very slowly, feeding at first on small crustaceanswhich are abundant in water and moist earth. The larger larva! of manyspecies feed almost exclusively on carth worms, whose body juices theysuck out. Although the larval stage may require months for development,the pupal stage will usually be short.FAMILY MUSCIDAEThe flies of the family Muscidae are mostly not bloodsucking flies.Principal among these genera which have the mouth shaped for suckingblood are the genera Glossina, Stomoxys, Lyperosia, Philaematomyia andHaematobia.Bloodsucking Fly LaroreThe genus Auchmeromyia of Africa is very peculiar in that both larvreand adults are bloodsuckers. The adult flies are sensitive to light and are

BIOLOGICAL NOTES ON BLOODSUCKING FLIES 229usually found in the darkest parts of the native huts. The females havetwo periods of oviposition about one month apart, and may deposit atotal of as many as 83 eggs. They oVIposit on the ground in the huts,preferably where urine has been voided. 'l'he larvm are exclusively bloodfeeders. They are able to resist starvation for long periods. If fed regularlythey may mature in about 15 days. They remain in hiding duringthe day and suck the blood of sleepers at night. Pupation occurs inthe puparium or last larval skin. The fly is probably spread from villageto village in the egg or larval stage in the dirty mats which the nativescarry about with them.Travelers in Africa should always avoid sleeping in native hutsor on the ground in the vicinity of corrals or native villages, because ofthese larvre and also many other venomous and disease-bearing pests .•The African genus Choeromyia also has bloodsucking larvre, theattack of which is not to he confused with the myiasis caused by thelarvre of related genera, because these larvre are free living and do notremain attached to the host.Biting Species of MuscaThe genus Musca apparently is a transitional genus as it containsboth non-bloodsucking and bloodsucking flies. Musca pattoni Austen,.1f. gibsoni Patton and Cragg, 1Jf. convetrifrons Thomson, M. nigrithora.r:Stein, M. bezzii Patton and Cragg and M. corvina Fabricius, all of II.ldiaexcept the last, which is European, are bloodsucking. But these fliesare incapable of puncturing the skin of an animal. They feed on theblood and serum exuding from the bites of other bloodsucking flies.These flies breed in cow dung. M. pattoni always deposits in dung whereit is collected in heaps, while gibsoni and conve:dfrons deposit in isolatedpatches of cow dung.True Biting FliesThe true biting Muscids belong to the subfamilies Stomoxydinae,Glossininae and Philaematomyinae.Philaematomyia is a genus closely resembling Musca in appearance.It contains three Asiatic speci~s, of which the best known is P. insignisAusten, which only attacks cattle. It breeds in cow dung where it iscollected in heaps. Both sexes feed on blood although they have alsobeen seen feeding on cow dung. This habit would surely make it possiblefor the fly to mechanically carry infectious diseases from dung to blood.It breeds quite rapidly.

230 SANI TAR Y ENTOMOL OGYStable FliesStomoxys is a genus found principally in Asia and Africa, althoughS. calcitrans Linnaeus, the well-known biting stable fly, is almost worldwidein its distribution (figs. 44-46, plate XVI). This species is capableof carrying rodent plague, anthrax, septicaemia, nagana, souma, dourine,urra, baleri, and Gambian sleeping sickness, and has been connected byScott with the ·transmission of equine infectious anemia and seriouslysuspected as a possible carrier of poliomyelitis and pellagra.A very complete bulletin by Bishopp is available for free distribution,describing the life history and control of the stable fly, so that it is notFro. 44 (left).- Eggs of the stable fly (Stomoxys calcit1'ans) attached to a straw.Greatly enlarged. (A fter Bishopp.)FIG. 45 (center).-The stable fly: Larva or maggot. Greatly enlarged. (AfterBishopp.)FIG. 46 (righl:).-The stable fly: Adult female, side view, engorged with blood. Greatlyenlarged. (After Bishopp.) From U. S. Dept. Agr., Farmers' Bull. 540, fi~.I, ~, 5.necessary to give a full discussion in this lecture. It generally breeds inmoist straw and hay. Stacked straw which has been wet and partlyrotted and hence is no longer available for stock food is a very favorablep lace for the fly to breed. Such straw should be dried as soon as possibleby scattering, and then either be burned or plowed under. The stablefly does not often develop in manure, but where it does it may be controlledby measures taken against the house fly. This species is veryannoying to mules, horses, and cattle and often to man. Horses and mulesoften become frantic in their efforts to escape the flies.As much care should be taken to prevent the breeding of the stablefly as the house fly. They are carriers of entirely different series ofdiseases and both are dangerous. Especial care must be observed to

BIOLOGICAL NOTES ON BLOODSUCKI~G FLIES 231LATE XVI.-The stable fly, Stomoxys calcih·ans. Fig. I (upper).-Eggs in straw.Fig. ~ (lower right).-Pupae in straw. Fig. 3 (tower left) .-Adults 011 leg ofcow. (Bishopp.)

SANITARY ENTOMOLOGYprevent breeding in straw which falls out of the stalls and windows ofthe stables. Where the stables adjoin a road, considerable straw mayfall out of the windows and remain outside the building in a place wherethe horses do not come, and no one may think of removing this strawwith the daily removal of manure. Here is an excellent place forStomoxys to breed. Wherever marine weeds and debris are washedashore and form considerable masses, Stomoxys is likely to breed. Inplate XVII is shown the proper method of stacking straw to preventfly breeding.PJ.ATE XVII.-Straw stack showing proper method of building straws tack.(Bishopp.)Horn PliesHaemotobia sa'flguisugens is an Indian bloodsucker, which attackscattle and horses. The principal species of horn flies belong to thegenus Lyperosia,2 of which L. irritans Linnaeus (plate XVIII) and L.exigua l\feijere arc the two commonest bloodsuckers. The latter isoriental. The horn fly was treated very fully by 1\1arlatt in a circularnow out of print. This species is so c/lllcd because of the habit of theadults of clustering on the base of .1'1 cow's horn. The flies also clusteron other parts of the animal and causc great annoyance. Even when notfeeding the flies rest on the cattle. The eggs are laid singly on the surfaceof wet dung. The moment the dung is dropped a swarm of flies dart fromthe animal to the dung and remain there a few seconds, during which time2 Dr . .J. M. Aldrich does not recognize Lyperosia, but places our American species inHaematobia.-"W. D. Pierce.

BIOLOGICAL NOTES ON BLOODSUCKING FLIES ~:33PLATE XYIII.-The horn ft.y, Lype1"osia il·ritans. Fig. 1 (upper).-Flies on cow. Fig.2 (lower).-Cow pasture showing droppings improperly left to breed flies.(Bishopp.)

SANITARY ENTOMOLOGYmany eggs are deposited. The flies immediately return to the cow. Thelarvre migrate from the dung when about to pupate and the pupll.ria areusually found at some distance away or under the sides of the patch ofdung. The horn fly in America requires about Ii days from egg toadult. .Protection of the animal from the hom fly by the use of repellents issuggested. In this connection Graybill's bulletin on repellents shouldbe consulted. Dipping yats and the cattle dip of the Bureau of AnimalIndustry (see Chapter XXXI, p. 44~), now used in the control of theTexas fever tick, aid materially in reducing. hpm fly numbers. ....>Two practical methods are available for attacking the larvlE andpupre. One is to throw lime on the dung, but the better method is to spreadout the dung so as to favor its rapid drying or to allow a number of pigsto run with the cattle. In their efforts to obtain undigested food particlesthe pigs will effectively destroy the dung as breeding places for the fly.Tsetse FliesThe tsetse flies of the genus Glossina are among the most dreaded insectsof Africa. They are the carrier,; of three or more types of sleepingsickness, of aiJ;lo, nagana, souma, horse sickness, baleri, Ilnd othertrypanosomiases of many domestic and wild, animals. There are quitea number of species, and probably all are important, but, G. morsitansWestwood and G. palpalis Robineau-Desvoidy, are the best known. Excellentdiscussions of each of th~ important species and tables for differentiationare given in the textbooks of Hindle, and Patton and Cragg.The reproduction in this genus is very remarkable, resembling thatof the Pupipara and is prohably the result of their exclusively bloodsuckingmode of life. The female lays a single larva at a time, which isretained and nourished in the oviduct until it is full grown. After thelarva is born it at once burrows into the ground and pupates. The larvais generally of a yellowish white color and bears at its posterior extremitya pair of large dark-colored protuberances between which is a depressioninto which open the spiracles of the eighth seginent. It pupateswithin the puparium or last larval skin. The puparium is broadly ovoidin shape and by its caudal appendages affords It means of distinguishingthe species.The habitats of the various species should be rather thoroughlystudied by anyone expecting service in the African tropics. In generalthe flies are found in moist forest regions, especially along river courses,but the temperature, mois.ture, and shade requirements Seem to varyfor the different species.

BIOLOGICAL NOTES ON BLOODSUCKING FLIES !35PUPIPARAThe suborder Pupipara is composed of several families of the queerestflies in the order. The insects of the families N ycteribiidae, Streblidaeand Hippoboscidae are all ectoparasites on warm blood vertebrates. Allof the Streblidae and N ycteribiidae of which the life history is known,are parasitic on bats and some of them are quite probably the carriersof bat diseases. In the family Hippoboscidae we find the genera Lynchia,Hippobosca and Ornithomyia, mentioned as carriers of disease, and alsoMelophagus to which belongs M. OvmU8 Linnaeus, the sheep tick. Theflies of the genus Lynchia which carry pigeon malaria, live almostexclusively on pigeons. They deposit larvre in the pigeon houses; theselarvre become puparia in an hour. Hippobosca is composed principallyof species parasitic on mammals, one of which is thought to carry thegall sickness of horses in South Africa. The females deposit larvre whichare incapable of movement. . They slowly darken until the pupariumresembles a seed. Lipoptena cervi is parasitic on deer. MelophagusOvVnU8. which is wingless, lives on sheep, sometimes proving to be aniniportant pest. This insect may be eradicated by giving two thoroughdippings at !4-day intervals in lime-sulphur-arsenic solution or in standardcoal tar-creosote or cresol dips, or nicotin solution (Imes).Outside of the stable fly and sheep tick, control measures for bitingflies are not well worked out. Of course the primary essentials areprotection of the animals from the bites of the flies and prevention ofbreeding.REFERENCESBishopp, F. C., 1913.-The Stable Fly. G. S. Dept. Agric., Farmers' Bull.540. Available for free distribution.Graybill, 1I. W., 1914.-Repellents for Protecting Animals from theAttacks of Flies. U. S. Dept. Agric., Bull. 131.Hindle, Edward, 1914.-Flies in Relation to Disease. Blood-SuckingFlies. Cambridge Dniv. Press.Imes, Marion, I9I7.-The Sheep Tick and Its Eradication by Dipping.U. S. Dept. Agric., Farmers' Bull. 79B. Available for free distribution.Jobbins-Pomeroy, A. W., I9I6.-Notes on Five North American BuffaloGnats of the Genus Simulium. U. S. Dept. Agric., bull. 3!!9.Malloch, J. R., I9I4.-American Black Flies or Buffalo Gnats. U. S.Dept. Agric., Bur. Entom., Tech. Bull. ~6.Marlatt, C. L., I910,-The Horn Fly. U. S. Dept. Agric., Bur. Entom.,Circ. 115.Patton, W. S., and Cragg, ~. W .• 1915.-A Textbook of Medical Entomology.

CHAPTER XVIBiology and Habits of Horse Flies 1J. L. TVebbIn various parts of the United States and in many foreign countrieshorses, cattle, and similar animals sufrer severely from the bloodsucking}labit of the so-called horse flies of the genus Tabanus (plate XIX).PLATE XIX.-Tabanidae attacking cattle: Tabanus phaenops on cow's jaw, and T.punctifcr on top of shoulder. (Bishopp.)The life history and habits of different species may vary greatly. Yetthere are certain conditions common to all species. In general, theflies of this genus arc to be found in or near swampy areas of the country.~ This lecture was read October 7, 1918.236

BIOLOGY AND HABITS OF HORSE FLIES 237The larval stage of most species is passed in the ground, and ll.certain degree of moisture is necessary for proper growth and development.JUost species !equire very wet, or saturated soil, others are ableto develop in moderately moist earth.EGGS .AND EGG LAYINGThe eggs are deposited by the female fly in clumps of several hundredeach, on vegetation, rocks, or other objects overhanging suitable placesfor development of the larvre. When the eggs hatch, the young larvredrop to the soil or water beneath and disappear from sight. Here theyremain for several months, sometimes for one or two years, when, afterpassing through a short pupal period, they emerge as adult lfIies.In some cases the .egg mass as well as the place of oviposition is·characteristic of the species, and renders identification easy, once theobserver sees one of which he knows the identity.In the Sierra Nevada Mlountains of Eastern California where I han!been studying tabanids for the past two years, the egg masses of the twomost important species are very easily distinguished. '.rhe egg mass ofTabanus pwnctifer Osten Sacken is oblong, somewhat pyramidal in shape,and about the size of the end of a man's little finger (plate XX, fig. 1).It is usually deposited-upon a bull rush or coarse grass stem, and fromone to three feet above the surface of the soil or water. When deposited,as is the case with all horse fly eggs, the mass is milk white. In a day or80, however, the color darkens to a mottled gray and white. Eggs of thisspecies arc found most abundantly along lake shores. The egg mass ofTabanus phaenops Osten Sacken is to be found on grass blades, threeor four inches above the soil in swampy places in meadows. This mass isconsiderably smaller than that of Tabanus pwnctifer, is elongate, andusually contains but two layers of eggs, while t.he other species usuallyhas about fi,'e layers. The egg mass of T. phaenops is black a day ortwo after oviposition. This mass is inconspicuous and extremely hard tolocate in nature.In the Egyptian Sudan, Harold King found the eggs of Tabanuskingi Austen deposited in rounded masses on rocks rising from the edgeof a stream, generally overhanging the water, and from 6 inches to 15inches above the water level. He also found the masses of Tabanusditaeniatus Macquart on grass growing in rain pools. The shape of theegg mass of this species was variable,-some being long and narrow,others short and broad. The same worker secured ovipositions ofTabanus par Walker in a cage, on the under sides of leaves of a waterweed growing in a vessel of water. He also secured the egg masses ofTabanus taeniola Palisot de Beauvois, the tabanid most frequently

~38 SANITARY ENTOMOLOGYPLATE XX.-TabanU8 punctifer. Fig. 1 (upper left).-Egg masses on grass. Fig.2 (upper center).-Larva, dorsal view. Fig. 3 (upper right).-Larva, lateralview. Fig. 4 (lower left).-Pupa, lateral view. Fig. 5 (lower right).-Pupa,ventral view. (Webb, photos by Dovener.)

BIOLOGY AND HABITS OF HORSE FLIES 239accused of causing the death of camels, from grasses and weeds overhangingrain pools. These masses were placed on the upper sides ofthe plants as they hung over the water.In Ohio, Hin:e records finding the egg masses of Tabanus stygius Sayprincipally on the leaves of Sagittarin standing in shallow water, thefemale fly llabitually placin~the eggs just above the point where thepetiole meets the expanded part of the leaf.l'Iibmain, working in the Philippines, used a large cage to secureovipositions of Tabanus striatus Fabricius. He found that egg layinginvariably took place in the early afternoon, never later than ~ o'clock.Under cage conditions egg masses were deposited on projecting splintersof wood, suspended fibers of jute sacking, fine brass wire, a. single animalhair, coarse iron wire, leaves of trees, and the woodwork on sides andceiling of the cage, invariably upon the shaded portions,-as the undersidesof beams and partitions. The egg mass in Borne cases entirelysurrounded the object on which it was deposited. The cage contained 0.tank of water 'with growing water plants. Apparently l\Iitzmain didnot find eggs in the open.In Southern Nigeria, Neave found the eggs of TabanUll corax Locwin the bush on reeds or grasses overhanging mud.Near Alturas, California, during the past two seasons, I have foundthe egg masses of an unidentified Tabanus, to be very abundant on theundersides of leaves overhanging a small creek. They were found on theleaves of willow, alder, and rose bush; also occasionally on the leavesof Populus and on coarse grass blades.I have never been fortunate enough to observe the process of egg laying,although on one occasion I came upon a female of Tabanus punctiferwhich had just finished ovipositing, and was still in position, head downwardson a stem of coarse grass. She was occupied at the time in brushing'theend of the abdomen over the pure white egg mass, apparentlycovering it with a. kind of transparent cement. She was not disturbedby my close approach. In fact, I broke off the stem on which she restedand observed the brushing process at close range for some little timebefore she took flight.:Seave mentions the fact that the eggs of Tabanus corax in SouthernNigeria arc covered with an almost impervious cement. On one occasionan egg mass of this species, after being kept for two days in 70 percent alcohol, produced a few larv&! after being taken out of the alcohol.However, not all species of Tabanus cover the eggs with cement. Theeggs of TabanUll phaenops in the Sierra Nevada Mountains are not socovered, and fall from their place of attachment soon after hatching.The number of eggs contained in the mass varies considerably. Theeasiest way of ascertaining the number in any given mass is by counting

240 SANITARY ENTOMOLOGYthe larvre that issue therefrom. During the past summer the larvreemerging from ten masses of Tabanus phaenops eggs were counted. Thenumber per mass ranged from 156 to 885, giving an average of 281 + permass. Larvre from fifteen masses of Tabanus punctifer eggs were counted.The range was found to be from 159 to 701 larvre,-an average of 866 +per mass. However, this method of arriving at the number of eggs permass was very inaccurate in the case of Tabanus pwnctifer, as practicallyall these egg masses were, to a greater or less extent, parasitized, andin several of the masses a large per cent of the eggs failed to hatch.Larva! from a series of five unidentified Tabanus egg masses collectednear Alturas, California, were also counted. Here the range was from826 to 890,-an average of 509 + per mass, with no parasitism.Mitzmain records that the number of eggs per mass of Tabanusstriatus in the Philippines varies from 270 to 425. He observed theoviposition under cage conditions and found that the eggs were depositedat the exact rate of 10 per minute.References in literature to the incubation period are extremely scarce.King gives the period for Tabanus kingi as about 5 days, and for TabOJnlUspar as 5 to 6 days. These species occur in the Egyptian Sudan. Neavehrives the incubation period of Tabanus cora:c in Southern Nyasaland asabout 5 days. Mitzmain determined the period for Tabanus striatus inthe Philippines to be from 8 to 5 days.In my own experience in the Sierra Nevada Mountains, I have foundthat the eggs of Tabanus phaenops under laboratory conditions hatch infrom 6 to 7 days, while those of Tabanus punctifer require 14 days. However,in one case, a mass of T. punctifer eggs, after being kept a few daysin the laboratory, was placed outdoors in the sun, with the result thattIle incubation period was sllortened to 11 days. No doubt if the masshad been kept in the open from the time of oviposition a still shorterincubation period would have been recorded. The eggs of the unidentifiedspecies collected near Alturas, California, hatched in from 7 to 8 daysunder laboratory conditions.Usually most of the eggs in a mass hatch at about the same time, butin the case of Tabanus pltaenops I have found straggling larvre emergingseveral hours after the majority of the larvre were in the water at thebottom of the incubation vial.LARV./EIn arranging for the incubation of Tabanus eggs I am accustomed touse a large glass vial with water in the bottom. The egg mass is thensuspended in the vial over the water, usually by placing the stem orleaf, to which the mass is attached, against the side of the vial, and press-

BIOLOGY AND HABITS OF HORSE FLIES 241ing a cotton stopper into the mouth of the vial tight enough to hold theegg mass in position. When the larvre emerge they fall into the waterwhere they will remain alive for several days if undisturbed. The younglarvre of Tabanus phaenops and those of the unidentified species fromAlturas sink to the bottom of the water and remain there alive and ingood condition, without rising to the surface for air. On the other hand,newly emerged larvre of Tabanus pwnctifer (plate XX, fig. 2) remain atthe surface of the water constantly. In aU these three species, the firstmolt occurs within a very few hours after hatching, and the cast skinsare to be found floating in the water.Mitzmain is the only author I find mentioning the molting of Tabanuslarvre. He noted S molts in the case of the larvre of Tabanus st1iatus inthe Philippines. The first molt begins with larvIE 7 days old, the majoritymolting before the 10th day. The second molt usually occurs after aninterval of at least 4 days, and in some larvre as much as 8 days, that is,when 1'5 to 18 days, old. The third molt, which discloses the pupa, isvery variable as to the time of its occurrence, some individuals not pupatinguntil S months after the larvre emerge from the eggs, the majority,however, pupating in a much shorter time. In fact, Mitzmain reared fliesfrom deposition of egg to adult in 52 days.As was stated in the beginning, the eggs are deposited above situationssuitable for the development of the larvre, so that the young larvrewhen they dr~p from the egg mass immediately find themselves at home.If it is a species which lives in mud under water, the eggs will be foundoverhanging water, and' upon dropping from the eggs the young larvrewill simply sink through the water to the mud beneath. If it is a specie~which prefers mud not submerged, the eggs will be found in the rightposition and the larvl!! upon dropping to the mud, immediately burrowinto it. .'I'he food of Tabanid larvre consists of small crustaceans and otherminute forms of animal life of a soft texture. As the larvre increase insize they may take coarser food. In breeding jars, I have seldom usedany other food than earth worms cut into sections, and such small formsof life as may be gathered up with the mud placed in the jar. The larvreare cannibalistic and eat each other readily. l\Iitzmain states that thelarvre of Taba1llU8 striatus seem to prefer their own kind even when otherfood is available. For this reason it is well in attempting to rear larvreof this genus, to place but one larva in each rearing jar. I have"however,in some cases successfully reared more than one individual in the same jar.Sometimes it is much easier to locate the larva! of a given species thanthe eggs. In most cases in my own experience, I have found the larvrefirst. In the mountain valleys of Eastern California where considerableareas of pasture land are irrigated, the larvre of TabOlnus phaenops are to

SANITARY ENTOMOLOGYbe found in low places whe-re the ground is continuouslY wet. They areusually quite near ilie surface, and can be located by scratching in the mudand grass humus with the fingers. Where there is an accumulation of olddead grass matted down ·in water, larvle are frequently found in thisgrass. While this species pref~rs quite wet conditions, it is capable ofwithstanding considerable drought. In making a test of drought resistanceI allowed one or two breeding jars containing larvre of this speciesto dry out completely .. One larva survived these conditions and produceda perfect adult. The exact length of the larval stage of this specieshas not yet been determined.I have found the larvre of Tabanus plllflctifer to be quite numerousalong the shore of a lake in the Sierra Nevada Mountains. There wasconsiderable debris,-weeds, grass, and bulrushes washed up on theshore. It was in this mass of partially decomposed vegetation keptsaturated by the waves of the lake, that the larvre seemed to flourish.Another Tabanus larva of an unidentified species was found in thesame general locality in the moi~t earth along the sides of small rivuletshigh up on the lower mountain slopes.Prof. Hine records finding the larvre of Tabanus viva.r Osten Sackenin Ohio in the mud of a stream bed under' riffles.Likewise, King found larvre of Taban'US kingi in the Egyptian Sudan,under stones in a shallow stream where the water rippled over and aroundthe stones. The larvre were usually found ·under rocks not covered bywater. These larvle possessed pseudopodia specially fitted' for clinging tothe stones and crawling up to the surface of the water to breathe.The same writer found the larvre of Tabanus ditaeniatus living in mudat the bottom of a more sluggish stream, and coming to the surface ofthe water periodically to breathe.King also mentions rearing adults of Taban'US par from eggs obtainedin a cage. The larvre were kept in jars of mud, and this mud wasallowed to dry up several times, and for a period of 57 days no growthwas made, yet when normal conditions were restored, the larvre began togrow and completed development. This is somewhat in line with my ownexperience with Taban'US phaenops, already mentioned,In the Philippines, Mitzmain found larvre and pupre of Taban'IUatriatus in large numbers in sand at many points on the shore of Lagunade Bay.Neave records finding Tabanus larvle in Northern Rhodesia in Julyand August in the sand and mud of river banks. They often occurred,especially if the mud was inclined to be dry, at a depth of as much as·6 or 8 inches.According to Hine some species of Tabanus larvre live in water for atime and crawl out into dry ground, consequently one often finds Tabanid

BIOLOGY AND HABITS OF HORSE FLIES !43larvre by digging in dry groun,d along the borders of ponds. He alsostates that the l.arvre of Tabanus atratus Fabricius are sometimes found inrotten logs. It is probable that Hine uses the term "dry ground" in acomparative sense, and that both the dry ground referred to and therotten logs contained some degree of moisture.The length of the larval period variee greatly in different species, andeven among different individuals of the same species. The shortest periodsfor this stage are found, as might be expected, in the tropics. Thus,Mitzmain records a minimum larval period of 9 days for TabanU8 striatU8in the Philippines. The maximum period is given for this species as Smonths. Neave gives the larval period for Nyasaland Tabanids as 6months or more.In Ohio, Hine found in rearing Tabanus lasiophtholm'US Macquartunder laboratory conditions that in one instance the larval period wasfrom June 30 to March 10, approximately 8lA! months. In the case ofthe species which I have been studying in the Sierra Nevada Mountains,the larval periods have not yet been detel'fIlined, but all signs point toperiods extending over two winters. As a matter of fact, data on thelarval periods of species of Tabanus are verv meager.l'UP&When the time for pupation arrives, the larva usually seeks drierquarters, though some moisture is usually necessary to maintain lifeduring this period. Larvre living in the mud of stream beds usually worktheir way to the drier soil of the stream banks in preparation fo'r pupation.Pupre of most species are much more difficult to locate in nature thanlarvre. The length of the pupal period is usually comparatively short.Mitzmain gives the period for TabOlT1llJ,s striat'US in the Philippines as fromS to 7 days, while IGng records that of Tabanus par in the AngloEgyptian Sudan as 6 to 8 days. Neave states that this period in NyasalandTabanids varies from 10 to 16 or 18 days. In rearing Tabanuslasiophthalm'US in Ohio, Hine found the pupal period to be 15 days.My records show that under laboratory conditions in the SierraNevada Mountains this period In Tabanrts phaenops is from 14 to 22days, while that of TabanU8 pwnctifer (plate XX, fig. S) is 27 to 28 days.LIFE CYCLEThe shortest life cycle from egg deposition to emergence of adult,which I find recorded, is 48 days, in the case of Tabanus ditaeniatU8 inthe Anglo-Egyptian Sudan. King gives the life cycle as 48 to lSI days.

.~44 SANITARY ENTOMOLOGYMitzmain found the minimum life cycle of Tabanus striatus in thePhilippines to be 52 days.The life cycle of Taba'TI/US lasiophthalmus was found by Hine in oneinstance to be about 9 months.. He states that the cycle of Tabanusst'!Jgius probably requires two years.As has already been indicated in discussing larval periods, it isprobable that the species of Tabanus in the Sierra Nevada Mountainsrequire two seasons for their life cycles.HABITS OF ADULTSOnly female adult horse flies attack stock (plate XIX). The malesare never found taking any interest whatever in warm-blooded animals.Their food consists of the nectar of flowers and other sweet substances.Females also feed readily on sweet substances. I have quite often captureda few in a fly trap baited with banana. It appears that the primaryobject of the blood meal is to enable the female to develop eggs, althoughthis diet may also be taken. for nourishment. .The males are usually to be found in the grass, or the foliage of trees,or on the trunks of trees, and when the females are not sucking bloodthey will usually be found in the same situations.In temperate climates females are most active on still, sunshiny days.It is unusual to find them flying on cloudy days or when strong wind isblowing.In taking a meal of blood a female Tabanus will usually insert andwithdraw the beak several times, puncturing the skin of the host in anew place each time, before finishing the meal. The length of timeoccupied in taking a meal in cases observed by the writer has varied fromabout 3 to 11 minutes, and during this time the position may be changed5 or 6 times. Mitzmain has seen Tabanus striatus in the Philippines feedfor 23 minutes. I have allowed flies to bite my arm and feed to satiety.It is not a continuously painful process. The only part of the performancethat is painful is the insertion of the beak, which takes but afew seconds. After that ihe drawing of the blood by the fly causes nosensation whatever in the arm. However, the habit of changing positionso often during a meal is somewhat annoying.Horses are much more nervous under the attacks of Tabanus thancows. The latter often allow the flies to feed without much of anyattempt to brush them off, but a horse fights constantly. Where theattack is severe, the horses in a pasture will bunch up together formutual protection in rubbing against each other. Under such conditionsit is possible that each fly will attack several horses, being brushed offseveral times before the meal is finished. This makes an ideal condition

BIOLOGY AND HABITS OF HORSE FLIES l!45for the spread of disease, if there are diseased animals in the herd. Thi~habit of bunching up under fly attack applies also to cattle, where theattack is severe.I have never succeeded in obtaining any data on the number of bloodmeals a female will take. Mitzmain states that in the Philippines femalesof TabM11U8 striatus bite not oftener than once iIi ! days.CONCERNING CONTROL MEASURESNo universal remedy, or control measure, for horse flies can be given,owing to the diverse habits of the different species. In all cases, someknowledge of the life histories and habits of the species involved isnecessary before anyone can intelligently set in motion control measures,and I may say here that the life histories of very few species of Tabanusare now known.In some cases drainage of the larval habitat would undoubtedly bea good control measure. But the degree of drought resistance of thespecies in question should be ascertained before placing reliance uponthis method of control.In Russia a species of Tabanus has the habit, in the adult form, offlying to water and dipping the abdomen. Porchinski, the Russianentomologist, advocates the oiling of the surface of the water as a controlfor this species. It appears that Porchinski has used this methodwith good results. He applied the equivalent of a half pint of kerosene tosix square feet of water surface. If this was not sufficient to do the work,a like amount was used the next morning. It must be borne in mind,however, that not all species of Tabanus have this dipping habit, and thatin order to make the measure effective, the water would have to be comparativelystill, as otherwise the oil would soon pass off with the current.Occasionally the importation of egg parasites may be an effectivecontrol measure. At the present time, Tabanus punctifer in the AntelopeValley, Mono County, California, is apparently largely controlled by anunidentified hymenopterous egg parasite.Hine mentions the fact that in confinement small catfish eat the larvreof Tabanus stygius. It is possible that the stocking with catfish ofstreams inhabited with Tabanus larvre might have good results.In the way of protection of animals from the attacks of adult flies,various devices h""ve been tried, such as nets, hoods, etc. In the SierraNevada Mountains, I found in one locality, a very useful horse hood inuse to ward oft' the attack of Taba'fI/US phaenops. This species attacksmost viciously about the head and neck of horses. The hood is a simplearrangement made of light canvas to slip over the head and neck, witheye and breathing holes at the proper places.

~46 SANITARY ENTOMOLOGYVarious repellents, mostly of an oily nature, have been tried as sprays,by different investigators, but none of these has proven very satisfactoryas the effect is not lasting.BIBLIOGRAPHYHine, J. S., 1905.-Tabanidae of Ohio with a Catalogue and Bibliographyof the Species from America North of Mexico. Ohio State UniversityDept. Zool. and Ent., spec. paper, No.5. 57 pp.Hine, J. S., 1904.-Tabanidae of the Western United States and Canada.Ohio State University, Contrib. Dept. Zool. and Ent., No. ~1, pp.~17-~48.King, H. H., 1908.-Third Report of the Welcome Research Laboratories,Gordon Memorial College, Khartoum.King, H. H., 1911.-Some Observations on the Bionomics of Tabal1l:U8ditaeniatw Macquart, and TabQl1l,w kingi Austen. Bull. Ent. Research,vol. 1, pp. fl65-fl74, fig. 7.Mitzmain, M. B., 19I5.-The Biology of Taban'U,s striatu8 Fab., theHorse Fly of the Philippines. Philippine Journ. Sci., vol. 8 B, pp.197-~~fl.Neave, S. A., 1915.-The Tabanidae of Southern Nyasaland with Noteson Their Life Histories. Bull. Ent. Res., vol. 5, pp. ~87-3~O.

CHAPTER XVIIDiseases Transmitted by Mosquitoes 1W. Dwight PierceProbably more entomologists and sanitarians are familiar with. thefacts of mosquito transmission of disease than with any other phase ofa review of their role will not be amiss, especially as it. a different form from that usually adopted in textall of the chapters on disease transmission arein one , that is, by a systematic arrangement of theorganisms transmitted. We may perhaps get a new conception of therelation of mosquitoes to parasitic organisms by this arrangement. ThoseQrganisms which are parasitic only need to be listed in order thatstudents take into account the possibility of confusing them with thepathogenic organisms being sought.Teachers using these lectures as material for the study of theirclasses may find it of value to have the students make rearrangementsof the subject by the name of the disease or the species of insects involved,or by the method of transmission.In our study of the non-bloodsucking flies we found that the diseasetransmission was principally through the feces, although also throughthe vomit, but never by direct inoculation. In the discussion of thebloodsucking flies it was shown that they usually transmitted diseasewhile in the act of sucking blood. All known cases of disease transmissionby mosquitoes are by direct inoculation at the time of the bite. In denguefever the organism has not been demonstrated; in malaria of all types wehave a known organism which undergoes a definite life cycle in the mosquito;in filariasis we also have the mosquito serving as an intermediatehost for the early stages of the worm.For complete studies of the life history of the malaria organism inthe mosquito refer to Hindle (1914) in which you will also find lists ofAnopheles of the worl~, with tables for identification, tables of malariacarriers and much more of a valuable nature, which should be carefullystudied. Many other works deal very carefully with the subject, however.The names of mosquitoes used in this and following lectures are onthe authority of the late Frederick Knab.S This lecture WBS presented August 19 Bnd issued August SS, 1918, Bnd has beenmore or less modified to its present form.247

~48 SANITARY ENTOMOLOGYDISEASES OF UNCERTAIN ORIGIN TRANSMITTED BY MOSQUITOESDENGUE FEVER, one of the severe fevers of the tropics, sometimescalled break-bone fever, occasionally occurs in the United States. It isundoubtedly caused by a living organism which requires over two daysto reach the stage necessary to produce the symptoms of the disease wheninoculated into human beings. It is so small that it will pass through thepores of a filter which will retain Micrococcus melitensis, which is only0.4 micron in diameter. This minute organism is taken up by mosquitoesand transmitted to man. Graham-Smith and Ardate have observed smallbodies in the red blood corpuscles, which are described asround, but sometimes elongate, bodies about one-fifth'size of a red corpuscle. They divide ·up into ml.become extra-corpuscular, and complete a cycle of sct. Graham(1908) fed Cule:c quinquefasciatus Say (fatigans Wiedemann), on denguepatients and claimed to have found his organism in the mosquitoes up tothe fifth day after feeding. He succeeded, after an incubation periodof four to six days, in infecting .healthy people by the bites of mosquitoesfed on dengue patients in two series of experiments, claiming the transmissionto be due to the Culex, but he states that Aedes argenteus Poirret(Stegomyia fasciata Fabricius) were present in many if not all of hisexperiments. Ashburn and Craig (1907) in the Philippines also claimedto have proved transmission by the bite of the same mosquito, but Clelandand Bradley (1918) challenge the results of both these investigations.Nevertheless, Bancroft (1906) conducted experiments obtaining twoapparently successful cases of transmission of the disease by Aedesargenteus, ten and twelve days after these had bitten dengue patients,while in the three failures the test patients were bitten fifteen, fifteen andseventeen days after the mosquitoes fed on individuals suffering fromdengue.Observations made by Legendre in Hanoi led him to suggest Aedes(Stegomyia) as probably a carrier of the virus.Cleland, Bradley, and McDonald (1918, 1919) conducted extensiv~experiments (1918) with both Cule:c quinquefasciatus (fatigans) an,Aedes argenteus (fasciata) and obtained positive results wi~h the lattlnin four out of seven tests, and negative results with the former in t'dtests. The mosquitoes after biting dengue patients were conveyed to di)tricts where dengue fever did not exist. The incubation period in man t\these cases was from six to nine and a half days. Later experiments(1919) corroborated this work.Poliomyelitis was experimented on with negative results by Howard

DISEASES TRANSMITTED BY MOSQUITOESand Clark, using Culel1l pipi6'IUJ Linnaeus, C. BoZlicitana Walker and C.cantator Coquillett.i49PLANT ORGANISMS TRANSMITTED BY MOSQUITOESThallophyta: FwngillfYl1lococcidi'lJlllZ ategomyiae Parker, Beyer and Pothier (1903) is ayeast normal to the mosquito Aedes argenteua (Stegomyia caloptuMeigen). It was thought by its describers to be the causative organismof yellow fever, but this was disproven by the work of subsequent authors(Castellani and Chalmers, p. 1005).Thallophyta: Fwngi: Sch~;:omycetes: BacteriaceaeBacterium anthracia Davaine, cause of ANTHRAX, was experimentedupon with mosquitoes by Morris. Paorophora sayi (Dyar and Knab) andAedes sylvest ria ,(Theobald) Dyar and Knab commonly bite livestock inLouisiana and are very annoying. Out of 86 tests with these mosquitoes,feeding them on guinea pigs for different periods and at different times,from three hours before death to ten minutes after death, Morris obtainedinfection by the bite of the mosquito in 40 per cent of his tests.ANIMAL ORGANISMS TRANSMITTED BY MOSQUITOESProtozoaMastigophora: Bm;ucleata: H aemoproteidaeHaemoprote1U danilcwakyi (Grassi and F~letti 1890), cause of anA YIAN ANEMIA, passes its cycle of schizogony or asexual multiplicationin sparrows, larks, ravens, and birds of prey, and its cycle of sporogonyor sexual multiplication in a species of Culex. It occurs in Europe,Africa, India, and America.Haemoprote1U 'nOctuae Celli and San Felice (1901), cause of anAVIAN ANEMIA, passes its cycle of schizogony in the owls, Glaucidi'lJlllZnoctuae, Strilll (iammea, and Scops gin, and its cycle of sporogony in~t.;ulel1l pipi6'IUJ Linnaeus. Castellani and Chalmers (p. !95) give a detailedt escription of the life cycle as presented by Schaudinn, but in view of:ole fact that there is a belief that Schaudinn has confused this speciest~E'ith a Trypanosoma we will omit discussion. It is supposed to occur in~ Europe, North Africa, and America.Haemoproteus syrnii Mauer (1910), cause of an AVIAN ANEMIA,passes its cycle of schizogony in the wood owl, Syrnium aluco, and itssporogony in the mosquito, Culiaeta annulata Schrank (Theobaldia).

~50 SANITARY ENTOMOLOGYMastigophora: Bi'Tl!l.hcleata: LeucocytozoidaeLeucocytozoon dOlTlilewskyi Ziemann (1898), cause of an AVIANANEMIA,passes its schizogony in tJle owls Glaucidium noctuae and Syrniumaluco, and its sporogony in the mosquito Cule:c pipiens Linnaeus.The mosquito sucks up from the blood of the bird the gametocytes or preliminarystages of the sexual forms. These are taken into the stomachof the mosquito. The microgametocytes or male forms escape from theircapsules, and the nuclei break up into eight double chromosomes, which arereduced to eight simple chromosomes. These travel to the periphery andform the microgametes. The macrogametocytes develop into macrogametes.The gametes then conjugate and form the ookinetes, whichare of three forms, male, female, and indifferent. These break up intovery minute trypanosome-like bodies of the three forms which may divideby longitudinal fission. These are the forms which are inoculated intothe owl by the bite of the mosquito. (See Castellani and Chalmers, p.808.)M a8tigophora: Binucleata: Trypano8omidaeThroughout this volume Chalmers' new classification of the Trypanosomegenera is adopted, as it gives an arrangement which most nearlycorresponds to the biological relationships.Ca8teUanelia brucei (Plimmer and Bradford'1899) (Trypan08oma),the cause of NAGANA and JINJA, African animal diseases, is normallytransmitted by species of Glossina, but Martin, Leboeuf, and Roubaud(1908) successfully transmitted the disease from an infected to a healthycat by a species of Mansonia.CasteUanella evansi (Steel 1885) (Trypano8oma), the cause ofSURRA in animals, is normally carried by biting flies, especially theTabanidae, but Mitzmain (1914) records experiments with mosquitoesin which the parasite lived 42 hours in Aedes argente'U8 (calopus) and 30hours in Cule:c quinquefasciatus (fatigans) and C. ludlow;' Blanchard.Ca8tellanella gambiense (Dutton 190!) (Trypanosoma), the cause ofGAMBIAN SLEEPING SICKNESS of man, is normally carried bytsetse flies of the genus Glossina, but Roubaud and Lafont (1914) gaveexperimental evidence that it can be transmitted by Aedes argenteul(Stegomyia calopus). Heckenroth and Blanchard (1913) succeeded·transmitting the disease by the bite of M an8omoides uniformis Theobsfrom guinea pig to guinea pig, when both were in the same cage, and alswhen not in contact, ~4 hours after the mosquito had bitten the infecteanimal.Ca8tellanella rhode8iense (Stephens and Fantham 1910) (Trypano8oma),the cause of RHODESIAN SLEEPING SICKNESS, is

DISEASES TRANSMITTED BY MOSQUITOES !!51normally carried by the tsetse :flies of the genus Glossina, but Roubaudand Lafont (1914) have obtained experimental transmission with Aedesargenteua (Stegomyia calopus). -Trypanosoma (sens. lat.) noctuae Schaudinn (1904), which may beconfused with Haemoproteus noct'Uae Celli and San Felice, mentionedAbove, passes its schizogony in the owl, Gla'Ucidi'Um noctuae, and itssporogony in the mosquito, Culex pipiens.Trypanosoma (sens. lat.) ziemarvni Schaudinn, anothcr organismbadly confused with T. noctuae and Leucocytozoon danilcwakyi. is recordedfrom Cule.r pipiens fed on the owl, Glaucidium noctuae.A Trypanosoma sp. was recovered by Durham from Aedes argenteua(Stegomyia fasciata) whIch had fed on bats (Phyllostomus sp.), andanother Trypanosoma was recovered from a Culex by Mathis.Mastigophora: Binucleata: LeptomonidaeCrithidia fasciculata Leger (190!) is a parasite of Anopheles maculipenniaMeigen and Culex q'Umque/asciatus (fatigans). Laveran andFranchini (1914) record Leishmania-form bodies, possibly of this species,in mice infected from Anopheles maculipenniB.Leishmania brasiliensis Vianna (1911), the cause of ulcers knownas BOUBA or ORAL LEISHMANIASIS of man in Southern Brazil andNorthern Paraguay, is thought by Brumpt and Pedroso to be carried byTabanidae or Culicidae.Leishmania donovani (Laveran and Mesnil 1903) is the cause ofINDIAN KALA AZAR. It has been proven that the bedbug can carryit, but the normal carrier is unproven. Franchini (1911) fed Anophelesnear claviger Fabricius on cultures of this organism and found that theparasite persisted and developed in the mosquitoes for at least 48 hours.Patton (1907) obtained no results in experiments with Culex quimquefaaciatw(fatigana) , Stegomyia imgens and Anopheles stephensi Liston.Mackie (1915) also failed in his experiments with Culex andAnopheles.Leishmania tropica (Wright 1903) is the cause of ORIENTALSORE of man, which goes undcr various names, and it may really be acomplex species. In investigating Bagdad sore Wenyon (19110.) fedAedes argenteus (Stegomyia fasciata) on sores, and demonstrated in themosquitoes the :flagellate forms of the parasite up to 48 hours, but histransmission experiments failed. He later (1911b) succeeded in gettingthis mosquito to take up the parasites and demonstrated developmentalstages in the gut. No evidence of infection could be found in experimentswith Culex quimquefasciatus (fatigans).Leptomonas algeriense Sergent and Sergent (1906) is parasitic inCulex pipiens and Aedes argentetU (calopus).

SANITARY ENTOMOLOGYLeptomonas culicis (Novy, MacNeal, and Torry, 1907) is native toCulctl: pipiens and Cttlea: quinquefaBciatus (fatigans). Fantham and Porter(1915, 1916) fatally infected birds by feeding them on infected insects,proving it experiment~lly pathogenic to Passer domesticus andChelidO'ft urbica.Mastigophora: Binucleata: PlasmodidaeThe Plasm odiums are the causative organisms of malaria, which are allcarried by the bite of mosquitoes. The cycle' of schizogony occurs in man,CYCLE: OF SCHIZOC01tYIN HOMO SAPIENS (MAN).CYCLE OF S POROOON'"IN ANOPHELESSPP.LIFE CYCLE OF PLASMODIUMTHE CAUSE OF' PE:RNICIOUS MALARIA.Fro. 47. (Piel"ce.)and of sporogeny in the mosquito (fig. 47). This life cycle is very clearlyset forth in many textbooks and should be studied carefully by all students.Briefly it takes place as follows, starting with the minute sporozoiteinoculated in man by the mosquito. This sporozoite is an elongatesickle-shaped body which bores into a red bloo4 cell, and there forms anamoeboid shaped body known as the trophozoite, which gives off pseudopodiathat absorb nourishment from the cell. At first this trophozoiteis of uniform mass, but soon a vacuole is formed, and it may assume aring form. The trophozoite grows, withdraws its pseudopodia and becomesa schizont. This divides into many merozoites, which burst thecell and escape into' the blood stream. This completes the cycle ofschizogony which may begin again by the merozoite entering a red bloodcell and becoming a trophozoite. .On tp~ other hand it may develop into

DISEASES TRANSMITTED BY MOSQUITOES !53a. type of trophozoite which forms sexual bodies known as macrogametocytesand microgametocytes. These are the bodies which, when takenup by a mosquito, develop in the mosquito's body through the cycle ofsporogony. In the stomach of the mosquito the microgametocytes divideinto many tiny, elongate microgametes. The macrogametocytes changeinto macrogametes, and then conjugation of the gametes takes place.The resulting zygote is spherical, but it soon elongates into a small, wormlikebody which is actively motile. It is then known as the ookinete. Inthis stage it bores into the epithelium of the gut wall and becomes roundedand thinly encysted. When encysted it is known as the oocyst. In thisform it grows considerably in size and divides into sporoblasts, whichdivide into sporozoites. These tiny forms migrate into the salivary glandsand are inoculated into a. man at the time of a blood feast.The species of human malaria are Plasmodium vivatJJ Grassi andFeletti (189!) causing the tertian disease, Plasmodium malaria? Laveran(1881), causing the quartan disease, and LaverOllli,o, falciparum (Welch,1897) (also known as LavBrOlTlia malaria Grassi and Feletti, 1890, orPlasmodium falciparum) , causing subtertian, malignant tertian, oraestivo-autumnal malaria.Many species of mosquitoes of the group Anophelinre have beencharged with carriage of malaria but in many cases the evidence does notshow what species of organism is carried. The evidence is briefly summarizedbelow (see also Hindle, pp. 96-107).MALARIA OF UNKNOWN SPECIES.-The following species ofmosquitoes are recorded as carriers or thought to be carriers of some fannof malaria. These Anopheles are often arranged in various subgenera,which are, however, omitted from our discussion.Anopheles aitken. James (fragilis Theobald) is suspected as a malariacarrier by Daniels and Christophers (Hindle, p. !9).A. algeriensis Theobald was found by Sergent and Sergent in Algeriato be a carrier in nature, the sporozoite state being found.A. apicimaculata Dyar and I{nab has been suspected to be a carrierin Central America, but Darling records negative results.A. arabiensis Patton was found in nature carrying sparozoites byPatton in Aden Hinterland (Hindle).A. arden.sis Theobald appears to Castellani and Chalmers (p. 665)as a probable carrier of malaria in Natal.A. boliviensis Theobald (lutzii Theobald) is suspected by Lutz tobe a carrier in Brazil on what Knab (1913) considers insufficientgrounds.A. braziliensis Chagas is cited by Brumpt (1913, p. 748) as a possiblecarrier of malaria in Brazil.

~54 SANITARY ENTOMOLOGYA. cOU$tam Laveran ef Madagascar is listed as a malaria carrierby Castellani and Chalmers.A. ctdidfacies sergentii ~heobald of Algeria is listed as a malariacarrier by Castellani and Chalmers.A. farauti Laveran is recorded as carrying malaria in the NewHebrides (Brumpt, p. 741).A. grabhamii Theobald, of the West Indies and South America, islisted by Castellani and Chalmers as a malaria carrier (p. 665).A. jamesii Theobald is listed by Castellani and Chalmers as a carrierof malaria (p. 665).A. jeyporensis James is a carrier of malaria in India (Brumpt, p.746).A. karwari James and Liston was suspected by Staunton as a carrier,but Christophers (1916) states that there is no evidence againstit. ,A. maculipes Theobald is cited by Brumpt as a possible carrier inBrazil.A. martmi Laveran is Tegarded on epidemililogical grounds byLaveran as a malaria carrier in Cambodia. (Castellani and Chalmers,p.665.)A. mauritianus Grandpre (ziemann;' Grunberg) is regarded by Rossas a doubtful carrier, not actively transmitting in Mauritius. Itssynonym ziem(JlflJll,;' is recorded by Castellani and Chalmers as a carrierin Africa.A. mauritiaIT//lhS paludis Theobald is recorded as a carrier in WestAfrica by Castellani and Chalmers.A. minimus Theobald (febrifer) is according to Walker and Barber(1914, the most important mosquito conczrned in the epidemiology ofmalaria in the Philippines, being susceptible to infection and having ahigh avidity for blood.A. minimus christophersi Theobald is recorded by Castellani andChalmers as a carrier in India.A. nimba Theobald of Brazil is listed by Castellani and Chalmersas a carrier.A. pitchfordi Tower of Africa is recorded as a probable carrier byCastellani and Chalmers.A. puncttdata Donitz is listed as a carrier in New Guinea by Castellaniand Chalmers.A. pursati Laveran is considered by Laveran on epidemiological evidencea carrier iIi Cambodia.•A. rhodesiensis d'thali Patton at Aden is cited as a possible carrierby Patton (Hindle).

DISEASES TRANSMITTED BY MOSQUITOES ~55A. sinensis pseudopictus Grassi is recorded by Castellani and Chalmersas a carrih in Italy.A. turkhudi chaudoyei Theobald of Algeria is recorded by Castellaniand Chalmers as a carrier.'A. turkhudi myzomyifacies Theobald was taken in nature carryingsporozoites of Plasmodium in Algeria by Sergent and Sergent tHindle).A. 'Vincenti Laveran is recorded by Laveran as a carrier in Tonkin(Castellani and Chalmers).A. willmon James of Tonkin was taken by Mrs. Adie in nature carryingsporozoites of Plasmodium (Hindle).Of the above list we may consider therefore as proven malaria carriersalgerienais, arabiensis, minimUB, turkhudi myzomyifacies, and willmon.III the other cases the evidence is not sufficient.SUB TERTIAN MALARIA.-Caused by Laverania falciparumWelch (1897) (Laverania malaria! Grassi and Feletti 1890). This feveris also called tertian aestivo-autumnal and malignant tertian malaria.Records of transmission have been made for the following mosquitoes:Anopheles albimt1lnUB Wiedemann (albipes Theobald) is the commonestcarrier in Central and Tropical South America. Seventy per cent ofthose fed by Darling (1910) became infected. He traced development tothe sporozoite stage.A, O/IlInulipcs Walker, a common Australian species, has been shownby Kinoshita to carry this organism.A. argyrotarsis Robineau-Desvoidy is regarded as an undoubted carrierby Knab (1918) and Ludlow (1914) in the West Indies and SouthAmerica. Although Darling found zygotes in nature, Hindle questionsthe species of organism.A. barbirostns Van der Wulp of India, Malaysia, and China wasrecorded as carrier by Stephens and Christophers (Hindle).A. costalia Loew was shown by Ross, Annett, and Austen (1900) tocarry this organism in Tropical Africa.A. crucians Wiedemann was definitely proven a carrier in Louisianaby King (1916) who found oocysts and sporozoites in his experimentallyfedmosquitoes. He found 75 per cent of his mosquitoes infected.A. culicifacies Giles was shown by Stephens and Christophers to bethe commonest Indian carrier.A. formosaensis II Tsuzuki was found to be a carrier in Formosa byTsuzuki (190~) who proved the presence of sporozoites.A. fuliginosUB Giles was shown to be the carrier in India by Stephensand Christophers who demonstrated zygotes in the. mosquito.A. fwnestua Giles is an active and important malaria carrier inTropical Africa, its connection with this organism being demonstratedby Daniels.

256 SANITARY ENTOMOLOGY.fl. macmatus Theobald is a common carrier in India and the MalayStates, its relation to this organism being shown by Staunton •.fl. macmipalpis indiensis Theobald a common carrier in NorthwestTerai, India, was proven 0. carner by Stephens and Christophers whodemonstrated zygotes.A. maculipentni8 Meigen is the common malaria carrier in Europe,proven by many autho:rs since Grassi.•A. minimus aconitu8 Donitz and ~ s.ynonyms albiro8tri8 Theobal3,cohccsus Donitz, and formosaensis I ':I:{fuzuki, has been shown to be a· carrierof malaria in Malaysia and India. Staunton proved the carriage ofthis organism by a.lbirostris and Tsuzuki by formosaensis I.A. pseudopwnctipfNllTl,is Theobald (franciscani8 McCracken) wasproven 0. carrier in Panama by Darling (1910) who found zygotes in hisexperimental mosquitoes.A. punctipennis Say was first proven 0. carrier of this organismin Louisiana by King (1916) who found 20 per cent of his experimentalmosquitoes infected, and later Mitzmain (1917) corroborated this byfinding 27 per cent of his experimental mosquitoes infected.A. quadrimacmatus Say was first proven a carrier of this organismin the United States by T4ayer (1900), and later corroborated by Woldertin 1901, and Hirshberg (1904), and finally by I{ing (1916) whofound 23 per cent of his mosquitoes, fed on a certain case, infected.A. rossii Giles was shown by Stephens and Christophers to be a carrierin India, but not commonly.A. sinensis Wiedemann of Southeastern Asia was recorded as 0. carrierby Christophers (1916).A. tarsimacmatus Goeldi was found by Darling (1910) in Panamat~ be infected in 100 per cent of his experiments with this organism.A. theobaldi Giles was shown to be a carrier in India by Stephensand Christophers, who demonstrated zygotes in the experimental mosquitoes.A. turkhudi Liston was shown to be a carrier in India by Stephensand Christophers, who demonstrated zygotes in the experimental mosquitoes.A. umbro8us Theobald was shown to be a carrier in the MalayStates by Staunton, who demonstrated zygotes in the experimental mosquitoes.For American students of aestivo-autumnal or subtertian malaria; thefollowing species are therefore of importance-albimanus, arggrotarsi8,crucians, pseudopunctipennis, pwnctipennis, quadrimacmatus, and tarsimacmatus.For those of our troops who go abroad the other specieslisted above are of greater importance.QUARTAN MALARIA.-This type of .malaria is caused by Plas-

DISEASES TRANSMITTED BY MOSQUITOES !!57modi'lJ/l'T& malariae Laveran (1881). The following species of mosquitoeshave been proven to be carriers:Anophelcs algcricnsis Theobald was proven by Sergent and Sergent(1906) to be·a carrier in Algeria.A. costalis Loew was shown by Ross, Annett, and Austen (1900) tobe a carrier in Africa.A. culicifacics Giles is the most common Indian carrier and its relationshipto thi~ organism was proven by Stephens and Christophers.A. fuliginosus Giles is not an active carrier in India but Stephens andChristophers demonstrated the zygotes of this organism.A. fwnesta Giles is an active and important carrier in Africa, itsrole being proven by Ross, Annett, and Austen (1900).A. maculipewnia Meigen is the common European carner.A. myzomyifacies Theobald is a carrier in Algeria .. according to Sergentand Sergent (1906). -A. quadrimaculatus Say was proven a carrier in the United States byBeyer, Pothier, Couret, and Lemann (190!!).A. rossii Giles was proven capable of transmitting this organism inIndia by Stephens and Christophers.A. sinensis Wiedemann was shown to be a carner in China and SoutheasternAsia by Tsuzuki.A. stephensi Liston is claimed to be a carrier in India by Christophers(1916).A. theobaldi Giles was proven a carrier in India by Stephens andChristophers, who demonstrated zygotes in experimental mosquitoes.Thus it will be seen that only one species of mosquito in America,quadrimaculatus. has been demonstrated to be a carner of quartanmalaria.TERTIAN MALARIA.-Tertian malaria is caused by Plasmodium'Diva:c Grassi and Feletti (1892). It has been shown to be carried invarious parts of the world by the following mosquitoes:Anophelcs albimanus Wiedemann was found to be a. common carrierin Panama by Darling (1910), who demonstrated zygotes and sporozoites..A.. barbirostris Van der Wulp is recorded by Christophers (1916) asa carrier in India.A. bifurcatus Linnaeus is recorded as a carrier in Europe by Grassi.A. costalia Loew was shown by Ross, Annett, and Austen to be a carrierin Africa. .A. crucians Wiedemann was proven by Mitzmain (1916) to be capableof carrying this organism in Louisiana. Sporozoites were obtained.A. culicifacies Giles is recorded as the commonest carrier in Indiaby Stephens and Christophers.

258 SANITARY EN'rOMOLOGYA. fuliginosus Giles is recorded as a carrier in India by Christophel's(1916).A. funesta Giles is the most active and important common carrierin Africa according to' Ross; Annett, and Austen.A. intermedium Chngas is a carrier in Brazil according to Cruz.A. jesoensis Tsuzuki is recorded as a carrier by Christophers (1916).A. liston' Liston is an active and important carrier in certain teraitracts in India, recorded 'by I{inoshita.A. maculatu8 Theobald is recorded as a carrier in India by Christophers(1916).A. maculipalpi8 Giles is r~corded as a carrier in Asia by Christophers(1916).A. maculipenni8 Meigen is a common carrier in Europe.A. mediopunctatua Theobald is a carrier in Brazil according to Cruz(1910).A. minimus Theobald is recorded as a carrier in India by Christophers(1916).A. pharoensia Theobald is recorded as a carrier in Egypt by N ewstead,Dutton, and Todd (1907).A. pseudo1naculipes Chagas is recorded as a carrier in Brazil by Cruz(1910).A. punctipewnis Say was firl\.t proven a ca!rier in the United Statesby King (1916). Sporozoites were found. .Later Mitzmain (1916) corroborate~thisrecord.A. quadrimaculatu8 Say was first proven a carrier in the UnitedStates by Thayer (1900). This was subsequently proven by otherauthors, including King (1916).A. r088ii Giles is recorded as a carrier in India by Christophers(1916).A. sinensis Wiedemann is recorded as a carrier by Kinoshita inChina.A. stephens. Liston is recorded as a carrier in India by Liston andby Bentley. .A. superpictus Grassi is recorded as a carrier in Europe by Grassiand by Bignami and Bastianelli.A. theobaldi Giles is recorded as a carrier in India by Christophers(1916).A. turkhudi Liston is recorded as a carrier in India oy Christophers(1916).A. turkhudi hispaniola Theobald is a common carrier in Algeria andSouthern Spain according to Sergent and Sergent.Thus we find tertian malaria in America carried by albimanus, cru-

DISEASES TRANSMITTED BY MOSQUITOE..s !59ciana, intermedium, mcdiopwnctatus, p8eudomaculipe8, punctiptmll/,ia, andquadrimactdatua, three of which species occur in the United States.AVIAN MALARIA.-Several forms of avian malaria are known.Pla8modium danilewsky Grassi and Feletti (1890), a malaria of sparrows,partridges, finches, and crows is carried by Culex quinquefaaciatua(faUgana) , C. pipUma, Aedes 'IUfflWro8'IJ..s Meigen, and A. argewtCIAB( calopus) according to various textbooks.Plasmodium relictum, a malaria of the canary, was proven by Sergentand Sergent (1918) to be carried by Culex pipiena.Mastigophora: Spirochaetacea: SpirocTtaetidaeSpiroachaudinnia culicia Jaffe (1907) was found by Jaffe in thegut ,and malpighian tubules of Culex pipiens and Anopheles mactdiptffl/11,ia.Leptospira icteroidea Noguchi (1919) has been proven to be thecausative organism of YELLOW FEVER in investigations made inEcuador. Noguchi obtained pure cultures by inoculation of guinea pigswith blood of yellow fever patients. He isolated the organisms fromthree patients and also from mosquitoes and inoculated them into guineapigs, dogs, and marmosets (Midaa oedipua and M. geoffroyi). Theorganism is filterable.This dread disease of the tropics has been studied for years andmany other investigators have sought the organism without success. Seidelin,in 1909, described a parasite belonging to the Babesiidae in theblood and organs of yellow fever patients, as Paraplasma flavigmum,which he considered to be the cause of yellow fever, but this organismwas not generally accepted as the causative organism. The incubationperiod in man is three days and the mosquito to become infected must bitea patient during the first three days of his illness, and then twelve daysmust elapse before the infected mosquito can transmit the disease to man.The organism of yellow fever may pass through the pores of a PasteurChamberlain B. filter. The disease can be conveyed by subcutaneous injectionof the blood taken from the general circulation of a person sickwith the disease during the first three days of the disease, but can becarried nnturally only by the bite of a mosquito (Aedea argentCUB, usuallycalled Stegomyia fa8ciata), tha.t at least I! days before has fed on ·theblood of a person sick with this disease, during the first three days of hisillness. But Noguchi transmitted it by the bite of a mosquito from adiseased to a. healthy guinea pig in 8 days and 8-1!il days, and from manto guinea pig, ll3 days after biting"man. Prophylaxis therefore consistsin prevention of biting by mosquitoes, and mosquito extermination.There is no definite proof that the virus can be transmitted heredita-

260 SANITARY ENTOMOLOGYrily in the mosquito. There is indication of a granular stage of development.The optimum temperature for development is 26° C.The earliest suggestions Qf the possibility of mosquito carriage ofyellow fever were made by Josiah C. Nott in 1848, and Dowler in 1855.In 1881 Dr. Carlos J. Finlay made definite claims that the fever is carriedby the bite of a mosquito. In 1900 during the American occupationof Cuba a commission composed of Doctors Walter Reed, James Carroll,Aristides Agramonte; and Jesse W. Lazear began the investigationof the causation of yellow fever by first definitely discrediting the theoryof the Italian bacteriologist" Dr. Giuseppe SanareIli, that his Bacillusicteroides was the cause. This they proved to be identical with Bacillus8ui-pestifer. They then conferred with Dr. Finlay and began a thoroughinvestigation of the mosquito transmission theory. Dr. Finlay suggestedthe common house mosquito, Aedes argenteus (Stegomyia fasciata) asthe cause. The members of the commission submitted themselves to themaking of the tests. Dr. Carroll was the first to take the fever, beingbitten twelve days after a mosquito had bitten a yellow fever patient.In four days he took the fever. A week later Dr. Lazear, while conductingexperiments, was bitten by a mosquito, which he allowed to engorge,but to which he paid little attention. In five days he took the fever anddied in a week. In the course of experiments ten cases of fever were producedat will by the application of infected ~osquitoes, and all otherpossible means of infection proved useless (see Reed, etc.).Dr. Guiteras (1901) confirmed the transmission of yellow fever byAedes argenteus (Stegomyia fasciata) in seven cases, three of whichproved fatal. Later a French commission, Marchoux, ~alimbeni andSimond (1:903) in Brazil, and American commissions composed of Parker,Beyer, and Pothier in Mexico (1903), and Rosenau, Parker, -Francis,and Beyer (1905), corroborated the transmission of the disease by thismosquito. The last named authors tabulate the whole series of transmissionexperiments showing ~hat in 40 cases of transmission by mosquitobite, the incubation period after the bite exceeded three days and afraction in only ten cases, and was possibly less than three whole daysin only two cases. The maximum authentic record o'f the incllbationperiod is six days and two hours.Platyhelmia: It' asciolidaeA Clinostomum is recorded by Soparker (1918) which passes itsfirst stage in a snail, Planorbis e:rustus, and is found as a cercaria in thelarvre and adults of Culea: quinquefasciatus (fatigans) and Anopheles

DISEASES TRANSMITTED BY MOSQUITOES ~61r08sU. Fish swallowing the mosquito larvre take up the worm, whichcontinues its development toward maturity. 'The final host is notknown.N emathelmm.the8 : Nematoda: Filariidae 2Acamthocheilonema per8tans (Manson 1891), the cause of a f'l.rm ofhuman FILARIASIS in Africa, is probably carried by biting flies.Hodges in Uganda obtained an incomplete cycle in Man8onioide8 africa'TlllMlTheobald (Panoplite), Aede8 argentcus (calopUlJ) , A. sugens 'Viedemann,Anophele8 costalia Loew, and a Culex, and negative results with a longseries of mosquitoes (Dye, 1905). Low (1903) obtained incomplete developmentin Taeniorhynchu8 fU8copcnnatUlJ.Dirofilaria immitia (Leidy, 1856), cause of CANINE FILARIASIS,has been provcn by NOEl, Dye (1908), Grassi, and Fiilleborn (191~) topass its intcrmediate stages in the following mosquitoes-Anophelesmaculipenmis Meigen (claviger Fabricius), A. algeriensis Theobald, A.-bifurcatus Linnaeus, A. sinensis Wiedemann (pseudopictUlJ Grassi), A.superpictus Grassi, Culex quinquefa8ciatus Say (fatigans Wiedemann),C. malariO! Grassi, C. penicillaris Rondani, and Aedes vexans Meigen(Culex) exceptionally in C. pipiens, and with difficulty in Aedes argentcus(Stegomyia calopus). The microfilaria or embryo worms are taken upby the mosquito with the blood of the dog. They soon pass from thestomach into the Malpighian tubules. In ten days their development iscomplete and they migrate towards the head and into the proboscis.When an infected mosquito containing filarire in its proboscis feeds on adog, the worms escape by boring through a delicate membrane whichunites the labellre, and thus get on the surface of the skin. If this is sufficientlymoist they penetrate the epidermis and may be found in the subcutaneoustissues, whence they work toward the heart and great vesselsof the dog and there develop into adults.Dirofilaria repens Railliet and Henry (1911), cause of SUBCUTANEOUS CANINE FILIARIASIS, passes its intermediate stagesin the mosquito Aedes argenteus, its development having been demonstratedby Bernard and Bauche (1913). Its life history is quite similarto that of D. immitis.Filaria bancrofti Cobbold' (1877), the cause of. HUMAN FILARIASIS or ELEPHANTIASIS, passes its intermediate stages in the mosquitoes.Complete development. has been demonstrated in Anopheles r088;Giles in India by James; A. c08talia Loew in West Africa by Annett,Dutton, and Elliot; Culex pipiena in China by Manson; C. quinquefa8ciatusSay (fatigans Wiedemann, ciliari8 Bancroft, nigrithorax 8k1l,8ei Giles)in China by Manson, in South Carolina by Francis, in Australia by Ban-I For further discussion of the following worms see Chapter V.

SANITARY ENTOMOLOGYcroft, in the West Indies by Lebredo (under the name pipiena) and alsoby Law, in the Philippines by Ashburn and Craig, and in India by Cruikshankand Wright; Aedes pseuilosc'Utellaris Theobald in Fiji; MO/TIrsonioides africanus Theobald by Daniels in Nyasaland; M. wniformisTheobald, and Aedes argenteus Poirret (Stegomyia calopus Meigen, A.fasciata Fabricius, Culex taeniatus Meigen) in Nigeria by Daniels, andin the West Indies by Law.Complete developmcnt has not been dcmonstrated as forms have not. been actually seen in the proboscis, although advanced stages have beenrecorded in Anopheles sinensis Wiedemann (minutus Theobald, pseudopictusGrassi, peditaeniatus Leicester, nigerrimus Giles) and barbirostri~Van dcr Wulp in Malaysia by Leicester; A. argyrotarsis Robineau-Desvoidyin West Indies by Law; A. albimanus Wiedemann (albipes Theobald)in West Indies by Vincent; M ansonioides an'l1A.tlipes Theobald inMalaysia by Lcicester, and in Australia by Bancroft; Mansonia pseudotitillansTheobald; Culex microarvnulatus Skuse; C. geli(Zus Theobald, andC. sUiens Wiedemann, Aedes perplexa Leicester, A. scutellaris Walker,Scutomyia albolineata Theobald and Taen.iorhynchus domesticus Leicesterin Malaysia by Leicester.Francis (1919) reports absolutely negative results with Aedesargenteus (calopus) in South Carolina.The embryo microfilaria entcr the mosquito's stomach with the blood.They rupture the sheaths which contain them, pierice the walls of thestomach and find their way to the muscles of the thorax, where theydevelop. They finally work into the proboscis and escape during the actof feeding, through Dutton's membrane, as worked out by Lebredo (1905).They enter the skin through the bites or through pores.Filaria demarquayi Manson (1897), another cause of HUMANFILARIASIS, was found by Fiilleborn to pass its immature stages inthe thoracic muscles of Aedes argenteus (calopus). Mense also recordsCulex quinquefasciatus and Anoplteles albimanus as hosts.Nemathelmintltes: Nematoda: MermithidaeAgamomermis culicis Stiles (1903) is recorded from Culex 801licitanaWalker in the United States.From a purely American standpoint we must guard against mosquitoesas carriers of malaria, yellow fever, dengue, and filariasis, buttroops operating in Mediterrancan countries would also havc to considerpossiblc transmission of tropical sores and Kala Azar. In South Americaother fonns of sores; in Africa sleeping sickncsses may be carried bymosquitoes.The burden of all this evidence is that mosquitoes should not be

DISEASES TRANSMITTED BY MOSQUITOES 263q.permitted to breed near human habitations, and especially near Armyestablishments.REFERENCESAshburn, P. M., and Craig, C. F., 1907.-Philippine Journ. Science, vol.- 2B, pp. 1-14,98-152.Bancroft, T. L., 1906.-Australian Med. Gaz., vol. 25, pp. 17, 18:Bernard, P. N., and Bauche, F., 1918.-Bull. Soc. Path. Exot., vol. 7,No. I, pp. 89-99. .Beyer, G. E., Pothier, O. L., Couret, M., and Lemann, 1. I., 1902.New Orleans Med. and Surg. Journ., vol. 54, pp. 419-480.Brumpt, E., 1912.-Precis de Parasitologie.Castellani, A., and Chalmers, A. J., 1913.-Manual of Tropical Medicine,2nd edit. .Chalmers, A. J., 1918.-Journ. Trop. Med. and Hyg., vol. 21, No. 22,pp.221-224.Christophers, S. R., 1916.-Indian Journ. Med. Research, vol. 3, No.3,pp. 454-488.Cleland, J. B., Bradley, B., and McDonald, W., 1918.-Journ. Hygiene,vol. 16, No.4, pp. 317-418, 9 charts.Cleland, J. B., Bradley, B., a:Qd McDonald, W., 1919.-Journ. Hygiene,vol. 18, No.3, pp. 217-254.Darling, S. T., 19lO.-Studies in Relation to Malaria. Isthmian CanalCommission, pp. I-S8.Dye, L., 1905.-Archiv. de Parasit., vol. 9, pp. 5-77.Fantham, H. B., and Porter, A., 1915.-Ann. Trop. Med. and Parasit.,vol. 9, No.4, pp. 543-558.Fantham, H. B., and Porter, A., 1916.-Journ. Parasit., vol. 2, No.4,pp. 149-166.Franchini, G., 1911.-The Lancet, vol. 2, p. 1268.Francis, Edward, 1919.-U. S. Treas. Dept., Hygienic Lab., Bull. 1l'7,34 pp., 10 plates.Graham, H., 1903.-Journ. Trop. Med., vo]' 6, pp. 209-214.Grassi, B., and Feletti, 1891.-Centralbl. f. Bakt. und Parasitenk., vol.9, p. 463.Guiteras, J., 1900-1901.-Revista de Med. 'l'rop., vol. 2, No. 10, pp.157-182.Heckcnroth, F., and Blanchard, M., 1915.-Bull. Soc. Path. Exot., vol.6, pp. 442-448.Hindle, E., 1914.-Flies in Relation to Disease. Blood-sucking Flies.Cambridge Univ. Press. (Gives Bibliography of Malaria Transmission,pp. 168-165.)

264 SANITARY ENTOMOLOGYHoward, C. W., and Clark, P. F., 1912.-Journ. Expel'. Med., vol. 16,No.6, pp. 850-859.Jaffe, J., 1907.-Arch. f. Protistenk., vol. 9, pp. 100-107.King, W. V., 1916a.-Amer: Journ. Trop. Dis. and Prevo Med., vol. 3,No.8, pp. 426-432.King, W. V., 1916b.-Joul'n. Expel'. Med., vol. 23, No.6, pp. 703-716.Knab, F., 1913.-Amer.- Journ. Trop. Dis. and Prevo Med., vol. 1, pp.33-43.Laveran, A., and Franchini, G., 1914.-Bull. Soc. Path. Exot., vol. 7,pp. 605-612. .Law, G. C., 1903.-Brit. Med. Journ., vol. 1, pp. 722-724.Lebredo, M. ~., 1905.-Journ. Infect. Diseases, Suppl. No.1, pp. 332-352.Ludlow, C. S., 1914.-U. S. War Dept., Office Surgeon Genl., bull. 4,pp. 1-94.Mackie, F. P., 1915.-Indian Journ. Med. Research, vol. 2, pp. 942-949.Marchoux, E., Salimbeni, A., and Simond, P. L., 1903.-Rapport de10. Mission Fran9aise, Ann. Inst. Pasteur, November, vol. 17, pp.665-731.Martin, G., Leboeuf, and Roubaud, E., 1908.-Bull. Soc. Path. Exot.,vol. 1, pp. 355-358.Mitzmain, M. B., 1914.-U. S. Treas. Dept., Hygienic Lab., bull. 94.Mitzmain, M. B., 1916.-Public Health Reports, May 12, pp. 1172-1177.Mitzmain, M. B., 1917.-Public Health Reports, July 6, pp. 1081-1083.Morris, H., 1918.-Louisiana Agr. Exp. Sta., bull. 163, 11 pp.Noguchi, H., 1919.-Journ. Amer. Med. Assoc., vol. 72, No.3, pp.187-188.Noguchi, H., 1919.-Journ. Exper. Med., vol. 29, No.6, pp. 547-596;vol. 30, No.1, pp. 1-29; No.2, pp. 87-107; No.4, pp. 401-410.Parker, H. B., Beyer, G. E., and Pothier, O. L., 1903.-U. S. Publ.Health & Marine Hosp. Serv., Yellow Fever Institute, bull. 13, 48 .pp.Patton, W. S., 1907.-Scient. Mem. Officers Med. and Sanit. Depts.,Govt. India, n. S., Nos. 27, 31.Reed, Walter, 1901.-Am. Med., July 6.Reed, Walter, and Carroll, J., 1902.-Am. Med., vol. 3, February 22.Reed, W., Carroll, J., Agramonte, A., and Lazear, J. W., 1900.-Phila.Med. J ourn., Oct. 27, vol. 6, pp. 790-796.Reed, W., Carroll, J., and Agramonte, A., 1901.-Journ. Am. Med.Assoc., February 16, vol. 36, pp. 431-440.Rosenau, M. J., Parker, H. B., Francis, E., and Beyer, G. E., 1904.-

DISEASES TRANSMITTED BY MOSQUITOES 265U. S. Publ. Health & Marine Hosp. Serv., Yellow Fever Inst., bull.14, pp. '49-101.Ross, R., Annett, H. E., and Austen, E. E.,1902.-Report of the Malaria.Expedition of the Liverpool School of Tropical Medicine, LiverpoolSch. Trop. Med., Memoir 2, pp. 1-58.Roubaud, E., and Lafont, A., 1914.-Bull. Soc. Path. Exot., vol. 7, No ..1, pp. 49-52.Sergent, Ed. and Sergent, Et., I906.-Ann. Inst. Pasteur, vol. 20, pp.!l41-255, 864-888.Sergent, Ed. and Sergent, Et., 1918.-Bull. Soc. Path. Exot., vol. 11,.No. 4,p. 281.Soparker, M. B., 1918.-Indian Journ. Med. Research, vol~ 5, No.8,.pp. 512-515.Staunton, I918.-Journ. London School Trop. Med., vok2.Stephens, J. W. W., and Christophers, S. R., 1908.-The PracticalStudy of Malaria, University Press, Liverpool School Trop. Med.,pp. 1-414.Stephens, J. W. W., and Christophers, S .. R., I899-1902.-Reports tothe Malaria Committee of the Royal Society. Nos. 1 to 8.Thayer, W. S., I900.-Philadelphia Med. Journ. vol. 5, pp. 1046-1048.Tsuzuki, J., 1902.-Arch. f. Schiff's- u. Trap. Hyg., vol. 6, pp. 9,.285-295.Walker, E. L., and Barber, M. A., 1914.-Philippine Journ. Science,.Manila, vol. 9B, No.5, pp. 881-489.Wenyon, C. M., 1911a.-Kala Azar Bull., vol. 1, pp. 86-58.Wenyon, C. M., 1911b.-Parasitology, vol. 4, No.8, pp. 278-344.

CHAPTER XVIIIWhat We Should Know About Mosquito Biology 1W. D%oi"ght Pierce and C. T. GreeneEntomologists are generally better informed about the life historyof mosquitoes than of most of the insects which carry disease. It istherefore more essential a~ this time to sketch over some of the pointsto which we as sanitary entomologists must pay attention. Anyonestudying mosquitoes must, before completing his study, digest the wonderfulmass of material in Ho\vard, Dyar, and Knab's Monograph, especiallyvolume 1.All mosquitoes pass their early stages in w:ater. They cannot developin any other medium.The adult mosquito is known to everyone, but its eggs depositedon the water are the least known. The larvm, commonly known as wiggletails,and the peculiar shaped pupm are fairly well known.The different species of mosquitoes are more or less selective as tothe type of water in which they breed, and careful study of mosquitohabitats is essential to all who have to do with mosquito sanitation.Therefore we must, at least in this lecture, consider the habits of all ourAmerican disease-carrying mosquitoes. Many of the others may becapable of carrying disease, but no proof has been brought forwardagainst them.In the preceding lecture it was shown that the following mosquitoesof the United States are disease carriers:Dengue fever is carried by Culex quinquefallciatus (fatigans), andAedes argenteus (Stegomyia calopus or fasciatus).Yellow fever is carried by Aedes argenteus.Subtcrtian or aestivo-autumnal malaria is carried by Anophelescrucians, pseudopunctipennis, pwnctipennis, and quadrimaculatus.Quartan malaria is carried by Anopheles quadrimaculatus.Tertian malaria is carried by Anopheles crucians, pwnctipennia andquadrimaculatus.Filariasis is carried by Culex quinquefasciatus and Aedes arg'ertteus.These six species of mosquitoes are then the ones most to be feared• This lecture was presented to the class September 16, 1918.266

'VHAT WE SHOULD KNOW ABOUT MOSQUITO BIOLOGY 267in our own country. One traveling in other countries must guardagainst entirely different species.OVIPOSITION AND THE EGG STAGEMosquitoes lay their eggs in various ways. The mode of depositionbest known is that of laying all the eggs at once in a so-called raft.The eggs are cylindrical, rounded at the ends and tapering toward theupper end. They are placed in an upright position and fastened togetherby a viscous secretion. They are deposited upon the water or ncar it.Such is the type of oviposition of Culex and several other genera.Some mosquitoes, as Culex jenningsi, surround the eggs with a gelatinousmass which furnishes the first food to the newly-hatched larvae.The various species of Anopheles deposit the eggs separately in smallnumbers on the surface of the water. The eggs lie upon their sides andare kept afloat by a peculiar hydrostatic organ, a partial envelope whichis more or less expanded, particularly along the median portion of theegg. This organ is variously shaped in the different species of Anophelesand is called a float.Of the mosquitoes which lay single eggs, some fasten them by tI.gelatinous substance at the margin of, the water, others lay them onthe ground where they remain until rains provide sufficient moisture fl)rhatching. Some of these eggs are enabled to float because of spinosetubercules which hold the air between them. The species of Aedes laytheir eggs singly and not all at once. It often happens that eggs laidin the summer in northern latitudes layover to th~ next spring.Aedes argenteua Poirret, the yello,v fever mosquito, lays eggs measuring0.53 mm. long and 0.15 mm. in diameter. They are black, fusiform,very slightly flattened on one side, slightly more tapered toward themicropylar end; sculptured with rough, somewhat irregular rhomboidalcallosities forming spiral rows. Under natural conditions the eggs arelaid singly in small irregular groups some distance above the marginof the water. They are laid in from one to seven days after the female hasfed upon blood, and usually at intervals after successive blood meals.Culex quinque{asciatus Say, the dengue fever mosquito, lays its eggsin boat-shaped masses floating on the surface of the water. It may layfrom 180 to 350 in a maf!.s in 7 to 11 rows. The eggs hatch after one tothree days. An egg mass of a Culex mosquito is shown in fig. 48.AnoplU!les cTUcians Wiedemann has an elongate fusiform egg. (fig. 49c) slightly more tapered toward one end, both ends rounded.The dorsal surface is granular, the ventral surface coarsely hexagonallyreticulate. The floats occupy about half the sides in top view, and arcseparated at the middle by nearly one-third the diameter of the egg.

268 SANITARY ENTOMG./0GYThese eggs are laid singly, a' small number at a time, upon the surface ofthe water.Anopheles pumctipennis Say (fig. 49a) has an elongate fusiform egg~reticulate ventrically, finely granular dorsally. The floats are large~extending nearly to the apices, closely approximated medianly on thedorsal surface, arcuately produced at the sides to the apical fourths~FlO. 48.-Eggli and larvae qf Culex. Enlarged. (Howard.) From U. S. Dept. Agr.,Farmers' Bull. 155, fig. 5.widely separated on the ventral surface, and showing only on middlethird of sides. The eggs are laid singly or in small groups upon thesurface of the water.Anopheles quadrimaculatu.s egg is shown in fig. 49b.THE LARVAE AND THEIR HABITSAll mosquito larvm are aquatic. .By far the most of the larvm occurin small deposits of water, although certain species occur in large bodiesFIG. 49.-Eggs of malaria mosquitoes: a, ..dnopheleB p'IJnctipfl"71i~; b, ..d. quadrimaculat'UB;c, A. crucia1l8. (After Howard, Dyar and Knab.)of water. Those species which lay their eggs on the ground in dryregions, hatch as soon as rains occur, and the larvre go through a veryrapid development. Such species show a rather marked periodicity inbroods. Species which have abundance of water breed continuouslyduring the warmer seasons. One is apt to find mosquito IarvIE whereverwater occurs.The food of the larvre varies, but usuaUy consists of the minute forms

WHAT WE SHOULD KNOW ABOUT MOSQUITO BIOLOGY 269of plant and animal life in the water, although certain species arepredaceous, and some are scavengers upon the dead animals and insectlife in their habitat. .The larvre of mosquitoes are very peculiarly constructed. The mouthis furnished with tufts of filaments which are constantly in vibration. Thehead is large, the antennre long, the thorax somewhat swollen, and theabdomen slender. The sides of th!;! body are furnished with stiff bristles.From the next to the last segment there protrudes a long tube nearly asthick as the body itself, and it is this tube that touches the surface ofthe water when the larva rises to breathe. When in this position thelarva ranges downward in various attitudes characteristic of the species.The object of this tube is to get air. At the extremity is a breathinghole, or spiracle, and into it run two main trachere which extend throughthe body of the insect with many branches which carry air to all partsFIG. SO.-Larva. of the yellow-fever mosquito. Much enlarged. (Howa.rd.) From U. S.Dept. Agr., Office Seey., Cir. 61, fig. 14.of its tissues. The true anal end of the body is furnished with four moreor less developed tracheal gills.When suspended from the surface the wriggler's mouth parts areconstantly in vibration, bringing into its mouth any minute particleswhich float in suspension in the water.It is when the larva extends its breathing tube from the surface ofthe water that it offers the greatest opportunity for control. All effortsto maintain an oil film on the surface of the water are. aimed at cloggingup this tube when it comes to the surface, and thus cutting off the airsupply.Occasionally the larva d«;!scends to the bottom, jerking its body violentlyfrom side to side. The anal tracheal gills undoubtedly assist inthis motion. The larvre are active and move backward through the waterby these jerky movements. They can move slowly forward by the actionof the mouth brushes. Some species arc specially equipped for obtainingair from the water or from plants and do not come to the surface. Thisis fortunately not the case with those we are most interested in.Aedes argen.teus larva (fig. 50) has the head rounded, widest behindthe eyes. The thorax is rounded, wider than long, with moderate, rather

270 SANITARY ENTOMOLOGYsparse hairs. The abdomen is rather long, .the tracheal tubes are broad,band-shaped. The air-tube is stout, short, strongly tapered on outerhalf, over twice as long as wide, with the pecten running nearly halfway,followed by a single tuft of a few hairs. Each single pecten-tooth is arather long spine with two large and some small teeth within and smallones without. The lateral comb of the eighth segment is composed often scales in a single ro,v. The anal segment is short, wider than long,almost ringed by the plate, which nearly touches ventrally, but is notunited. The ventral brush,is moderate, directed posteriorly. The analgills are long, wide, tracheate, with rounded tips.The larvre live in accumulations of 'vater in artificial receptacles.Originally it was a tree-hole-inhabiting species, but is now wholly domesticatedand is found in houses and in the vicinity of human habitations.The larvre thrive very well in water containing food refuse and inmuddy water. ~Culex quitnqucfaaciG'&..u larva (see fig. 48) has the bead rounded,widest through the eyes. The thorax is rounded, wider than long. Theabdomen is moderate, with the anterior segments shorter. 'l'he trachereare rather broad. The air tube is rather stout, tapered on outer half,four times as long as wide, with the pecten running about one-third, eachpecten-tooth is broad with three to six branches. The lateral comb ofthe eighth segment is composed of many spines in a triangular patch.The anal segment is a little longer than widc, ringed by the plate. Theventral brush is well developed, confined to the barred area. The analgills are rather short and broad, longer than the segment, taperedtoward tips.The larvre are found most frequently in artificial receptacles, butalso in ground pools in the vicinity of habitations when the water issufficiently polluted. The species thrives best in water charged withanimal matter and sho,vs a preference for filthy water. Breeding goes oncontinuously while conditions are favorable. Under the most favorableconditions the larval pcriod may be five or six days.Anopheles crucians larva has the head round.ed, elongate, bulging atthe sides, with the frontal portion before the antennre conically produced.The thorax is rounded quadrate, about as long as wide. The abdomenis stout, with the anterior segments shorter. The air tube is sessile, subquadrate,roundedly angled posteriorly. The lateral plates of the eighthsegment are posteriorly armed with a series of about eight long, stoutspines, sep~rated from eaeh other by from one to four short spines. Theanal segment is about as long llS wide, with a small dorsal plate. Theventral brush is well developed, of long branched tufts. The anal gillsarc moderate, about as the segment, slightly constricted centrally, bluntpointed.

WHAT WE SHOULD KNOW ABOUT MOSQUITO BIOLOGY ~71The larvre live in ground-pools, usually in tidal marshes. Breedingalso occurs inland. Below New Orleans it is an abundant pest in thesalt and brackish water marshes, where it occurs in undiminished numberseven in the winter.Anopheles pseudopunctipennis larva differs but little from the precedingbut may be separated in the table which follows.This species is somewhat discriminating in choice of breeding place.It prefcrs as a rule watcr of great purity and rapidity of current. Thelarval food is by preference the soft green algro. It has been found.however, in irrigating ditches, in clear quiet pools formed by the overflowof a watering trough, in ditches, pools and puddles, in tanks, wellholesand spring-holes full of algro.Anopheles p'Ulflctip8'nnis laryre (fig. 51) are found in all sorts of waterin ground-pools and streams and occasionally in artificial receptacles.The larvre are found all the season, breeding being continuous until winter.FIG •• n.-Larva of the malaria mosquito, .t.lnophe168 pl£nctipenni8.Dyar and Knab.)(After Howard.The larvre occur most commonly in swamps containing algro. Larvrehave been found repeatedly in rain puddles, the water muddy and withouttrace of algal growths.Anopheles quadrimaculatus larva is most like that of pwnctipC'Tl/1£i ••The larvre occur in natural collections of water of a more or less permanentnature. They often occur in the same locations as punctip8'1b1l.iflbut are morc: addicted to permanent stagnant water, such as the edgesof sluggish rivers and marshes containing algro, less to springs andrunning water, and do not occur in temporary ground-pools filled by rains.The larvre of Anopheles are to be distinguished from Culex and Aedesby the habit of feeding. The two latter genera have larvre with longbreathing tubes by which they hang from the surface of the water withthe head downward, and feed on the life under the surface. Anopheleslarvre have very short breathing tubes. They are surface feeders andare held to the surface by the tube and the fan-shaped abdominal tufts.The head is turned completely over with the mouth uppermost in the actof feeding.

SANITARY ENTOMOLOGYThe American disease-carrying Anopheles larvIE may be partially.separated by the following table:1. Abdomen with five pairs of fan-shaped tufts, the first pair small,pfJJTI,Ctipe'nnis Say, quadrimaculatua Say.Abdomen with five pairs of fan-shaped tufts, 2.2. First and last pair of fan-shaped tufts smaller than the others,crucians Wiedemann.Fan-shaped tufts all. equal, each element in the tuft with long,slendl'r apical portion, tpseudopunctipe1l/fl.ts Theobald."FIG. 52 (left).-Pupa of Culex. Greatly enlarged. (Howard.) From U. S. Dept.Agr. Farmers' Bull. 155, fig. 8.FIG. 53 (center).-Pupa of Anopheles quadrimac'Ulattt.. Greatly enlarged. (Howard.)From U. S. Dept. Agr. Office Seey., Cire. 61, fig. Hl.FIG, 54 (right).-Pupa of Aedes argente'U", the yellow fever mosquito. Greatly enlarged.(After Howard, Dyar, and Knab.)THE I'UP..EUnlike other insect pupre, the mosquito pupre are active and capableoOf moving rapidly through the water. They depend upon communicationwith the air for respiration. The respiration takes place through a pairof appendages on the thorax, called the respiratory trumpets. By lashingthe pair of chitinous plates at the apex of the eight segment, calledpaddles, the pupa can descend rapidly. It rises to thc surface as soonas it ceases its efforts. The mosquito pupa is also peculiar in that itpossesses eyes, which enable it to see the approach of an enemy and makeits escape. Figures of the three genera discussed in the paper are given0( figs. 52-54). IADULT MOSQUITOESThe adult mosquitoes are known to all of us. The males take onlyvegetable food, but the females also require a blood feed, in many species,before they can oviposit. Various species attack insects, frogs, birds,and all types Qf mammals for their blood feed. Culea: quim,que/asciatuafeeds at night, Aedes argenteus in the day time, and the Anopheles duringthe twilight hours of early morning and evening.

WHAT WE SHOULD KNOW ABOUT MOSQUITO BIOLOGY !!73Table of Adult American Disease-Carrying Mosquitoes1. Pq.lpus of female as long as the beak (see fig. 55b) and the wingsbrown with yellowish-white spots or markings, (Anopheles), S.Palpus of female shorter than beak (see fig. 55a) and wings withoutdefinite spots or markings,(Aedes, Cule31), f&.Ap&FIG. 05.-Types of mosquito mouthparts: a, Short palpus form; b, Long palpus form.(Greene.) A = antenna, B = beak, P = palpus.2. A dark brown species with two curved, silvery white lines (resemblingan inverted lyre) on top of body. Yellow fever mosquito.(fig. 57),Aedes arge-nteus.FIG. 66 (left!-Adult Ou16:r: BolUcita1l8. Much enlarged. (Howard.) From U. S. Dept.Agr. Farmers' Bull. 155, fig. 10..FIG. 57 (right).-The yellow fever mosquito, Aedes argeme'UB: adult female. Muchenlarged. (Howard.) From U. S. Dept. Agr. Office of Seq., eire. 61, fig. 18.Pale reddish-brown species with top of abdomen much darker andwith five yellowish-white bands across the top (for a Culexsee fig. 56),Cule31 quinqucfasciatus.3. A dark brown species with a vein near the base of the wingyellowish-white and this vein having three distinct dark spots,Anopheles cmcians ..

274 SANrrARY ENTOMOLOGYA dark brown species with the wings mostly brown having alarge, yellowish-white spot on the front edge of wing towardsthe tip, and oa smaller light spot close to the tip. Fringe atthe tip of wing dark,Anopheles pWTu;tip8'1llni8.A species very slightly smaller. Wings clear except along frontedge where there are three large, yellowish-white spots towardsthe tip. The third spot is at the tip and the fringe at the tip ofthe wing is yellowish-white, Anopheles pseudopwnctipl!1llnis.A brown species with the wings without pale, conspicuous markings.Wingso with four dark-gray to black spots on outer half(fig. 58),Anopheles quoilrimaculatus.Fro. 58.-A malarial mosquito, Anopheles quadri~a(''Ulat'UII Male at left and femaleat ri&ht. Greatly enlargeod. (Howard.) From U. S. Dept. Agr., Offiee of Seey.,eire. 61, fig. 8.The yellow fever mosquito is more definitely marked than any ~therspecies of mosquito known. The general color is a dark-brown. On topof the thorax or back there are two silvery-white, curved lines whichresemble an inverted lyre.REFERENCESHoward, L. 0., Dyar, H. G., and Knab, F., 19111l-1917.-The mosquitoesof North and Central America and the West Indies, 4 vols. This veryfine monograph is the largest and most complete on this subject.Dyar, H. G., and Knab, F., 1917.-The genus Culex in the United States.Insecutor Inscitiae l\1enstruus. Vol. 5, Nos. 10-12.

CHAPTER XIXMosquito Control 1W. Dwight PierceProbably more money and more concentrated effort has been devotedto mosquito control throughout the world than to the control of anyother disease-bearing insects. The anti-mosquito work now under way inthe United States, under direction of the Public Health Service, is thebiggest sanitary undertaking this country ever has gone into. When weconsider the vast efforts of India, Italy, Panama, Cuba, and other countriesagainst these insects we realize the importance of the problem.PREVEN'rION OF MOSQUITO BREEDINGBy far the most important measures to be taken arc those which preventthe breeding of mosquitoes, and therefore, we have to deal in somemllnner with water. If general mosquito control is sought, it is not essentialto ascertain the species breeding, but when large communities orarmies are to be protected against disease-bearing mosquitoes, time maynot permit of general mosquito control but may necessitate particularattention to the haunts of the disease bearers.ScoutingThe preliminary measures to be taken, therefore, are the organizationand training .of scouting parties designated primarily to search out thebreeding haunts of these species, and report them to the details or squadsdesignated for control work. The scouts must be trained entomologistsskilled in the knowledge of mosquito haunts. They must examine thewater in all receptacles in and around buildings, and in discarded vessels.They must seek out all puddles, hoof prints, wagon ruts, tree holes,ditches, and streams, and carefully examine these. A chart should bekept showing the location of all water and this can be marked in variousways to indicate the species present. Colored pin-markers on a wallchart are very serviceable. A field chart would have to be marked otherWIse.• This lecture was read September 90 and distributed October 7, 1918, It has beengreatly revised.275

276 SANITARY ENTOMOLOGYDetermination of Source of MosquitoesIt is of primary impo~ance in planning 0. mosquito campaign todetermine the direction and distance of flight and behavior of mosquitoesin the area to be controlled. Zetek (1918, 1915) has elaborated methodsfor determining these points. He uses as dyes aqueous solutions of eosin,fuchsin, gentian-violet, bismarck-brown, methylene-blue, and orange-g,mixing one gram of dry stain to 50 c.c. of water. By means of anatomizer 0. fine spray is allowed to fall upon the mosquitoes. They shouldnot be sprayed directly. ,Evening hours are best for their release andcare must be taken not to carry away individuals on the body of theagent. There should be careful observations of wind, climatic condition,direction of flight of the mosquitoes, and the movement of human beings.To determine the flight window traps, examination of buildings andgeneral sweeping are necessary. The place and hour of collection mustalways be noted. To detect the dye a testing solution is made of threeparts glycerin, three parts alcohol, and one part chloroform and thespecimens are individually touched with a camel's-hair brush moistened!herein.Leveling and Filling Water HolesDetails of men may be designated to look after the leveling of groundwhere water is apt to gather and remain, and to fill up small puddles,pools, hoof marks, ruts, etc., which serve no useful purpose and wheredrainage is inadvisable. Holes in trees should be filled up with cement.Stumps which hold water should be grubbed out and the stump holesfilled. In rocky streams pot-holes in the rocks often breed many mosquitoes.If possible the rock should be grooved, or removed, or theholes may be filled with cement.Ditchilng and Clearing Streams and SwampsOther details may be designated to clear stream beds and drain lmvlands. Spring lands, bogs, and swamps furnish an 'abundance of mosquitoesand are the first places to receive the attention of the ditchingsquads. Ditches must be constructed to carry off standing water. Theseshould be laid out by an engineer. The ditches must have straight banksand even bed and must be kept free of vegetation. Sometimes it is necessaryto spray the vegetation along the ditches with oil, and burn. Allborrow-pits and puddles caused by grading roads and railways shouldbe connected up by a ditching system or filled. Flowing streams usuallyhave trees along their sides. Under such trees water is often trappedand forms a quiet, undisturbed place for lJlosquito larvre. Trees must not

MOSQUITO CONTROLgro\v on the edge of the bank. Tree roots must be removed from thestream. Any kind of vegetation growing in the bed of a stream favorsmosquito breeding as it affords some protection against natural enemies,and prevents adequate artiticial control. The stream bed must be clearof vegetation. The banks must be straightened and without overhangingledges. There should be no obstruction to the free flow of the stream.If it meanders, a new and straight course ought to be constructed andthe old course tilled. Springs which furnish good water should be boxedand protected. Le Prince and Orenstein very ably describe in theirbook the method of clearing streams and propagation areas in junglesin the tropics.Clearing of Weed-Filled Bays and Lakes•Large bodies of water in which dense growths of grass and weedsoccur furnish great problems in many localities, and in tropical countriesespecially, where feasible, it is often desirable to furnish the mosquitosquad with two motor boats and submarine saws or other implementsfor cutting and removing vegetation. If this cut vegetation remainsit aggravates the situation. Large lily leaves, which when alive furnishno place for breeding, will often, when dry, form cups for water inwhich mosquitoes breed prolifically.DrainageThe construction of drainage systems should be done preferably by asanitary engineer who understands the mosquito phases of the problem.The main ditches should be constructed tirst and later the laterals added.Sometimes where weed growth is rapid it is desirable to have a doubleparallel series of ditches, one only operating at a time except during heavyrains, with the idea that the idle ditch can be cleaned and shaped up.It is essential that the floor level of the ditch affords no opportunitiesfor puddles to form after the greater part of the water has passed off.In permanent ditching it is sometimes feasible and advisable to line theditch with concrete or at least to line the bottom. Weep-holes should bemade at sufficient intervals to carry into the drain water which gatherson the outside of it. Branch ditches should enter the main ditch at anacute angle or on a curve. At the junction of ditches there should be asplash wall to confine tlie water within the ditch. Pot-holes formed indirt ditches should be tilled up after rains with gravel or stone and tampedhard (see Le Prince and Orenstein, pp. 137-144).In certain soils where seepage water outcrops abundantly on hillsides,it is sometimes practicable to install an intercepting tile drainage

278 SANITARY ENTOMOLOGYsystem. The tiles are laid at right angles to the flow of the seepageat the highest seepage water level, with a space of one-eighth to a quarterinch bet'Veen joints. The grade of the trench bottom must be true.Tiles must not be located on soft mud where they may sink. The outletshould be well above the ground surface (see Le Prince and Orenstein,pp. 180-186).Dr. C. W. Metz (1919) has set down certain very valuable principlesin drainage, and describes the methods of surface and vertical drainageused by the Public Health Service. The treatment depends upon thesources of the water. The methods described above will suffice for rainwater. For seepage water where tile drainage is not to be used theditches must be dug at right angles to the flow of the seepage water, thatis, across the exposed end of the water table. These ditches may be connectedto main ditches which 'will carry the flow down the hillside pa.rallelto the seepage flow. If the ,vater table is too deep to be intercepted byone ditch, it may be necessary to dig additional intercepting laterals atintervals lower down. A swiftly running ditch is better than a sluggishone. Water. confined in a narrow chdnnel will run more swiftly, give lesssurface, and be easier to oil, hence V-shaped ditches are usually preferableto wide-bottomed ones. The shape of the ditch will largely dependupon the nature of the soil. Where wide ditches are apt to form puddlesin dry season, a small V-shaped ditch the width of a shovel may be made, down the middle of the large ditch.Vertical drainage consists of sinking wells to conduct the waterthrough relatively impervious soil into water-bearing sand or gravel.Such drainage is advisable only where surface drainage is difficult orexpensive. In case the underlying stratum is deep down, holes shouldbe bored and drain heads installed. The drain head will consist of aculvert-like box at the level of the bottom of the lake or pond which willconduct the water to the well. The receiving end will be screened to keepout debris with a coarse screen and a fine screen. The other end of theculvert is closed. Over the well will be a hole about one-fourth or onethirdthe diameter of the well, and this likewise will be covered with ascreen. 'A pipe or funnel from the hole in the culvert into the well willreduce washing and crumbling of the sides of the hole. Soft soils willrequire that the well be cased with tile or iron pipe.Anyone engaged in marsh drainage should familiarize himself withthe methods in vogue in the great salt marsh drainage work of the Stateof New Jersey (Headlee, 1915).When ditches become matted with algre and other matter and containmosquito Iarvre, in some localities it is possible to construct water gatesto permit temporary impounding of water, which will enable the ditch

MOSQUITO CONTROL !79squads to thoroughly flush the ditch below the gate and remove allmosquito larvm and algm.LarvicidesThe ditching, draining, and clearing of waterways insure a regularflow, carry off all surplus water, and reduce but do not prevent mosquitobreeding. It is necessary to use some additional means of control andfor this purpose various larvicides have been applied, but principallykerosene, c~de oils of paraffin and asphaltum base, as well ascreosote oils.The question of the effect of oils on mosquito larvre is most thoroughlydiscussed by Freeborn and Atsatt, who find that the t9xicity ofthe petroleum oils as mosquito larvicides increases with an increase involatility, the more volatile oils producing "the more marked lethaleffects. The volatile constituents of the oils contain the principlesthat produce the primary lethal effects. The lethal effects are producedby the penetration of the trach_l\al tissue by the volatile gases of the oils.In the heaviest and least volatile oils having a boiling point greater than!50 0 F., this action may be supplementary or apparently secondary tothe efFect of actual contact of the oil with the body tissue, or perhapsto mechanical means such as suffocation or plugging of the trachem.They found that oils which killed very quickly did so by means of thevolatile gases, whereas in the case of oils with slow effectiveness themechanical suffocation may be the cause of death.This paper is so recent that it has not been possible to obtain amass of evidence on the practical effectiveness of different grades of oilsused as larvicides. Kerosene and crude oil are the oils most commonlyused in general practice. Le Prince and Orenstein prefer crude oil tokerosene because of the film made by kerosene, its greater expense, inflammability,and liability to be wasted because of its transparency.These authors have set down a number of requirements for a goodlarvicide:1. It shall have a high toxic power, so that a small quantity maysuffice for a large volume of water.2. It shall kill rapidly in order that subsequent dilution and weakeningby rain have as little effect as possible .. S. It must be uniform in its toxic power and capable of standardization.4. It should mix freely with brackish and alkaline waters.5. It must be harmless to man and domestic animals, when in thedilution necessary for larvicidal action.6. It shall not be susceptible to rapid deterioration.7. It must be inexpensive.

lil80SANITARY ENTOMOLOGYThey did not find any substance which fulfilled all these conditions,but found a soap (now known as the Panama larvicid~) to meet most oftheir requirements. This was made of the following jngredients:Resin150 to 200 poundsSoda (caustic) 30 "Carbolic acid (sp. gr. 0.97) 150 gallonsThis makes a liquid soap which freely: emulsifies with fresh water.The carbolic acid must have at; least 15 per cent of phenols and nogreater specific gravity than 0.97.This larvicide is manufactured as follows: Heat the carbolic acidin a steel tank with steam coil. 'When steaming hot add the resin andcontinuously stir the mixture by means of a paddle agitator until completesolution is efFected. Dissolve the caustic soda in 6 gallons of waterand add to the mixture. Heat and stir for five minutes. Draw a sampleand pour into water. If it emulsifies the process is complete, and theproduct may be put into shipping drums which must be tightly closed.OilingThere are many ways of applying the oil. The most common methodis by knapsack sprayer or, where the ditch is along the road, by horsedrawntanks fitted with a spraying bar. For slow-moving water andstagnant water, as well as the treatment of ruts, puddles, hoof prints,and so forth, these methods are satisfactory. Dr. Metz found thathe got excellent results in boggy lands especially by applying a thinmist of commercial creosote.A very small quantity will kill mosquitolarv!e.For moving water there are many devices for maintaining a regulardripping of oil from a suspended vessel upon the surface of the water.Such devices can easily be rigged up by any practical man. Dr. M. J.White of the Public Health Service modified this method by conductingthe oil to the water by means of a wick (Metz 1919).The war has brought about the new and even more efficient methodsof oiling which have been developed along many angles by Dr. W. L.Mann, the Post Surgeon, and Lieut. E. C. Ebert of the Marine Corps atQuantico, Va., with the assistance of Pharmacist's Mate Carl Duncan.They have found that sawdust impregnated with crude oil will hold it fora long time and will slowly give it up to the water. They therefore placethe sawdust impregnated with oil in a; box and sink it in a flowingostream(fig. 60) ; or they throw a few grains of sawdust in. a hoof print, or ahandful on a puddle; or they fix a floating boom to hold back of i:t a

MOSQUITO CONTROL 281quantity of sawdust and give off a constant film. Thus for each condition,with a slight modification of the application, they obtain an excellentand lasting film not destroyed by rains. Dr. Metz modified thismethod by putting the oil-soaked sawdust in bags which he fastened tothe bottom of streams. Probably no other system of oiling is as adaptableor as satisfactory as this sawdust method. Geiger and Purdy (1919)0 _-.. oA0 r,--. -- .J... ,-FIG. 59.-Bubmersible automatic bubbler for distributing oil oyer surface of water.(Ebert.)have just reported success in reduction of mosquito incidence in ricefields by broadcasting oil-impregnated sawdust and without injury tothe rice.Dr. Ebert, early in 1918, developed an automatic oiler (fig. 59) consistingof a cylinder sunk beneath the water which takes in water andFIG. GO.-Method 01 petrolization with oil soaked sawdust.(Ebert.)displaces the oil, the amount of displacement being regulated by spigots.This oiler dropped under a bridge in a big river or placed in a largetidal bay amidst rank vegetation produces a constantly, evenly distributedfilm of oil which is very effective. The size of the cylinder isgauged by the size of the stream,. The distance to be placed apart mustdepend upon the film obtained. Lieut. Brigham (1918) of the ArmyMedical Corps used the same principle when he filled a bottle with crudeoil, cut two grooves in the cork and poured oil in one groove. Whendropped in the water this automatically bubbled. To reach inaccessible

282 SANITARY ENTOMOLOGYpools he fitted a parachute to the bottle and shot it with a bow gun,using rubber bands for power.A rtificial Con~ainers of Mosquito Larva:In mosquito work much attention must be given to all types ofartificial water containers, as rain barrels, cisterns, latrines, tin candumps, garbage cans, gutters, water pitchers, flower vases, aquaria,table isolation receptacles in tropjcal countries, cesspools, sewers, toiletsand flushing boxes" traps in sinks, drinking fountains, water troughs,etc. Flushing, periodic emptying, covering with pil film, stocking withfish, are among the possible 'expedients available in one or another ofthe cases. Capt. D. L. Van Dine and Dr. W. V. King have devised a newtreatment for water in fire barrels and water tanks for storage ofwater to be used in cleansing cans, in each of which cases oil is veryundesirable. These receptacles may be treated with borax at the rateof lh pound to 10 gallons of water; or with 1 pound of salt to 10 gallonsof water.Fish as Mosquito ControlAmong the principal natural enemies of mosquitoes are flsh and inpermanent ponds and lakes and streams, the stocking with the properspecies of fish may be considered as one of the most satisfactory methodsof mosquito control. In this country top m~nnows and goldfish arecommonly used for this purpose. The Bureau of Fisheries lists the followingfresh water fish available for introduction in American watersinfested by mosquitoes: 'l'he killifishes, Fundulus diaphanus, F. dispar, F.n9tatus, F. chrysotus, and F. nottii; the top minnow, Gambusia affinis;Heterandria formosa, Mollienisia latipinna, ErliTUJacanthus obesus, E.gloriosus, M esogoniatius chaetodon, Centrarchus macropterus, Lepomiscyanellus, L. gibbosus, Elassoma zona tum, Notemigonus crysoleucas,Labidesthes sicculus, and CarassiuB auratus (goldfish). (Radcliffe 1915.)For use in salt water or brackish witter the following fishes are available:Fundulus majalis, F. heterocliteus, F. similis, Lucania parva, L.'tJtfflusta, and Cyprinodon 'tJariegatus. (Radcliffe.)The most complete summary of the species of fish available in variousparts of the world is given by Hegh (pp. 140-150). Howard, Dyar andKnab and also Le Prince and Orenstein discuss the subject. The methodsused in distributing fish in various types of water in India are describedby Wilson (1917).In this country anyone desiring to stock a reservoir or other bodyof water with fish should immediately communicate ,vith the Bureau ofFisheries at Washington.The Panama larvicide and creosote arc toxic to fishes, and

MOSQUITO CONTROLundoubtedly some of the volatile oils are also, although the literaturespeaks only in general terms on this subject.De8truction of Adult M 08quitoe8Howard, Dyar and Knab, and also Hegh, ci~ various methods ofdestruction of adult mosquitoes in dwellings, such as puffing powderedpyrethrum into nooks frequented by mosquitoes, fumigation by burningpyrethrum, sulphur or cyanide fumigation, vapors of cresyl and of creoline.Le Prince and Orenstein describe a labyrinth trap for windows,quite similar to the Hodge window fly trap. Hegh figures and describesother fly traps.PROTECTION FROM MOSQUITOESProtection of Dwellings from M 08quitoesIn mosquito sections the screening of all habitations against mosquitoesis essential. This must be done thoroughly and the screens mustbe carefully examined and repaired. When holes or openings occur inthe screening, the mosquitoes enter and are trapped and the building isoften worse off than if unscreened.For protection against Anopheles alone, a 16-mesh wire screen issufficient, but small Aedes can pass through this and therefore 17 orIS-mesh is necessary. Le Prince and Orenstein give the specifications forthe IS-mesh screen to be of 90 per cent pure copper and not more thanone-half of one per cent of iron for damp tropical countries, the gauzehaving eighteen strands of wire of one one-hundredth of an inch diameterin each linear inch. The best type of screen for salt or acid air willprobably be a screen coated with an acid proof, noncorrosive alloy suchas Gageite. In many parts of the United States other types of wirescreening are thoroughly efficient. 2Where mosquitoes are abundant the double door vestibule arrangedso that the two doors can not be opened at the same time is highlydesirable when practicable. In tropical countries with verandas aroundthe entire house, the entire screening of the verandas is essential. Lieut.Brigham (1918) describes an ingenious mosquito electro cuter.Protection Qf the IndividuaZCampers are in the habit of using almost anything that will make adense smudge to drive away mosquitoes. The fumes of burning pyrethrum.• Mr. F. C. Bishop has for several yeat:s been making tests of serviceability of manytypes of screening in various parts of the country, and although he has not submitteda final report, will gladly advise anyone desiring this infonnation for official purposes.His address is Box 208, Dallas, Texas.~SS

SANITARY ENTOMOLOGYpowder are not obnoxious to most persons and are very effective in freeinga room of mosquitoes. The powder slightly moistened and moulded intoa candle will burn s~owly lik~ punk. The essential oil of the powder maybe volatilized by placing on a metal screen above a lamp chimney. Theodor is only slightly perceptible and not unpleasant.For protection of the body, camphor, oil of citronella, oil of cassia,and other essential oils are found efficacious. Howard, Dyar, and Knabrecommend as the best in their experience:Oil of citronellaSpirits 'of camphorOil of cedar1 oz.1 oz.lh oz.This may be rubbed on the clothes or body. A few drops on a bathtowel hung over the bed will keep Culex pipiena away for a whole night.Graybill lists many repellents against flies which have been tried onanimals. The most successful substances tried by him were 50 per centpine tar in cotton seed oil, or 10 per cent oil of tar in cotton seed oil,when applied lightly. Fish oil is a very effective repellent. Bishopp'sfish oil repellent is very effective in keeping flies from livestock whenapplied lightly. It consists of:Fish oilOil of tarOil of pennyroyalKerosene'1 gallon! ounces! ounces% pintMosquito nets for the bed are used in many parts of the South wherethe buildings are unscreened. Campers who sleep in hammocks mayeasily arrange a good sleeping net by tying a rope to the hammock supportsand .hanging from this a tent-shaped net which can be fastened atthe ends and tucked in beneath the blankets.Hegh illustrates mosquit.o bars for tent coverings, for tent doors,and soldiers' cots, and also a mosquito bar fastened inside a soldier'ssmall field-tent so that the sides of the tent can be raised to give air.Various type of protective headgear have been described for trQops intropical count.ries, two of which are illustrated by Hegh. Simpson illustratesa new headgear invented by his wife, which can be worn by dayand at night.The references cited below are worthy of study in conncction withthis lecture. There are many other works in all languages on thespecial problems of different countries, most of which are listed byHoward, Dyar and Knab.

MOSQUITO CONTROLl'l85BIBLIOGRAPHYBrigham, p .. H., 1918.-An automatic oiling device. Mosquito electrocuter.Military Surgeon, vol. 48, No. l'l, pp. 224-226.Freeborn, Stanley B., and Atsatt, Rodney F., 1918.-The effects ofpetroleum oils on mosquito larvle. Journ. Econ. Ent., vol. 11, No.8,pp. 299-807.Geiger, J. C., and Purdy, W. C., 1919.-Experimental mosquito controlin rice fields. Journ. Amer. Med. Assoc., vol. 72, No. 11, pp. 774-779.Graybill, R. W., 1914.-Repellents for protecting animals from theattacks of flies. U. S. Dept. Agr. Bull. 181, 26 pp.Headlee, T. J., 1915.-The mosquitoes of New Jersey and their control.N. J. Agric. Expt. Sta., Bull. 276, pp. 10-185. Illustrates commO~lmosquitoes.Hegh, E., 1915.-Comment nos Planteurs et nos Colons peuvent-ils seprob~ger contre les Moustiques qui transmettent des maladies. Ministerof Colonies, Service of Agriculture of Belgium, Etudes de Biologicagricole, No.4, 200 pp.Howard, L. 0., Dyar, R. G., Knab, F., 1912.-The Mosquitoes of Northand Central America and the West Indies. Carnegie Institution ofWashington, vol. 1, pp. 820-449.Howard, L. 0., 1911.-Remedies and Preventives against Mosquitoe~.U. S. Dept. Agr., Farmers' Bull. 444.Le Prince, Joseph A., and Orenstein, A. G., 1916.-Mosquito Control inPanama, The Eradication of Malaria and Yellow Fever in Cuba andPanama. G. P. Putnam's Sons, 855 pp.Mann, W. L., and Ebert, E. C., 1918.-Some suggested improvements inmethods of petrolization of mosquito breeding areas. Military Surgeon,November 1918.Metz, C. W., 1919.-Some aspects of malaria control through mosquitoeradication. Public Health Reports, vol. 34, No.5, January 31,pp. 167-183.Radcliffe, L., 1915.-Fishes destructive to the eggs and larvm of mosquitoes.U. S. Department Commerce, Bur. Fisheries, econ. eire. 17,pp. 1-19.Simpson, W. J. R., 1919.-The sanitary aspects of warfare ·in SoutheasternEurope. Journ. Trop. Med. and Hyg., vol. 22, No.7, pp.58-66.Zetek, J., 1918.-Determining the flight of mosquitoes. Ann. Ent. Soc.Amer., vol. 6, No.1, pp. 5-21.Zetek, J., 1915.-Behavior of Anopheles albimolfl/us Wiede, and tarsimaculataGoeldi. Ann. Ent. Soc. Amer., vol. 8, No.3, pp. 2U-27,1.

CHAPTER XXLouse Borne Diseases 1w. Dwight Pier~eThe parasitic lice belong to two closely related orders, the Anopluraor Siphunculata, commonly called sucking lice or vermin, and the Mallophaga,called biting lice, differing principally by the formation of themouth parts. The sucking lice are parasitic principally on mammals,and the biting lice on birds, but some of the latter also attack mammals.They at:e more or less definitely limited according to their species todefinite species or genera of animal hosts. All cause great annoyance andworry and probably by their .attack frequently cause death of the host,especially young hosts.We are especially concerned with the sucking lice in this lecture,but will include a few notes on the biting lice. Some of the most seriousdiseases of man, especially when congested in crowded populations or inarmies, are caused or carried by lice. Probably many fatalities amongwild animals and birds are due to inoculable diseases carried by lice, whichhave never been investigated.I. DIRECT EFFECT OF LOUSE ATTACKThe attack of lice on the body is in itself exceedingly annoying andleads to a great deal of itching and scratching. The attack by thevarious species of lice is differentiated by terms applicable to each. Theattack by the body louse, Pediculus corporis DeGeer, or as it is knownby Nuttall (1917), Pediculus humOlTlus var. corporis, is known as PEDICULOSIS CORPORIS. The attack by the head louse, Pediculus humanusLinnaeus, commonly known as capitis DeGeer is called PEDICULOSISCAPITIS. Attack by the pubic louse, Phthirus pubis Linnaeus, is knownas PHTHIRIASIS.1. Types of Pediculosis CorporisNuttall (1917) has described a considerable number of recorded typesof dermatitis caused by louse attack.1 A lecture on this subject was delivered June S, 1918, and distributed in mimeographedform, but on account of the great change in the subject since then, the presentlecture is practically rewritten.286

LOUSE BORNE DISEASES 287URTICARIA~-The attack of the body louse, popularly called"cootie," produces minute haemorrhagic spots which are accompanied bymore or less urticaria, the itching leading to scratching. The bites areprincipally distributed over the neck, back and abdomen. Peac~ck foundlouse rash distressingly common among the British troops.MELANODERMIA.-In tramps, chronic drunkards, and vagabondswho have harbored lice for many years, the skin over the areas most frequentlybitten becomes rough, hardened, and deeply pigmented, a conditionknown as morbus errorum or vagabond's disease. This skin pigmentation,also called melanodermia, may extend to the mucous membranes,being visible in the mouth and is sometimes confused with Addison'sdisease (Nuttall 1917).ECZEMA.-Frequently the attack of the lice causes an eczematousinflammation of the skin, with exudation of lymph.PYODERMIA.-Nuttall records PUSTULAR DERMATIJ'IS andPRURIGO SENILIS due to louse bite. Smith (1918) considers thepyodermia (ecthyma, etc.) caused by the body louse a more serious disablingskin disease than scabies. Various authors have claimed thatthe lice sometimes burrow under the epidermis forming so-called "coveredlouse-ulcers," which on opening liberate many lice.TOXEMIA.-Moore cites instances of intoxication of the systemfrom louse injected toxins.9]. Types of Pediculosis CapitisHead lice may produce urticaria, eczema and pyodermia, of which themost important type is mentioned in the next paragraph. Pinkus statesthat the inflammation of the scalp may lead to falling out of the hair.PLICA POLONICA.-As results of eczema or pustular dermatitis ofthe scalp the exudations of the skin lead to formation of scabs andcrusts in the hair especially at the nape of the neck, and this conditionhas been called plica polonica because it is so frequently observed amongthe poor Jewish population of Poland. (NuttaIl1917.)3. Types of PhthiriasisThe pubIc nce occur in the pubic regions principally, but are alsofound in the axillae, eyebrows, and other parts of the body. Theycause great discomfort unless the host is hardened to them. (Nuttall1918.)PRURITUS.-The ai:tack of this louse causes a pruritus wh~ch canbe violent and leads to much scratching day and night. It is thought thatthe itching is primarily caused by the toxic saliva of the louse.

~88 SANITARY ENTOMOLOGYPYODERMIA.-Crab louse attack may result in papular eruptionscomplicated by eczematous inflammation.BLEPHARITIS.-Dubieuilh and BeilIe state that when the lice areabundant on the upper eyelids they may cause blepharitis of the ciliaryborders of the lids with a val:'iable amount of pruritus.TOXEMIA.-Payne attributes fevers and headaches to toxic actionof Phthirus. Nuttall has also recorded a rise in bodily ·temperature dueto the attack.MACULAE COERULEAE.-The occurrence of this louse upon thebody is usually indicated by the presence Qf bluish spots on the skin dueeither to a genuine pigmentation according to Oppenheim or a toxicerythema according to Huguenay. Nuttall (1918) gives quite a discussionof the subject.MELANODERMIA.-Nuttall (1918) states that this louse may alsocause a discoloration of the skin amounting almost to blackness andinvolving the mucous membranes and nails.4. Effects of A ttack of Other Lice,Railliet has seen Haematopinus form real subepidermal nests in anold horse.Imes states that biting cattle lice, Trich'odectes scalaris often formcolonies around the base of the tail, over the withers, and on other partsoC the animal, and produce lesions resembling those of scab. Theselesions vary in size from one to five inches in diameter. The skin overthese areas appears to be raised and ringworm may be suspected, butwhen the lesion is manipulated the scarf skin falls off, exposing the licegrouped on the raw tissues beneath. Under such conditions the irritationmay be fully equal to thnt caused by scab.The sucking en ttle lice, Haematopinus eurysternU8 and LinognathU8vituli. act as a contributing cause to increase the death rate amongpoorly nourished cattle of low vitality. Even mature cattle of full vigorwhen very lousy will not gain weight and there is a loss in the productionof meat and milk.Chickens, turkeys, pigeons, and all other poultry as well as wild birds,are abundantly parasitized by biting lice and are seriously injured bythe attack. The tirst symptoms of lice infestation usually are droopiness,lowered wings and ruffled feathers. Diarrhea follows and thechickens often die in a few days. Older fowls may not show ill effectsother than decrease in egg production.

LOUSE BORNE DISEASES~89II. TRANSl\fISSION OF DISEASES BY LICE1. Diseases of Plrunt OriginTltaUophyta: Fwngi: A8comyccte8: GymnoasceaeAchorion 8choenleiJni (Lebert 1845), the cause of FAVUS, or PORRIGO, a fungus disease of the hair follicles, may be spread by head liceaccording to Aubert (1879).Thallophyta: Fwngi: HyphomycetesMalas8ezia species, causing the scaly skin diseases called PITYRIASIS, are claimed to be spread by lice by Aubert (1879).Thallophyta: Fwngi: Schizomycetes: Coccaccae'StaphylococcUll pyogcnea aureua and albus, the cause of IMPETIGOCONTA(HOSA, an acute contagious pustular inflammation of the skincan be carried by head lice, as was proven by Dewevre (189!) by removinglice from impetigo cases and placing them on the heads of healthychildren, who some days later developed the disease. This claim hasbeen supported by various authors. Widmann (1915) attempted totransmit Staph'y'lococcus septicaemia by louse bite and failed although herecovered living cocci frpm the louse feces after 60 hours but not later.In view of recent findings with other louse-borne diseases, we may expectthat infection could have been obtained by slightly abrading the surfaceon which the lice had defecated.Diplococcus intraccllularia meningitidis Weichselbaum. Pizzini(1917) found a strong parallel in two Italian outbreaks of CEREBROSPINAL MENINGITIS with the occurrence of lice on soldiers and civilianswho contracted the disease. Some patients were found to have intheir underclothing louse vectors of the l\Icningococcus, or they werefound to have handled ga;rments infested with such lice. The monthsduring which the disease is prevalent are those during which lice aredefinitely parasitic.. DiplococcUll pemphigi co'Tlttagiosi Manson, the cause of TROPICALIMPETIGO, is said by MacGregor (1917) to be carried by lice.Pncumococcus.-In experiments conducted by Widmann (1915), hesucceeded in making lice bite mice in which he had produced Pneumococcussepticaemia. He could not infect other mice by means of the louse bitesbut found the louse feces infective .during the first !4 hours. The cocciwere confined to the intestinal tract and did not multiply therein.

!t90 SANITARY ENTOMOLOGYCONJUNCTIVITIs.-DeFont Reaulx (191!t) and other writers regardhead lice as the cause of PHLYCTENULAR CONJUNCTIVITIS, andHudson (1914) states that it!! sequela PHLYCTENULAR KERATITISprevails among Board School children in England, causing much sufferingand corneal scars with resultant disabilities. He refers severer casesprimarily to head lice, infective material being carried from the sJlp tothe eyes by the hands.OTHER SEPTICAEMlAs.:'_Sobel in 1913 as a result of eleven years'experience with New York school children states that head lice are theindirect cause of pyogenic infection, frequently leading to involveme~of the lymphatic glands followed by suppuration, and that lice alsoindirectly cause IMPETIGO CONTAGIOSA, DERMATITIS, FURUNCULOSIS, ECZEMA AND FOLLICULITIS. Pinkus in 1915 describessimilar results and states that the inflammation of the scalp may lead tothe falling out of the hair.Thallophyta: F'IIRlgi: Schizomycetes: BacteriaceaeBacillus pestis Kitasato, the cause of PLAGUE, is referred to byvarious authors. Swellengrebel and Otten (1914) experimenting withclothes lice from plague patients in Dutch East India, and DeRandt(1916) have succeeded in causing death by plague in experimental animalsby subcutaneous inoculations of crushed lice. Herzog in Manilafound Bacillus pestis in three head lice from a child dead of plague(Bulloch and Douglas, 1909). There is no evidence that plague can becarried by the bite of lice.Bacillus typhosus Eberth.-In like manner Abe (1907) claims tohave recovered Bacillus typhosus from body and head lice fed onTYPHOID FEVER patients in 75 per cent of the insects examined.Bacillus Zeprae Hanson.-McCoy and Clegg (1912) have likewisefound Bacillusleprae in two head lice out of many examined from patientsBuffering with LEPROSY.Summary of Pltmt-CaU8ed DiseQ8e8All of the various cases cited above are probably to be consideredpurely as examples of mechanical transmission by scratching of the feeesof the lice containing the organism into the skin. The organisms ofimpetigo contagiosa, tropical impetigo, favus, pityriasis, Pneumococcusand Streptococcus septieaemias, phlyctenular conjunctivitis and keratitis,plague, typhoid fever, leprosy, and meningitis arc all bacteria or fungi.It is to be hoped that experiments in inoculation of feces will be carriedout with those organisms in which the exact role of the louse is still unde-

LOUSE BORNE DISEASEStermined. The almost irresistible desire to scratch a louse bite shouldmake louse transmission of any organism taken up from the blood, whichcan successfully pass through the lice in their feces, a very easy matter.In case of typhoid fever, if there is transmission it might be through soilingfingers on crushed lice. This consideration leads me to suggest thatsome one take up the question of louse transmission of gonorrhoea,syphilis, smallpox, and other diseases, giving special attention to inoculationof infected feces.fl9111. Diseases of U'Ilknortm or Uncertain Orig~BERI-BERI.-l\:Ianson (1909) has advanced the hypothesis that licemay possibly transmit beri-beri or polyneuritis, a disease whose cause isundetermined. Bradford, Bashford, and \Vilson (1919) have found afilterable virus in acute infective polyneuritis. Daniels conducted anunsuccessful attempt in transmitting beri-beri from man to an orangoutangby means of lice, due probably to the inability of the lice to liveon the host. (Castcllani and Chalmers, p. 1!16.) He did not attemptinoculation of the feces, apparently expecting. to convey the disease by thelouse bite. The majority of writers treat beri-beri as a nutritional diseasedue to absence of vitamiries.TYPHUS FEVER.-Acting on the suggestion of Sergent and Foleyin Algeria, the transmission of typhus fever by the louse was first provenby Nicolle, Comte, and Conseil (1909) working in Tunis. They successfullytransmitted typhus from monkey to monkey by means of the bites ofinfected lice (Pediculus corporis) that had fed on a typhus fever patient1-7 days previously. A few months later Ricketts and Wilder (1910)working independently in Mexico reported successful infection of monkeysthat were bitten by Pediculus corporis previously fed on typhus patients,and they also infected monkeys by placing the gut contents of such lice onscarified skin, three days after the lice had fed upon a typhus monkey.Shortly thereafter Ricketts succumbed to an attack of typhus.Further proofs of transmission of typhus fever by louse bites werepublished by Wilder (1911), Goldberger (1912), and Anderson and Goldberger(191fl); proofs of transmission by inoculation of crushed licewere published by Wilder (1911), Goldberger (191!), Prowazek (1918)and Nicolle, Blanc, and Conseil (1914). The last named authors provedthat the feces of lice when inoculated were infective at least 6 days afterthe lice had fed on a typhu~ fever patient. .Wilder (1911), Sergent, Foley, and Vialatte (1914) and Do. RochaLima (1916) claim that typlms fever is hereditarily transmitted by lice,but Anderson and Goldberger (1912) and Nicolle, Blanc, and Conseil(1914) hold that there is no proof of heredit~ry transmission.

SANITARY ENTOMOLOGYNo definite organism has been finally fixed on as the cause of typhusfever although several have been described. Plotz (1914) and others,with excellent reasons, regard IJacillus typhi l13Jtmthematici as the cause.Bodies called Rickettsia prowazeki DIl. Rocha-Lima (1916), are describedby Da Rocha-Lima, Noeller (1916), and others, as the causative organism,and it is claimed that they undergo multiplication in the cells of themidgut of infested lice. Whether Rickettsia is the cause of the disease ora product of the contagium'is still uncertain. Stempell (1916) describesa Protozoan, StricTceria jilrgensi, which he suspects to be the cause oftyphus, and claims that it undergoes part of its development in the intestinesof Pediculus corporis, and i~ sometimes transmitted to man inlarge numbers. Rabinowitch (1914-1916) regards Diplobacillus exanthematicusas the cause; Penfold (1916) describes a Micrococcus; Proescher(1915) describes minute Diplococci and Diplobacilli as present in theendothelial cells of the human subject. Finally Futaki (1917) hasdescribed Spiroschaudirttnia exanthematotyphi from tbe liver and urine ofpatients dying of typhus and has found the same organism in lice. Brumpt(1918) discu!!ses Rickettsia prowazeki Da Rocha-Lima, the so-calledcause of typhus fever, and claims that it is a coccobacillus and that hefound it in 73.6 per cent of the lice (Pediculus corporis) from healthyprisoners in France. He found that these lice infected with this organismremained infective all their lives and therefore c~mcludes that Rickettsiacannot be the cause of typhus fever, even though it may be transmitted bythe lice to men and again taken up by them. In experiments on himselfwith infected lice he did not produce any infection. Brumpt perhapsfound the Rickettsia pediculi which is associated with normal lice.TRENCH FEVER.-This disease has only recently been recognized,having passed even in the early days of the war under the initials P. U. 0.,or pyrexia of unknown origin. Many of the greatest investigators in thevarious armies concentrated attention on this baffling disease of thetrenches which stood among the highest of the disabling diseases of theWestern front. The :first records of the connection of the louse werecontained in statements of Davies and Weldon (1917, 1918) that one ofthem had produced the disease in himself by permittin'g infected lice(Pediculus corporis) to bite him. The incubation period was H! days.Early in 1918 two separate committees, the British under Sir DavidBruce and Major W. Byam, and the American under Dr. R. P. Strong,succeeded in Iproving louse transmission. The English committee (Bruce1918) in an experiment in which lice were crushed on a scarified areaof skin of volunteer patients incubated the disease in eight and ten days.In experiments with the feces of lice fed on trench fever patients, a smallamount of dried excreta rubbed on a scarified area of skin, incubated thedisease in three men on the sixth, ,seventh and eighth days. Blood from

LOUSE BORNE DISEASES 293one of these men on the second day of fever inoculated in another volunteerproduced a typical attack after an incubation period of five days. As thelice will usually leave a man with fever and migrate to a man with normaltemperature, it is easy to see how the disease is propagated.The British Trench Fever Committee's reports presented by MajorByam and others (1918) summarize the findings of the committee under18 paragraphs. They proved transmission of the fever by the feces oflice, that the disease is not native to the louse, and that it is not hereditarilytransmitted. The feces of the lice were only infective on the eighthto twelfth day after the lice had taken up the virus, proving a developmentalcycle in the lice. Transmission by the bite alone was not obtained.The incubation period after inoculation is at least (ight days.On the other hand the American Trench Fever Committee (Opie 1918 ;Strong, etc., 1918) claims that the fever is transmitted by the bite ofthe lice from 19 to 25 days after the virus was taken up by the lice.This is probably the sum of the developmental period in the louse and theincubation period after inoculation. They claimed that the virus is notfilterable, but is inoculable. The patients were allowed to scratch, andprobably this was the way inoculation took place. It is quite possible,however, after lice have been confined on the skin for a time and haveconsequently covered the entir~ surface with their excreta, that they mayinoculate the virus when they puncture the skin through this film ofexcreta.Arkwright, Bacot, and Duncan (1918) published a long series ofstudies with Rickettsia bodies which they think show Ii very possibleconnection with trench fever. Apparently these bodies occurred principallyin lice capable of causing infection. The lice do not show thesebodies in their feces nor do their feces become infective until five to tenor twelve days after feeding on infective blood. The majority of licewhose feces showed Rickettsia were infective and caused trench fever,while the majority which did not show Rickettsia were not infective.These same authors (1919) continued their studies with Rickettsiaquilntana, the bodies found associated with trench fever. Rickettsia isfound in the lice on the fifth to twelfth days after feeding on a trenchfever patient. Lice are infective on the fifth to twelfth days. Infectedlice contain Rickettsia and their feces are high in the bodies. There isno hereditary transmission in lice. Whether Rickettsia is the cause orthe product of the contagium, is undetermined.L. Convy, and R. Dujarric de la Riviere (1918) described Spirochaetagallica as a probable cause of trench fever.The Haemogregarina, gracilis Wenyon, suspected to be connected withthe disease, has since been proven not to have any connection.Bradford, Bashford, and Wilson claim to have found a filterable virus

!il94SANITARY ENTOMOLOGYin trench fever, the organism measuring 0.3 p, to 0.5 p,. and being anaerobic.A similar organism was recovered from four separate supplies ofinfected louse excreta.VOLHYNIAN FEVER.-This obscure European fever also called theHiss-Werner disease, is claimed by Topfer (1916) to be carried by lice.Jungmann and Kuczynski (1917) have confirmed this, claiming that anearly diagnosis of Volhynian fever is possible by examination of the licetaken from patients. Da Rocha-Lima (1917) points out the similarityof this disease to typhus fever, and described· RicA'cttsia pediculi whichhe believes is the causative organism, and which develops on the epithelialcells in the lumen of the stomach of the louse. Arkwright, Bacot andDuncan (1919) regard R. pediculi as normal to lice. Five-day fever, alsocalled Febris qumta-na, is identical with Volhynian fever. Werner andDenzler (1917) describe two cases of transmission by bites and lice.3. Diseases of ;inimal OriginProtozoaMaBtigophora: Bmucleata: TrypanosomidaeTrypanozoon lewisi Kent (Trypanosoma, Lewisonella), a conunonparasite of rodents, often nonpathogenic, is transmitted by several speciesof fleas but Von Prowazek has demonstrated that it may also completeits development in the rat louse, Polyplarc spinulosa Burmeister. The ratbecomes infected by licking up the insect deJections.Mastigophora: Binucleata: LeptomonidaeLeptomona8 pediculi (Fantham) (Herpetomonas) is the only truelouse parasite described. Fantham and Porter (1916) have even demonstratedthis organism experimentally pathogenic to IJfus· musculus. Itoccurs in the alimentary tract of Pediculus corporis and P. l17Lman7.ts.Leishmania donovani (Laveran and Mesnil) is the cause of TropicalLeishmaniasis or INDIAN KALA AZAR. The normal carrier is undetermined,but positive results have been obtained with the bedbugs, Cimerchemiptert£8 and C. Zectularius. Patton and also Mackie have failed toget results with lice. Possibly these failures were also due to the conductof the biting experiments rather . than scratching in experimentswith lice and their feces. It would pay to reinvestigate the lice in connectionwith the disease.

LOUSE BORNE DISEASES 295Mastigophora: Spirochaetacea: SpirochaetidaeSpiroschaudilwnia carten (Mackie) is the cause of ASIATIC RELAPSING FEVER. Mackie (1907) in India was the first to investigatethe transmission of relapsing fever by lice. He found a striking coincidencebetween the cases of fever among Indian school children and theprevalence of lice (Pediculus corporis). Mackie found the spirochaete in14 per cent of the lice from the boys and 2.7 per cent of the lice fromthe girls. He noted that the spirochaetes multiplied within the gut ofthe lice and that they could be found in the ovary, testis and Malpighiantubules of the insects, but did not find them in the ova laid by infectedinsects. Bisset (1914) only found Spirochaetes in the gut and coelomiccavity of the lice. The organism, Spiroschaudinrntia carteri Mackie, isconsidered as a biological species not morphologically separable from S.recurrenti8.Spiro8chaudwwa berbera (Sergent and Foley) is the cause ofNORTH AFRICAN RELAPSING FEVER. Following up Mackie'swork, Sergent and Foley (1908) in Algeria carried out experiments withlice and obtained positive results by the inoculation of a monkey (Cynomolguscynocephalus) with a single, crushed, infected louse (Pediculu8corporis). Pediculus humanus has also be,en recorded as an intermediatehost. Nicolle, Blaizot and Conseil (1912), also working in North Africa,found that when body lice were fed upon infected blood, the spirochaetesdisappeared rapidly from the insects' intestinal tract within 24 hours.On the eighth to tenth day, typical, active spirochaetes reappeared in thelice. Thousands of lice were allowed to bite monkeys and a man withonly negative results. Infection was obtained in one of the authors bycrushing an infected louse on excoriated skin, the incubation period of thefever being five days. They determined in one experiment that the infectivityof the lice was hereditarily transmitted. Eggs laid 12 to 20 daysafter the parent lice had fed on relapsing fever blood were placed at 28°C. and began to hatch on the seventh day. The young larval lice andsome unhatched eggs were now crushed and inoculated into a monkeywhich subsequently developed relapsing fever. The spirochaetes werenot discoverable mieroscopica~ in the eggs. As the result of the workof Sergent, Foley, Nicolle, Blaizot, Conseil and others, it is proven thatthe liee are infect~e, though inconstantly, up to five days after aninfective meal, and constantly on the sixth day, although during thisperiod spirochaetes are absent; on the eighth to ninth days the spirochaetesmayor may not be present and infectivity is exceptional. Afterthe spirochaetes become fully developed in the lice infectivity vanishes.They may be infective up to the fifteenth day. The apyrexial stage ofthe spirochaete in man and the developmental ~r granule stage in the

~96 SANIT.ARY ENTOMOLOGYinsect are so minute that they have not yet been demonstrated. Theorganism Spiroschaudirnnia bttrbera Sergent and Foley is considered as a .. biological species, not morphologically separable from S. recurrentis.Spiroschaudinnia 'l"ecurrentis (Lebert) causes EUROPEAN RELAPSING FEVER. Although many authors consider the above mentionedrelapsing fevers as identical with the European fever, the evidenceof louse transmission was' slow in coming. Manteufel (1907) found thatthe rat louse, Polyplax spinulosus, may carry the disease from rat torat, and suggested that possibly Pediculus corporis could carry it toman. Other authors made similar suggestions. Finally Toyada (1914)found crushed lice infective for mice up to three days after they had fedon infective blood. Since the outbreak of the great war the convictionof the role of the louse as a vector of European relapsing fever has becomevery strong. In fact repressive measures used in Roumania againstthe louse were effective against the fever. This disease can also be carriedby the bedbug, Cime:c lectulam.u.Spiroschaudinnia duttoni (Novy and Knapp) causes RELAPSINGFEVER OF TROPICAL AFRICA which normally is transmitted to manby the tick Ornit1wdoros moubata, but Neumann (1909) found that itcould occasionally be transmitted from rat to rat by means of the ratlouse, Polyplax spin'ldosus.Spiroschaudimmia sp., cause· of MANCHURIAN RELAPSINGFEVER, is claimed by Toyada (1917) to be transmitted by lice.Leptospira icterohemorrhagiae (Inada !lnd Ido) causes INFECTIVE OR EPIDEMIC JAUNDICE, also known as Weil's disease whichis infective to man and rats. In the European trenches the rat is regardedas the reservoir of the disease. The spirochaete is excreted byway of the urine or feces of rats or men and is consequently easily communicatedthrough the trenches. It is readily communicated throughthe mouth or through abrasions in the skin (Dawson, Hume and Bedson,1917). Stokes conducted negative experiments with Pediculus corporia,but these experiments were not directed toward obtaining infec~tion through crushing or scratching lice or feces into abrasions of theskin. This phase of the subject will bear further investigation especiallysince Dietrich (1917) declares that the disease can be carried byPediculus corporis.Telosporidia: Haemogregarinida: HaemogregarinidaeHaemogregarina (H epatozoon) gerbilli (Christophers) cause of theANEMIA OF THE JERBOA, Gerbillus indicus in India, is believedby Christophcrs (1905) to pass its cycle of sporogony in the rat lousePolypla3J stephe.nsi C. and N:

LOUSE BORNE DISEASES 297Haemogregarina (Hepatozoo'Tt) fwnambuli (Patton), cause of theANEMIA OF THE PALM SQUIRREL, Funambulus pennatii in Indiawas found in the vermicule stage in the gut and coelome of the louse,Haemotopmu8 sp., but further development was not observed.MetazoaPlatyhelmia: Cestoda: Cyclophyllidea: TaeniidaeDipylidium canmum (Linnaeus), the DOUBLE-PORED DOGTAPEWORM, may have as an intermediate host the biting louse of thedog, Trichodectes latus Nitzsch (cani8 De Geer) according to Melnikow,although it usually passes its intermediate stages in fleas.This completes the summary of the evidence which has so far beenpresented against the lice. There are many species of sucking lice ofwild and domestic animals, and there are many obscure or little knownanimal diseases. It is naturally to be expected that the literature ofanimal disease transmission by lice will grow.I have attempted also to show that the majority of the louse-bornediseases pass through the body of the louse and out through the fecesand that they gain access to the host in the following ways: the rubbingor scratching into a skin abraSIon of infective portions of the insect body,or its dried or fresh feces; the carrying of the contamination on fingerswhich have scratched the louse or its feces, and transfer of the contaminationon the fingers to the mouth or the eye; the licking up of the lice ortheir feces by animals which cleanse themselves with the tongue. Directtransmission by bite apparently does not occur except possibly in typhusfever.It remains therefore to reiterate that all types of skin diseases andblood diseases in which the louse might be suspected should be reinvestigatedin case the usual types of inoculation mentioned above have notbeen tried.lIIBLJOGll.APHYAbe, Naka9. 1907.-Miinch. med. Wochenschr., vol. 54, p. 1924.Anderson, J. F., and Goldberger, J., 1912.-U. S. Treas. Dept., Hyg.Lab., bull. 86, pp. 101-130.Arkwright, J. A., Bacot, A., and Duncan, F. M., 1915.-Brit. Med.Journ., Sept. 21, pp. 307-309.Arkwright, J. A., Bacot, A., and Duncan, F. M., 1919.-Journ. Hyg.,vol. IS, No.1, pp. 76-94" plates 2, 3.Aubert, 1879.-Les poux et les ecoles. Unpoint d'hygiene scolaire Lyon.Rev. in Ann. de Dermatol., 1880, 2 ser., vol. 1, p. 292.

9198 SANITARY ENTOMOLOGYBisset, E., 1914.-Proc. Srd All-India Sanit. Conference, Lucknow, vol.4, pp. 114-119. Suppl. to Indian Journ. l\fcd. Research.Bradford, J. R, Bashford, E. F., and Wilson, J. A., 1919.-Brit. Med.Journ. No. smn, Feb. 1, 'pp. 19l7-12S.Bruce, Sir David, and Committee, 1918.-Brit. Med. Journ. No. 9l986,pp. S54, 355.Brumpt, E., l~lS.-Bun. Soc. Path. Exot., vol. 11, No. S, March 13,pp. 249-9l5S.Bulloch, W., and Douglas, S. R., 1909.-In Allbutt and Rolleston'sSystem of Medicine, London (Macmillan), vol. 2, pt. 2, p. 374.Byam, W., 1915.-Brit. Mcd. Journ, l\iay 25, pp. 590-591.Byam, W., Carroll, J. H., Churchill, J. H., Diamond, L., Lloyd, L.,Sorapure, V. N., and Wilson, R. 1\1., 1915.-Journ. Amer. Med.Assoc., vol. 71, No.1, pp. 21-26; No.2, pp. 110-113.Castellani, A., and Chalmers, A. J., 1913.-Manual of Tropical Medicine,2nd edit., pp. 1216, 1460, 1463.Christophers, S. R., 1905.-Sci. Mem. Officers' Med. & San. Dept., Govt.India, n. s., No. IS.Convy, L., and Dujarric de 10. Riviere, R., 1915.-C. R. Soc. BioI., vol.Sl, Jan. 19l, pp. 9l2-9lS.Do. Rocha-Lima, H., 1916.-Miinch. med. Wochenschr., vol. 6S, No. 39,pp. lSSl-lSS4.Da Rocha-Lima, H., 1917.-Miinch. med. Wochenschr., vol. 64, No. 44,pp. 1422-1426.Davies, F. C., and Weldon, R. P., 1917.-The Lancet, Feb. S, pp. lS3~IS4.Davies, F. C., and Weldon, R. P., 1915.-Journ. Royal Army Med. Corps,vol. 30, No.1, pp. 92-94, Jan.Dawson, B., Hume, W. E., and Bedson, S. P., 1917.-Brit. Med. Journ.No. 9l959, pp. 345-354.DeFont Reaulx, P., 1912.-Arch. de Parasitol., vol. 15, pp. 385-397.DeRaadt, O. L. E., 1916.-Meded. Burg. Geneesk. Dienst. Ned. Indie,Batavia, 1915, pt. 4, pp. 39-40.Dewevre, lS92.-C. R. Soc. BioI. Paris, No. 11, pp. 23!i!-2S8.Dietrich, W., 1917.-Zeitschr. f. Immunitatsf., I. Origin., vol. 9l6, Dec.2S, pp. 568-581.Dubreuilh, W., and Beille, L., lS95.-Parasites animaux de la peauhumaine. Paris, Masson et Cie, pp. 107-140.Fant.ham, H. B., and Porter, Annie, 1916.-Journ. Parasit., vol. 2, No.4, pp. 149-166.Futaki, K., 1917.-Review in Brit. Med. Journ., No. 2968, p. 491.Goldberger, J., and Anderson, J. F., 1912.-U. S. Treas. Dept., PublicHealth Reports, vol. 27, pp. 297-S07.

LOUSE BORNE DISEASESHudson, A. C., 1914.-Lancet, vol. 2, p. 966.Huguenay, 1902.-Gaz. des hOp., p. 591.Jungmann, P., and Kuczynski, M.· H., 1917.-Deutsche med. Wochenschr.,vol. 43, No. 12, pp. 359-362.Lambert, A., 1918.-Columbia Alumni News, pp. 1038-1039.MacGregor, 1\1. E., 1917.-Bul. Ent. Res., vol. 8, pt. 2, pp. 157-163.Mackie, F. P., 1907.-Brit. Med. Jburn., vol. 2, pp. 1706-1709.Manson, Sir P., 1909.-In Allbutt and Rollcston's System of Medicine,London (Macmillan), vol. 2, pt. 2, p. 627.Manteufel, 1907.-Arb. a. d. kais. Gesundheitsamte, vol. 29, p. 355.McCoy, G. W., and Clegg, M. T., 19H1.-U. S. Treas. Dept., PublicHealth Reports, vol. 27, pp. 1464-1465.Moore, W., 1918.-Journ. Amer. Med. Assoc., vol. 71, No. 18, pp. 1481-1482.Neumann, R. 0., 1909.-l\fiinch. med. Wochenschr., vol. 56, p. 477.Nicolle, C., Blaizot, L., and Conseil, E., 1912.-C. R. Acad. Sci. Paris,vol. 154, pp. 1636-1638; vol. 1'55, pp. 481-484.Nicolle, C., Blanc, G., and Conseil, E., 1914.-Arch. Inst. Pasteur,Tunis, "01. 9, pp. 84-Hll.Nicolle, C., Comte, C., and Conseil, E., 1909.-C. R. Acad. Sci. Paris,vol. 149, pp. 486-489.Noeller, W., 1916.-Berlin. klin. Wochenschr., vol. 63, No. 28, pp. 778-780.Nuttall, G .... H. F., 1917.-Parasitology, vol. 10, No.1, pp. 1-188.Nuttall, G. H. F., 1918.-Parasitology, vol. 10, No.3, pp. 375-381.Opie, E. L., 1918.-Journ. Amer. Med. Assoc., vol. 70, No. 24, p. 1888.Oppenheim, M., 1901.-Verhandl. d. Gessellsch. deutsche Naturf. u.Aerzte, vol. 73, pt. 2, Med. Abt., p. 451.Payne, J. F., 1890.-Brit. Journ. Dermatol., vol. 2, pp. 209-212.Penfold, W. J., 1916.-Trans. Soc. Trop. Med. and Hyg., vol. 9, pp.105-115.Pinkus, F., 1915.-Med. Klinik, Berlin, vol. 11, No.9, pp. 239-241.Pizzini, L., 1917.-Il Policlinico, Rome, vol. 24, Sez. Med., No.5, pp.212-228 .•Proescher, F., 1915.-Berlin. kUn. Wochenschr., vol. 52, pp. 805-807.Prowazek, S., 1913.-Berlin. kIin. 'Vochenschr., vol. 50, pp. 2037-2040.Rabinowitch, M., 1916.-Review in Trop. Dis. Bull., vol. 8, pp. 484-485.Ricketts, H. T., and Wilder, R. M., 1910.-Jount. Amer. Med. Assoc.,vol. 54, pp. 1304-1307.Sergent, E., and Foley, H., 1908.-Bull. Soc. Path. Exot., vol. 1, pp.174-176.299

300 SANITARY ENTOMOLOGYSergent, E., Foley, H., and Vialatte, C., 1914.-C. R. Acad. Sci., Paris,vol. 158, pp. 964-965.Smith, J. F., 1918.-Journ. Royal Army Med. Corps, vol. 30, No.5,p. 51~ .Sobel, J., 1913.-New York Med. Journ., vol. 98, pp. 656-664.Stempell, W., 1916.-Deutsche med. Wochenschr., vol. 62, No. 111, pp.439-442.Strong, R. P., Swift, H. F., Opie, E. L., MacNeal, W. J., Baetjer, W.,Pappcnheimer, A. M., and Peacock, A. D., 1918.-Journ. Amer. Med.Assoc., vol. 70, No. 2~, pp. 1597-1599.Swellengrebel, N. H., and Otten, L., 1914.--Centralb. f. Bakt., 1 Abt.,Orig. vol. 74, pp. 1592-603.Topfer, H., 1916.-Miinch, med. Wochenschr., vol. 63, No. 42, pp. 1495-1496.Toyada, H., 1914.-Zeitschr. f. Hyg. u. Infektionskr., vol. 76, pp. 313-320.Toyada, R., 1916, 1917.-Saikingaku Zasshi, Nos. 250 and 259, Sept.10, 1916, and April 20, 1917. Reviewed in Trop. Dis. Bull., vol. 10,p. 271, and vol. 11, p. 203.Werner, H., and Benzler, J., 1917.-Miinch. med. Wochenschr., vol. 64,No. 21, p. 695.Widmann, E., 1915.-Miinch. med. Wochen~chr., vol. 62, pp. 1336-1338.Wilder, R. N., 1911.-Journ. Infect. Dis., vol. 9, pp. 9-101.

CHAPTER XXIThe Life History of Human Lice 1R. H. Hutchison and W. Dwight PierceUntil the outbreak of the great war there had been a great mass ofdesultory writing upon the three species of human lice, but this was inall languages and few had made any attempt to classify and arrangethe knowledge thus obtained. Since the beginning of the war, however,the louse has been a major problem and there have been more titles publishedon it than on any other disease-carrying insect. The first comprehensivework was published by Hase (1915-1916) in a series of papers.These were followed by several excellent monographs by Professor Nuttall(1917-1918), the second of \vhich gives a complete bibHography ofthe literature on human lice, a summary of the evidence of disease transmission,exclusive of the recent work on trench fever, and extensivebiological studies. With the large number of students recently concentratingon these Yermin, we may expect that our literature will begreatly enriched with many more fine contributions.The human lice have generally been regarded as belonging to threedifferent species, Pediculus humanus Linnaeus (capitis DcGeer), P. corporisDeGeer (vestimenti Nitzsch) (plate XXI), and Plztltirus pubisLinnaeus (inguinalis Redi). Bacot carried out hybridizing experimentswith humanus (capitis), and corporis, carrying the offspring to the thirdgeneration. It is on the strength of su·ch studies that Nuttall united thetwo under the name humanus, and for convenience, designated one capitis(head louse), and the other corporis (body louse) as varieties of thisspecies. Other writers are not wholly convinced in regard to the unionof the two species and we shall await further studies with interest.The true P. humanus, or head louse, is usually confined to the head,mostly about the occiput and ears, but it may spread over the body,establish itself on other hairy parts, and may be confined to the pubichairs and multiply there. The body louse, P. corporis, lives usually onthe body and in the clothing and is very rarely found on the head.The pubic louse, Phthirus pubis, is usually found on the hairs in thepubic region but may occur in other hairy parts of the body.1 This lecture was presented June 17, 1918, and distributed the same day. It hasbl'en greatly revised.301

502 SANITARY ENTOMOLOGYThe body, head, and pubic lice are found on all races of men andseem to show some varietal differences according to the host. Noneof these species occurs on any other host than man, although a closelyrelated species Pediculus consobrinus Piaget occurs on a monkey (Atelespentadactylus ).Children and old people are much more likely to be affected with headlice than active men and women, and girls because of thei.r long hair aremuch more ·frequently infested than boys. On the other hand, menseem to be more often the subjects of attack by corporis and pubis.In the civilian population of this country there are indications of im-PLATE XXI.- The clothing louse, Pediculu8 corporis. Fig. I.-Female, ventral view.Fig 2. Male, dorsal view. (Pierce and Hutchison, photos by Dovener.)porlant changes in the general problem. In times of peace the louseproblem is most acute in jails, poorhouses, and like institutions; amongvagrants and the extremely poor classes; among gangs of laborers, as inconstruction camps, lumber camps, threshing gangs, etc.; and among im~migrants. Since our entrance into the war there have been economicchanges which have shifted some of these centers of infestation. Forexample, there have been many camps of laborers engaged in temporaryconstruction work. Reports indi~ate that lice give considerable troublein some of these. There has probably been an increase in the size andnumber of lumber camps. On the other hand, we have been informed bythe captain in charge of the House of Detention at New Orleans, thatthe vagrant population, which has always been their worst source of

THE LIFE HISTORY OF HUl\lAN LICE 303infestation, has been reduced more than two-thirds. It is also well knownthat immigration has been greatly reduced.The urgency of the problem in the armies led to extensive investigationsof control measures and of the biology of lice. The knowledgeof the biology of the body louse wa surprisingly meager up to the timethe war began. It is our purpose in this lecture to call attention to someof the vital points in the biology of lice, and to point out their relationto practical control work, for without a knowleuge of these points, onecannot expect to intelligently interpret the results of control work. SomeFIG. 61.-Wristlet method used fo\, breeding lice.(Hutchison, Photo by Dovener.)of the more important and recent additions to our knowledge of lousebiology are due in no small measure to the improved technique for rearinglice as evolved by .Bacot, Sikora, and Nuttall. Warburton's method ofplacing the insects on cloth in plugged tubes, feeding them twice dailyand placing the tube in the pocket or incubator between feeds, has beenlargely followed, with modifications by other workers, but after manyattempts at rearing lice under more normal conditions and providing themwith unlimited opportunities for feeding, Nuttall finally worked out thetwo methods which he describes under the names of the "felt cell method"and the "wristlet method" (fig. 61). For the details of these methods itis best to consult the original description in Nuttall's (1917b) article onthe biology of Pediculus humanus. In fact, we have avoided g'lVlllg a

8041 SANITARY ENTOMOLOGYstereotyped account of the life history, on the assumption that this articlewill be read by all those interested.The first point to be noted is the fact that body lice may oecur onthe body as well as on the clothing. Nuttall has brought out convincingevidence that nits as well as lice themselves are often found upon the bodyhairs, especially in the axillae, the hairs of the breast, and at times on thepubic hairs and even the hairs of the thigh and leg. We have Seen twocases in which both lice an«:l nits were present in the axillae. The importanceof this point as regards control measures is obvious. Disinfectionof the clothing is not sufficient, but must be accompanied by a thoroughbath with some insecticidal liquid, such as cresol-soap, or the kerosenesoap used by Boyd in his work with the Mexican laborers of the Sante FeRailroad.Moreover, it was soon discovered from actual experience in this warthat a disinfection of a part of the clothing was entirely ineffective; forexample, if clean shirts are provided, while the trousers have not beencleaned, lice quickly migrate from the trousers to the clean shirt whichaffords them new areas for deposition. Thus conditions are soon as badas before. .A second point having an important bearing on control measuresis the number of eggs laid per female and their rate of development. Theimportance of the improved technique for rearing lice, mentioned above,consists in showing that previous statements, regarding the number ofeggs laid, elearly underestimated their power of reproduct.ion. 'Vhen thelice are fed but twice a day only four to five or six eggs are obtained perday, while by the wristlet method Nuttall obtainl!d as high as twelve eggsper day per female, the average being about ten. He states that corporismay lay !75 to 800 eggs during its lifetime. By the same methodthe senior writer has obtained as high as fourteen eggs per day, with anaverage of about eleven per day over a period of twenty-five days.'l'he eggs are elongate, oboval, with a granulated cap or operculumat the outer end (plate XXII). They are cemented singly to a hair (inall three species), or a thread (P. corporis). Occasionally a single hairwill be covered with them. Oviposition usl1ally commences in P. corporiswithin two days after maturing.\Vhen a female is ready to oviposit she clings to a hair or thread,and slipping backward, grasps it also with the gonopods and the posteriorlobes of the last segment. A drop of cement is excreted, followedby the egg, which is thus firmly cemented to the hair and the insectmoves away. Thc entire operation consumes about 17 seconds. Theoperculum is usually directed away from the root of the hair.Oviposition takes place most readily at about 30 0 C. (86 0 F.) andceases at !OO C. (68 0 F.). They lay rll:pidly at 37 0 C. (99 0 F.) although

THE LIFE HISTOHY UF HUMAN LICE 305PLATE XXII.-Eggs. of the Clothing Louse, Pediculus corporis. Fig. 1 (upper).":'_Massof eggs, sli ghtly reduced, between seams of trousers. (Photo by Dovener.) Fig.g (center).- Great enlargement showing eggs hatching. (Photo by Paine.) Fig.3 (lower).- Very. great enlargement showing structure of eggs, with exuviae within.(Photo by Paine.)

806 SANITARY ENTOMOLOGYthis temperature shortens their lives. Infected persons who remove theirclothing at night consequently become less heavily infested than thosewho wear their clothing conti?uously. The periodic cooling of the clothingand the lice therein leads to their progeny being materially reduced.Nuttall and Bacot are both agreed that capitis prefers to lay itseggs on hairs, but tl}ey do not agree as to whether corporill prefers clothto hairs for oviposition.The length of the egg period varies from 5 to 16 days under normalconditions and may be 'retarded to the 35th day, or possibly later, by-cold periods. Under European conditions of humidity, apparently 30°,C. (86° F.) gives about the optimum condition for hatching, althoughthe shortest period experienced was at 37° to 88° C. (99-101° F.). In,experiments at New Orleans at 87° C., hatching occurred in four to,eight days; while the eggs hatched in six to seven days at temperaturesof 33° to 34° C., and in eight days at 30° C. The effective zone forthe egg stage is from slightly under 20° to 40° C. (68-108° F.). Attemperatures of 40° to 45° C. the embryo dies. In this connection,Nuttall has made some very unfortunate remarks. He discredits the:seven-day record with two individuals at 20 0 C. made by Widmann, theten to twelve-day records at the same temperature made by Heymann,.and Legroux's statement that they rarely' hatch at 16-18° C., becauseSikora and Hase recorded failures at 20° and Nuttall and Hindle failedto hatch eggs at 22° C. It is quite possible at 20° C. at one humidityto obtain death; at another humidity, 12-day development; at another, 7-day development; and at still a different humidity, possibly a very longdevelopmental period. All of Nuttall's remarks on temperature effectsmust be more or less discounted because of his ignoring the importanthumidity factor. In fact, he states that there is no evidence that eggsmaintained at 22° C. or under are capable of hatching, but he quotes.quite a series of retarded development records in which the eggs weremaintained for more or less long periods at low temperatures. For instance,Widmann kept eggs for 24 hours at 10° C., a'nd then transferredthem to 26-30° C., and they hatched in 17 days. After keeping eggs atgo C. for two or three weeks, Heymann transferred them to a favorabletemperature and they developed in 15 days. The length of time the eggscan stand a given low temperature will depend to a large measure on thellUmidity. At a given temperature it appeared that dryness may retarddevelopment two or three days or more. Thus it may be seen that thereis still work to be done on the effect of humidity on the incubation period.In testing various insecticides for their effect on the eggs, it is neces.aary to provide the proper temperatul'e conditions; otherwise, failure to

THE LIFE HISTORY OF HUMAN LICEhatch may be due to low temperature rather than to the chemical or otheragent tested.In interpreting results from control experiments, it is important tobear in mind that lice will lay infertile eggs. Isolated females to whichmales have not had access will lay eggs at about the normal rate. Sucheggs are all sterile and show no development. There is no evidence ofany parthenogenesis. But even females to .whieh males have had accesswill lay some i~fertile eggs especially near the beginning and end of theirlives. Nuttall says that at constant temperature of 30° C. we mayexpect about 70 per cent of a given lot of eggs to hatch. Of those whichfail to hatch, some are fertile, some undergo partial development, butfor some unexplained reaSon fail to complete development. He points outthat "hatching alone is not therefore a true test of fertility." For accuratework, eggs of known age should be used, preferably after they havereached the stage when the eyes appear as faint brown spots on eachside of the head of the embryo. By examination with the binocular, thepresence of these eye-spots will indicate the number which are fertile, andtheir absence, the number stetile.The freshly laid egg is almost transparent, but as the embryo develops,the egg assumes a yellowish color and the eyes first appear aspinkish spots, gradually turning red or brown in color, finally becomingblack. After the limbs become clearly defined and the claws and eyesdarken, there are slight· movements of the limbs, and of particles withinthe body of the embryo, and periodic pumping movements of the pharynxbegin to appear. These pumping movements become more frequent astime for emergence approaches. Sikora and Nuttall were the first tograsp the meaning of these pumping movements and show that theyare intimately concerned with the act of emergence. When the larva isready to emerge, the air is pumped in rapidly through the so-called aircanals of the operculum. The air is accumulated in the anterior end ofthe shell, the body of the embryo completely filling the remainder. Aspumping continues, the air is passed on through the gut, "the bubblesbeing distinctly seen through the transparent glassy shell as they passbackward" and are expelled through the anus and accumulate in the posteriorend, thus pushing the embryo up against the operculum. "Thispressure of the air cushion tin ally overcomes the resistance of the operculumand the latter springs open." The head of the larva is thus forcedout and assumes a normal position. Soon the first pair of legs is withdrawn.These are quickly brought into action and with their aid theremainder o~ the body is soon withdrawn. This highly interestingprocess is important in its relation to control measures. In the firstplace, if oily or greasy substances lire used they occlude the air canalsof t.he operculum and the larva dies. Some substances when applied toso';

308 SANITARY ENTOMOLOGYyoung eggs, may evaporate without acting directly on the embryo andleave the air canals open by the time the embryo has reached the stageof pumping movements. In control experiments results have been obtainedwhich indicate tliis, the mature eggs being destroyed and theyounger eggs emerging some days later, showing that the chemical hadnot affected the contents of the egg, but killed the older eggs by occlusionof the air canals, and passed off' in time to permit the younger ones tohatch. .Another point of importance is that proper temperature conditionsmust be provided in such experiments, to permit normal emergence aswell as normal incubation. If the temperatures are too lmv the processof emergence is slow and the vitelline membrane will dry before the larvahas freed itself. As a result the larva dies with the head and first pair.of legs and part of the thorax outside the shell, but the posterior endof the body and the second and third pairs of legs stick to the driedmembrane, or it may be that the larva will die without bursting the membrane.In some cases lanre have been found with all but one leg freefrom the membrane, but this so firmly stuck fast as to prevent escape. Itis important, theref~re, to bear in mind that the eff'ect of low temperaturesmay entirely outweigh the effect of the control measure under trial. Effectivetemperature is higher than for most other insects.The egg shell is very tough and resistant to chemicals as is alsothe cement by which it is fastened and there is no known way of removingthem without first destroying the fibers or hair to which they are attached.Hase describes how the Russian prisoners tried to reduce infestation byhanging shirts on a wire and beating with sticks, and Legendre recommendsvigorous brushing with a stiff brush. Rase is doubtless correctin pointing out that beating fails to dislodge many of the lice or to crushany of the eggs and that brushing may tear loose some fibers with attachedeggs, but actually destroys very few. On the contrary, it iopointed out that this may be the means of spreading the infestation toother men rather than affecting any reduction. Rase carried out experimentsshowing that lice can crawl up to the surface after burial in severalinches of dry sand or earth. If shaken or beaten out of the clothingto the ground and pressed into the sand under the heel they will crawlto the surface and attach to the firs't host near them, which they haveabundant opportunity to do in a crowded prison or prison camp, espe·cially when the weather permits the prisoners to lie down on the ground.Eggs brushed from clothing will hatch if temperatures arc favorable, andthe issuing larvre reach new hosts in the same way.Many experiments have been carried out by Hase and Nuttall with aview to determining what kind of materials lice prefer for oviposition.They agree in showing that rough materials such as felt, wool, and flannel

THE LIFE HISTORY OF HUMAN LICE 309arc preferred. However, in case of necessity, the lice can and will ovipositon smooth materials such as silk and sateen. It has been suggested thatinfestation could be greatly reduced and even remedied entirely by wearingfor one to twent}-four hours a broad band of felt or rough wool underthe clothes, with the idea that lice would collect on this, and they andtheir eggs could then be destroyed by burning. But the preference oflice for such material and the difference between this and the uniform isnot marked enough to make it really effective.In practical control work the question is likely to arise as to howlong disc;arded but untreated clothing will remain infective. The answerto this, of course, depends. on how long lice can live without foodand hOlY long it takes for all the eggs to hatch. Experiments showthat lice can live without food from two to three days at 55° C., threedays at 50° C., three to five days at !!2° C., and about seven days at10 0 C. The lice cannot live long without food unless at ineffective temperatures,the longest period recorded being ten days at 5° C.(41 0 F.). The longest record of fed adults is 46 days for a femalerecorded by Bacot. One male lived 5!! days and fertilized eighteen females.As stated above, eggs will hatch in sixteen days at !!5° C., butbelow !!!!O C. they usually do not hatch. How long a period of low temperaturesthey can endure, and still hatch when the temperature is againraised, is not known beyond a statement by Nuttall that he delayed hatchingto 55 days by low temperatures. Certainly the safest plan would beto allow 30 to 40 days of cool weather or-two weeks of hot weather forall the eggs in discarded clothing to hatch.There are three larval stages, or possibly we may

310 SANITARY ENTOMOLOGYThe lice seem to avoid light except when hungry. They seem tobe quite sensitive to excessive warmth and will leave a fever patient.In the absence of definite humidity data we may roughly describethe zones of climatic influence on the lice as follo,vs: The zone of minimumfatal temperatures for eggs is below ~lO° c. (68° F.) and for adultslies below zero centigrade (32° F.). The zone of the dormancy in adultsextends from about _10° to 5° C. (14° to 41 ° F.). The zone of sluggishmo~ement without reproductive activity and with practically nodigestive processes extends from 5° to flO o C. (41 to 68° F.). Digestionceases at 12° C. The zone of optimum activity lies between 20° and 40° C.(68° to 140° F.) with the optimum about 30° C. Practically all egghatching occurs within this zone, as does all oviposition, practically allassimilation of food, and all normal activity. From 40° to 44° C. thelice are wildly active. This zone represents one of exhaustion in whichdeath of eggs occurs. Above 44° C. (112° F.) lies the zone of maximumfatal temperatures. In control work 54° C. (13JO F.) for one-halfhour is s~fficient to kill all stages, and 60° C. (140 0 F.) for one-quarterof an hour gives a very thorough control.There are several other phases of the biology of lice ,vhich may bementioned briefly. For example, the locomotory powers would repaystudy. Their inability to make any headway on clean smooth metal orglass when inclined at an angle of more than 2° to 30, and their inabilityto crawl on smooth vertical surfaces such as rubber gloves or boots, ascontrasted with their gymnastic skill on threads or fibrous materialsand their power of clinging to anything which they clm clasp with theirclaws, explain the different protective unifornis worn by those who havehad to do with typhus epidemics.Their different reactions to light when fully fed or when hungry havea bearing on the question as to how they find new hosts.Thert: are yet many phases of the biology which need elucidation.For example, the question as to the state of development of the olfactorysense and whether this comes mto use 'in finding a new host. Rase concludesthat they have a fairly keen olfactory sense because they arequickly repelled by substances like tar and ethereal oils. According tohim. they recognize and avoid the odor of horses.-the clothin6 of thoseartillery men who drive and care for the horses is saturated with thehorse odor and free from lice. while others in the same battery withoutthe horse odor are infested. On the other hand. a hungry louse placedon a glass slide near a freshly drawn drop of blood is apparently entirelyunaware of the proximity of food. Likewise a hungry louse on a pieceof cloth is apparently unaware of the prese'nce of a human hand and a-chalice to feed, until a finger has bee~ pushed within one-half inch or

THE LIFE HISTORY OF HUMAN LICE 311less of it, and that may be a positive reaction to the heat radiation fromthe hand rather than an odor reaction.REFERENCESHase, A., 1915.-Beitriigc zu einer Biologie der Kleiderlaus. Zeitschr. f.Ilngelwandte Entomol., Band. ~, Heft ~, pp. !il65-859, 47 figs.Hase, A., 1915.-Weitere Beobachtungen tiber die Laiiseplage. Centralb.f. Bakteriol. Parasitenk u. Infektionskr., 1 Abt., Orig., Band. 77, pp.'153-168.Hase, A., 1916.-Ueber die Entwickelungstadien der Eier und ueber dieLarven der I{leiderlaus. Naturw. Wochenschr., Band. 31, pp. 1 et seq.(inaccessible) .Nuttall, G. H. F., 1917.-Studies on.Pediculus. Parasitology, vol. 9, pp.~93-3!il4, fl pl., 12 text figures.Nuttall, G. H. F., 1917b.-Parasitology, vol. 10, No.1, pp. 1-183. Sev~eral articles including complete bibliography.Nuttall, G. H. F., 1918.-Parasitology, vol. 10, No.3, pp. 375-405,figs. 1-5.

CHAPTER XXIIThe Control of Human Lice 1W. Dwight Pierce and R. H. HutchisonNever in the history of, the world has the subject of insect-bornediseases become so prominent as it has since the discovery that severalof the great diseases which ravage nations and armies are borne bylice, and that personal prophylaxis alone will combat these diseases.The knowledge of the means of conveyance of a disease is the firstrequisite for the successful preventive measures. Had the scientists notknown how typhus fever was spread the entire nation of Serbia, and possiblymost of the peoples of eastern Europe and the poor peoples of allthe war-stricken nations as well as the men in the trenches might havebeen wiped out by now. As a matter of fact, probably one-third of theSerbian nation and hundreds of thousands of Roumanians, Austrians,Russians, Germans, and Turks were lost before the medical authoritiesobtained the necessary grip on the situation. The lice would have goneon disabling the men in western trenches with trench fever if they had notbeen proven to be the vectors.THE RAVAGES OF LICEThe eastern theatre of war has long been scourged with louse-borneepidemics. During the Crimean war the British troops became seriouslyinfested, becoming anaemiated and debilitated and death carried off manyof them. The only remedy available was to put the wet flannels in thesnow for two days-this killing all but the nits (Shipll!y).Typhus fever ravaged the Bulgarian troops during the two Balkanwars to such an extent that it was estimated by a staff officer that theylost more soldiers in a short period of tiJl1e from fleck typhus than fromall other diseases combined.During the present war, the lice at first were most serious in theeastern theatre, probably due to the greater congestion of populationamong the Slavic peoples. The Germans first had to combat them amongthe Russian prisoners, finding the French almost completely free. But1 This lecture is a modification of one read June 24 and c1istributed June 27 and of asynopsis presented September 18 and distributed October 4, 1918.312-

THE CONTROL OF HUMAN LICEby mixing the prisoners, and the exchange among them of souvenirs, especiallyshoulder straps under which the lice clung in masses, the licebecame generally distributed. It was not long before the German armiesfound the louse a very live problem and their scientific journals are fullof papers on the control of the vermin.In Serbia a few cases of typhus fever occurred in October, 1914,and in January, 1915, the disease was epidemic among Austrian prisonerswho were greatly crowded and necessarily compelled to live under veryunsanitary conditions. The disease quickly spread from them to otherindividuals, and as there was no quarantine, and the Austrian prisonersand the infected individuals were sent or allowed to go to various partsof the country, Serbia was soon a1Hicted with a terrible and widespreadepidemic. Weakened by the ravages of war, the country was not preparedfor an epidemic and for a time typhus raged almost at will. Themajority of the Serbian doctors, who were few in number, became afflicted.The epidemic was at its height in April when the number of cases wasat least 9000 a day, but it was impossible to gauge the number of casesin the rural districts. At least 100,000 men, or a quarter of the army,were destroyed in this epidemic which was checked by the energetic effortsof the medical officers, assisted by Dr. R. P. Strong and his Americancolleagues. The work of the Serbian Sanitary Commission is briefly detailedby Doctor Strong in various reports.In Roumania typhus fever and relapsing fever became epidemic in •the winter of 1916-17 and the conditions which occurred there are veryvividly portrayed by Wells and Perkins (1918). Rulison (1918) givesthe history and statistics of the epidemic from its beginning through thegreater part of 1918, estimating ~6,000 deaths from typhus fever up toFebruary IS, 1919.It was inevitable that the louse should reach the western trenchesand contaminate them with disease, and we find that trench fever wassoon considered the most disabling disease of this front. Reports showthat a very high percentage of the men in the trenches became verminous.SISRESERVOIRS OF LOUSE BREEDINGBefore discussing the control measures, we must also know whencearise these infestations of lice which can infect whole nations, becauseprophylaxis must take into accQunt the reservoirs of the pest. In theUnited States, where cleanliness and bathing are more or less the generalrule, there have never been great outbreaks of these vermin exc~p'tin time of war. In certain parts of the world, however, the louse is anever-present associate of man. This is especially true of the ignorant andthe densely populated portions of the world, the Mexican and South

314 SANITARY ENTOMOLOGYAmerican peons, the European peasants, the Mohammedan populationsof Africa and Asia. Among the Mohammedans, their religion" forbidskilling insects and from childhood they become inured to their attack.War serves to aggravate con~itions by concentrating refugees and pris~oners in crowded, unhygienic zones, and by mixing troops from all stationsof life and from all races. Among our own people, lumber camps, miningcommunities, jails, poorhouses, lodging houses, construction camps,ghettos, negro communities, Mexican colonies, Indian reservations, tramps,and vagabonds are the principal reservoirs of infection which infect ourarmies and the civil population. Ignorant, degraded people everywhereare sources of lice. Our public schools, where children from all strata ofsociety mingle, furnish constant trouble as distributing centers of headlice, as the children's hats and clothing hanging on racks afford easymeans of spreading the vermin. Infection from lice may occur as justmentioned in clothes racks, public transportation, public halls, publictoilets, hotels and lodging houses, and by coming in direct contact withlousy individuals.CONTROL MEASURESOut of conditions as described above have arisen heroic methods oftreatment. Wh~n things are done in armies they must be done on a largescale. Consequently we find that Dr. Strong's commission beganto educate 'the Serbian nation on the necessity of bathing and cleansingthe wearing apparel, and similar efforts were later made in Roumania.And furthermore, with the cleansing came the control of the epidemics.The British in 1915 began isolating German prisoners for 14 daysafter capture, for observation, and they treated or destroyed theirclothing and bathed them as promptly as possible. The isolation ofprisoners was later practiced quite generally.It has become a well-defined principle now that new acquisitions to amilitary camp must be treated for lice. This treatment is called delousingor disinsection. Men returning from the trenches, prisoners ofwar, men who have been on furlough, new recruits, and new units mustbe inspected and given a complete delousing treatment on general principles.This treatment often varies in detail but consists of thoroughbathing, cleansing of the clothes and ac.coutrements, and disinfectionof bedding and baggage.On the Mexican border the United States Public Health Service hasfound it necessary to exercise a rigid supervision over refugees fromMexico, as the disturbed political conditions in that country have resultedin a spreading of typhus fever from the plateau regions, where itis endemic, to all parts of the country. The immigrants are stripped andgiven identification tags for their clothing and baggage, and then they

THE CONTROL OF HUMAN LICE 315themselves are given thorough spraying with kerosene or gasoline emulsion,and then baths with warm wa!:!

316 SANITARY ENTOlfOLOGYEither there must be a thorough system of inspection on entrance, or allapplicants must be assumed to be infected, and accordingly bathed andhave their clothing sterilized.CONTROL OF LICE ON THE BODYControl of Crab LouseThe crab or pubic louse is confined usuany to the hairy portions ofthe body, including the head and the eyebrows. Its eggs are attachedto the hairs, and the lice themselves remain fixed to the body, with thehead imbedded. Prophylaxis for it is therefore largely personal. Theinfected .person should bathe in hot water and use an insecticidal soapsuch as the kerosene emulsion soap described above, and then anoint theinfected parts with yellow oxide of mercury ointment, mercurial ointment(blue ointment), carbolic acid ~ per cent followed by olive oil, or vermijellymade up by the following formula:Texas fuel oil, sp. grav. 0.86, b. p. !50 to 350 0 C ........... 50 partsCrude vaseline ........................................ ~o partsSoft soap ............................................ 30 partsThe cutting or shaving of pubic or axillary hairs is to be avoidedbecause of the discomfort caused. Powders such as N. C. I., etc., shouldnot be used in the pubic regions.Control of Head LouseThe head louse is usually confined to the head and lays its eggs on thehairs. The usual approved prophylaxis consists of daily combing andbrushing and periodic washing. It is well to keep children's hair short.Many children's institutions clip the boys' hair, and clipping of hair is acommon military practice. Several insecticidal hair washes are used:I. Wash head with equal parts of kerosene and vinegar or ~5 percent acetic acid for one half hour, keeping the head covered with a towel.The vinegar separates the eggs from the' hairs, while the kerosene killsthem. Use a fine-toothed comb to remove the eggs and lice. Wash thehead with warm ,vater and soap containing kerosene (Nuttall).!. Have patient lie down with the head over edge of bed above ILbasin resting on a chair, so that the hair lies in the basin. Pour thecarbolic water over the hair so that it falls into the basin and sluice itabout until the hair is soaked, for ten minutes. Drain, wring out moderately,and wrap head in flannel towel. After an hour wash the hair or

THE CONTROL OF HUMAN LICE 317let it dry with the carbolic in it. To remove the eggs, apply ~5 per centacetic acid and use fine comb (Nuttall).3. Anoint head with a mixture of equal parts of kerosene and oliveoil, wrap the head in a.towel and sleep in it. Apply vinegar and removeeggs with a fine comb, then wash out with warm water and soap. Thismay be repeated for two or three nights if necessary.4. Hair oil and pomades, as used in certain classes and races, areefficient.Control of Body LOU8eThe body louse occasionally lays its eggs on the hairs of the body,but most of the measures involving treatment of the body are aimed atpreventing attack. In handling this louse it must be borne in mindthat simultaneous with freeing the body there must be control of theinfection in the garments and living quarters.The bath is the first important step in control of the body louse.Bath Outfita.-Early in the war it became apparent that portablebathing and disinsecting apparatus must be developed. In Russia, Brink(1915) late in November, 1914, devised a portable traveling bath capableof bathing a regiment of 4000 to 4500 men in 1% to 2 days.Many modifications of this have been devised but we may give ingeneral a composite of these, which may serve as the model.The outfit may consist of a wagon train with tents or portable huts,or a train, or at halting stations may consist of permanent structures.The portable wagon or tractor-drawn outfit can most nearly approachthe trenches and is considered the best by Brink. The equipment shouldbe capable of washing and cleaning the clothing and equipment of at least100 men an hour and to discharge each man in about half an hour, thusmaking it possible to wash an army unit in the course of a shorttime.There is also supposed to be a distinct separation between uncleanand clean, and the cleaned men must not mix with the uncleaned.Diarobing.-In a bathing unit, the men come into the receiving tent,car, or room, and undress, receiving numbered tags for identification oftheir belongings. In the disrobing room each man places his clothingin a bag, his accoutrements in another receptacle, personal belongingswhich do not need fumigation in still another, all of these receptaclesbearing the number given to him. These articles may be treated invarious ways as described under the various headings.Bath.-The men proceed into the bathroom and receive either showeror tub bath, and in some cases pass through several baths. In the Russianportable outfits the bath equipment consists of folding benches, zinccovered tubs, lVash basins, spoon measures for liquid soap, sacks for

S18SANITARY ENTOMOLOGYsterilization of clothes, little numbered tags, canvas folding tanks forwater, kerosene lamps to be used at night, and a barber shop. Naphthasoap is used as the cleansing agent. On the Mexican border at EI Paso themen are first sprayed with gasoline soap (for which kerosene soap shouldbe substituted) and then walk through a continuous spra.y in a tank ofwater about a foot deep. On the Sante Fe Railroad, according to Boyd,the Mexicans are given a ten-minute bath in kerosene and soap-suds(equal parts), with a kerosene and vinegar bath for the hair. Our ownarmy has now established elaborate bath and disinfection houses.In at least one of the baths hot water should be used. The liquidsoap described above, applied as a spray, is a very good method andprevents contamination by means of the soap.Either before or after the bath, they enter the barber shop, wherethe hair is clipped if there is any evidence of head lice. Bags should betied around the neck to catch the hair, which is burned. The men ma.yalso be shaved.They then pass into the dressing room where they receive cleanunderclothes and their outer garments and other possessions disinfectedand disinsected.Soaps.-In the bath, soap is one of the essentials. All soaps are notinsecticidal, and others are not sufficiently effective. Recent tests haveshown that gasoline and gasoline soap emulsion are not thoroughly effectiveremedies (Hutchison and Pierce). The following soap formulae areconsidered effective:1. Liquid kerosene soap emulsion made by boiling one part soapchips in four parts water and then adding two parts kerosene oil. Thisjellies when cold, and one part of this jelly added to fou_r parts of warmwater makes a good liquid soap at very small cost.!i!. Five per cent carbolic acid and soft soap, equal parts.S. 5 per cent cresol and soft soap, equal parts.4. Two per cent lys01 and soft soap, equal parts.For wounded men, after a shower, Adler-Herzmark recommends soapingdown with a brush, using an emulsion of petroleum 1 part, soft soap!i! parts, and lysol solution 1 part. Afterwards apply'S per cent cresolointment to the hairy parts .. Sponge Baths.-It is often impossible for soldiers, especially, to geta genuine bath, so they must resort to sponge baths and treatment ofthe body and garments to reduce, at least, the infestation.A good treatment consists of sponging off the body with water, usingthe above-mentioned kerosene emulsion soap, or sponging with !i! per centcrude carbolic acid solution, and then anointing the body with ordh."'\arygrease or with vermijelly, which we have already described.'........__Ver11iicmes and Repcllents.-Whell unable to follow out the plan of

THE CONTROL OF HUMAN LICE 819bathing and cleaning the clothing, the only means left is to use somekind of vennicide or repellent. Nuttall has described experiments withmany chemicals, b~t Moore has gone into the subject much more exhaustively.Both reported unfavorably regarding sachets, although the followingsubstances have been found to exert repellent action on the lice:oils of anise, cloves, eucalyptus, naphthalene and carbolic acid. Insecticidalpowders are frequently favored. Moore (191So.) lists manyeffective powders but reports the most effective to be made of:Creosote .................................. 1 cc.Sulphur .................................. ~ gr.Talc ...•................................. ~O gr.Naphthalene is very commonly used and is effective, but its continuoususe may injure the eyes. One of the commonest powders in generaluse is known as N. C. I. powder and is made of:Naphthalene ........................... 96 per centCreosote ............................... ~ per centIodofonn .............................. ~ per centThe specialists of all the nations have sought to find a substancewith which clothing could be impregnated and rendered vennicidal.Moore has suggested wearing a cheesecloth suit impregnated with saturatedsolution of sulphur in creosote on the outside of the underwear, buton the whole he reports (Moore, 1915b) after testing many substances,that the cost of application is too high for the results obtained, andnone are effective longer than a. week. Moore and Hirschfelder subsequentlyreported more hope- of success from naphthalene and cresol compoundsthan from anything else.CONTROL OF LICE IN CLOTHINGIn order to properly delouse a unit~ the cleansing of the clothing isof utmost importance. There are many satisfactory systems of treatmentand "it is therefore a question of choosing the one which is mostpracticable l.mder the existing conditions.1. LawndryThe laundry method of disinsection as described by Pierce, Hutchison,and Moscowitz, is the best and most efficient, given sufficient :timeand the necessary equipment. In this process the clothes are deloused,disinfected, cleaned, and pressed. Every step in, the laundry is in-

S~OSANITARY ENTOMOLOGYsecticidal. Laundries are to be found in all American cities and havebeen installed in practically all American cantonments and are found inmany European centers. Portable steam laundries were used by theAmerican army, and in the future should always be a part of an army'sequipment. There is no resulting damage to the garments if carried outas described below, which is according to standard laundry practice. Inall ordinary cases, the following formula is sufficient for the treatmentof woolen goods: .1. Wash fifteen minutes at ISI° F. in heavy suds and light load.~. Rinse three times, thr.ee minutes each, at ISI° F.S. Extract.4. Run in drying tumbler fifteen minutes, at a minimum of 140 0 F.The goods should not be perfectly dry when removed.5. Iron.In case the garments are suspected of containing very resistent disease..germs, the regular washing formula may be preceded by one of thefollowing measures:a. In the washer, run a current of live steam fifteen minutes, revolvingcylinder every five minutes, and discharging water of condensationevery five minutes. Remove the garments and shake until almost dry.Then turn the hot water into the washer and when the proper temperatureis reached, put in the garments for the wash as describedabove.b. In the washer, submerge in water at 165 0 F. for twenty minuteswithout motion, except a few revolutions every five minutes. Removethe garments until the new water has been brought to ISI° F. and thenbegin the wash as described above.Flat work, khaki and cotton underwear are washed by formulaerequiring hotter water and are hence thoroughly disinfected and disinsected.~. Dry CleaningUniforms and overcoats may be preferably dry cleaned rather thanwashed because of the stain-removing value of the dry cleaning process(Hutchison and Pierce, 1919). In this process the garments are deloused,disinfected, cleansed, have stains removed, and are pressed. Drycleaning establishments exist in most large cities. Many of the armycantonments had them installed and some units went overseas with ourtroops.This process is not insecticidal in every step, but is essentially soin s. complete process. The gasoline wash, contrary to expectations, willnot kill all submerged eggs, even after 54 hours.

THE CONTROL OF HUMAN LICE 321a. For an establishm~nt fully equipped with rotary washers and drytumblers, we recommend the following cleansing formula:1. Wash goods 30 minutes in new, distilled, or clarified benzole,naphtha, or gasoline, having a specific gravity not less than 56 0 Baumeby hydrometer test; using one gallon of cleaning fluid to every tWG poundsof goods, two ounces of standard dry cleaning soap to every ten poundsof goods, one ounce of 26 per cent ammonia to every twenty-five poundsof goods.2. Extract 3 minutes.3. Rinse 15 minutes in new or distilled fluid.4. Extract 3 minutes.5. Dry in tumbler 30 minutes at a temperature not less than 160 0 F.at point of discharge from tumbler.6. Iron.In case drying rooms are used in place of tumblers follow the first, four steps and then:5. After thoroughly drying and deodorizing, hang in dry room attemperature of not less than 160 0 F. for 30 minutes.6. Run in dust wheel 20 minutes.7. Iron.b. In case the dry cleaning establishment is not equipped withmodem machiner'y, the following method will be practicable:1. Soak in benzole 3 hours.2. Wring out and dry.3. Iron thoroughly.This modified process is too long for army practice but will do fOlsmall commercial trade.c. Dry cleaning establishments equipped with Barbe system machineryin which hot gasoline is used in the wash, have a thorough insecticidalprocess in every step.3. Steam SterilizationThe 'Process of sterilization most commonly used in army practice involvesthe use of steam in some form. There is probably more danger toclothes from the use of steam than from any other metlIod of treatment.Unless properly applied, steam will shrink, wrinkle and dis colo! woolens.It is probably by a few minutes the quickest process of sterilization, butsteam does not cleanse or remove stains. When we consider that a uniformmust ofteh be subsequently treated either by laundry or dry cleaningto make it look presentable, we can readily see the advantage ofusing one of these processes for the entire operation of sterilization andcleansing. There is a proper way of handling each of the steam pro-

SANITARY ENTOMOLOOYcesses to avoid the greater part of the damage. Nuttall (1918) hasgiven a very exhaustive study of the methods of steam sterilization,especially with reference to autoclaves, so we will content ourselves withmerely citing the most approved fonnulae.a. Live or current steam fumigation was proposed by Stammers, whodevised the Serbian barrel. Hunter (1918) has given a rather fulldescription of several of the dominant types. Exposure to live steam20 minutes in any kind of chamber is sufficient if the clothes are looseand pennit circulation of the steam. Care lJ1ust be taken not to overload.The first method described below utilizes the laundry wash wheel andwas devised by Pierce, Hutchison and l\:[oscowitz. It is probably thequickest method yet proposed. The three other methods were describedby Hunter.1. The live steam sterilization in the wash wheel has been describedin the discussion of the laundry process, and only requires fifteen minutes.The clothes must not be packed any tighter than for a normal washingload. They must not be tumbled except once in five minutes to removewater of condensation. When taken out of the wheel they should beshaken well before hanging up to dry.!to Stammers' barrel disinfection, called the Serbian barrel, is apracticable field disinfector available often where no other sterilizationcan be carried out. It consists of an old wine barrel with five or six roundholes in the bottom, placed on a circular boiler of cast iron or galvanizediron. The space between the boiler and the barrel is filled with a narrowsausage ring filled with sand to prevent escape of the steam except throughthe barrel. A fire is built in a pit beneath the boiler. Cross bars areplaced in the bottom of the barrel to keep the clothes from the holes.When the steam is escaping too hot for the hand, the time required fordelousing is one hour. The barrel is covered with a heavy wooden lid.S. A galvanized iron bin with water in bottom and a grid to keepthe clothes from the water, placed over a fire, will serve for a smallquantity of garments on the same principle as the barrel. An ordinarygarbage can as used in the army will serve.4. In Egypt and S~bia, trains were fitted out and connected bysteam pipes from the engine so that steam could be released in the carsthrough perforated tubes. The steam has cxit through cracks aboutthe doors, and reaches within the car a temperature about 105 0 C.(!t!n 0 F.). The clothing is placed in bags or on shelves and may almostfill the car. Sterilization lasts one hour.h. Enclosed steam has been more commonly used and has likewisebeen the cause of most of the trouble. It may be applied either at no~

THE COXTROL OF HU:\lAN LICEor increased pressure, and in normal atmospheres or in vacuums (plateXXIII). Fulton and Stamford recommend the following procedurE!:1. Place woolen blankets or uniforms on hangers or loosely on traysin the sterilizer.!to Introduce 60 pounds steam into· the outer jacket to prevent subsequentcondensation within the sterilizing chamber.3. Create a 15 or ~O-inch vacuum to facilitate penetration of theclothing by the steam.4. Sterilize with steam.a. No pounds (atmospheric pressure) for one hour. •b. Twelve pounds steam for 10 minutes.PLATE XXII I.-Steam sterilizer in delousing station of U. S. Army Medical Corps.. The can-iage is transferred along the rails in the foreground to rails leading intothe other room where another carriage is seen. (Hutchison.)5. Produce 15 to ~O -inch vacuum to facilitate drying.6. Open the door of the sterilizer about 4 inches for 10 minutes toallow gradual cooling of the contents of the sterilizer.Steam under pressure will disintegrate woolens if the exposure is prolonged.The bacterial sterilization requires preliminary vacuum andloose packing. Garments placed in bags are likely to have the wrinklesset, if water of condensation settles in them when the steam has not penetratedat a sufficiently high temperature. If the cooling or drying is'\'Cry rapid, wrinkles and shl'inkage are quite likely to result.•

SANITARY ENTOMOLOGY4. Hot A.ir DelousingHot air was used very extensively for delousing the armies, especiallyon the eastern front. This system is not sterilizing, nor is it especiallydangerous to the garments except when allowed to get too hot. Stagnanthot air has less effect than fresh hot air. The garments must be hungloosely. Provision should.be made for circulating the air so that all ofthe clothes will receive the necessary amount of heat, which is 131 0 F.(55 0 C.) for 30 minutes, or 140 0 F. (60 0 C.) for 15 minutes. The heatchamber may be a portable box such as a fireless cooker; a room heatedby steam pipes or hot air; a sad hut; a steel autoclave; or an improvisedoven. Very high heat must not be used on dry garments as it will disintegratethe fibers of woolens and cause shrinkage.5. F'I.II1nigationWhen fumigation chambers are available and the clothing is needed forimmediate wear, this is one of the quickest means of delousing. Thefumiga tion chamber may he:ok. A room, 'With cracks tightly scaled, and ,vith vestibuled doors.A sign of warning should he posted and the door kept. locked during fumigations.Only persons understanding fumigation should he permittedaround, and they should wear gas masks.1:i. A chest or box is sufficient for carbon bisulphide or chlorpictin.c. A portable unit, such as an automobile with an air-tight chamber,and with hangers or shelves. The gas generator may be placed behindthe chauffeur's seat.d. A vacuum chamber as in steam sterilization. The same cylindermay be made available for either steam or gas.The fumigation may be either at normal atmospheric pressure orin a vacuum. When a room is to be fumigated one should see that thereare no persons in the building, as few buildings are constructed so thatI:he gas can not penetrate to other rooms.To fumigate an entire building, or a room, close tightly all openingsin building and seal up cracks with paper, unless the insects are inthe double walls, in which case seal the cracks on the outside. It maybe necessary, if the building is too loosely constructed, to increase dosagesor make a tarpaulin to cover the entire structure. Such measures shouldonly he taken in case the normal fumigation is unsuccessful. Any ofthe following methods are practicable. Entomologists prefer cyanidebut many army officials prefer sulphur.a. Sulphur corrodes metal, so aU movable metal should be taken outof the building. Sulphur fu~igation is described in Public Health Bull.

THE CONTROL OF HUMAN LICE 3~534 (1910) with special reference to ships, and in Entomology Btill. 60(1906) with reference to general fumigation.1. Clayton gas is generated by burning common roll brimstonein an oven or generator outside of the building. A very high heat isgenerated. The gas is passed Over two baffle plates before reachingthe outlet pipe which is cooled by water circulating in pipes aroundit in an ordinary steam boiler tank. The gas then is passed into thebuilding to be fumigated. This gas is a mixture of sulphur dioxideand sulphur trioxide. As the gas is heavier than air there must becirculation through the roof of a building or hatch of a ship until thegas begins to come out in quantity.~. Bum sulphur candles, being careful to isolate them by sufficientmetal from all woodwork, at rate of 4 pounds per 1,000 cubic feetfor .6 hours.b. Cyanide is one of the best known gases used for fumigation.1. Sodium cyanide only is now available. Generate in earthenjars, placing in the jar 1112 oz. sulphuric acid and ~ oz. water to everyounce of cyanide to be used. Arrange the cyanide in a package suspendedover the jar so that it can be released by the operator at adistance by pulling or releasing a cord. The gas is generated veryrapidly and is exceedingly dangerous. Use 10 oz. of cyanide for each1,000 cubic feet and expose for ~ hours. This will kill all other insectspresent.~. Potassium cyanide should be used at the rate of 1 oz. cyanideto 1 oz .. sulphuric acid, and 3 oz. of water.s. Chlorocyanogen (CICN), in experimental work, gives promiseof being fully as effective as HeN and much safer to use, because theirritation of the membranes of the nose and eyes gives warning of anyleak long before sufficient gas has escaped to produce any toxic effect.The most practical method for fumigation of any kind would be amobile motor fumigator with hose attachments capable of treating anybuilding, tent, or car. If this unit had a tight fumigation room, garmentscould be hung therein and practically fumigated. The installationshould be equippe~ with generators for cyanide, formaldehyde, orsulpllUr fumigation, and be placed in charge of practical fumigationexpert~.Vacuum fumigation has received several very successful trials. On theMexican border it has been used by the Public Health Service, wherea hydrocyanic acid gas fumigation is used. Many steam sterilizers nnwin use are available for gas fumigation. The following formulre haveheen tested and proven satisfactory:1. For chests, trunks, and tightly-packed garments ~5-inch vacuum,

.326 SANITARY ENTOMOLOGY30 minutes exposure, 4 ounces so~ium cyanide per 100 cubic feet(Lamson).ll. For loosely-hung clothes, 20-inch vacuum, 30 minutes exposure,3 ounces cyanide per 100 cubic feet (,:.amson).3. The hydrocyanic acid gas (DANGEROUS) is generated in anair-tight generator, which is connected by a pipe with the fumigationchamber, by combining 21h parts of sodium cyanide solution (made bydissolving 4 lbs. of sodium .cyanide, guaranteed to contain 51 per cent.cyanogen, in 1 gallon of water), 1 part of commercial sulphuric acid(184 sp. gr., or 66° Baume) and 1 part of water.Create 25-inch vacuum. Generate gas 5 minutes in generator. Washover into fumigation chamber. Break vacuum so as to fumigate innormal atmospheric pressure 25 minutes. Remove gas by producing25-inch vacuum. Return to normal pressure. Open door slightly and runvacuum pump a few minutes. Remove material. (Sasscer.) (~ee Fed.Hort. Bd., Service and Reg. Announcement 21, Dec. 4, 1915.) ONLYEXPERIENCED MEN CAN BE PERMITTED TO HANDLE. Incase of asphyxiation from cyanide it is imperative to walk the patientup and down in the open air or to resort to artificial respiration. Fewfatalities result under such treatment.For fumigation in boxes the following gases are available:R. Chlorpicrin in galvanized cans using 4 cc. to 1 cu. ft. for 30minutes and applying a little heat. DANGEROUS GAS. (Moore.)b. Carbon bisulphide is an inflammable but efficient fumigant buttoo slow for most army purposes. Place garments in any kind oftight box and pour in the liquid at the rate of 1 lb. to 1000 cu. ft.of space. Leave for 24 hours.6. StorageStorage of infested garments, dry at 54°-68° F. (12°-20° C.), fortwo or three weeks is effective. Bedding and clothing may be put awayin naphthalene crystals or moth balls.7. Impromptu Delousmg ArrangementsUnder temporary conditions none of the above-mentioned· methodscan be used to cleanse the garments and in such cases hot water washingor the use of other expedients is necessary. The outer clothing shouldbe ironed and brushed at least once a week.A great number of remedies have been suggested and tried, but fromthese we may select a few which appear to be especially good. Thereprobably will be times when one or another will be more practicable.

THE CONTROL OF HUMAN LICEa. Boil clothes in water five minutes.b. Soak woolens in hot water at 13P F. (55 0 C.) 15 minutes.c. Soak clothes in insecticides.1. Immerse in benzole bath for S hours.~. Wash for 15 minutes in 10 per cent solution of one of thefollowing soaps; then wring out and dry.To obtain a 10 per cent solution dissolve S pounds in abucke.t of water. The odor will be retained a long time andkeep lice away.a. Naphtha soap 65%Cresol 35%b.· Naphtha soap 65%100% crude carbolic acid 35%c. Naphtha soap 65%Xylol 35%3. Soak for 10 minutes in 2 per cent 1I0lution of cresol, wringout and dry. A quart of cresol in 12¥2 gallons of water is enoughto kill the lice in the body linen of 62 men, each garment beingwrung out to recover as much as possible of the liquid.d. Handpicking, if done thoroughly and regularly,. is ofteneft'ective.e. Hot ironing if done well is effective.CONTROL OF LICE IN LIVING QUARTERSIn addition to control of the lice on the man and his garments, it isnecessary to control them in his lodgings, for the lice are quite likely tobe scattered through bedding and clothing, especially in army quarters,and in lodging houses, and places where men subject to lice infestationare likely to congregate.The quarters should be treated as follows:1. Cleanse beds with gasoline or kerosene. Permit no fires.2. Send bedding and linen to laundry.3. Thmigate mattresses and pillows in fumigation chamber withcyanide as described for clothing; or,4. Fumigate the quarters as described abov.e.When men are on active duty in war time, lice become very abundantin the trenches and dugouts. The men brush themselves oft' and the eggsand lice fall to the ground to reinfect other men. The following controlmeasures will be of assistance:1. Spray walls with cresol or phenol solutions 2 to 5% strength.2. Scrape walls, sprinkle the dust with corrosive sublimate andremove.

S!l8SANI'rARY ENTOMOLOGY3. When possible provide in dugouts a disinfecting kettle or box orbarrel in which clothes can be treated with an insecticide as describedunder clothing.4. When possible, remove bedding and other comforts in which licemight lurk, to the rear, for disinfection.CONTROL OF LICE IN HOSPITALSWhen working in communities or camps where louse-borne diseasesare common, it is imperative that the hospital attendants take everymeasure possible to prevent, infection of themselves from patients andprevent spread of lice from patient to patient. The following recommendationsare therefore of value in such cases.Control of Lice in Hospitals1. Moisten floors and walls with cresol or phenol.2." 1£ possible patients should be washed before placing on cle'!n beds.3. Attendants should wear clothes with, few openings.4. Band legs of wooden beds with corrosive sublimate to prevent infectionfrom other beds.5. Cleanse each bed before putting a new patient on it.6. Obtain free ventilation with fresh air.7. Have bedding disinfected for each case;Louse-Proof Garments for Medical AttendfJln.ts, Etc.1. Smooth clothing, preferably rubber or oiled silk.2. Long coats, extending below the knee and buttoning behind.3. Sleeves narrow at the wrists.4. Rubber gloves drawn up to overlap edges of sleeves.5. Collars to button close around the neck.6. Head covered by a hood.7. Rubber or smooth leather top boots.s. A onc-piece suit fastened at shoulders by buttons, with trousersclosed at ends like stockings. Wear sandals over the fe'et. Rubber cap.9. Smooth capes are sometimes of value.10. Smooth silk underwear may afford a measure of protection.BIBLIOGRAPHYBoyd, Mark S., 1917.-Am. Journ. Pub. J!ealth, vol. 7, No.8, pp. 667-671.Brink, 1915.-Voyenno Med. J., Petrograd, vol. 264, Med. spec. pt., pp.440-449.

THE CONTROL OF HUMAN LICE 3~9Fulton, Dudley, and Staniford, K. J., I91B.-Journ. Amer. Med. Assoc.,vol. 71, No. 10, pp. B~3-B~4.Hunter, William, 191B.-Brit. Med. Journ., Aug. U, No. 300B, pp.198-~0l.Hutchison, R. H., and Pierce, W. Dwight, I9I9.-Proc. Ent. Soc. 'Vash.,vol. ~1, No.1, pp. 8-~0.Moore, W., 191Ba.-Journ. Lab. Clin. Med., vol. 3, No.5, pp. ~60-~68.Moore, W., 191Bb.-Journ. Amer. l\led. Assoc., vol. 71, No.7, pp.530-531.Nuttall, G. R. F., 191B.-Parasitology, vol. 10, No.4, pp. 411-586.Pierce, C. C., I917.-U. S. Public Health Reports, vol. 3~, No. 1~, pp.4~6-4~9. ,Pierce, W. D., Hutchison, R. R., and Moscowitz, A., 1919.-NationalLaundry Journal, Chicago, vol. Bl, No.1, pp. 4-14.Rulison, R. R., I91B.-New York State Journ. Med., vol. 1B, No. 11, pp.443-451.'Shipley, A. E.-Brit. Med .• Tourn. No. ~807, p. 679.Strong, R. P., 19I5a.-Boston Med. and Surg. Journ., vol. 173, No.7,pp. ~59-~6~.Strong, R. P., 1915b.-Med. Rec., Nov. ~O, p. 892.Wells, H. G., and Perkins, R. G.~ 19I8.-Journ. Amer. Med. Assoc., vol.70, No. ll, pp. 743-753.

CHAPTER XXIIILice Which Affect Domestic AnimalsPart 1.Cattle Lice and Their ControllG. 'R. La'Tn8on, Jr .. Nearly every species of animal bearing hair or feathers is subject tothe attack of from one to a dozen species of lice. A given species doesnot infest all kinds of animals, but is confined to certain related kinds.Lice are divided into two cardinal groups, according to their methodof feeding. One order, the Mallophaga, includes biting lice like thebird lice and the small red lice on dairy animals, which feed on the dryskin, hair or feathers, but do not suck the blood. The other order, theSiphunculata, the sucking lice, fatten themselves by sucking the animal'sblood. These of course are the most annoying, injurious, and dangerous.Some of the sucking lice, under certain conditions, may transmit fataldiseases, but none of the cattle lice are known "to do this. The presentlecture deals only with the species which infest dairy and beef cattle.The place where stock is kept has a part in the degree of infestation,for cows that are placed near other badly infested cows have a greateropportunity for becoming lousy than those that are stabled with cattlethat are comparatively free from lice. Where lice have occurred yearafter year, there is a greater danger of infestation than where the stableshave been kept clean, well ventilated, and well lighted. The lice cannotmaintain life for any ex'tended period of time away from the cows. Ifthe stables are kept clean, well lighted, and ventilated there is somewhatless danger of infestation.Too much stress, however, has been placed upon the condition ofbedding and stables and not enough upon the. condition of the stock, forit is doubtful if any cow is ever entirely free from lice for the whole year,even where the stables are kept scrupulously clean and well managed.Careful examination of the infested herd will show that there is considerabledifference in the number of lice on different cows; some are very1 This lecture was presented November 11, 1918. It is based primarily upon conditionsin dairy herds, and therefore all of the recommendations may not be applicableto range condltions.-W. D. Pierce.330

LICE WHICH AFFECT DOMESTIC ANIMALS 381badly infested early in the winter, some will have 8 few lice on them, andothers will seem to be free from them.The degree of dryness of the skin is often closely related to the numbersof lice on the different cows. When cows are not in good physicalcondition this results in a lack of natural oiliness of skin and makes conditionsideal for lice to increase. It will bc noted that the variation inthe numbers of lice on cows varies with the breed; that Holsteins arenotably among the most infested; that Ayrshires and Guernseys areintermediate; and that Jerseys are not so badly infested. Calves, whichhave less oily skin than older stock, a;re more generally infested with lice.There is a mal'ked difference in the season of the year when lice aremore numerous. The skin secretions are reduced in the winter and it isthen that the lice are most numerous. In the summer only a few canbe found. Certain cows in a herd will be infested early and will continueinfested through the winter. The fact that Holsteins, being usuallyeither black and white, or having the combined markings, make the licemore cons}licuous, seemed at fiTst to otier a solution ior the reasonwhy they have been generally conceded to be the most heavily infestedbreed of cows. Considerable study has, however, borne out the factthat this greater susceptibility is due to the general lack of skin secretionof the breed. For these reasons, it is believed that not only shouldwe try to keep the stables clean, well lighted, and well ventilated, butalso keep the stock in good physical condition. The fact that the lackof oiliness of skin tends toward lousiness indicates a logical control measurefor these parasites.Cattle lice are by no means uniformly distributed over a cow, particularlyif they are of the sucking species. The upper portions of the neck,shoulder tops or withers, escutcheon and the switch of the tail are usuallythe parts that are infested with the largest numbers.The forehead, portions between the horns, and the throat are placeswhere the lice are next most likely to be found. It is these places, especiallythe upper portions of the neck and withers, that the dairymenshould watch for indications of their presence and it is to these placesthat the insecticide or control measure should be applied most liberallyand most thoroughly. While the small red biting lice move about somewhat,the sucking lice remain stationary during the greater portion of thetime before reaching maturity, feeding continually.SUCKING LICEThe short-nosed cattle louse, HaemDttopim/tbIJ euTYsternus Nitzsch, isthe best known of the. cattle lice. It is very broad and measures in the

ss~SANITARY ENTOMOLOGYfemale about one-eighth to one-fifth of an inch, while the males are alittle smaller and a little narrower.The eggs or nits are white and can be distinctly Seen glued tightly tothe hairs along the shoulders. From thirty-five to fifty eggs are laid bythe mature females and these are laid a few each day. The egg-layingperiod may extend over a period of ten to fifteen. days. These eggshatch in from seven to .eight days and the young hee commence drawingthe cow's blood near the point where they were hatched. The rateof growth depends somewhat upon the blood supply in the portion ofskin where they work. They mature in from fifteen to eighteen days,when the females in turn lay eggs.The long-nosed cattle louse, Haematopinus 'lJituli Linnaeus. is oftenspoken of as the "blue louse," or the louse attacking calves, though itOccurs frequently on older stock. It is distinguished by being darker incolor and slender in shape with a long pointed head. When seen on thecattle it seems to be literally standing on its head with mouth-parts buriedin the skin, feeding on tIle blood of the animal that it infests. It isfound more commonly on the neck and shoulders of the animal.The mature insects are a dark bluish gray in color, giving them anappearance of being either blue or black, and they are about one-eighthof an inch long. Their color and their small size allow them to passunnoticed especially on stock of a darker c~lor. If one will turn backthe hair until the skin of the animal can be seen, their pJ.'esence may bemade out by the shining surfaces of the abdomen. If they can be madeout on the calves having white markings, they can usually be assumed tobe present on the others, and there should at least be a close observationof all the calves.The eggs of this louse are dark, nearly black, and hatch in fromeight to nine days. Like the previously mentioned species, these licemove about but little before maturity, but continue feeding near thepoint where they were ha.tched. They in turn lay eggs in fifteen toeighteen days.BITING LICEThe little red cattle louse, Trichodectes 8calaria Nitzsch, is perhapsthe most generally found on cattle. It seems to be out of place as it isof the biting group, and this group is most commonly found on birds. Itfeeds on the hair and loose scales of the skin, and the drier the skin of thecow, the more,numerous these lice become, until they can be made out bythe thousand, closely matted in the hair. They are most commonlyfound on the neck and shoulders, though in bad cases they are foundpretty generally over most partsof -the animal. Unlike the two previ-

LICE WHICH AFFECT DOMESTIC ANIMALSously mentioned species, they move about considerably among the hairs,having feet well adapted for this purpose.These lice are small, yet visible with the naked eye, measuring aboutone-thirteenth of art·ipch. They are reddish in color, having distinctbands across the abdomen. The general shape of the body is quite differentfrom that of the sucking lice, for their heads are broad and blunt,while those of the sucking lice are much more pointed.The problem of working out the life history of these lice was muchmore difficult, and the length of time during the various stages couldnot be worked out with the degree of accuracy that was possible withthe less active sucking species.rhe eggs hatch in from five to seven days. The period from hatchinguntil the lice are mature and eggs are laid again, is about fourteen days.The eggs arc delicate white, flask-shaped forms, having a small 'Cap orlid on one end that is removed when the egg hatches, while the other endis firmly glued to the hair.It was found more difficult to exterminate these small red lice eitherwith sprays, oils or fumigations than it was to kill the larger suckinglice. This was possibly due to their more resistant chitinous covering,their large numbers and their activity.SSSMETHODS OF STUDY OF LIFE HISTORIESMuch time was taken to determine the periods of incubation of theeggs of different species of the cattle lice and the length of time necessaryfor the lice to mature, because this was considered an important featurethat would determine the proper length of time between applications ofcontrol measures. It would be difficult to find any s\lbstance activeenough to kill the embryo louse in ,-the egg, thus preventing it fromhatching, and at the same time not be so active as to do injury to theskin of the cow. The control must therefore be based on some other phaseof the life cycle.In order to make sure of no previous infestation, the method was toisolate a new-born calf and place adult female lice that had been fertilizedupon the shoulders of the calf and watch for the first presence ofeggs. As a rule these were found a few days after the lice were placedon the calf. Eggs were examined each day and as many of the old liceas could be found were removed from the animal. It was surprisinghow many of the sucking lice could be found after they had been placedon the shoulders of the calf, for they moved but little from where theywere first placed. The calf was thrown on a bundle of hay each day atthe same hour and the caps on the eggs were watched. Where these werefound removed, the period of incubation was recorded.

884 SANITARY ENTOMOLOGYAfter the young had developed for several days and were sufficientlylarge to handle readily, they were placed upon the escutcheon of a cowthat had been inspected thoroughly and found free from lice. Other licewere left on the calf. In a given number of days eggs could be foundon both the calf and on the escutcheon of the cow. These eggs wereagain watched until they hatched and in thiE way the periods of timewere recorded, and checked often enough to be reasonably sure of theaccuracy of the results.With the biting lice the work was much mo.re difficult because thesedo not remain in one place. Celluloid caps, somewhat like those used forprotecting vaccination points, were used to contine the lice. Areas wereshaved leaving small tufts of hair on which the lice could breed, andadhesive tape bound the caps to the calf. 'l'he electric incubator kept atthe approximate temperature of the cow's skin was used to supplementthe observations made on the animal itself.CONTROL MEASURESA control measure or remedy for cattle lice, in order to be practical,must be cheap, reasonably easy to apply, effective in killing the lice, andat the same time do no injury to the cow. It should not be so poisonousthat the accidental consumption by animals would endanger their life.At the same time the material used for control should be commonly sold,and thus be within the reach of purchasers even in the remoter countryvillages.Clipping.-Clipping the stock over the portion of the animal mostlikely to be infested is not an uncommon practice, and, where the hairis long and the animal is very badly infested, it helps to bring the oilor wash where it will be most effective. We have found, however, thatanimals that have been clipped are more liable to show a considerablescurting of the skin because the application reaches the skin more quicklyand in larger quantities than when it is held on the hair and thus reachesthe skin gradually. There are those who feel that .the animals do notlook as well when clipped.If control measures are used early, thoroughly, and repeated throughoutthe winter, clipping will be unnecessary.OILSRaw Lmseed Oil.-Of the many difFerent measures for the control oflice on dairy cows and young stock, raw linseed oil gave the best resultsfrom the standpoint of economy of material and labor of application,killing the lice, but not injuring the skin, and at the same time not

LICE WHICH AFFECT DOMESTIC ANIMALS 335making it necessary to thoroughly drench the cow. It has no poisonousproperties. It is a logical remedy, since the lack of oiliness in theskin of the cow is a fundamental reason for her being lousy. Linseedoil can be put on at the time of grooming or cleaning the cows, thusdoing two things in one application. From four to five cows can betreated with a pint.Raw linseed oil can be best applied with a brush having bristles ofunequal length, of which the rice fibre brushes are probably most durable.When applied with a sponge, the shedding hairs become matted on thesponge, making application a lit~le more difficult.It takes about five minutes to apply linseed oil to the cow's coatand a slight oiliness will remain for several days, which is a desirablefeature. On some animals the loose skin may scurf or lift, giving onethe impression that some little irritation has been caused. But if one willgive the condition study, he will see that there has been no in1lammationor reddening of the tissues, but that the loose epidennis has lifted.The use of raw linseed oil as a control for cattle lice is neither neW'nor patent. It has been used by scores of dairymen in the past withgood results. Some have used it once and expected that applicationshould last for the whole year and have been anxious to get some onetreatment that would do for all the time. A few others have possiblynoticed a slight scurfing of the skin on some animal and have decided thatit was burned by the application. If, however, raw linseed oil is appliedin the right manner and repeated at necessary intervals, it will befound to be one of lhe most effective agencies for the control of cattlelice, and will save time, labor, and injury to the animals ..The use of boiled linseed oil is not recommended as there is somelittle danger of burns in using it, particularly if it is rubbed forciblyinto the skin.To avoid any danger of raw linseed oil scurfing or burning the skinobserve the following directions. Do not rub the skin too vigorouslywhen applying the oil. Do not allow the animals that have been treated togo out in the strong sunlight until at least twelve hours after applying theoil. Do not exercise the animal after the treatment. Do not 'cover thecow. Do not use the boiled or refined linseed oil.Linsee-:l oil is used internally for other purposes and is a saferemedy if properly applied.'SPRAYSMany dairymen practice spraying cows and some have obtainedgood results from using spray materials such as creolin, kerosene emulsion,tobacco solution, and arsenical washes. A small bucket pump an-

:S36 SANITARY ENTOMOLOGYswers for this spraying. Thoroughness is essential and it is sometimesnecessary for two or three to work on the same animal at the same timebrushing the spray material into the hair before it runs off.Some dairymen do not take measures against the lice on their cowsbecause they feel that spraying is the only method that will reachthese insects, and that the danger from the animals catching cold aftersuch a treatment more than offsets the injury of the lice. There is butlittle danger of cows-catching cold if they I\re in good health, particularlyif the day is not too cold, and if· the cows are covered well afterthe treatment.Our trials indicate that the average spraying material such as creolin,kerosene emulsion, or an arsenical ·wash, together with the labor factor,costs about ten cents per animal for each treatment ..There are disadvantages in this treatment, including the labor andtime factors: the amount of equipment necessary; and the fact that anumber of these sprays are not effective enough to kill the lice, or theyare too strong for the cow's skin, or their effectiveness does not last forany considc.rable time after the application. The most important ofthese control measures are listed and their advantages and disadvantagesmentioned.Creolin.-Of the materials used for spraying cows a solution of creolinis one of the most common. The strength should not be less than fourper cent to kill the lice, and not more than five per cent, as this will causesome scurfing. A four and one-half per cent solution will give the bestresults for creolin.Kerosene Em'lLlsion.-This emulsion has been used with satisfactoryresults by some dairymen. It is made by shaving one-half pound oflaundry soap in one gallon of soft water that has previously beenbrought to the boiling point. When the soap is all dissolved, removefrom the fire and add two gallons of kerosene oil. Stir this thoroughly,and if you have a bucket pump, place this in the mixture, turning thenozzle back into the bucket so the material is constantly passing throughthe pump. This will form a cream emulsion. If any free oil separatesfrom this mixture continue pumping until the oil ceases to show. Thenmix this amount ,vith twenty gallons of water and apply either with aspray pump or with a brush! preferably the former. In using keroseneemulsion we have observed that the lice were not killed with a mixturethat was so weak that it would not do injury to the skin of theanimals to which it was applied. For this reason the linseed oil gives muchbetter results.Arsenical Washes.-Arsenical washes are also used for the control ofcattle lice, but owing to the great care necessary in using them, both fromthe danger of poisoning and the possible injury that may occur by using

LICE WHICH AFFECT DOMESTIC ANIMALS 337them too strong or in applying them too vigorously, it has been felt thatless dangerous applications can be made with even better results.One thing can be said for them, however, and that is regarding theireffectiveness. That the lice aI:e killed by "the application of arsenicalwashes there is no doubt.One formula recommended is as follows:1A lb. caustic soda (85% pure).1jz lb. white arsenic (99% pure) fine powder ..1jz lb. sal soda.112 pt. pine tar.30 gallons water.In preparing and using any arsenical dip or wash one should rememberthat arsenic is a poison and take precaution to avoid injury.If animals arc allowed to drain where they may drink the solution, orfeed when the solution is dripping off of them, they arc liable to b;!poisoned.Care' should be taken too ~hat the hands should not be exposed anymore than necessary.The arsenical washes may be necessary to use for dips for lar~herds and under range conditions, where tick infestations also occur, buttheir use is questioned for smaller tick-free herds.For fuller information regarding arsenical dips and washes for cattleon range see Farmers' Bulletins Nos. 608 and 909.Nicotin washes.-These arc questionable owing to the fact that extremecare must be taken in order to keep the wash away from the cowsso that they will not get some of it internally. Cows are particularlysusceptible to poisoning from tobacco decoctions.MISCELLANEOUS REMEDIESGreases.-Mercurial ointment is one of the most effective of licekillers though it is very liable to cause burns even when it is diluted considerably.This ointment dilij.ted with twelve parts of vaseline was usedon some cows and burns resulted from the application.Kerosene Oil O/TId Lard have been used considerably for cattle licebut the danger of injury to the skin with the use of kerosene oil, unlessvery thoroughly mixed with some diluent, is always ,present.With the majority of the greases, the inability to spread properlymakes their application expensive because of the quantities of materialrequired to cover the regions infested by lice.Powders.-Dusting powders are usually sulphur, naphthalene, and

338 SANITARY ENTOMOLOGYpyrethrum. These are not recommended.control for such methods to be effective.Cattle lice are too difficult toTIME FOR THE APPLICATION OF CONTROL MEASURESThough cows are infested with the largest numbers of cattle liceduring the months of January and February, yet the measures for theircontrol should be applied long before that time; in fact, they should beused within a week after they have been brought into the barn for thefall and winter. A second ~pplication should follow twelve or thirteendays afterward. The purpose of these two applications is to rid thecows of the lice that are on them before they become numerous andspread to more susceptible animals. The lice may not be seen at thistime but the dairymen should not reason that the lice arc not present.This gives a proper length of time for all of the three species of cattle liceto hatch from eggs, but not long enough for them to lay eggs again and bein a resistant stage where the treatment will not reach them.Treatment should be repeated at intervals of a month from thesecond treatment. In case animals show any great number of lice,treatment should be given and repeated in twelve or thirteen days.Treatment with linseed oil can be made at the usual time when thecows are being groomed and cleaned.From five to six treatments during the fall' and winter should controlthe lice in the average herd.SKIN INJURmSOne of the most troublesome phases of the study of the control ofcattle lice was to determine the strength of insecticides that would killthe lice but would not injure the skin, thus causing the hair to come outbadly or making distinct burns.The skin of the cow is very susceptible to injury when comparedwith the skin of other animals. It is known that cows have been killed bythe application of certain insecticides recommended for the control ofcattle lice. This indicates that caution must be taken in the use of controlmeasures that have not been sufficiently tested. Caustic washes cannotbe used without danger of their doing considerable injury, unless theyare very accurately measured and applied very carefully to the skin ofthe animal.It is k'TIown that e:cposure to direct sunlight and active exercise afterapplication contributes to cause skin injury with 'TIearly every one of thecontrol measures for cattle lice.It is doubtful if there is any appliCD.tion that will kill lice on cows

LICE WHICH AFFECT DO}IESTIC ANDIALSthat will not cause a slight degree of scurfiness on the cows at times. Ifone will look at 0. condition of scurfiness carefully he will find that looseportions of the epidermis have lifted, and fragments are thick in thehairs, yet there is no irritation or reddening of the tissues and hence noreal injury. Scurfiness is a condition that may occur without any applicationto the skin and it should not deter the dairyman from using a controlmeasure that does not cause a real injury. Scurfiness passes in ashort time and leaves the skin clean underneath.,SS9Part~.Lice Affecting Chickens, Hogs, Goats, Sheep, Horses, andOther AnimalsF. C. BishoppThe habits and control of lice on cattle have been discussed in anotherlecture. Owing to the marked economic importance of lice on otheranimals, the diversity of their habits and the great difference in themethods of handling the hosts, an additional lecture is devoted to thesubject.LICE INFESTING DOMESTIC FOWLSFowls are infested with biting lice (order Mallophaga) only. Thereare a large number of species living on the various domestic fowls. Thechicken is infested with about ten species (seven of these commonly), theturkey with four, the pigeon with eight (three commonly), the duck five,the goose seven, the guinea fowl six, and the peafowl four.Of course in listing the number of lice on the different hosts enumeratedthere is some duplication. We find that under certain conditionschicken lice are to be found on several of the other domestic fowls andthis is true to some extent with forms which are found on other species.There are a number of factors which influence the transference of anyof these parasites from their normal hosts. Ordinarily most of themare quite closely restricted to one species of fowl and the habits of thelouse and the host are so interrelated that it is doubtful if many ofthem will continue to hreed successfully on strange hosts, although ofcourse they may be harbored for a time. When several species of fowlsare closely associated, especially on roosts, there is tl considerable chancefor the interchange of the different species of .parasites and we can notalways say that when a given species is found on an unusual host it.will succeed in establishing itself and breeding thereon. Furthermore wehave observed that the young of a species seems to be attacked by asmaller number of species than the adult fowls. In fact some of thespecies of lice most commonly found on adults do not seem capable of

340 SANITARY ENTOMOLOGYbreeding on the young. This has been observed in the shaft louse ofchickens. On the other hand some of the species, for instance the headlouse of chickens, appear to thrive better on the young than on theadults.Life Hiatoriea.-Very few of the so-called bird lice have been studiedfully. Our lack of knowledge of the life histories and habits of theseparasites is partly due to the difficulty of successfully rearing themunder control. There is a marked difference in the habits of the differentspecies of lice occurring on the same host. This may be explained bythe fact that the parasite has become modified in structure and functionof body parts to live under certain restricted conditions. For instance,on the chicken we find the head louse breeding largely on the head ofchickens and seldom occurring on other parts. This species hangs tothe down on young chickens and is usually found closely adhering to thebase of the feathers on the heads of grown fowls. The body louse on theother hand has adapted itself to living on the skin of the host andis not commonly found on the feathers. This species is very active anddepends for protection on its agility on the comparatively bare parts ofthe skin. The shaft louse usually rests along the shaft of the feathersbut can run freely on the skin, going from one feather to another. Thewing louse is ordinarily found between the barbules on the larger wingand tail feathers, and the fluff louse, a very 'awkward and sluggish species,clings to the fluffy parts of the feathel'S, principally on the thighs andsides.The eggs of the different lice arc laid in the regions where the liceare usually found. The head lice eggs are attached singly to thefeathers on the head and neck. The body lice attach their eggs to thebase of feathers and are usually found in masses, especially on the baseof the feathers below the vent where sometimes the masses become exceedinglylarge-nearly half an inch in diameter.The life histories of a few of the common species have been workedout by Mr. H. P. Wood and the writer. The head louse will serve as anexample. The eggs of this species hatch in from four to five days intominute pale rather active larvae and these after molting their skins severaltime~ become adults in from 17 to 20 days, and egg laying begins afew days later. As far as we have observed, the length of the developmentalperiod of the different species is quite similar.It is difficult to get any ac'curate record of the longevity of lice on thehost but we believe they live for several weeks if not months. When removedfrom the host the longevity is comparatively short and this ofcourse assists in the application of control measures. The body liceusually die within a few hours, while the head and wing lice are morepersistent. Professor Theobald records "keeping the shaft louse alive for

LICE WHICH AFFECT DOMESTIC ANIMALS 341nine months apart from the host. This seems f::xceptional as we havenever observed longevity to exceed three weeks. While specimens of licemay drop off with feathers, we find in the method of treatment which isdescribed below that no concern need be felt for the reinfestation of aflock from this source. It also appears that wild birds play very littlepart in the carrying of these pests. Of course it is possible that sparrowsor other birds intimately associated with domestic fowls might accidentallycarry a few specimens from one yard to another.Injury and Lossss.-It is difficult to weigh the loss produced by lice.It is generally believed by poultrymen that where they are at all abundantthey materially affect the development and egg production in fowls. Certainit is that young chicks are fI'equently killed by the attack of the headlouse and this also applies to young turkeys and ducks. Just how theinjury is produced is still a matter of debate. Since the lice do not suckblood it is generally believed that the injurious effects are produced bythe irritation caused by the gnawing and running about of the parasites.We have seen repeated instances of the rapid increase in weight of grownfowls after they have been freed of lice and experiments now under wayseem to indicate clearly that egg production -is markedly affected by evenmoderate infestations of lice. In addition to these adverse effects it hasalso been found that lice, especially when present in numbers, mutilatethe plumage of the fowls. This is of special importance in showbirds.While no disease has been demonstrated to be carried by poultrylice, it is not improbable that they may playa part in the transmissionof some maladies of fowls. They have been suspected of being concernedin the spread of the so-called chicken pox, or sore head, and favus.Methods' of Control.-While there are a number of insecticides whichare fairly satisfactory in reducing the number of lice on poultry, experimentscllrried out by Mr. H. P. Wood and the writer at Dallas, Texas,indicate that none of them are as satisfactory as sodium fluoride. Thecommercial grade ranging from 90 to 97 per cent N aF is used. This isa white powder readily soluble in water and with comparatively low toxiceffect on the higher animals. It has been found that one light applicationis sufficient to completely rid a fowl of all species of lice. The actionof the material is rather slow, especially when it is used in the dustform. Usually it takes ahQut four days for all lice to disappearfrom the feathers. Since the lice chew their food and since other parasiteswhich suck the blood from the host arc not destroyed to a largeextent, it is believed that the material acts largely as a stomach poison.Hatching of the eggs does not appear to be prevented but the young licesuccumb very soon after emerging from their shells.Sodium fluoride may be applied either as a powder or in solution.

342 SANITARY ENTOMOLOGYWhen comparatively few fowls are to be treated or if chicks or unhealthyindividuals are concerned, it is advisable to follow what we tennthe pinch method of application. For grown fowls about twelve pinchesof the powder are placed on different regions of the bird at the base ofthe feathers and distributed as follows: One pinch on the head, one onthe neck, one on the throat, two on the back, one on the breast, onebelow the vent, one on the tail, one on either thigh, and one scattered allthe under side of each wing when spread. With young chickens usuallyone pinch is sufficient, this being distributed on the head, neck, alongthe throat and on the back. A few people have reported loss of youngchicks through the application of the powder to them at night. We aretherefore recommending that the treatment be done during the early partof the day while the chicks are active. This gives opportunity for excessdust to be shaken oW before roosting time. Another precaution is toapply the treatment where the dust will not have opportunity to get intothe food or water. As the dust is very irritating to the nose and throat,At is advisable to wear a dust guard or a moistened cloth tied over the nose,and mouth when applying it.By the dry method one pound is sufficient to treat 100 grown fowlsand they can be gone over at the rate of about one to every two or threeminutes, with one man working.In following the dipping method, the sodium fluoride is dissolvedin water at the rate of one ounce or three level tablespoons to each gallon.A tub is well filled with this solution which should be tepid (70 0 to 80 0 F.)but not warm, and the fowl, held by grasping the base of the wingsover the back, is lowered quickly into the water. With the other handthe feathers are ruffled so as to allow the liquid to penetrate to the skin.The head is then ducked, lightly rubbed to induce penetration and thefowl released. By this method the danger of not· treating all portionsof a fowl is practically eliminated, the time of treatment is reduced toabout three-fourths minute per fowl and the amount of material alsomarkedly reduced. The irritating eWect of the dust on the operator isalso avoided.It is of course necessary to cnose a warm day so that the featherswill ciry quickly. It should be stated, however, that the plumage is notthoroughly wet as would be the case with most dips. The featheI'6 becomecompletely dry in a couple of hours. There is absolutely no stainingor injury to the feathers, no tainting of flesh and no skin irritationproduced either by the dipping or dusting methods. As the material iscorrosive it is inadvisable fo)' one doing the dipping to subject lesions onthe hands to the liquid and the utensils used should be emptied immediatelyafter completing the work.Since one application will completely destroy all forms of lice on II.

LICE WHICH AFFECT DOMESTIC ANIMALS 343{owl, there is absolutely no reason why lice should not be completely eradicatedfrom a flock. Of course to accomplish this every bird must betreated at about the same time. All that is necessary to maintain alouse-free condition is not to allow infested fowls to come in contact withthe clean flock.It has been found that a thorough application of flowers of sulphurwill destroy all lice, but since a much larger amount is necessary theexpense of treatment is greater than when sodium fluoride is used andthere are also said to be some deleterious effects from the free use ofsulphur although this has not been observed by the writer. Mercurialointment or blue ointment is extensively used against lice. If applied asgenerally recommended it will not accomplish the complete destruction ofthe lice present and repeated applications are necessary to keep themin check, which would be expensiv(!. There is also some danger of producingmercurial poisoning by the free use of this material. The socalled"Cornell Powder," consisting of a mixture of carbolic acid, gasolineand plaster of Paris, is quite effective, but as the eggs of the lice arenot destroyed two or more applications are necessary to accomplish whatcan be done with one application of sodium fluoride and the trouble ofmixing the material is considerable.For the treatment of pigeons it is advisable to dip them individuallyin sodium fluoride solution made as above described but with the additionof one ounce of laundry soap to each gallon of water in order to increasethe ~etting power. The squabs must also be treated.Turkeys may be treated precisely as arc chickens, either by the pinchor dipping methods. The large birds should receive abo,ut eighteenpinches of powder and of course a large tub is necessary for properdipping.It is recommended for exterminating lice from a flock, that the treatmentbe given if convenient in the late summer aft~r the young chickenshave matured and the flock ,has been culled and reduced to a minimum.Of course if lice are present there is no objection to treating at any timeduring the year and the quicker the treatment can be given the better.As poultrymen generally recommend hatching of chicks early in thespring this tends to reduce the loss from lice and other poultry parasites,but of course this should not be depended upon when so simple a methodas the sodium fluoride treatment is available.LICE INFESTING RABBITS, CATS AND DOGSDomestic rabbits are not infrequently infested with an elongate, bluesucking louse. They seem occasionally to become sufficiently numerous,especially on young rabbits, to retard growth and reduce vitality. The

344 SANITARY ENTOMOLOGYwriter knows of no experiments which have been carried out with thecontrol of this species. No doubt care would have to be exercised ittchoosing insecticides to apply to rabbits.Cat lice are comparatively uncommon. A few cases of infestations ofcats with sucking lice have been observed by agents of the Bureau, butthe species concerned has not been determined. The biting louse,Trichodectes subrostratus Nitzsch, seems more common and occasionallycats which have not received proper care are heavily infested.Complete freedom from the biting lice should be secured by a lightbut general application of sodium fluoride 'to the host. Dips containingphenols should be used, guardedly, as cats arc sensitive to theiraction.Dogs are occasionally observed heavily infested with the suckinglouse, Haematopinus piU/erus Burmeister. Tne biting louse, Trichodecteslatus Nitzsch, is far more common than the sucking form and it is especiallyannoying to puppies. This parasite has been found to yield readilyto a single application of sodium fluoride in the dust form. When suckinglice are present two dippings in kerosene emulsion or in one of the standardcoal tar dips should be given at ten-day intervals.THE HOG LOUSEThroughout the entire United States and in fact throughout thegreater portion of the world hogs are infested ~ith a large and repulsiveappearing louse with sucking mouth-parts. The species is known scientificallyas Haematopinus suis Linnaeus. This parasite assumes itsgreatest importance in the wnrmer portions of the country and is especiallyinjurious to hogs which are poorly fed or kept in insanitarycrowded pens.Although the species may live for a few days (about five) apart fromthe host we need consider only the treatment of the host in controllingit. Of course it is well to remove hogs from the pens where they havebeen kept for five or six days after each treatment. The eggs are laidon the hair, especially behind the shoulders, in the flanks along the belly,and behind the ears. They hatch in about thirteen to twenty days, accordingto Watts, the lice mature in about ten to twelve days, and thefirst eggs are deposited a day or two later.Little need be said here regarding the injurious effect of the louse.It is gfmerally accepted as an important retarding factor in hog raising.Where it is allowed to multiply uncontrolled the skin becomes inflamed,scabby and thickened and the animals present an unthrifty appearance,growth is retarded and fattening is practically impossible. It has beenheld by a number of authors that the species may playa part in the·

LICE WHICH AFFECT DOMESTIC ANIMALS 345transmission of different diseases of hogs including cholera, althoughthey are now generally believed to be of little importance in this connection.Control Measures.-For the breeder of hogs in considerable numbersthere is undoubtedly no better method for controlling hog lice thanthrough the use of the dipping vat. A number of insecticides have beenfound effective against them, including crude petroleum (two inches floatingon water in the vat), kerosene emulsion, and many of the standardcoal tar dips. It is important to get the hogs completely under the dip.In order to insure complete destruction of the species it is necessary torepeat the dipping a second time after a lapse of ten days.For the small raisers the expense of insbllling a vat is unnecessary astbe application of any effective material with a spray pump or by handwith a brush is satisfactory. The concrete hog wallow containing wateron which is floated a film of crude .petroleum is fairly satisfactory, althoughif these wallows are not properly kcpt they may be objectionablefrom a sanitary point of view. Others use various types of hog oilers bywhich the oil is applied to the animals as they rub against the appliance.Still others simply sprinkle the oil on the backs of the hogs from a wateringpot. Other insecticides are sometimes applied in the same way.Many oils, including kerosene oil, seem to be quite effective.The application of insecticides by the use of wallows, hog oilers, sprinklingcans and similar mcyhods can not be relied upon to destroy all licebut will give a moderate degree of control if repeatedly attended to.'1'0 avoid burning the hogs, or other injurious effects, they shouldbe treated towards evening or on cloudy days and should not be overheatedeither before or after applications. .It has been observed that hogs fed on garbage are comparativelyor entirely free of lice. This condition is undoubtedly the result of continualapplication of grease by the wallowing of the hogs in the garbage.LICE ATTACKING SHEEPThe lice infesting sheep seldom become so abundant as to be con~ideredof much importance. The so-called foot louse, Linognathu8 pedaliaOsborn, a suctorial species, was found by Osborn at Ames, Iowa, on sheepimported from Canadtl. It was present only on a comparatively few ofthe sheep. Evidently the species is not at all common in the UnitedStates. It occurs, so far as known, only on the legs, especially in theregion of the dew claws and not on the heavy wool-parts of the host. Thisimmediately suggests the use of a shallow wade vat by which a gooddelousing agent might be applied without coming in contact with thewool on the body of the host.

346 SANITARY ENTOMOLOGYThe biting louse, Trichodecte8 sphaerocephalua Nitzsch, of sheep ismuch more frequently met with than the sucking species and has beentaken in various parts of the United StEl:tes. It never seems to becomeabundant on the heavily wooled breeds.It has been reported that the thin wooled sheep raised by the Indiantribes in northern New Mexico and Arizona are often heavily infested withlice. Undou_btedly there is a close correlation between the character andamount of wool and the reproduction of lice on the host.Sodium fluoride may De successfully employed against the biting lousebut on account of the close covering of ""001 the application must bethorough. The same methoQ of application as suggested for the bitinglice of goats should be used. Of course where sheep are dipped for thesheep tick (Melophagus ovinu8). or scabies, the lice will be kept undercontrol. Nicotine sulphate or lime-sulphur arsenic dip seem very effectiveagainst both the lice and the sheep tick. The fonner should contain about0.07 per cent of nicotine sulpliate. The latter consists of a lime-sulphurdip of the formula: 8 pounds un slacked lim~, ~4 pounds flowers of sulphur,and water to make 100 gallons. Take 150 gallons of this concentrateand S50 gallons of warm water and add a concentrated arsenical solutioncontaining 1~ gallons water, 1~ pounds sal soda and 4 pounds whitearsenic.BITING AND SUCKING LICE OF GOATSGoats of all breeds are subject to the attack of lice but this ten !ncyseems especially marked among the angoras. The biting lice consistingof two species, Trichodecte8 climax Nitzsch and T. herm8i Kellogg andNakayama, are the principal species. The former of these is the predominantfonn.Practically every flock of goats in the Southwest is infested andsome years the injury is very marked. The annoyance retards the growthof the kids and injures the condition of flesh of the goats, but the mostobvious loss is brought about in the reduction of the mohair clip. Theirritation produced by the lice induces much rubbing, which of coursepulls out and mats the mohair and there also appears to be considerableloss through the actual cutting of the hair by the lice themselves. Certainlarge goat raisers in Texas estimate 0. loss of twenty per cent in theclip some years and often individual goats are so denuded that shearingis not profitable. The quality of the mohair is also said to be materiallyaffected when the lice are abundant.The lice are present on all parts of the host, especially on theheavily haired portions and the whitish eggs are attached to the hairsnext to the skin.The sucking louse, Linognathus 8tenopsi8 Burmeister, frequently be-

.LICE WHICH AFFECT DOMESTIC ANLUALS 347comes a pest of importance in goat flocks. The lice are especially injuriousto the kids, and their attack together with that of the biting liceis thought to cause material reduction in the number of kids raised tomaturity. On the kids the lice are present on all parts of the body but onthe mature goats they are usually more numerous where the hair is notvery thick.Control.-In proceeding against goat lice it is important to determinewhether biting or sucking lice are giving trouble. In many flocks theformer are practically the only kind present and in such cases it is moreeconomical to treat the flock with sodium fluoride in the dust form thanto dip it. This is especially true when dipping vats are not at hand.We have found that a high degree of effectiveness (90 to 100 per centdestruction) may be obtained by applying the sodium fluoride with adust gun to the flock in a pen or as the goats are driven through achute. It does not seem to be necessary to drive the dust into the mohairespecially and only a small amount-about one-third of all ounce perhead-is necessary.In the experiments carried out by Mr. D. C. Parman at Uvalde,Texas, nicotine sulphate used at a strength of 0.07 per cent nicotine wasfound to give complete control of sucking lice but was less effectiveagainst the biting species. On the othcr hand the standard arsenicaldip (white arsenic 8 pounds, sal soda ~4 pounds, pine tar one gallon, andwater 500 gallons) gave complete destruction of both forms of lice withone dipping. As tIle arsenical dip is probably the cheapest material obtainableit should be recommended above all others where both biting andsucking lice occur in a flock. G"oats are usually bunched and sheared inthe spring and fall, and following shearing is a good time to treat theentire flock for lice.LICE OF THE HORSEHorses are quite commonly infested with one biting and one suckingspecies, HO!matopinus asini Linnreus and Trichodectes parumpilo8U8Piaget. It is the writer's impression that the biting louse predominatesthroughout this country, however, it is not an infrequent occurrence tofind herds heavily infested with the sucking louse. It is probable that acareful study of the lice of horses will show that in certain regions onepredominates, while in others the other form may be more abundant.While it is probable that both torms can breed on asses and mules it iscertainly true that these animals are much less subject to louse attacksthan the horse.Horses which are worked more or less regularly and properly groomedare usually troubled very little from lice, but colts alld animals on the

.848 SANITARY ENTOMOLOGYrange are frequently so heavily infested as to produ~e injurious effects.One's attention is usually attracted to the lice on account of the rubbingand biting of the animals which may in some cases become almost amania. The hair is frequently rubbed off in spots so as to expose theskin in the regions where the lice are most abundant, notably around thebase of the tail and on the neck.Control Measures.-On farms where comparatively few horses arekept the lice can most cQIlveniently be brought under control by carefulgrooming of the animals, and an occasional light application at groomingtime of lard with a small amount of kerosene added or raw linseed oil.This treatment would undoubtedly answer in the case of army horses, althoughit would probably be advisable in such instances as well as onranges where horses are raised extensively, to install dipping vats anddip all animals twice at an interval of two weeks. The standard arsenicalsolution is the best for this purpose. This treatment is also effectiveagainst cattle lice.Where biting lice alone are concerned sodium fluoride can be appliedvery conveniently and will give complete control with one applicationat a very low cost. A powder gun may be employed and each animal'should be generally dusted using about one ounce. This is especiallyadapted to the treatment of animals in the winter when the greasing orwetting of the host is undesirable. It is the winter season, too, whenthe lice are most abundant and injurious.IMPORTANT 1I111LIOGRAPHICAL REFERENCESBishopp, F. C., and Wood, H. P., 1917.-Mites and lice on poultry.U. S. Dept. Agr., Farmers' Bull. 801, pp. 1-26, May.Bishopp, F. C., and Wood, H. P., 1917.-Preliminary experiments withsodium fluoride and other insecticides against biting and sucking lice.Psyche, pp. 187-189, December.Hall, Maurice C., 1917.-Notes in regard to horse lice, Trichodectesand Haematopinus. Journ. Am. Vet. Med. Assoc., vol. 51, n. s., vol. 4,pp. 494-504, July.Herrick, G. W., 1915.-Some external parasites of poultry. CornellExp. Sta., Bulletin 359, pp. 229-268, April.Imes, Marion, 1918.-Cattle lice and how to destroy them. U. S. Dept.Agr., Farmers' Bull., pp. 1-27, February.Lamson, G. H., Jr., 1916.-Some lice and mites of the hen. Conn. Agr.Exp. Sta., Storrs, Conn., Bull. 86, pp. 171-196, March.Lamson, G. H., Jr., 1918.-Cattle lice and their control. Conn. Agr.Exp. Stn., Storrs, Conn., Bull. 97, pp. 1-17, November.

LICE WHICH AFFECT DOM£STIC ANIMALS 349Osborn, Herbert, 1896.-Insects affecting domestic animals. U. S. Dept.Agr., Div. Ent., Bull. 5, pp. 1-302.Stevenson, E. C., 1905.-The external parasites of hogs. U. S. Dept.Agr., Bur. Anim. Ind., Bull. 69, pp. 1-44.Watts, H. R., 1918.-The hog louse. Tenn. Agr. Exp. Sta., Bull. 120,pp. 1-1l)~

CHAPTER XXIVDiseases Carried by Fleas 1, W. Dwight PierceFleas pass their immature stages in filth outdoors and indoors. Thelarvl!! breed in dirt and are usually to be found where animals are common,but they may breed in the dirt of kennels and stables, in the opencountry, in carpets, and closets of houses and especially in cellars. Theyare always to be found where rats or mice are common.Because of the fact that the larva imbibes filth and the adult sucksblood, we should seek other possibilities of disease transmission whichhave not hitherto been investigated. Past investigations with fleashave dealt principally with the possibility of conveying disease by thebite of the adult flea. The work which has been done on flies and whichwas quoted in a preceding lecture showed that larvIE could take up bacteriaand that these would persist into the adult stage. It is thereforeessential in the future investigations of disease transmission by fleas thataccount be taken of the possibility of the flea larvre taking up the organismfrom the filth in which they breed and retaining these organismsto be transmitted by the adult. That they may do this is demonstratedin the case of the tape worms mentioned below.Fleas do carry disease, that we know. But probably they can carrydiseases which they have never been credited with. There lies our fieldof investigation.The arrangement of organisms transmitted by fleas follows thatadopted for previous lectures.PLANT ORGANISMS TRANSMITTED BY FLEASThallophyta: Fwngi: Schizomycetes: Bacteriacet1!Bacillus pestis I{itasato, the cause of BUBONIC PLAGUE of manand rodents, is carried by fleas. Nine species of rodents, mainly rats and1 This lecture was presented on October SS, 1918. It is considerably modified forthe present edition.350

DISEASES CARRIED BY FLEAS 351mice, are proven hosts of plague. The following :fleas have been provento be carriers of the organism: Xenopaylla cheopia Rothschild, Ceratophyllu8faaciatus (Bose) Curtis, C. acutus Baker, C. ailantiewi Wagner,Pule:c irritan8 Linnaeus, Ctenocepllalus canis (Curtis) Baker, Leptopayllamusculi Dug~s and PygiopayUa altalae Rothschild.The first successful record of transmission of plague by fleas wasmade Jby Simond in 1898, and corroboration was first obtained by Verjbitskiin 1903 and Liston in 1904.Many other workers have since then proven the role of the :flea incarrying this disease. A synopsis of the evidence is presented by Hermsin his textbook. The flea takes up the organism with the blood of thehost. The stomach of the rat flea, Xenopaylla cheopi8, is capable ofreceiving as many as 5000 germs while imbibing the blood from a plaguerat. Both males and females may carry the infection and they mayremain infective during an epidemic for ~o days. The Indian PlagueCommission found the bacilli only in the stomach and rectum of thefleas and never in the salivary glands or body cavity and rarely in theesophagus. They conclude that the normal course of the bacilli is to bevoided in the feces and to be inoculated by scratching in of the feces.Bacot and Martin, however, have come to the conclusion that plague canbe transmitted during the act of biting when a temporary blocking orobstruction of the proventriculus takes place, causing bacillus-laden bloodto be forced back or regurgitated into the wound, thus producing infcc.:tion.Bacteriwm tularenae McCoy and Chapin, cause of a fatal RODENTPLAGUE which affects the California ground squirrel, Citellua beecheyi,may also be transmitted by fleas. McCoy and Chapin placed fleas(Ceratophyllus acutus Baker and C. faaciatu8 Bosc) with an inoculatedguinea pig and allowed them to remain there until the animal died. Theywere then collected, and crushed and inoculated into healthy guinea pigs.The four animals inoculated with crushed C. fa8ciatu8 immediately afterthe fleas were removed from the dead guinea pig, died of the disease; twoof four inoculated after ~4 hours, died; and one out of four inoculatedafter 48 hours, died. Two out of four animals inoculated with crushedC. acutus immediately after removal from the dead guinea pigs, died, butnone died that were inoculated on subsequent days, although some developedan apparently chronic fonn of the disease. They also succeeded inobtaining one actual case of transmission. About 100 fleas collected froman animal dead of the disease were placed in a clean ca~ with a healthyground squirrel. It died 15 days later and presented the usual lesionsof the plague-like disease, the bubo being in the neck.

35~ SANI'rARY ENTOMOLOGYANIMAL ORGANISMS TRANSMITTED BY FLEASProtozoaMastigophora: Binucleata: Trypanosomitla:As stated elsewhere the classification here used was recently proposedby Chalmers. It is especially interesting that all flea-borne diseasesbelong to the genus Trypanozoon Luhe (Lewisonella Chalmers) 2 inwhich the final stage of development in the definitive host (the insect)occurs in the hind gut, and infection is contaminative.Trypanozoon blanchardi (Brumpt), cause of a trypanosomiasis, supposedlynonpathogenic, in rodents of the genera Myoxus and Microtushas been found by Brumpt (1913) to develop in the flea, Ceratophyllusla'lJcrani I.-averan and Pettit. The life cycle is identical with that of T.lewisi and T. nabiasi and is effected entirely in the large intestine of theflea. Metacyclic trypanosomes occur in the rectal ampulla and are foundin the dejections. It is not found in the salivary glands.Trypanozoon duttoni (Thiroux), cause of a trypanosomiasis, supposedlynonpathogenic, in mice of the genus Mus, has been found byBrumpt (1913) to develop in the fica, Ceratophyllus hirundinis Curtis.The evolution of this species occurs in the large intestine of the flea andis comparable to that of 1'. lewisi, T. nabiasi, and T. blanchardi. It isnot found in the salivary glands.Trypanozoon lewis;' (Kent), cause of a trypanosomiasis, rarely pathogenic,in rodents of the genera Epimys, Acanthomys, Mus, Myoxus, andl\feriones, etc., passes its cycle of sporogony in fleas (fig. 62). The lifecycle has been investigated in Ceratophyllus fasciatus (Bose) Curtis,Ctenocephalus canis (Curtis) Baker, and Ctenopsyllus musculi (Duges)Wagner, and it has been shown that Pulex irritans Linnaeus, andXenopsylla cheopis Rothschild may serve as true hosts. In additionCeratophyllus lucifer Rothschild, C. hirundinis Curtis, Ctenophthalmusagyrtes (Heller) Baker, and PUlex brasiliensis Baker. are recorded ascarriers. Fantham, Stephens and Theobald summarize the life cyclein the flea. When infected blood is taken up by the flea, the parasitespass with the ingested blood direct to the mid-gut of the flea. In thestomach they penetrate the cells of the lining epithelium and multiplyby division inside the epithelial cells. They first grow to a large size, thenform large spherical bodies within which nuclear multiplication occurs.Anyone of these large spherical bodies contains at lirst a number of nuclei,kinetonuclei, and developing flagella, the original flagellum still remainingattached for a time. The cytoplasm then divides into daughter"This synonymy is according to Mesnil. Bun'. Inst. Past. vol. 17, p. 190.

DISEASES CARRIED BY FLEAS 353trypanosomes which are contained within an envelope, formed by the periblastof the parent parasite. Inside the periblast envelopes are a numberof daughter trypanosomes wriggling very actively; the envelope finallybursts and releases them, usually about eight, in the host cell. Thedaughter forms escaping from the host cell into the stomach of the fleaare fully formed, long trypanosomes. They then pass into the rectum,where they assume a crithidial phase, and become pear-shaped. Thekinetonucleus has traveled anteriorly past the nucleus toward the flagellum.The crithidial forms attach themselves to the wall of the rectumand multiply by binary fission. In this form the parasite probablyHosr I (RODENT).HosT I MIOr.RATS (EI'IMYS.ACANTHOMYS.Mus.Myoxus. MBRIONZ5).Hosr II fLEAS (CIRATOPHYLLUS.Cn:NOCEPHIILUS.CTBNOPSyLL .... RrLBlC,XBNOPSYLL...).LIFE CYCLE or TRYPANOSOMA LEWISI.,,'Ill, 61. (Pierce,)exists throughout the life of the insect. From the crithidial forms smallinfective trypanosomes develop. These are small, broad, and stumpy,with the kinetonucleus behind the nucleus, and the flagellum longer.B.rumpt (1913) declares that transmission occurs exclusively by rodentslicking up the feces of infected fleas. These feces contain little metacyclictrypanosomes which are able to traverse he~lthy mucous membranes.The life cycle as described has been figured' graphically in 'the samescheme as used in previous lectures.•Trypanozoon nabiasi (Railliet), a rabbit trypanosome, presumablynonpathogenic, attacks the genus Lepus and was found by Brumpt(1913) to be transmitted by the rabbit fleas Ctenocephalus- Zeporis(Leach) Baker and Spilopsyllus lcporis (Leach) Baker. The life cycle

854 SANITARY ENTOMOLOGYis identical with that of T. lewisi and has metacyclical forms in the rectum.It is never found in the salivary glands.Trypano%oon rabinowitschi (Brumpt), a trypanosomiasis affectingthe genus Cricetus, is carriE!d by .the fleas Ctenocepholus canis (Curtis)Baker, Ctenophthalmu,s aSBimilis (To.schenburg) Baker and Ceratophyllusfasciatu,s (Bosc) Curtis. According to Brumpt (1918) Noller hasproven the development of this organism in the rectum of fleas. Thelittle metacyclic trypanosomes are found in the rectal ampulla.M astigophor(J: Binucleata: LeptomonidaeCrithidia ctenophthalmi Patton and Strickland is parasitic inCtenophthalmus agyrtes (Heller) Baker.Crithidia hystrichopsyllae Mackinnon is parasitic in Hystrichop,yllatalpae (Curtis) Rothschild.Crithidia pulicis Porter (1911) not Wenyon (1908) is parasitic inPulex irritans Linnaeus. Miss Porter described its life cycle in theflea. The preflagellate stage is probably taken up by feeding on dejectaof infected floo.s. The preflagellates have a somewhat frail appearance.Division rosettes are frequent. The flagellates have relatively short {reeflagellum and a large undulating membrane. These are followed by apostflagellate stage in which mUltiplication is by longitudinal division.Infection is contaminative, the postflagellatcs in the feces being thesource of infection. There is no evidence of hereditary transmission.Crithidia pulicis Wenyon is parasitic in Xenopsylla cleopatrae.Leishmania infantum Nicolle the cause of INFANTILE KALAAZAR of the Mediterranean region and Asia, is, according to experimentsof Basile, probably naturally transmitted by the fleas Ctenocephaluscanis and Pulex irritans. He apparently obtained the disease by takingfleas from bed clothes of infected people, and also from infected dogs, andfeeding them on healthy dogs.Castellani and Chalmers inclined towards the Basile theory but Wenyonis not convinced. Basile found Leishmania-like forms in the mid-gutof the flea. He also found other forms, some with flagella and some without,and concludes that there is a cycle of development with preflagellate,flagellate and postflagellate forms.Leptomonas sp. Balfour (1906) is described from Xenopsylla cleopatrae.Leptomonas ctenocephali (Fantham) is parasitic in the gut of theCtenocephalus canis. Fantham has described preflagellate and flagellateforms. In experiments of Laveran and Franchini (1918) dogs, inoculatedfrom mice infected with this organism by feeding on feces of theflea, died. The disease caused by this organism cannot be distinguished

DISEASES CARRIED BY FLEAS 855from canine kala azar, which suggests to some writers the insect originof that disease. Fantham, however, does not consider this organismrelated to Leishmania.Leptomonas ctenophthalmi (Mackinnon) is described as a parasiteof Ctenophthalmus agyrtes.Leptomonas ctenopsyllae (Laveran and Franchini) occurs in the gutof Ctenopsyllus musculi.Leptomo1UJ,s debreuili (Brumpt) is 0. parasite in the squirrel flea.Leptomonas pattoni (Swingle) is 0. native to Ceratophyllus fasciatus,C. lucifer, and Xenopsylla cheopis. According to Fantham and Porterit has been found naturally in the blood of mice. Ingestion of feces offleas infected with this organism has caused death or disease in whitemice, according to Laveran and Franchini (1914).Mastigophora: Spirochaetacea: Spiroclw,etidaeSpiroschaudi1llT/,ia ctenocephali (Patton) has been described fromCtenocephalus canis in India.Telosporidia: Gregarinida: .Agrippinidae.Agripp~ bo1UJ, Strickland occurs in the gut of the larvae of the ratflea, Ceratophyllus fasciatus in England.Telosporidia: Haemogregarinida: HaemogregarinidaeHaemogregarilna (HepatolJoon) jacmi Balfour, the cause ofANAEMIA of the jcrboas, Jaculus gordoni and J. orientalis, is thoughtto be carried by the fl;a Xenopsylla cheopis. Balfour noted large cystsin X. cleopatrae which Christophers thinks possibly belong to thisspecies.MetazoaPzatyhelmia: Cestoidea: Cyclophillidea: TaeniidaeDipylidium canilwwm (Linnaeus), the DOG TAPEWORM, has for itsintermediate hosts the dog flea, Ctenocephal'US canis (Curtis) Baker, thecat flea, C. canis felis (Bouche), and the human flea, Pule:r: irritansLinnaeus. It may also be carJ'ied by the dog louse Trichodectes latus(canis). Neumann, however, regards the fleas as most important. Theripe proglottids which contain the eggs of the tapeworm. by their ownmovement, pass through the host's anus and get into the fur where theybecome partly dried and disintegrated and fall. to the ground. Part of

356 SANITARY ENTOMOLOGYthe segments, the oncospheres, are released by the disintegration and arethen ingested by the flea larva or the louse. Sonsino contended that theadult flea could not ingest the egg of this worm and Joyeux (1916) hasdemonstrated this fact. He ·was abl{Jo demonstrate that the larvae.canand do ingest the egg easily. The embryos when they reach the intestineescape from their envelopes, the oncospheres, and penetrate into the generalcavity. They are imbedded in the adipose tissues and are very difficultto demonstrate. Here they remain during the metamorphosis.When the adult flea is formed the hexacanth immediately begins to develop,even before its host ~gins to feed. On the second and third days1DtVELOfMENT Of(;Y5TICE~COIDr~~~.r:r~';:IR,PE i'R.::TT~::I", liea BR£I\KINGESTS U,. AND RELf.,I\S£,OhCO.:_ .... IEIII' ONQO$PHERES. )DEVELOPMENT Of TAPE WORMLIFE CYCLE OfDlPYLIDJUM CANINUM.THE DOG T"PE WOIIM.flOST J. flrAC, (C"TE...,OC[PHALUS OAIIIIS. C."ELIS,PULEX I ft.UT ... N I ).HoST D. D •• ~C,,".s """'~'AA'S).CAT IF ••,s ""TUS)•.r"'C~AL (CANIS .AU~EUS).FIG. 63.(Pierce.)it is enlarged and the primitive lacuna begins to form. From this pointit develops into the cysticercoid. The dog or cat becomeS' infested bybiting or licking up the infected fleas or lice on its body. The flea canspread the infection to human beings that accidentally swallow the insects.Possibly in case of children, infection takes place by kissing petsor by pets stealing a drink from a bowl, the contents of which are afterwardsgiven to children.Platyhelmia: Ce8toidea: Cyclophillidea: HymenolepididaeHymenolepis diminuta (Rudolphi), the YELLOW-SPOTTED TAPEWORM of the rat, may pass its intermediate stage in larvae of a numberof insects of different orders. Nicoll and Minchin found the cysticercoid

DISEASES CARRIED BY FLEAS 357in four per cent of rat fleas, Ceratophyllus fasciatus, and succeeded in infectingrats by feeding them on fleas. Johnston in Australia has corroboratedthe fact that this flea is a host, while Joyeux has proven that infectiontakes place easily in the larval stage, but is impossible in the adultflea. Johnston has found XenopsyUa cheopis to be a host. Joyeux hasinfected larvae of Pulex irritans and Ct(!'TU)cephalus coois. He found thatthe embryo develops independently of the metamorphosis of its host.The rodents become infected by licking up infected insects.Hymenolepis nana (Von Siebold), the dwarf tapeworm of rats andman, may possibly pass its intermediate stage in fleas. Nicoll and Minchinfound a cysticercoid in Ceratophyllus fasciatus resembling thisspecies, and Johnston in Australia also found a similar cysticercoid inXenops1JUa cheopis.Nemathelminthes: Nematoda: SpiruridaeProtospirura muris (Gmelin), a STOMACH PARASITE of rats andmice, has a larva similar to one found by Johnston encapsuled in thegeneral cavity of the rat flea, Xenopsylla cheopis.Nemathelminthes: Nematoda: HiZonUlaeActllnthocheilcmema recond.tum (Grassi), a cause of CANINE FILARIASIS, possibly passes its embryonic development in fleas. Grassi andCalandruccio found larval nematodes in fleas, Ctenocephalus canis, C. felis,and Pule:c irritans that they assumed belonged to the species A. relJPnditum.The embryos, according to Grassi, perforate the intestinal wallof the flea which has ingested blood containing the parasites. The lattermake their way into the fatty tissue where they are almost always to befound lying singly in the fat cells. The fat cells increase in size as theparasites grow, the latter being curled up once or twice within the cell,the nucleus of which remains uninjured. The embryo undergoes fourstages of development in the flea. 'rhere is no positive proof of the methodof transmission.SUll4MARYIn summary, therefore, we may call attention especially to the factthat the flea carries plague, is apparently the carrier of infantile kalaazar, and is an intermediate host of one- of the human tapeworms. Inaddition it is intermediate host of various animal diseases.Unlike the louse-borne diseases, the life cycles of the organilrtns causingflea-borne diseases are quite variable.The bacilli of plague and rodent plague are taken up by the bite

358 SANITARY ENTOMOLOGYof the flea and are voided in its feces and obtain entrance to the host bythe scratching in of feces of infected fleas, or by the licking up of thefeces or the flea.The five trypanosomes' are all taken up from the blood and passthrough a definite life cycle in the flea, passing out of its feces, andobtain entrance to the host by being licked up in the feces. This mayalso happen in the case of leptomonads. 0The crithidias and -leptomonads belong primarily to the fleas alone,and pass through their cycle of existence jn the flea body and out of itsfeces and are taken up by feeding on the infected feces, probably bythe larva. .The tapeworms are taken up as eggs by the larvre feeding in filthydirt. They develop in the flea and are taken into the vertebrate hostwhen it licks up the flea from its body.The filaria is taken from the blood of the host as an embryo, anddevelops in the :Bea, but we do not know how it gets back to thehost.In addition to all these diseases caused by organisms, fleas may causea dermatitis. This is especially true of the chigoe, Dermatophilu8 penetram,which becomes fixed to its host and sometimes even causes AINHUM, or the loss of a member, such as a toe. It will be discussed in thenext lecture on :Beas.REFERENCESBacot, A. W., and Martin, C. J., 1914.-Journ. of Hygiene, Plague SupplementIII, Jan. 14,1914, pp. ~3-439.Brumpt, E., 1913.-Bull. Soc. Path. Exot., vol. 6, pp. 169-1'10.Fantham, H. B., Stephens, J. W. W., and Theobald, F. V., 1916.-TheAnimal Parasites of Man.Herms, W. B., 1915.-Medical and Veterinary Entomology. MacmillanCo., 393 pp.Johnston, J. R., 1915.-Proc. Roy. Soc. Queensland, vol. !4, pp. 6S-91.Joyeux, Charles, 1916.-Bull. Soc. Path. Exot., vol .. 9, No.8, pp. 5'78-579.Laveran, A., and Franchini, G., 1913.-C. R. Acad. Sci., Paris, vol. 47,No. 18, pp. 744-747.Laveran, A., and Franchini, G., 1914.-Bull. Soc. Path. Exot., vol. 7.pp.605-6I1l.Liston, W. G., 1905.-Journ. Bombay Nat. Rist. Soc., vol. 16, pp.Jl5S-273.McCoy, G. W., and Chapin, C. W., 191!.-Journ. Infect. Diseases, vol.10, No.1, pp. 61-72.

DISEASES CARRIED BY FLEAS 359Porter, Annie, 1914.-Parasitology, vol. 4, No.3, pp. 237-254.Seurat, L. G., 1916.-Bull. Scient. France et Belgique, ser. "{, vol. 49,fase. 4.Simond, P. L. S., l898.-Ann. de l'Inst. Pasteur, vol. a, p. 625.Verjbitski, D. T., 190t:::_Journ. of Hygiene, vol. 8, p. 162.

CHAPTER XXVThe Life History and Control of F1eas 1F. C. BiahoppThe importance of flea control probably needs no further emphasIsthan that already apparent after reading the lecture on the relationof fleas to disease. It should be borne in mind that the plague has beenone of the most terrible scourges in the history of the world and that itsreduction to an inconspicuous place in Europe and the western hemispherehas been the result of the knowledge of the relationship between rats andfleas and Bacillus pestis, the causative organism of the disease. Asidefrom the part which fieas play in the transmission of this dreaded maladyand certain other human ailments, they are often of decided importanceon account of the annoyance to man produced by their crawling aboutover the body and biting. The susceptibility to attack of individualsseems to vary greatly. In many cases a few fleas produce but littleannoyance and the bites leave no after effect. In other instances thecrawling of the fleas produces much annoyance and the bites have beenknown to form lesions of more or less serious character and often slowto heal.To proceed intelligentlir with flea control it is important to have agood general knowledge of their habits and distribution. Eleven speciesof fleas have been shown capable of carrying plague. Eight of thesehave been found to occur on one or more species of rat (Epimys spp.)and two on ground squirrels. Of these, the Indian rat fiea undoubtedlyplays the principal role in the transmission of bubonic plague. Thefollowing list includes most of the forms which may be ~onsideredimportant to man either as vectors of disease organisms or as annoyers:Pulex irritans, Ctenocephalus' canis, Ct. felis, CeratophyllUIJ fasciatus, C.aniaiu, C. acutus, X enopsyZZa cheopia, X. scopUlifer, CtenophtlwZrnusagyrtes, Dermatophilus penetram, Echidnophaga gallinaccus, Hoplopsyllusanomalus.The host relations of fleas are very important, as has been seen byconsidering the relationship of the insect to disease transmission. Unfortunatelymost of the fleas are not very closely restricted to certain hosts,especially when forced by hunger to seek blood., .• This lecture was read November 4, 1918.360It might be stated at

THE'", "IFE HISTORY AND CONTROL OF FLEAS 861the outset that all fleas are dependent upon blood for their existence.There is considerable variation in the degree to which certain species arerestricted as regards their host, and we ahould not go too far in drawingconclusions as to whether certain species will not feed on certain hostsas our judgment is based usually on a comparatively small number ofexperiments under more or less artificial conditions, or upon examinationsof a small number of host species, often in restricted districts.Fleas pass through four distinct stages-egg, larva, pupa (in acocoon), and adult. The eggs are readily seen with the naked eye, especiallywhen on a dark background. Most of them are deposited by thefemales while the latter are on the host. They fall off the host, mostlydropping in the bedding material where they hatch in from two to twelvedays. This is responsible for a 'Concentration of the adults about thesleeping places of the hosts, and favors them by being within easy reachof the hosts, both old and young, and also in supplying the larVa! withthe partially digested blood excreted by the adult fleas, for food. Thenumber of eggs laid varies greatly according to species, availability of.~~~a-FIG. 64.-Larva of the European ra~ flea, OeratophylluB faBciattUl. Greatly enlarged.(Bishopp.) From U. S. Dept. Agr., Bull, 248, fig. 8.food for adults, etc. Bacot, of the Lister Institute, has counted asmany as 448 eggs deposited by a female human flea. Comparativelyfew are deposited each day but the egg laying may be extended over manyweeks.The Larvae.-The larvae are wliitish, legless, and eyeless maggots, distinctly,segmented and provided with numerous hairs (fig. 64). Theyare usually les,s than one-fourth of an in~h in length when grown, and quiteactive, disappearing quickly in breeding material. LarVa! of some ofthe larger species -may considerably exceed this length. They are to befound in the dust in which vegetable and animal particles are mixed.The larval stage is extremely variable, mostly depending on temperature,abundance of 'food, and degree of moisture and humidity. The length ofthis stage has been found 'to range from one to twenty weeks. Underfavorable conditions from oll,e to three weeks may be taken as the usuallength of the period.The Pupa.-All flea larVa! spin cocoons in which the pupa isformed. These are oval and not easily seen on account of the numerousparticles of dust, sand, etc., which is woven in or stuck to the silkencocoon. This stage ranges from a week to nearly a year. The extremelong periods were observed by Bacot to take plac.e only in cool weather.

362 SANITARY ENTOMOLOGYWith the Indian rat fiea the period was greatly lengthened when themean temperature fell below 65° F., human fiea below 50° F., and theEuropean rat flea below 40° F. In cooler climates the winter is probablypassed in this stag~ but in warmer countries adult activities never cease.Fro. 65.-The dog ilea «(JtenocephaIUlf cani,): a, Egg; h, larva in cocoon; c, pupa; d,adult; 8, mouth parts of same from sidell' antenna; g, labium from below; h, 0, II,much enlarged; a, 6, f. g. more enlarge. (From Howard.) From U. S. Dept.Agr., Bull. 248, fig. s. -The adult fieas often remain in tlle cocoons for weeks and emerge whendisturbed.Life Cycle.-The cycle is completed under favorable conditions inFla. 66.-The human flea, Puler:c irrita1l8: Adult female. Greatly enlarged. (Bishopp.)one to four weeks, but it may extend to one and one-third years inextreme cases.Length of Life of Adult Fleas.-A knowledge of the length of life ofthe adults is of much importance in relation to control measures anddisease dissemination. Under coOl, moist conditions Bacot found thehuman fiea to live 125 days, the European rat flea 95 days, the dog flea

THE LIFE HISTORY AND CONTROL OF FLEAS 36358 days, the Indian rat flea 38 days, and the bird or chicken flea (Ceratoplzillusgallinae) 1fl7 days. When fed daily this longevity was greatlyincreased; human flea 518 days, European rat flea 106 days, dog fleafl84 days, Indian rat flea 100 days, and the bird flea 845 days. Mitzmainfound the European rat flea to live 160 days in California and the groundsquirrel flea (Ceratophyllua acutua) 64 days. In warm weather thelong.evity without food is but a fe,v days.The human flea (Pulex irritana) (figs. 66,67) was formerly thoughtto restrict its attention largely to man. Investigators have found, however,that it probably develops normally on the hedgehog and othersstate that it is occasionally found on dogs and cats, especially during thewinter. Our own observations indicate that it is a very common parasiteof hogs; so much so in fact that it might be called the hog flea insteadFIG. G7.-The human fiea, Puler» irritana: Adult male. Greatly enlarged.From U. S. D. A. Bull. 248, figs. 5, G.(Bishopp.)of the human flea. Also that it may be found in considerable numberson dogs at all times of the year even in regions where it is not a pestof importance to man. It has been ta.ken on several species of rats, butin limited numbers. This form appears to be well adapted to a freeexistence, usually leaving the host after partaking of a blood meal andthis habit may tend to make it of greater importance as a disseminatorof disease. It has almost world-wide distribution but its abundance indifferent regions varies greatly. In the United States it is very prevalentin California and the Southwestern States where it is the principalcause of flea annoyance t() man.The dog and cat fleas (Ctenocephalus cania Curtis and Ct. feliaBouche (fig. 65) may be discussed together as their habits appear to bevery similar and as some authors stilI" believe they are not distinct speciesbut only varieties. They have a rather wide range of hosts, including thedog, cat, man, and a number of wild animals, especially of the dog and

364 SANITARY ENTOMOLOGYcat family. They are occasionally found on rats. They are quite widelydistributed throughout the temperate and tropical parts of the world.In the United States they often occur as household pests, and in theCentral and Eastern States they usually take the place of the human :fleaas parasites of man, most of the outbreaks in these regions being fromeither one or the other of these species.The European ra"t fiea CeratophyllUll fa8ciatw Bose is ratherclosely restricted to the several species of rats and mice but it has beenfound to bite man in the absence of its preferred hosts and probablyalso will feed on other animals. It is the predominant rat fiea in th ..United States and over the greater part of Europe, and in this regionlJlust be considered one of the principal vectors of plague. In the tropicsit is much less abundant, occurring only in the cool season.FIG. 68.-The European rat fiea, Oeratophyllu8 fallciatu.: Adult female.enlarged. (Bishopp.)GreatlyThe Tropical or Indian rat :flea (XenopsyZla cheop;,s Roth.) isundoubtedly the principal disseminator of bubonic plague in India andother parts of Asia. It is also now to be found in practically all theother tropical and subtropical countries of the world, but it is oftenrestricted to the seaport towns, as in the case of the United States, whereit appears not to have penetrated far inland. This species is primarily arat fiea, being taken on all species of rats and mice', but it feeds readilyupon man and also will attack small domestic animals and some wild ones.The mouse flea (CtenopsyUa mUllculi Duges) is to be found in manyparts of the world but is especially abundant in Mediterranean Europe,Australia, and the southern part of the United States. It is often foundin numbers on rats as well as mice, but rarely bites man even in theabsence of its preferred hosts.The Asiatic rate :flea (CeratophyZlw anis'Lb8 Roth.) appears to takethe place to a large extent of the European rat :flea, in Japan and portionsof northeastern China. A specieS" of grl;>undhog flea (CeratophyllUll

THE LIFE HISTORY AND CONTROL OF FLEAS 365silantiewi Wagner) occurs in numbers on the "tarbagan" or groundhogin Manchuria and was thought to be concerned in the transmission ofplague from that host to man in the recent Manchurian outbreak. However,subsquent investigations apparently failed to substantiate thistheory.The field mouse flea (Ctenophthalmus agyrte8 Heller) occurs in Englandand other parts of Europe. It is common on voles and field miceand also on rats living in the open. It has no inclination to bite man.This species probab~y plays little part in the dissemination of plague,but when the disease gets among wild rodents it no doubt would aidin spreading it from animal to animal.Pygiop8ylla ahalae Rothschild has been shown capable of carryingplague. It is an East Indian Island species and according to De RaadtFIG. 69.-'I'he sticktight flea, Echidnophaga galli7lacea: Adult femole. Greatly enlarged.(Bishopp.) From U. S. Dept. Agr. Bull. 248, figs. 2, ~.it is .abundant on rats in coffee plantations in Java, but rare on rodentsin buildings. He avers that the species of fleas found on rats may beused as an index to the source of the rat population of a given place.The squirrel ~as (CeratophyUu8 acu,tus Baker and Hoplop8yUu8anomalu8 Baker) are abundant in the western United States on groundsquirrels. They have been shown capable of transmitting plague, andboth feed readily on man and will feed on rats.The sticktight flea (Echidnophaga gallinace'Us Westwood) (figs. 69 170) is an important pest of poultry in the southern United States. Thisspecies is widely distributed in the subtropical and tropical parts of theworld. It atttacks several wild b1'rds in addition to domestic species andhas been taken on rats in numbers. It bites man with avidity.The chigoe or penetrating flea (Dermatophuu.s penetrans Linnaeus)is troublesome in the West Indies, Mexico, and northern South America,and has been introduced into West Africa and from there to India.It burrows into the skin of the feet, especially around the toenails. Many

866 SANITARY ENTOMOLOGYanimals, including man;hogs, dogs, cats and the larger domestic animals,are attacked.The flea (Xenopsylla 8copulifer Rothschild) occurs on rats in GermanEast Africa. It is closely allied to X. cheopis and partially replacesthat species in the region mentioned. Its possible relations with plaguetransmission have not heen determined.FACTORS INFLUENCING ABUNDANCE OF FLEASThere is a very close correlation between various climatic factors andflea abundance. This applies to practically all species in groo.ter orless degree. In the United States it may be said that in general fleasFIG. 70.-Head of rooster infested with the sticktight :flea. (Echidnophaga gallinac61J).Somewhat reduced. (Bishopp.) From U. S. Dept. Agr., Bull. 948, fig. 7.are more abundant during moderately warm weather when there arefrequent rains or high humidity. The effect of seasonal and climaticconditions on fleas has a very important bearing on the plague. Thishas been well shown by the Indian Plague Commission which found thatthere is a rather close correlation between the abundance of fleas and theprevalence of the disease, and that flea abundance in turn depended uponclimatic conditions. They showed that in the case of the European ratflea there is a marked decrease in numbers with the oncoming of the hot,dry season. These fleas begin to disappear in early April and from May15 to November not a single specimen is seen. The Indian rat fiea,which is the principal plague conveyer in that region, was found to heabove the mean average in number during the period from N ovemher toMay, with the maximum about April. During the rest of the year-Juneto September-the fiea prevalence is below: the mean, the absolute minimum

THE LIFE HISTORY AND CONTROL OF FLEAS 367being reached in August to September, the maximum being six times lessthan in April. The plague season in the districts where these observationswere made ,is from February to May, inclusive. The maximum isusually reached early i::1. May, sudden decline being experienced withthe dropping bfF in numbers of the fleas early in June.The degree of annoyance to man from fleas depends to a large extentupon the relative abundance. Thus in the southern part of the UnitedStates, while fleas are active throughout the year, they are reduced solow during the winter months that they confine their attacks largely tosmaller animals. During the spring the breeding increases rapidly andoften severe outbreaks are experienced. In the Northeastern States theseoutbreaks are more frequent during the latter part of summer and earlyfall.There is also marked correlation between the character of soil andflea ab1;lndance. Sandy land is uniformly more conducive to :flea developmentthan the heavy soils. However, soils with a large amount of humusseem al~o to favor flea' breeding. We do not expect to encounter widespreadflea abundance in black land regions, but this does not interfere\vith severe local outbreaks. -CONTROL OF FLEASThe general consideration of flea control must be governed by theconditions l1nder which one is working. When we consider regions whereplague is known certainly not to exist, little concern need be felt overthe presence of an occasional flea, and all that is necessary is to takeprecautions that they do not become annoyingly abundant. Occasionallypremises already infested may be encountered and in such cases it is necessaryto know what steps to take to reduce the numbers immediately. Onthe other hand, in regions where the presence of plague may be suspected,the elimination of all fleas is desirable, and one must give attention tothe scattered fleas as well as the heavy infestations. Of course in suchsituations the prime move should be against the rats which act as hostsfor both the plague bacillus and the fleas which carry it. In cases wherethe plague has become established in rural districts among groundsquirrels or other native roden:ts, their destruction also requires attention.The procedure in such cases must necessarily be governed by the durationof occupancy of a given place. For permanent elimination ratproofingis essential. This consists in the elimination of all loosely constructedbuildings and the concreting of floors, basements and wharves.While the rat-proofing is going on war should be waged against therats by poisoning, shooting, and trapping. Where plague is -known to'exist in a city or village being cleared of rats, every precaution should

868 SANITARY ENTOMOLOGYbe taken against flea bites. Workers should be provideJ with closelyfittingclothes and leggings and certain other methods of body isolationas discussed in a subsequent paragraph.When operating in regions where plague is suspected, it is also importantto choose locations for troops which are apt to be free fromrats. The billeting of men in old buildings, warehouses, barns, etc., shouldunder such conditions be entirely avoided.Control of Hosts.---.To kpep down heavy infestations of those speciesof fleas which a~e annoying to men and animals, one of the essential steps.is to exercise control over the hosts. Of course, this principle is involvedin the elimination of rats and squirrels in plague areas. When alliinfestationis encountered, the first thing that should be inquired into is thepossible hosts and their haunts. Usually the main trouble can be tracedto the sleeping places of dogs, cats, hogs, or to hen houses, or spacesbeneath houses and barns frequented by poultry. In the case of thehuman :flea the infestation may be more or less general over the' premises,but there are nearly always centers where they are concentrated andoften these are associated with pet animals. When the principal breedingplaces have been located the hosts should be destroyed if possible, orfreed from adult fleas, and kept under control. A definite sleepingplace should always be provided for dogs and cats, and these may bekept free from fleas, after treatment, by cleaning out the beds regularlyand spraying with coal tar disinfectant. The host animals may be freedof fleas by washing them thoroughly in a S per cent solution of creolinand water, or by using Ilny other standard saponified creosote compound.Kerosene emulsion made according to the formula: One pound soap, twogallons kerosene, one gallon water, reduced one to nine, is also very effective.In the case of cats these substances must be washed out of the furwith warm water and soap shortly after treatment to avoid burning ofthe skin. 2"There premises are heavily infested with adults it is 6rst necessary todestroy this stage and this may be accomplished by fumigation, if thebuilding is fairly tight, either with hydrocyanic gas, five ounces cyanideper thousand cubic feet; or by burning sulphur at the rate of four poundsper thousand cubic feet. As has been pointed out, many adults remainquiet in pupa cases or may be buried in sand or cracks where they aresomewhat protected from the effects of the gas. In destroying the immaturestages we can take advantage of the destructive effect of extremes inmoisture or dryness. Where complete flooding of infested areas is feasible,this has been known to accomplish the destruction of all stages. In othercases, loose boards and trash should be removed and burned and the• Powdered derris has been found very efficacious in destroying fleas on animals.One grain scattered in the hair of a do~ will kill all fleas present.

THE LIFE HISTORY AND CONTROL OF :FLEAS 369infested areas sprinkled heavily with salt and wet down by sprinkling.Repeat the wetting operation at intervals of five to ten days, accordingto the condition of the soil. U suaIly two or three treatments aresufficient.Where fumigation can not be practiced and it is desirable to get ridof the adults at once without waiting for them to starve, a number ofprocedures may be followed. If in habitations, sprinkling flaked naphthaleneover the floor at the rate of four or five pounds to each two 01' tIneehundred feet, closing the rooms up for a few hours, and then sweepingthe material to the next room' together with the stunned fleas is veryeffective. Pyrethrum may be used in a similar way. In barns and basementsspraying with kerosene emulsion will accomplish the destructionof most of the active adults.Where adults are abundant in sheds, barns, and hog yards, we havefound that the light but general spraying of the infested areas withcreosote oil (ut least 10 per cent tar acids) will accomplish strikingresults.In buildings where fleas are breeding in the cracks of the floors orunder rugs and carpets, these should be removed, the house thoroughlyswept and the floors washed with strong soap or lye water, or if feasible,they may be sprayed with gasoline or kerosene emulsion. The free useof sweeping compounds and floor oils will largely eliminate subsequenttrouble. .In treating premises infested with sticktight fleas it is important thatall fowls be excluded from beneath houses and barns. These conditionsprevail largely in the South where this pest becomes annoying. If thisprecaution is taken and the fowls are kept in sheds which admit plenty of8un&hine and air, and the infested places be treated with salt and waterno attention need be given to the fleas upon the host.Repellents, Isolation and Trapping.-The wearing of shoes and leggingswill largely exclude the chigoe flea. While cleaning up infestedpremises it has been found that the laborers can exclude the fleas and atthe same time catch large numbers of them by wrapping the legs withpaper covered with tanglefoot. To prevent fleas attacking one at nightthe use of flaked naphthalene or pyrethrum dusted in the bed clothing willgive a degree of immunity.Since fleas are comparatively limited in their ability to jump (greatestheight of any species about eight inches, greatest horizontal distanceabout thirteen inches) cots and beds may be protected by isolating theirlegs in pans of water or by wrapping them with paper or cloth treatedwith tanglefoot. The bed clothing should, of cour~e, be kept tucked upso as not to reach near the floor and individuals should remove all clothingand be free from ficas when entering the bed.

'870 SANITARY ENTOMOLOGYTo pr

THE LIFE HISTORY AND CONTROL OF FLEAS 371solutions are advised for the latter, and cooling applications, such asmentholized or camphorated ointments for the itching. In the case ofinfestations of the chigoe the insect should be promptly removed byexcision and the part kept as free from infection as possible.LIST OF REFERENCESBacot, A. W., 1914.-A study of the bionomics of the common rat fleasand other species associated with human habitations. With specialreference to the influence of temperature and humidity at variousperiods of the life history of the insect. J ourn. Hyg., Plague SupplementIII, Jan. 14, pp. 447-654.Bacot, A. W., 1914.-The effect of the vapors of various insecticidesupon fleas at each stage in their life history and upon the bedbug inits larval stage. Journ. Hyg., Plague Supplement III, !Jan. 14, pp.665-681.Bacot, A. W., and Ridewood, W. G., 1914.-0bservations on the larvae offleas. Parasitology, vol. 7, No. ~,June 19, pp. 157-175.Bacot, A. W., and Petrie, G. F., 1914.-The fleas found on rats and otherrodents living in association with man and trapped in the towns,villages and Nile boats of Upper Egypt. Journ. Hyg., vol. 14, No.4,pp. 498-508, Dec. 23.iJishopp, F. C., 1915.-Fleas. U. S. Dept. Agr., Bull. No. ~48, Aug. 14,31 pp.Bishopp, F. C., 1915.-Fleas as pests to man and animals, with suggestionsfor their control. U. S. Dept. Agr., Farmers' Bull. 683, Nov.8, 15 pp.Canalis, P., 1916.-Some experiments on the ~ecticidal action of ClaY"ton Gas. Bull. Mens. Office Internat. d'Hyg. Publique, vol. 7, No.3,March, pp. 457-463.Chick, Harriette, and Martin, C. J., 1911.-The fleas common on rats indifferent parts of the world and the readiness with which they biteman. Journ. Hyg., vol. 11, No. I, April 8, pp. 1~~-136.Conradi, A. F., 1902.-Remedies for fleas. N. H. Agric. Exp. Station,Bull. No. 94, October, pp. 89-92.Creel, R. H., 1915.-Hydrocyanic acid gas; its practical use as a routinefumigant. U. S. Pub. Health Rpts., vol. 30, No. 49, Dec. 3, pp. 3537-3550.Creel, R. H., and Faget, F. M., 1916.-Cyanide gas for the destructionof insects. U. S. Pub. Health Rpts., vol. 31, No. 23, June 9, pp.1464-1475.De Raadt, O. L., 1915.-Contribution to the knowledge of the epidemi-

372 SANITARY ENTOMOLOGYology of plague in Java. Meded. Burgerlijk. Geneesk. Dienst Ned.Ind., pt. 4, pp. 20-3B.Howard, L. 0., 1909.-House Fleas. U. S. Dept. Agr., Cir. No. lOB, 4 pp.Illingsworth, J. F., 1915.-Hen Fleas. The Hawaiian Forester and Agriculturist,vol. 12, No.5, May, pp. 130-132.Jennings, A. H., 1910.-Rats and Fleas in relation to bubonic plague,with sI!ecial reference to Panama and the Canal Zone. Sept. 14,1~ pp. .Kitasato, 1909.-Rat Heas, with their special reference to the transmissionof plague in Japan. Trans. Bombay Med." Congr., p. 98.Liston, W. G., 1904.-Plague, rats and Heas. Journ. Bombay Nat. Hist.Soc., vol. 16, 'p. !!53.Liston, W. G., 1914.-Report of the Bombay Bacteriological Laboratoryfor the year 1913. Bombay, Govt. Central Press, 24 pp.McCoy, G. W., and Mitzmain, ·M. B., 1909.-Experimental investigationof biting of man by Heas from rats and squirrels. U. S. Pub. HealthRepts., vol. 24, No. B, Feb. 19, 7 pp.Martin and Rowland.-Observations on rat-plague in East Suffolk. Appendixto the report of the medical officer to the Local Govt. Board.Mitzmain, M. B., 19l0.-General observations on the bionomics of therodent and human Heas. U. S. Pub. Health Bull. No. 3B, 34 pp.Neumann, L. G., 1914.-Parasites and parasitic diseases of the dog andcat. Paris: Asselin et Houzeau, 34B pp.Nuttall, G. H. F., Strickland, C., and Merriman, G., 1913.-0bservationson British rat Heas. Parasitology, vol. 6, No. I, April 17, 19 pp.Raynaud, L., 1909.-Prophylaxis de la peste en Algerie. Revue D'Hig.et de Police Sanit., vol. 31, p. 101.Reports on Plague Investigations in India, Journ. Hyg. (1906), vol. 6,No.4; (1907), vol. 7, No.3, pp. 323-476; vol. 7, No.6, p. 693;(190B), vol. B, No.2, pp. 162-308; (1910), vol. 10, No.3, pp. 315-568; (1912), vol. 12, Plague Supplement II, pp. 800-325.Rothschild, N. C., 1906.-Note on the species of fleas found upon rats indifferent parts of the world. Journ. Hyg., vol. 6, p. 483.Shipley, A., 190B.-Rats and their animal parasites. Journ. Econ. BioI.,vol. 8, No.3, p. 61.Swellengrebel, N. H., 1913.-Record of observations on the bionomics ofHeas and rats and other subjects, bearing on the epidemiology ofplague in Eastern Java. Meded. Burgerlijk. Geneesk. Dienst Ned.Ind., vol. 2, pt. 1, 90 pp.Tiraboschi, C., 1904.-Les rats, les souris et leurs parasites cutanes.Archiv. Parasit., vol. B, p. 161.Van Dine, D. L., 190B.-Report of the Entomologist. Ann. Rept. HawaiiAgr. Exp. Sta. for 1907, May 26, pp. 36-37.

THE LIFE HISTORY AND CONTROL OF FLEAS 373Verjbitski, D. T., 1905.-The part played by insl!cts in the ep:demiologyof plague. Journ. Hyg., vol. S, p. 162.Waterston, J., 1916.-Fleas as a menace to man and domestic animals,their life history, habits, and control. British Museum (NaturalHistory) Economic Series No. 3;20 pp.NOTES ON THE CHIGOE, DERMATOPHILUS PENETRANSW. Dwight PierceMr. Bishopp has mentioned the chigoe in his lecture, but I believethis exceedingly interesting flea is deserving of a more extended statement.In South and Central America it is also known as La Nigua.It breeds in the flesh of man and animals, attacking the pig, cow, goat,sheep, horse, dog, cat, lion, and gorilla and probably other vertebrates.When the female is impregnated she attaches herself to the skin, boresin and remains stationary. When the eggs are mature they are eitherpassed out while the female is fixed to the skin, or the flea may becomedetached. The female while attached swells to a great size. The larvaebreed in dirt and pupate in a cocoon. The favorite points of attack areon the heels, balls of foot, palm of hand, and between the finger~, althoughthey attack other parts of the body.The attack is very painful, and in severe cases may result in ainhum,the loss of a member, especially a toe. Brumpt says this flea frequentlyinoculates the germs of tetanus, Bacillus tetani. This belief is also heldby Quiros, who notes the large number of cases of tetanus following niguaattack.In cases of heavy infestations Quiros uses a pomade composed asfollows:Salicylic acid~.5 grams.Ictiol (ichthyol)10.0Yellow vaseline1G..~ "In a few days the infested area encrusts and fall j off, leaving the skinfree from parasites.In cases which might lead to amputation Quiro'. hatiles in petroleum.He advises against the use of iodine, which is da'lgerous in these cases.Prevention of breeding, restriction of hogs 'rom wandering arou,ndhabitations, wearing 'of shoes" and cleanliness a.te prophylatic measures.

CHAPTER XXVICockroachesA. N. Caudell.Contending with bedbugs for general unpopularity come cockroaches,noisome creatures scarcely less widely known, or less thoroughly disliked,than those smaller odorous and odious pests. The importance of roachesin houses and camps is consider.able, not only as unsanitary and disgustingvermin, but as mechanical carriers of disease, and also very likelyas intermediary hosts to certain disease-causing organisms. Experimentshave shown these insects eminently fitted for both roles, and their importancewarrants attention by housekeeper and sanitarian.No more offensive insect frequents the habitation of man than thecockroach. These insects have long been known as pests of the householdand are found throughout most of the civilized world, especially intemperate and tropical regions. The ancients are said to have called themZucifuga. by reason of their nocturnal habits, but the more modern namecockroach, or the briefer designation roach, is the one by which theyare now universally known. Certain species are, however, given specialcommon names, which may vary in different regions, as water bug, Crotonbug, German roach, etc., which are names by which the little, brown,house roach is known in various places.Not all cockroaches are loathsome. creatures of disgust, in fact thereare very few of the many hundreds of described forms that are of anymaterial economic importance. Some species of roaches are handsome inform and color, in some cases resembling certain beautifully coloredbeetles, a decided contrast to the flat noisome- creatures of the kitchen.Economically, roaches are of importance only as household pestsand disease disseminators, there being but comparatively few instancesof their injuring living plants or doing other damage to things out ofdoors. But in houses and camps they injure many things, defile food inpantries, eat paint from pictures, covers from books, glue from stamps~and gnaw holes in clothing. They will devour almost anything, and havebeen recorded as biting off eyelashes, gnawing toenails, and biting thegreasy fingers of sleeping children.As a rule but one species of roach occurs at one place in injuriousabundance, two or more forms rarely occurring together in any number.374

COCKROACHES 875When numerous they congregate, especially in kitchens where it is warm,damp, and not overly clean. On shipboard they often abound to such anextent as to cause much damage, in some cases entire supplies of certainfoods being spoiled by eating, or rendered nauseous by their contact, adisagreeable odor being imparted by secretions from certain scent-glands,situated in the bodies of the insects. The readiness with which they arctransported with food supplies make their introduction into militaryand other camps a matter of great probability, and when once infested,such places are soon thoroughly stocked with these skulking creatures ..BIOLOGYThe life histories of our household roaches are very similar. The eggs.are deposited incased in an oblonl;f, leathery pod, called an ootheca, andcontaining several eggs each, arranged in two longitudinal rows. In some·cases this ootheca is carried around for some time by the I]lother roach"partially protruding from the tip of the abdomen. But generally they aredeposited in some cranny and sometimes the ootheca of Periplaneta isglued in folds of clothing, or in a leaf if of outdoor occurrence, andcovered over with bits of matcrial chewcd off by the insect. I have myself'seen instances of this, once on a garment and twice on leaves, and therecognition of the ootheca in such cases is not at all clear until it is.uncovered._When first hatched from the egg the young roach resembles the adultin general form, but is apterous and the body is soft and whitish in color.Soon, however, the chitin becomes oxidized and the normal color appears.A number of molts occur during growth, the old skin splitting along thedorsal line of the thorax, and through this slit the insect emerges, theprocess being one, requiring some considerable exertion; every part ofthe body sheds its old covering, antennae, feet and all. The freshly moltedroach, like one newly hatched, is whitish in color, but a few hours serveto restore the natural colors. In the last two instars the wings appear ina rudimentary condition, at the last molt appearing fully developed.This appearance of rudimentary wings is the only character separatingthe stages of -the roach which correspond to larva and pupa of insectswith complete metamorphoses. The terms larva and pupa are not generallyapplied to insects with incomplete metamorphoses, the term nymphbeing there used, the degree of development being indicated by the numberofthe instar, or period between two molts. A single roach may produceseveral egg-masses in a season, and in the common house species the periodof development from egg to adult varies with the food supply, climaticconditions, etc.'Vhile in some tropical and subtropical regions certain species of

876 SA~ITARY ENTOMOLOGYBlaberus, Leucophaea, etc., occur in houses, the main forms with whichthe sanitarian has to deal comprise but four species, Blatta oricntalis,Blattella germanic a, Periplaneta americana, and Periplaneta au,stralasiae,especially the first two. These four domesticated species are easily separaied,being very distinctive in appearance, the two species of Periplanetaonly offering any difficulty in this respect. But even their differentiation iseasy by the figures and descriptive notes given herein, and by use of thefollowing key, which is based upon easily appreciated characters.KEY TO THE FOUR PRINCIPAL HOUSEHOLD COCKROACHES1. Size small, total length' usually no more than one-half inch; pronotaldisk with two, longitudinal, parallel, blackish stripes; last ventralsegment of the abdomen of both sexes entire (fig. 7!il).Blattella ge1"TTlJl1lnica .(Linnaeus) Caudell.Size medium or large, rarely much less than one inch in length, usuallymore; pro notal disk not marked as above; last ventral segment ofthe abdomen of the male entire, of the female longitudinallydivided---!il.2. Size medium, length about one inch; color black or dark brown, thepronotum unicolorous above; tegmina and wings abbreviated, inthe male covering about two-thirds of thc abdomen, in the femalethe tegmina forming mere lateral pads and the wings absent (fig.71). Blatta orientalis (Linnaeus).Size large, generally considerably more than an inch in length; colorreddish brown, the pronotum above distinctly bordered with yellowishcolor; tegmina and wings fully developed in both sexes-S.3. Tegmina with a yellowish, humeral stripe in distinct contrast to thecolor of the rest of the surface; central dark area of the pronotaldisk sharply outlined--- Periplaneta australasiae (Fabricius).Tegmina not marked as above; central area of pronotal disk lesssharply outlined (fig. 73) Periplaneta americana (Linnaeus).Blatta orientalis (Linnaeus) (fig. 71)One of the most prevalent and widely distributed roaches is the Blattaorientalis of Linnreus, in the' Old W orId sometimes called the black beetle,a name now fortunately less(' used, for though it is black, the roach isnot a beetle. The common riame oriental roach is preferable for thisspeCIes.Blatta orientalis is a medium sized roach of a blackish color. Themale is an inch, or a little less, in length, of a very dark-brown color, andfurnished with both tegmina and wings, covering about two-thirds of the

COCKROACHES 377abdomen, the tegmina often showing a reddish yellow cast. ';l'he femaleis noticeably larger than the male, of a more uniformly black color andprovided with tegmina only, and these very short, being only about aslong as the pronotum. In addition to the lal'ger size and the shortertegmina, the female can be readily distinguished from the male by theventral surface of the terminal segment of the abdomen, which is planein the male and divided longitudinally for its entire length in the female.This species is truly a gregarious insect, all stages living amicablytogether and often in incredible numbers where conditions are favorablefor its occurrence. It is especially prevalent in cities, being, like theFIG. 71.-The Oriental roach, Blatta orientalis: a, Female; b, male; c, side view of female;d .• half-grown specimen. All natural size. (Marlatt.) From U. S. Dept.Agr., Farmers' Bull. 658, figs. 1, 4.other domesticated species, less generally abundant in rural sections. Itis a lover of warm, damp, unclean locations and often abounds in cheaprestaurants and such places. The female may deposit a number of eggcasesa season, each containing about--s~xteen eggs, and breeding is continuouswhen conditions of warmth, etc., are favorable.Blattella germanica CLinnaeus). Caudell (fig. 79l)The German roach, or Crot.:m bug, vies with the oriental roach in itsimportance as a household pe'5t. It enjoys about as wide a distributionas its larger relative and in f,ome sections it is the more important of thetwo. It is decidedly smaller than orientalis, the male being about one-halfinch long and the female a little longer. Tha general color j" yellowish

578 SANITARY ENTOMOLOGYbrown with two, usually conspicuous, longitudinal, blackish stripes onthe pronotum. Both sexes are fully winged, both tegmina and wingsexceeding the tip of the abdo~en in both sexes. The male is more slenderthan the female but the last abdominal segment does not exhibit sexualdifferences as in the case of the above s cies. It is a more active insectthan orientalis, breeds faster, and is no less prevalent in houses,but, beingless restricted to filthy surroundings, is more often found in houses of abetter cla:ss. But no ho'me; no matter how well kept, is immune frominvasion now and then by one or more of these roaches, as not a store offood, bundle of laundry, or .lot -of supplies of any kind can be broughtin without danger of one or more roaches being introduced.This species seldom occurs in company with the oriental roach, a houseoverrun with one species usually being free from the other.FIG. 7::?-The German roach, BZ(J)ttelia germanica: a, First stage; b, second stage; c,third stage; d, fourth stage; e, adult; f, adult female with egg case; g, egg case,enlarged; h, adult with wings spread. All natural size except g. (From Riley.)Periplaneta americana (Linnaeus) (fig. 73)This, the American roach, is less frequently abundant in houses thanthe smaller forms, at least usually so, though in- the warmer parts ofthe world it is frequently the prevalent household species. It is morefrequently reported as doing damage to plants in greenhouses, etc., andvery often it creates havoc indoors with books, clothing, and othermaterial.This roach is decidedly larger than either of the foregoing species,both sexes being about one and one-half inches in total length, oftensomewhat longer and rarely as much as a quarter of an inch shor~r.Both sexes are fully winged, the wings usually surpassing somewhat thetip of the abdomen. T_he general color is reddish brown with the pronotumgenerally -bordered around the disk with lighter yellowish color,usually in distinct contrast to the darker central portion. The ventralsurface of the last abdominal segment of the two sexes here differ as in

COCKROACHES 379the case of Blatta orientalis, being plane in the male and longitudinallydivided in the female.This species is thoroughly cosmopolitan in distribution, having beenrecorded from almost every portion of the world except the colder regions.In some sections it is the most common house species, though in the easternUnited States it is not usually so common as either of the smallerspecies discussed above.As stated in the first part of this paper, the egg-cases of Periplaneta,the exact species not determined, are glued to various substances andcovered over with particles che'Yed off by the insect. The egg-cases ofFIG. 73.-The American roach, Pe1iplaneta Americana: a, View from above; b, frombeneath. Enlarged one-third. (Marlatt.)americana have been found, by actual count, to vary considerably in thenumber of eggs contained, the average, however, being about a score.The adult insect lives well over a year, one in captivity having died onlyafter a confin_ement of one and one-third years. .Nothing is inviolable to injury by this large roach, and it, as well asother forms discussed here, will even eat its own eggs, or a disabled individualof its own kind, to say nothing of other insects, even the i11-smelling bedbug. This species is often reported as damaging living plants,a thing seldom charged to the account of the smaller roaches.Periplaneta americana is the only one of our common house speciesindigenous to the New World, its original home probably b€ing TropicalAmerica.

380 SANITARY ENTOMOLOGYPeriplaneta a'tWltralasiae (Fabricius) BurmeisterThis species is of the same general size and appearance as americanaand has practically the same habits. It is readily distinguishable fromthat species by the elytra, which have an elongate yellowish spot borderingthe outer margin next the pronotum. The yellowish margins ofthe pronotal disk is in greater contrast to the more clearly delineatedcentral portion than in americana and the' general size is also somewhatless.This roach is found mostly in warmet; regions and is more often thanany other species reported as' injurious to plants in greenhouses, conservatories,etc..REMEDIESRemedies galore, good, bad, and indifferent, mostly the latter, havebeen recommended for use against roaches. No extended discussion ofthe divers methods proposed for the discouragement or destruction ofthese household pests will be here entered into. Only a few of the morepromising methods of eradication will lie considered.Hydrocyanic Acid GasF'l.llTnigatio'l&In extreme infestation the best method of ridding a premise ofroaches is by fumigation, the best fumigant being hydrocyanic acid gasat the rate of 10 ounces per 1,000 cubic feet for one hour. While thoroughlyeffective, this treatment involves considerable cost, and, o~ing toits extremely dangerous qualities, necessitates extreme care in its application.Before attemptilng fumigation with this POISONOUS gas, detaileddirections shomO, be carefuJ),y studied. Such directions are givenin the lecture on the control of human lice (p. 3~4).Carbon BisuJ.phideA fumigant less dangerou,s to use than the above, but one requiringmuch precaution because of its inflammability, is carbon bisulphide. Thishighly volatile material distributed in open vessels, one pound to each1,000 cubic feet of space, will destroy roaches, but the rooms fumigatedmust be ones that can be very tightly sealed up, as indeed must be the caseIn any fumigation. This method is well adapted for use in the holds of shipsand other vessels. A fumigation of twenty-four hours will kill all verminin a tightly sealed room. 'I'he violently eIJJploaive nature of this materialnecessitates extreme care in its use. No fire of any kind must be aboutwhen it is in use.

Pyrethrwm PowderCOCKROACHES 381A safer, and sometimeo as e1l'ective, fumigant is pyrethrum powderburned in infested quarters. The only precautions here needed is to seethat the places under fumigation are tightly closed.SulphurFumigation for a period of six hours with fumes created by burningsulphur, four pounds per 1,000 cubic feet of space, is also recommendedfor the extermination of roaches. There are other substances possessingsome value as fumigants but the above-mentioned materials comprise themost promising of them.PoisonsIn cases of moderate infestation, or occurrence in situations inconvenientfor fumigation, some one of several substances poisonous toroaches can be employed. Our household species, however, especiallythe alert Croton bug, are not always easily persuaded to partake ofpoisoned food, as they appear to possess an uncanny knowledge of whatmaterials are unhealthy for them 'to eat. In their ability to look out forthemselves, and foil the attempts of man to destroy them, they have beencompared to that wily bird, the crow. But in spite of their intelligencein avoiding pitfalls set in their way, they are more or less subject tocontrol by various poisons and repellents.Sodium FloorideThis material has but recently come into prominence as a roachexterminator, but it is very surely the best remedy in the way of poisonsnow known. This powder probably kills both by contact and certainlyas an internal poison, and by its use an infested apartment may be sooncomphitely cleared of roaches. It is used either pure or diluted with onehalfpart flour or some other such substance. It is not injurious to manunless taken in considerable quantities and thus its use is not attended withdanger. The powder is scattered about the haunts of. roaches and blowninto cracks and crannies occupied by them with a dust gun, or blower.Boratl!Powdered borax, used pure a's a repellent, or mixed with some substanceattractive to roaches as a poison, is an e1l'ective remedy in manycases. One part of borax to three parts of pulverized chocolate is saidto be a good mixture.

S8! SANITARY ENTOMOLOGYPyrethrum PowderDusting with pyrethrum pO,wd~r is often recommended against roachesbut experiments show that for the best results it should be used fullstrength. It is not to be compared with sodium fluoride in its effectiveness.PhosphorusA standard remedy for roaches, and, one long in use, is phosphorus.This substance is used in the form of a paste composed of sweetened flourcontaining'} or! per cent of phosphorus. This paste is spread on bitsof cardboard and set about where it is easily accessible to the roaches.SulphurSulphur, in the powdered form, scattered about where roaches aboundis said to be an effective repellent.Castor OilOne would scarcely expect this oil to be repellent to the omnivorousroach, but articles smeared with it are said to be rarely attacked by them.Of all the poisons and repellents mentioned above, sodium fluorideranks the highest as an effective roach remedy.'TrapsVarious sorts of traps have been recommended for catching roaches,but at the best such means only serve to lessen the numbers of roaches,probably never resulting in extennination.'ENEMIESCertain hymenopterous parasites destroy the eggs of cockroaches andthere are a number of predaceous insects and other enemies noted as feedingon the roaches themselve:. The house centipede is recorded as killingthe Croton bug and it is said. that a toad or a, tree frog will clear a roomof roaches in one night.

CHAPTER XXVIIDiseases Transmitted by the CockroachW. Dwight PierceAs cockroaches are so often found in houses and especially apt tofrequent garbage al).d waste about a house, and frequent the food in thekitchen and on the table, it can readily be seen how easily they mighttransmit disease in case they are capable of carrying the organisms ontheir body or of retaining them in their systems. The cockroach feedson filth of many kinds and goes straight from this filth to food. As itfeeds on the food it contaminates the same with its feces causing noxiousodors which often ruin the food. We owe to Cao, the Italian investigator,our principal knowledge of the manner in which the cockroach can transmitdisease organisms. Cao worked with the bacteria which might befound in food and in carcasses and he may be said to have covered thegreater part of the bacterial organisms which the cockroach is mostlikely to be able to transmit. There can be no question of the desirabilityof controlling roaches in houses, hotels, and eating places. The necessityof this is the greatest in public eating houses where the roaches can feedon sputum and debris left by customers or by employees. A filthy employeeand a cockroach-infested restaurant make a combination to befeared.In the following pages will be found a summary of the records whichhave been made of the role of cockroaches in the transmission of organisms,es'p~cially disease organisms.PLANT ORGANISMSTkallophytq,: Fwngi: CoccaceaeMicrococc~ nig;ofa8ciem Northrup, cause of an insect bacteriasis,has been experimentally transmitted to Periplaneta americana by No!thrup.Sarcina alba Eisenberg has been isolated from the feces of Blattaorientalia by Cao in several series of experiments, but in no case was itfound to be pathogenic after passage through the cockroach, even whenfed in pure culture, or with other foods. In experiments with other383

384 SANITARY ENTOMOLOGYinsects, Cao has found this organism derived from the feces fatal to animals(Cao 1906a).Sarcina aurantiaca Lindner and Koch. Cao (19060.) isolated thisorganism from the feces of Blatta orientalis, and found it nonpathogenic. -In various experiments he fed it to roaches, finding that when fed in connectionwith a diet of bread and an infusion of putrid beef liver, a diet ofbread and an infusion of 1 per cent peptone, and a diet of bread witha putrid infusion of beef flesh, it became slightly pathogenic after recoveryfrom the feces of the roach.Sarcina lutea Schroeter was isolated by Cao (1906a) from the fecesof Blatta orientalis and found nonpathogenic. In various experiments hefed it to roaches in connection with other foods, finding it nonpathogenicin all but four tests when it was given with infusion of putrid liver, peptone,or beef, in which cases it was slightly pathogenic af.ter recovery fromthe feces of the roach.Staphylococcus pyogencs albus (Rosenbach) and S. p. aurcus (Rosenbach),the causes of many forms of SEPTICEMIA, have -been proven byHerms to be capable of carriage by the Croton bug, Blattella germanica,on its feet, and he has shown that it can contaminate food on which itfeeds, or with which it comes in contact, and also that both varieties canbe found on the cockroach in nature.Thallophyta: Fwngi: BacteriaceaeBacteriwm anthracis (Davaine), the cause of ANTHRAX, was fed byKuster to Blatta orientalis and later recovered from its feces.Bacteriwm cholerae gallinarum (Perroncito), the cause of FOWLCHOLERA, was experimented with by Cao (190680) in an attenuate formby feeding it to the cockroach Blatta orientalis. WIlen fed to starvedroaches without their food it passed through the intestines without anincrease in virulence, but when fed to the roach in conjunction with adiet of bread with a putrid infusion of beef liver the organism partiallyregained its lost virulence. Kuster also fed this organism to B. orientalisand recovered it from the feces.Bacillus coli Escherich, a pathogenic organism normally found in thealimentary canal of man and animals, sometimes cau.sing various types ofdiseases, has been isolated readily by Cao (1906a) from the feces of Blattao rientalis. He found that it remains in the intestines of the roach evenafter prolonged fasting. The various strains obtained varied in pathogenicity.When fed to the roaches in connection with other food it sometimesgreatly increased its virulence by passage through the insects.Bacillus fluorcscens liquefasciens Fluegge, a fluorescent organism, wasisolated by Cao from a series of Blatta. prientalis, but he obtained no

DISEASES TRANSMITTED BY THE COCKROACH 885pathogenic results from inoculations in this series. In another series oflliatta which had fasted for 45 days and whose feces contained nofluorescent bacilli and only a mildly pathogenic strain of Bacillus coli, hefed the roaches with this organism. One strain derived from the feces ofa pigeon which had proven absolutely innocuous was fed to roaches forfive days. The feces of the Blptta collected aseptically by squeezing theabdomen, killed a guinea pig in five days, with production of an abscessat the site of inoculation. From the pus was isolated a fluorescent bacilluswhich, when inoculated in pure culture subcutaneously, appeared pathogenicand killed a guinea pig and a cony in four and five days respectively,with production of a large purulence. Another strain isolatedfrom an infusion of putrifying flesh was fed to three roaches and aftereight days their feces were inoculated and killed a guinea pig in sevendays, with production of an abscess at the site of inoculation. Thefluorescent bacilli isolated from the feces were ~ually pathogenic. Athird strain obtained from the air did not acquire perceptible virulence inpassing through the roaches. A fourth strain isolated from earth inwhich were living many Lumbricus, acquired in the Blatta a notable pathogenicity.The feces contained germs which when isolated and inoculatedkilled a guinea pig in 54 hours with subcutaneous edema and slight enlargementof the spleen, and exhibited :its presence in the blood. He also conducteda considerable series of experiments in feeding this organism withother foods to the roaches, and demonstrated increased pathogenicity inmany cases after recovering it from the feces.Bacillu8 f/,uorc8cen8 nonliquefa8cien8 Eisenberg and Krueger was isolatedby Cao in two series of experiments from the feces of Blattaorientalis and when inoculated into a guinea pig caused its death in 48hours without striking pathological symptoms, although the organismmay be recovered from the blood. It was not so virulent in the cony, causingdeath in eight days without purulence at the site of inoculation. Whencultures of this organism were fed to starved Blatta one strain recoveredfrom the feces of the guinea pig_ passed through the intestines of theroach remaining innocuous, but a strain isolated from the earth had amoderate pathogenicity in the Blatta, producing abscess and death ofa guinea pig; the inoculation of pure culture killing a guinea pig in fourdays, with production of a large subcutaneous abscess. The germs wererecovered from the spleen and from the pus. Quite a series of experimentswere conducted with three strains of this bacillus, feeding them in connectionwith other foods, and in a number of these experiments two ofthe strains became moderately pathogenic.Bacillus megatTlerium Ravenel, a chromogenic organism found in soil,was isolated by Cao from the feces of a Blatta orimtalis in a single seriesof experiments. In all of his experiments with th.is organism he did not

386 SA.NITARY ENTOMOLOGYfind that it acquired. pathogenicity by passage through the intestines ofthe insect with or without other foods.Bacillus "proteisimile" Cao. An organism virtually described underthis name was isolated by Caa from the feces of Blatta orientalis in two ormore series of experiments in three different strains of varying virulence.One strain retained its virulence in successive passages for five months. Intwo experiments in which starved cockroaches with nonpathogenic feceswere fed on nonvirulent· cultures of this germ and on a diet of breadwith putrid infusion of beef liver, and on a diet of 1 per cent infusionof peptone, this germ became. intensely pathogenic' in the first case., killing,when inoculated, a guinea pig in two or three days, and in the second casein 36 to 40 hours, with acute septicemia. 0Bacillus "pseudo edema maligno" Cao, cause of MALIGNANTPSEUDOEDEMA, was isolated by Co.o in one instance from a series ofB. orientalis, and he found it retaining its virulence in successive passagesthrough many months.Bacillus radiciformis Tataroff, a saprophytic organism found in water,was isolated by Co.o from the feces of Blatta orientalis in a single seriesof experiments. In all of his tests with this organism, he did not findthat it acquired pathogenicity by passage through the intestines of theinsect with or without other fvods.Bacillus "similcarbonchio" Cao, an organism described by Cao as similarto B. anthracis, was isolated in pathogenic strains from Blattaorientalis by Cao. In one series of experiments it was isolated from anumber of B. orientalis, the feces of which, when inoculated into a guineapig, caused its death in 42 hours. From pure cultures isolated from thefeces, it was inoculated into a guinea pig and caused its death in 40 hours,with intense sero-sanguinolent edema and an enormous spleen. The organismwas recovered from the heart blood. A cony inoculated with pureculture died in 48 hours, with symptoms similar to those found in hematiccarbuncle. The germs were still found in the feces of the cockroachesafter 21 days fasting and retained their virulence, causing death withformation of a tumor on the spleen, but less intense. It maintained itsvirulence in successive' passages through many months. When fed tostarved cockroaches with nonpathogenic feces, two nonpathogenic strains(one from soil and one from the feces of Calliphora 'tJomitoria) failed toincrease their pathogenicity when eaten alone, or when combined withsterile bread, sour milk, putrid milk, rotten egg, and fresh flesh; but onestrain obtained slight pathogenicity when eaten with putrid flesh, moderatepathogenicity when combined with human feces, and intense pathogenicitywhen eaten with 00. diet of bread and putrid beef liver, a diet of breadand 1 per cent infusion of peptone, or a diet of bread and an infusion ofputrid beef flesh.

DISEA~ES TRANSMITTED BY THE COCKROACH 387Bacillus subtilis Ehrenberg, an organism frequently found in air,water, and soil, seldom pathogenic, was fed in three series of experiments,by Cao, in conjunction with other foods to starved roaches of Blattaorientalis. In two cases he obtained slight pathogenicity inducing localsuppurations but no killing of the experimental host.Baculus "tifosimile" Cao, a bacillus described by Cao resembling B.typh08U8, was isolated by Cli.O in three out of four series of experiment

388 SANITARY ENTOMOLOGYANIMAL ORGANISMSProtozoaSarcodma: AmOebina: AmoebidaeEndamoeba bla.ttae (Biitschli) passes both its sexual and asevualcycles in the intestines of Blatta orientalis.Mastigophora: Polymastigim,a: TetramitidaeTrichomonas orthopterwm Parisi is parasitic in Blatta species.Mastigophora: Binucleata: LeptomonidaeLeptomonas blattarum (Stein) is parasitic in endoderm of Blattaorientalis. .Telosporidia: GregarinUda: GregarinidaeClepsidrma blattarum Von Siebold is a parasite in the intestine ofPeriplaneta americana.Clepsidrima. serpentula DeMagalhaes is also a parasite in the intestineof Periplaneta americana.Gamoc!Jstis tenax Schneider is a parasite in the intestine of Blattellalapponica.Gregarina legeri Pinto is a parasite in the intestine of Periplanetaamericana.Gregadma blattarum Von Siebold is a parasite in the intestine ofBlatta orientalis, Periplaneta americana and Blattella germanica.Telosporidia: Coccidiidea: EimeriidaeDiploc!Jstis schtneideri Kiinstler is a parasite. in Periplaneta americana.Neosporidia: Myxosporidia: ThelohaniidaePlistophora periplaneta Lutz and Splendore is parasitic in Blattaorientalis and Periplaneta americana.Plistophora sp. causes neoplasia of the adipose tissue in Blattaorientalis.Ciliata: Heterotricha: BursarinidaeNyctotheTUs o'lJalis is parasitic in the intestine of Blatta o rientalis.

DISEASES TRANSMITTED BY THE COCKROACH 889MetazoaPlatyhel,!",ia: Cestoidea: HymtrnolepididaeDavainea madagascariensis (Davaine) is a tapeworm of man of whichthe life history is unknown hut Castellani and Chalmers suggest thatthe cysticercus may be found in the cockroaches Blatta orientalis andPeriplaneta americana.Nemathelminthes: Acanthocephala: GigamtorhynchidaeMoniliformis momliformis (Bremser), a parasite of rodents andoccasionally of man, may pass its larval stage in Periplameta americana,according to De Magalhiies.Nemathelminthes :" Nematoda: SpiruridaeA larval nematode, evidently one of the Spiruridae, is described fromthe visceral cavity of Periplalfl£ta americana by De Magalhaes.Gongylonema pulchrum Molin is a parasite of the hog. Ransom andHall report feeding eggs of a Gongylonema of the hog, presumablyof this species, to Croton bugs, Blattella germanica, and finding that theeggs hatched and developed to encysted larvae.Gongylonema neoplasticum (Fibiger and Ditlevson), a human parasiticworm which produces cancer-like tumors in the stomach of the rat,passes its intermediate stages in Blattella germanica and Blatta orientalis.It develops as far as an encapsuled larva in the cockroach, accorf;li~g toFibiger and Ditlevson.Gongylonema scutatum (Miiller), a very common parasite of cattle,can pass its first stages in the cockroach Blattella germanica, underexperimental condition~, according to Ransom and Hall.Spirora gas~rophila (Miiller), a parasite in the alimentary canal ofthe hedgehog, has been found by Seurat in the fourth stage encapsuledin the general cavity of Blatta orientalis."Nemathelminthes : Nematoda: OxyuridacOxyuris blatft1!orientalis Hammerschmidt is found in the cockroach:!sBlatta orientalis and Periplaneta americana according to De Magalhnes.Oxyuris bulhocsi De Magalhaes is also found in the intestine ofPeriplaneta americana according to De Magalhaes.Oxyuris diesingi Hammerschmidt is found, according to De Magalh'iiesin Blatta orientalis and PeriplOlTteta americana.

390 SANITARY ENTOMOLOGYOtc'/Juris kunckeli Galeb is, according to De Magalhaes, found inPeriplaneta americana.It will be seen by the evidence presented that the cockroach is apotential carrier of many disease organisms, but, however, it has not yetbeen proven to be -definitely a regular carrier of wany. Those diseaseswhich you can most surely expect to be transmitted from time to time bycockroaches are those in which the organism can be taken up from thefeces of man or animals and carried by the roaches to food.You can also see that the danger from cockroach transmission ofdiseases is in small towns w~ere there is little care about sanitation, andwhere there is no sanitary sewerage. Anyone who has traveled extensivelyin the small towns of America can readily see how cockroaches couldtransmit diseases by polluting 'food in hotel kitchens and even diningrooms, and even by polluting the bread and food in the grocery storesand meat markets.Noone has really made a cortsjstent study of the possibilities of cockroachtransmission of diseases and there is very little doubt that, if suchstudies could be conducted in a locality where disease transmission is possible,much evidence against the roach could be obtained.REFERENCESBarber, M. A., 1914.-Philippine Journ. Science, Manila, vol. 9 B, No.1,pp.1-4.•Cao, G., 1906a.-Annali D'Igiene Sper., vol. 16, n. s., pp. 339-368.De Magalhaes, P. S., 1900.-Arch. de Parasit., vol. 3, p. 45-69.Fibiger, J., and Ditlevson, H., 1914.-Anat. Path. Inst. and Zool. Mus.Univ. Copenhagen, vol. 25, 28 pp., 4 pIts.Herms, W. B., 1915.-Medical and Veterinary Entomology, pp. 41-4:'3.Herms and Nelson, 1913.-Am. Journ. Pub. Health, September.Kiister, H. A., 1902.-Inaugural Dissertation Doctorwiirde Univ~ Heidelberg,43 pp.Longfellow, R. C., 1913.-Am. Journ. Pub. Health, January, p. 58.Northrup, Z., 1913.-Michigan Agr. Exp. Sta., Tech: Bull. 18, 32 pp.Ransom, B. H., and Hall, M. C •• 1915.-Journ. Parasitol.,.vol. 2, No.2,pp.80-86. .Seurat, L. G., 1916.-Bull. Scient. France et Belgique, ser. 7, vol. 49,fasc. 4, pp. 310-314, 350. -

CHAPTER XXVIIIThe Bedbug and Other Bloodsucking Bugs: Diseases Transmitted,Biology and Control IW. Dwight PierceProbably no species of bloodsucking insect is better known throughoutall the world than the bedbug, Cimex lectulariu8 Linnaeus. Thisspecies and its congener, C. hem;"ptoroS Fabricius (rotwndatua) Signoret,live in the beds of man and suck human blood. There are a number ofrelated species, among which C. boueti Brumpt, in French Guinea, is alsosaid to suck the blood of man. The other species are bird and bat para.sites.On account of the habit of the bedbug of sucking the blood of man,but hiding by day in houses and vehiclea, this species has many opportunitiesof transmitting diseases, provided that its methods of life conformwith the requirements of the disease organisms. Girault has pointedout that the bedbug will feed on mice, living or dead. This is a. veryimportant point in considering its a,bility to transmit disease.Any disease which should be shown to be spread exclusively by thebedbug will undoubtedly have a localized distribution, and ·is very likelyto be confined to certain buildings or groups of buildings, but on theother hand may be spread long distances by travelers carrying thebugs in their baggage and on their clothes. 'It will never be possiblefor a disease carried by bedbugs to spread :r:apidly like a fly-borne 01mosquito-borne disease. As bedbugs have been found in houses withouthuman occupants for two years or more, we must assume that they obtainblood from rodents, and it is possible that in this wayan infection mightbe maintained in a dwelling. There is some very interesting literature onthe possible disease-transmitting role of bedbugs and this has been briefedand arranged below in the same manner that the discussions of diseasestransmitted by other insects have been arranged in preceding lectures.Certain other blood-sucking bug~ are included in the discussion.S This lecture was presented November 18, ]918, and distributed January 25. 1919,391

39~ SANITARY ENTOMOLOGYDISEASES OF THE PLANT KINGDOM TRANSMITTED BY BUGSThallophyta: fungi: BacteriaceaeBacillualeprae Hanson, the cause of LEPROSY, has been considerablyexperimented upon with a view to determining the possibility of bedbugtransmission. Carmichael, in 1899, suggested the possible connectionbetween bedbugs and leprosy. Long, in 1911, conduded experiments.He allowed two Qedbugs to bite lepers, in'the neighborhood of leprousnodules, and then examined, the alimentary canal of the bugs and foundthem to contain the bacilli. He cites in one of his papers the case of acertain man who slept in a hut formerly occupied by a leper. He wasbitten by bugs while sleeping there and later developed the disease. Skeltonand Parham think transmission by bedbugs in Zanzibar to be improbable.Thomson has conducted a few experiments with this organism,and Smith, Lynch, and Rivas have also published an article on the transmissibilityof the leper bacillus' by the bedbug. Ehlers found the leprosybacillus in the digestive tract of bedbugs in 'the West Indies in 1909 (see~umston 1918). Sanders in South Africa found the bacillus in ~o outof 75 bugs fed, when starved, on leprous patients. The bacilli occurred inthe proboscis up to the fifth day, in the digestive tube to the sixteenthday, and also in the feces. Goodhue also found the lepra bacillus in bugswhich have bitten leprous patients. It still is incumbent upon some oneto attempt the transmission of the leper bacillus by inoculation of fecesof the bedbug in skin abrasions. It would appear that scratching after abite would be the logical means of inoculating the disease.Bacillus pestis Kitasato, the cause of BUBONIC PLAGUE, has beenexperimented on by a number of authors to determine the possibility oftransmission by bedbugs. Yubitski conducted certain experiments whichare reviewed by Manning. Cornwall and Menon have also written onthe possibility of transmission of plague by bedbugs.Cumston (1918) reviews the literature, but signally fails to grasp thesignificance of the records he quotes. Like most other investigators hewas looking primarily for evidence of transmission by' bite. Jordanskyand I{lodnitzky succeeded in inoculat~ng mice with plague by having thembitten by infected bedbugs. They found large numbers of plague bacilliin the digestive tube of one bedbug and a few in anpther on the 36th dayafter they had bitten a pestiferous mouse. Nuttall and Wierzbitzky alsofound the bacillus in the digestive tube. In India Walker found ~~ro ofthe bugs in huts of natives infected with plague, to be infected with thebacillus. He also transmitted the plague to a rat by a bug .which hadbitten a pestiferous patient.

THE BEDBUG AND OTHER BLOODSUCKING BUGS 398·-:: Bacillus typhosus Eberth, cause of TYPHOID FEVER, may possiblybe transmitted by the bedbug, according to Riggs.DISEASES OF UNKNOWN ORIGINPOLIOMYELITIS or INFANTILE P ARAL YSIS has been suspectedby various authors of being insect-transmitted. Manning has.made a contribution to the study of the possible agency of the bedbugin the transmission of this disease and claims .that the bedbug fulfillsthe· necessary requirements as a carrier of this disease. Howard andClark (191!e) obtained definite experimental evidence of the possibility ofthe -bedbug as a carrier. In one. out of several experiments, ten bedbugsfed on a patient took. up the virus and when, seven days later,these were killed, ground up in salt solution, filtered, and injected, themonkey beca~e paralyzed and an autopsy showed typical lesions. Asecond monkey inoculated from this otie developed·a definite paralysis onthe 6th day and an autopsy showed characteristic lesions.DISEASES OF THE ANIMAL KINGDOM TRANSMITTED BY BUGSProtozoaM astigoplwra: Bi'TIIUCleata: TrypanosomidaeCastellanella brucei (Plimmer and Bradford) Chalmers (Trypano-8oma), the cause of NAGANA of animals, and probably identical withthe causative organism of SLEEPING SICKNESS, was experimentallytransmitted, according to Sangiorgi, to white mice by the bite of Cimexlectularius. This organism is normally transmitted by tsetse flies andhorse flies.Castellanella equinum (Voges) (Trypanosoma) the cause of MALDE CADERAS, a South American disease of horses, of which the wildanimal reservoir is probably the capybara, is probably transmitted bythe kissing bug, Triatoma infestans, but Sangiorgi succeeded in transmittingit to white mice by tlie bite of Cimex lectularius.Schizotrypanum cruzi Chagas (Trypanosoma) the cause of CHAGASFEVER, a disease of man in South America, is carried by sucking bugs.The disease has its reservoir in the armadillo· and related animals. Chagaliand Brumpt have proven that the natural invertebrate hosts are thekissing bugs Triatoma megista Burmeister, T. sordida Stal, T. geniculataLatreille, and T. chagasi, and, undoubtedly also Rlwdnius proli:r:ua Stiil.Gonzales-Lugo has obtained' experimental transmission' with the last

394 SANITARY ENTOMOLOGYnamed bug and Brumpt has proven it a durable host. Brumpt has alsodemonstrated development in the bedbugs Cimex lectulariua, C. boueti,and C. hemipterus.There are two types of reproduction of the organism in the insects.In the sexual method, about six hours after ingestion of blood the kinetonucleusmoves close to the trophonucleus with which it possibly blends;the flagellum and undulating membrane are now usually lost, but someforms retain the flagellum. The parasite becomes rounded and multipliesrepeatedly by division. After this has cea,sed it becomes pear-shaped,develops a flagellum and becomes a crithidial form and then passe.s intothe cylindrical portion of the intestine where it can be !icen in about !5hours after the ingestion of blood. The final stage is a small, trypaniformtype, long and slim with band-like trophonucleus and large kinetonucleus.This form is found in the hind gut in the body cavity and in the salivaryglands, and is the form by which the parasite is transmitted to a new vertebratehost. The development in the bug requires at least eight daysfor its completion.The asexual method of reproduction is a constant process and is asimple multiplication, giving rise to the crithidial forms which are foundprincipally in the hind gut.Originally the disease was supposed to be transmitted by the suckingof blood by insects. Brumpt declares that transmission is exclusivelyby dejections. As Rhodnius prolit.CUs passes ·its dejections immediatelyafter removing its beak, while the Triatoma species do not pass dejection~during their repast, Brumpt thinks it likely that Rhodnius is a morepotent transmitter, in view of the fact that dejections are infective. Inthis connection the bedbug ·has a very interesting habit which bears uponthe possibility of its transmitting the disease. Patton -and Cragg havepointed out that it defecates immediately after a feed, but unlike themajority of bloodsucking insects, does not pass out red blood, but onlythe remains of the last meal, a semi-solid sticky material. This blackfluid is passed out just after the proboscis is withdrawn, and the bughas a very characteristic habit of turning around and moving backwardsin such a way that the excreta fall in the neighborhood of thewound made by the proboscis. Blacklock has studied the multiplicationa~d infectivity of S. cruzi in Cimex lectularius, and concludes that theorganism is capable of living and multiplying in the bedbug for longperiods. The parasites found in the bedbug are infective on inoculationas early as 21 hours and as late as 77 days from the infecting feed.Transmission of the disease to healthy animals by feeding an infectedbug on them is of very rare occurrence. It was only once observed in thecourse of these experiments. In the light of Brumpt's work, we can nowsee that feeding experiments were almost naturally to be expected not to

THE BEDBUG AND OTHER BLOODSUCKING BUGS 395succeed, as the transmission of the disease is apparently only by contaminationthrough scratching in or inoculation of infected feces.Trypanozoon duttoni (Thiroux) (Trypano8oma) , an organismusually found in mice, has been shown by Brumpt to be capable of developingin Cimex lectulariu8. It is usually parasitic in fleas and istransmitted to the mice by their lickiIlg up the feces of the fleas or thetIeas them~elves. It is probably infective by means of bedbugs in thesame manner.Trypanozoon lewisi (Kent) (Trypano8oma), the caUSe of ,RATTRYPANOSOMIASIS, is usually carried by fleas, but Brumpt (1913a)finds that it can complete its cyclical development in Cimex lectularius.and he infected a rat with an inoculation of the rectal contents of a bugafter six days and also after 38 days.Trypano8oma (8en8. lat.) ve8pertilioni8 Battaglia, the cause of BATTRYPANOSOMIASIS, is transmitted by the bat bedbug, Cimex pipi8-trelli Jenyns, according to Pringault.M a8tigophora: Binucleata: LeptomonidmLei8hmania species, the cause of NON-ULCERATING ORIENTALSORE, passes part of its life cycle in the bug, Erthesina fullo (Thunberg),according to Carter.Lei8hmania donovani (Laveran and Mesnil), the cause of INDIANKALA AZAR, has been thought by many to be transmitted by insects.There is considerable conflicting evidence on the subject, a greater partof which is reviewed very thoroughly by Wenyon. Patton has demonstratedthe development of the organism in the bedbugs Cimex hemipterus(rotundatu8) and C. lectularius in India. Cornwall and La Erenais fedCimex hemipterus on citrated rabbit blood containing this organism,through a membrane, and obtained infection of the bugs and developmentof the parasites for a period of at least !!9 days. Cornwall and Menonhaving shown in previous papers 'that the bedbug cali not regurgitatethe contents of its stomach in th_e act of feeding and therefore can nottransQlit kala azar or Oriental sore by its bite, and being unable to findevidence of any intracellular stage of the parasite in the bug, turnedtheir attention to the contents of the _rectum. No one has been able todemonstrate the presence of ,any resistant stage in the feces of the bugs,although these authors have found active flagellates, and occasionallyrounded forms, as far down as the lower intestines of the infected ];Jugs,in a fairly large proportion of those examined. They failed to find anyform which could suggest an extra corporeal resistant stage. Theyhave found active flagellates in the stomach contents of the bugs for 29days.

396 SANITAR Y ENTOMOLOGYFIG. 74.-Bedbug: Egg and newly hakhed larva: a, Larva from below; b, larva fromabove; c, claw; d, egg; e, hair or spine of larva. Greatly enlarged, natural size oflarva and egg indicated by hair lines. (Marlatt.)FIG. 75.-Bedbug: a, Larval skin shed at first molt; b, second larval stage immediatelyafter emerging from a; c, same after first meal, distended with blood . . Greatlyenlarged. (Marlatt.)The life cycle in Cimex hemipteru8 and C. lectulariu8 has been demonstratedby Patton. The parasites are ingested by the bug, enclosed inthe large cells or leucocytes, and develop into fully flagellated formswithout reference to the temperature of the external air. The sizeincreases from 4 to 7 micra and vacuolation of the cytoplasm occurs onor after the second day. The single parasite may proceed directly toflagellation, by the appearance of an area stained bright pink by Giemsasolution and called the flagellar vacuole. This vacuole which has a darkcenter rapidly increases in size up to 1 to g micra and, passing to thesurface, sends out a pink brush which forms the flagellum by merelygrowing longer. The flagellate form has a dark blue, granular cytoplasmwith a circular trophonucleus which stains deeply in the center; and a.kinetonucleus lying across the long diameter and situated near the

THE BEDBUG AND OTHER BLOODSUCKiNG BUGS 397FIG. 76.-Bedbug: Adult before engorgement. Much enlarged.(Marlatt.)FIG. 77.- Bedbug, Oimex lectularius: a, Adult female, engorged with blood;' b, same frombelow; c, rudimentary wing pad; d, mouth parts. a, b, Much enlarged; OJ d, highlymagnified. (Marlatt.)(All from U. S. Dept. Agr. Farmers' Bull. 754, figs. 3, 4, 2, 1.)trophonucleus, and possesses a long flagellum consisting of a numberof filaments adhering closely together, inserted into a pale area near thekinetonucleus. These parasites may divide into two equal flagellate formsand apparently may go ,on dividing for some time. Instead of proceedingdirectly to flagellation, the parasite may show a division of its nuclei intotwo, with the formation of two flagella, and then division into twoflagellate parasites, or the nuclei may multiply without division CYf thecytoplasm, so that forms containing four to eight nuclei may be together,which eventually break up into separate flagellate forms. If thebug feeds on blood before the development is completed, the flagellatesare destroyed. Development is completed in ten to twelve days after asingle feed.Cornwall and La Frenais describe a thick-tailed form in the bugafter the 9l0th day. Cornwall and Menon state that the flagellate form

398 SANITARY ENTOMOLOGYthrives only at temperatures from 16 0 to ~6° C. (610 to 79 0 F.) andis therefore unfitted to exist in the human body. This is further evidencethat the flagellate is a typical insect form. They have failed to find apostflagellate cystic form in. the stomach of the bug.Transmission by insects has not been demonstrated, although there isconsiderable evidence that it" l:!'an nbt be transmitted by the bite of thebedbug in which the organism normally flagellates. Cornwall and Menonclaim that there are only two possible means of transmission left; ruptureof a bug containing flagellates in the neighborhood of a puncture orabrasion, and passage of ~ystic forms into the feces, and there is nodirect evidence for either. They lean to the rupture theory because itseems to account for the peculiar distribution of kala azar. It is comparativelyrare and often localized in certain dwellings. The bug doesnot live on the person, but in buildings and furniture. It does not generallycrawl over the skin when feeding but attacks exposed parts from afairly safe position. It mu~t therefore be a comparatively rare event fora bug to be ruptured on the skin of its occasional host. They may betransported from place to place in fur.niture and clothing, and may gofrom house to house in search of food. The bug is also more or lesslocalized. As the bug would be sac:cificed in the act of transmission, it isclear that a human reservoir of the disease must be at hand if the bugs ina building are to remain dangerous. Knowles suggests the possibilityof hereditary transmission in the bedbug or in intestinal worms.Leishmania tropica (Wright), the cause of ORIENTAL SORE, isalso thought to be transmitted by insects. Wenyon found that the bedbugCimex lectularius could take up the parasites and that develop~mental stages were demonstrable in its gut. Patton (191~) obtaineddevelopment of the parasite into flagellate forms in Ci'mex hemipterus atlow temperature (!!~O to ~5° C.) and produces considerable evidencein favor of these species as the natural carrier.Mastigophora: Spirochaetacea: SpirochaetidaeSpiro8chaudinnia berbera (Sergent and Foley), the cause of .NORTHAFRICAN RELAPSING FEVER, is spread by the body louse. Sergentand Foley have obtained negative results with Cimex lectulariu8.Spiroschaudinnia duttoni (Novy and Knapp), the cause of TROPICAL AFRICAN RELAPSING F'EVER, is normally spread by ticks.Breinl, Kinghorn and Todd in 1906 and Nuttall in 1907, were unsuccessfulwith transmission experiments with Cimex lectulal;us.Spiroschaudinnia recurrentis (Lebert), the cause of EUROPEANRELAPSING FEVER, is normally t:ransmitted probably by the body

THE BEDBUG AND OTHER BLOODSUCKING BUG~ 399louse. Nuttall in 1907 .experimented with the Russian strain of thisdisease and succeeded in transmitting relapsing fever, in one experiment,to a mouse by the bite of Cime.r lectulariu8. He found that usually thespirochaetes were digested by the bugs, the time depending upon the temperature.Fliigge, in 1897, infected monkeys with the contents of bugs,removed twenty-four hours after they had fed on relapsing fever blood.Karlinski and also Schaudinn observed the survival of spirochaetes intwo bugs for 30 days or more. Various authors have failed to transmitspirochaetes by bugs, but it is probable that these failures were becausethey attempted to transmit by means of the bite, rather than by crushingor scratching in the contcnts of a bug or its feces. Tictin, however,while suggesting that the bedbugs might transmit the discase by theirbite, also .suggested that it might be by their being crushed and thecontents entering the skin through excoriations due to scratching.In summary we may draw the conclusion that probably all diseaseorganisms which are capable of passing part of their cycle in the bedbugwill be found to be transmitted through the scratching in of thefeces of the bug, or by the rupturing of a bug while in the act of feeding,or over an excoriation of the skin. It is quite possible that any organismwhich the bug may take up from the hlood and which in like manneris infective to the blood can be transmitted under favorable conditions inthis manner.There is most certainly a very promising field for research in theworking out of the possibilities of disease transmission by blood-suckingbugs.LIFE HISTORY NOTESThis lecture deals primarily with the bedbugs of the genus Cimex,family Cimicidae, but also contains mention of the false bedbugs, orkissing bugs of the genus Triatoma (Conorhinus), family Reduviidae.The best discussion in English, with illustrations, of the genusTriatoma (Conorhinus) is given by Patton and Cragg. These bugs liveon. human and mammalian blood. The egg of Triatoma rubrofasciata(De Geer) of India is rounded at one end and flattened at the other,which for~s' a kind of operculum. It measures 2 mm. by 1 mm. Theincubation period varies from 20 to SO days. The development is similarto that of all winged Reduviids, each stage showing more developed wingpads, until the fully winged adult stage is reached. The developmentrequires several months from eggs to adult.Triatoma megista (Burmeister) of South America is almost entirely adomestic insect. The adults enter inhabited hOllses, but never those whichhave been abandoned. In old houses they are to be found in cracks and

·400 SANITARY ENTOMOLOGYholes in the walls, where they lay their eggs. The early stages, which ~rewingless, crawl out of their resting places in the walls as soon as thelights are put out, and make their way to the beds of the occupants ofthe house. The adults behave in the same manner, but as they are pow~erful·:8iers they can reach people who sleep in hammocks. The bite is saidto be painless and to leave no mark; this is quite unlike the bite ofTriatoma rubrofa8ciata, which, in the case of some people, leaves a distinctmark for weeks. The eggs of T. megista are laid in batches of from8 to 12, and as many as 45 such batches may be laid. They hatch in from25 to 50 days. A generati.on requires about 824 days.Triatoma 8angui8uga (Le Conte) is a native of the United Statesand is called the Texas bedbug, or the "blood-sucking cone nose." It·comes into the houses and sucks the blood of man. It is also found ~chicken houses and horse stalls, but its normal food is supposed to be thebody juices of other insects, including the bedbug.A number of other species are recorded as causing severe bites onman.The bedbugs Cimex lecttdarius Linnaeus, C. hemipteru8 Fabricius(rotwndatus Signoret) , and C. boueti Brumpt, attack man, while C. hin.unr,dinis Jenyns attacks the swallow, C. columbariu8 Jenyns the pigeon, andC. pipistrelli Jenyns the bat. The first named is cosmopolitan, the second'tropical and subtropical, ~he third South ~erican. The first two are·essentially domestic species. 'During the daytime these species hide in·cracks and crevices in the beds, furniture, and walls of bedrooms. Theyusually feed at night but will not uncommonly feed in the daytime if theycan do so without detection. The most characteristic feature of the bed':bug is the very distinct aitd disagreeable odor which it exhales. Theabsence of wings in the bedbug is of great advantage in control work,as it confines its range to those points it can reach in its roaming. The,eggs are white, oval objects having a little projection run around oneedge, and may be found in batches of from 6 to 50 in cracks and-crevices where the parent bugs go for concealment. A single female maylay as many as 190 eggs. The eggs hatch in a week or ten days in warmweather, but require a considerably longer time in cold weather. Theyoung are yellowish white at first, but in succeeding molts become darkerand darker brown. There is very little important difference in the.appearance of nymphal and adult stages. There are five molts coveringvarying lengths of seven to eleven or more weeks. The bedbug is capableof living for long periods without food. Normally fed bugs may livealmost a year, and partly grown specimens have been kept 60 dayswithout food. The bite of the bedbug is very poisonous to some persons,and their presence is sufficient to cause uneasiness and loss ofsleep. (Figs. 74-77.)

THE BEDBUG AND OTHER BLOODSUCKING BUGS 401Ha:mato8iphon inwdora Duges is a native American bug related tothe bedbug, found in the Southwestern States and Mexico. It wasprobably originally a parasitic messmate of birds and bats, but has nowbecome an important poultry pest, and in those regions, due to the closeassociations between poultry and human beings, is often a serious housepest.TREATMENT OF BITESTo allay the irritation caused by the bite of the bedbug T)eroxideof hydrogen, or dioxygen, may be used with good results.Tincture of iodine is also a good counterirritant.CONTROL MEASURESThere is practically no information on adequate methods of controllingthe TIjatomas.The bedbug when badly infesting houses may be controllcd by fumigation~ith hydrocyanic acid gas at the rate of 10 ounces of cyanid$! foreach 1,,000 cubic f~et, or fumes of sulphur at the rate of five pounds per1,000 cubic fect. Such fumigation should be carried out as describedelsewhere (p. 325).In cases of moderate infestation it is possible at a slightly greatercost of time and personal ~ffort, to eradicate the bugs by a liberaluse of benzine or kerosene, introduced with small brushes or feathers, orby injecting with syringes into all crevices of beds, furniture, or wallswhere the insects may have concealed themselves.Corrosive sublimate and also oil of turpentine may be used in thesame way.Careful inspection of beds and bedding, particularly mattresses, isimportant in any attempt to free a house of the bugs. The use of ironbedsteads and bedding which is easily examined and treated facilitatescgntrol.Travelers frequently have their luggage infested while at hotels andin trains. On arrival at home it would be well to carefully examine theclothing before putting it away.Very frequently bedbugs are introduced into homes with laundry workwhich is carried to the home of the washwoman. Such wash work shouldbe carefully i.nspected on receipt.'LIST OF REFERENCESBlacklock, B., 1914.-Brit. Med. Journ., April ~5, pp. '91~-918.Brumpt, E., 191~.-Bull. Soc. Path. Exot., vol. 5, No.6, pp. 860-867.

402 SANITARY ENTOMOLOGYBrumpt, E., 1915a.-Bull. Soc. Path. Exot., vol. 6, pp. 167-169.Brumpt, E., 1915b.-Bull. Soc. Path. Exot., vol. 6, p. 170.Brumpt, E., 1915c.-Bull. Soc. Path. Exot., vol. 6, pp. S8fl-SBS.Carmichael, 1899.-Med. News,.Jan. 21.Carter, R. M., 1911.-Trop. Med. and Parasit., ser. T. M., vol. 5,pp. 15-S2.Chagas, C., 1909.-Arch. Schiffs. u. Tropenhyg., Sept. 4.Cornwall, J. W., and La Frenais, H. M., 1915.-Ind. Journ. Med. Res.,vol. S, pp. 698-724.Cornwall, J. W., and Menon, T. K., 1917.-Ind. Journ. Med. Res., vol. 5,pp. lS7-159.Cornwall, J. W., and Menon, T. K., 191B.-Ind. Journ. Med. Res., vol. 5,pp. 541-547.Fuller, C., 1919.-Report on Typhus Conditions in Native Dwellings.Union of South Africa. Dept. Agric., local series bull. 57.Howard, C. W., and Clark, P. F., 1912.-Journ. Exper. Med., vol. 16,No.6, pp. 850-859.Knowles, R., 1918.-Ind. Journ. Med. Res., vol. 5, pp. 548-566.Long, E. C., 1911a.-Journ. Trop. Med. and Hyg., vol. 14, p. 17.Long, E. C., 1911b.-Brit. Med. Journ., Sept. 2.Manning, J. V., 19Ua.-Med. Times, vol. 60, April.Manning, J. V., 1912b.-Med. Rec., vol. 8fl, No.4, pp. 148-150.Marlatt, C. L., 1916.-U. S. Dept. Agr., Farmers' Bull. 154.Patton, W. S., 1907.-Scient. Mem. Officers' Med. & Sanit. Depts., Govt.India, n. s., Nos. 27. Sl.Patton, W. S., 1912.-Scient. Mem. Officers' Med. & Sanit. Depts.,Govt. India, n. s., No. 50.Patton, W. S., and Cragg, F. W., 19Ht-A Text Book of Medical Entomology,pp. 486-526.Pringault, E., 1914.-C. R. Soc. BioI., Paris, vol. 76, No. 19, pp. 881-884.Riggs, R. E., 191!.-Military Surgeon, vol. SI, pp. 279-288.Sangiorgi. G., 1910.-Centralb. f. Bakt. Paras. und Infekt., vol. 57,pp.81-84.Skelton, D. S., and Parham, J. G., 1915.-Journ. Roy. Army Med.Corps, vol. 20, No. S, pp. 291-292.Smith, A. J., Lynch, K. M., and Rivas, D., 1915.-Amer. Journ. Med.Sci., vol. 146, No.5, pp. G7l-681.'Thompson, David, 1915.-Brit. Med .. Journ., Oct. 4, pp. 847-849.Thompson, David, 1914.-Am. Trop. Med. and Pl,l-rasit., vol. 8, No.1,pp. 19-28.Wenyon, C. M., 1911.-Kala Azar Bull., vol. 1, No.1.

CHAPTER XXIXDiseases C~used or Carried by Mites and Ticks 1W. Dwight PierceThe Arachnid order Acarina, composed of mites and ticks, containsmany of the most serious carriers of causative agents of disease. Asall ticks are parasitic on animals and derive their entire nourishment fromthe blood of their hosts, it is naturally to be expected that in this groupwe will find a great proportion of the carriers of animal blood diseases.The mites are not all parasitic, but there are quite a number of familiesin which parasitic mites are found, and some of the families are parasiticexclusively in their habits.The most familiar of all the tick-borne diseases is the disease knownas TEXAS FEVER OF CATTLE which has cost the southern statesmillions of dollars, and has been the cause of restricting the shipmentof cattle from southern to northern states. The discovery of the role ofthe tick in the transmission of Texas Fever by Smith and Kilborne ofthe Bureau of Animal Industry, was one of the earliest discoveries inmedical entomology. Since that time the Department of Agriculture,through the investigations of the Bureaus of Animal Industry andEntomology has devoted a great deal of attention to this problem. TheBureau of Animal Industry has had charge of the eradication of thecattle tick in America and has succeeded in eliminating this ·pest fromlarge areas and from at least one state, the State of Mississippi.In South Africa tick-borne diseases are the principal limiting factorsto animal industry. The RELAPSING FEVERS of man in Africa arecarried almost exclusively by ticks. In our own country one of the mostserious local diseases is ROGKY MOUNTAIN SPOTTED FEVER inthe northern Rocky Mountains. The reJationship of the ticks and mitesto disease can best be shown by an arrangement of these diseases accordingto their causative organism.DISEASES CAUSED BY DIREOT ATTACK OF TICKS AND MITESACARINE DERMATOSIS or ACARIASIS. A great many differentspecies of mites are capable of causing various types of DERMATOSIS• This lecture was prepared for the present edition.403

404 SANITARY ENTOMOLOGYin man and animals. The BICHO-COLORADO ITCH is caused by themite Tctranychus molcstissimus Weyenbergh, which thrusts its hypostomainto the skin of man and animals in Argentine and Uruguay. InEurope a similar dermatosis iscaused by the related species T. tclariusLinnaeus, variety russcolus Koch. These two species belong to the familyTetranychidae.The disease known as "GONONE" in Celebes and New Guinea iscaused by the-Trombidian mites j1{icrotrombid~u.m wichmanni Oudemansand Schongastia 'Vandersandei Oudemans. This attack occurs both onman and animals. In Europe and America' attack by various alliedspecies is very common.' The ordinary name for the attack is REDBUGS or CHIGGERS. The principal species which have been describedas causing this attack are j1{icrotrombidium tlalsahuate Lamaire in •Mexico; Trombidium holoBericewm Linnaeus, T. inopinatum Oudemans,and T. aut'lllTTllTlalia Shaw in Europe; T. batatas Linnaeus in the WestIndies; Lcptus americanus Riley, and L. iritans Riley in North America;and also Trombidium striaticcps H. & 0., j1{ ctatrombidium lJOriccps H.& 0., j1{icrotrombidi'lllm pusillwm Hermann, and Allotrombidium fuliginosumHermann. The attack of chiggers is very painful and also difficultto relieve. Dusting of flowers of sulphur in the clothes is a good preventive.I have had fairly good success in taking a hot bath immediatelyafter coming from the field and then rubbing in ammonia.The allied species Leptus akamushi Brumpt not only causes adermatosis, but also a definite disease which will be treated in a laterparagraph. This is a Japanese species.A troublesome acarine dermatosis, which frequently causes swellingwhich may be dangerous, is caused by Holotltyrus coccinella Gervais IIIMauritius, which normally attacks dogs and geese, but also attackschildren.In the family Parasitidae quite a number of species are charged withcausing dermatosis. Dermanyssus gallinac Rcdi and D. hirwndinis Hermann,common avian parasites may also cause dermatosis in man. D.gallinac sometimes causes papular eczematous derm-atosis. Liponyssusbacoti Hirst, a rat parasite in Australia, Africa and South ,America,occasionally causes dermatosis of people working in stores and granaries.URTICARIASIS is caused by various species of the family Tarsonemidae.The mite, Pediculoides 'Ventricosus Newport, causes a diseaseknown under a number of different names, as GRAIN ITCH or ERYTHEMA URTICARIA. This mite becomes globular and reproducesits young at a very rapid rate. It burrows under the skin and is verypainful. Many -workers in harvest fields are attacked by this mite, especiallyin Europe. It occurs quite commonly in America. A similar dermatosisis caused by TarS01l1nnus wncioot!U, T. intcctus, and Crithoptes

DISEASES CAUSED OR CARRIED BY MITES AND TICKS 405monunguiculoBuB Geber. These three species may all be synonyms ofPediculoideB 'lJentricoBus.A disease known as VANILLISMUS is caused in Europe by mites ofthe family r.ryroglyphidae, AleurobiuB farina,e DeGeer, which is found incorn, TyroglyphuB Biro' Linnaeus, and HiBtiogaster entomophaguBLaboulbime. In this same family are found other mites which causediseases, posing under special names such as COPRA ITCH, caused byTyroglyphus longior ca~teUanii Hirst, in Ceylon; GROCER'S ITCH,caused by GlyciphaguB prwnorum Hermann, in Europe; COOLIE ITCHor GROUND ITCH, caused by Rhizoglyphus paraBiticuB Dalgetty, inIndia.The itch or scab mites belong to the family Sarcoptidae. SCABIESor SARCOPTIC ITCH is caused by a species of the genus Sarcoptes, ofwhich various species are described for the different animal hosts as follows:SarcopteB Bcabiei hominiB Raspail, causing scabies of man inEurope and America, with the variety cruBtoBae FUrstenberg causingNORWEGIAN ITCH of man; S. boviB of cattle (Sarcoptic Scab is comparativelycommon in cattle in the United States, frequently a serIous'disease among bulls and dairy cattle); S. caniB Gerlach of the dog;S. oviB l\:Iegnin of the sheep; S. equi Gerlach of the horse; S. BuiB Gerlachof the pig; S. aucheniae Railliet of the llama; S. dromedarii Gervais ofthe camel and dromedary and frequently of man; S. caprae of the goatand rarely of man; S. leoniB Canestrini of the lion and rarely man;S. 'lJUlpiB Furstenberg of the fox. A similar itc11 is caused by Notoedrescati cati Hering and other varieties which attack felines, rodents, horses,and man. The sarcoptic mites live in burrows in the epidermis. Ointmentscontaining sulphur are the best for these mites.PSOROPTIC ITCH or MANGE is,caused by a species of the genusPsoroptes, of which PBoropteB communiB oviB Hering causes SHEEPSCAB; variety boviB causes TEXAS ITCH of cattle; variety equi causesmange of horses and dogs. T}le psoroptic mites have piercing mandiblesbut do not burrow, although they may be greatly protected by scabformation over them. Among the dips used for the control of this itchare an 8 per cent kerosene emulsion used by Gillette; and the Rutherforddip prepared by steeping 1 pound tobacco and adding thereto 1 pound ofsulphur and 4 gallons of water, to be applied at 6 or 8-day intervals.CHORIOPTIC ITCH in the horse is caused by ChoriopteB equi Gerlach(Bymbiotes Verheyen) which attacks the hocks of the horse andcauses the hair to fall out and sores to form. It also causes an itchof cattle, goats, and sheep. This species has piercing mandibles butdoes not burrow. Accol'ding to Banks a mixture of 1 part carbolicacid to 15 or !O parts of oil will destroy the mite.SCALY LEG of chickens is caused by Cnemidocoptes mutans Robin.

406 SANITARY ENTOMOLOGY•PLATE XXIV.- Scaly leg mite on chickens.Fio. 1 (Upper).-Scaly feet of chicken, caused by mite attack. FIG. fJleg mites, greatly enlarged. (Bishopp.)(Lower)-Scaly

DISEASES CAUSED OR CARRIED BY lVlITES AND TICKS " 407•The mites form a crust of dead skin on the legs of the chickens (plateXXIV). The related species, Cnem,idocoptes. gullinae Railliet, causes thehens to pluck their feathers. The mites work at the base of the feathersPLATE XXV.-Dipping scaly "legs of chicken ~n crude oil (Bishopp.)" and are called depluming mites. These mites are controlled by dippingin crude petroleum (plate XXV).DEMODECTIC MANGE, when caused by D emodex folliculorumSimon, gives rise to BLEPHARITIS, SEBORRHEA or BLACKHEADS. Many animals and man are attacked by this mite. Probablya .majority of persons harbor this mite. D emodectic mange is a commonand practically incurable disease in dogs. Demodex phylZoides Csoker

408 SANITARY ENTOMOLOGYcauses white tubercles on the skin of swine in the United States andCanada; Demode:c bovis Stiles causes swellings in the hide of cattle inthe United States and other countries, damaging the hide.GUANO ITCH of man ~nd dogs is caused by TydC'lJ,s molestus Moniezin Peru and Belgium; it is found in guano.SEBACEOUS TUMORS in birds are caused by species Harpyrynchus.H. longipilus Banks attacks the crossbill. Mice are attacked bythe mites Psorergates simplex 'f1W,8culinus Mich, which lives in cavitiesbeneath the surface of the skin, and Myoliia musculi Schrank which developsin the hair follicles.ACARIASIS OF THE SENSE ORGANS. OTOACARIASIS iscaused in man by Clieyletus eruditus Schrank and Acaropsis mericourtiLaboulbene which attack the external auditory meatus. Rhizoglyphusparasiticus has also been recorded as causing Otoacariasis. Psoroptescuniculi Megnin causes a rabbit ear mange which may result in death.Otodectes cy'TWtis causes an otoacariasis of the dog and cat, which tormentsthe animals, resulting in convulsions and fits. Demode:c folliculorumSimon is also credited with causing otoacariasis.Some of the ticks are also responsible for attacks of otoacariasis, asfor instance the spinose ear tick Ornith.odoros megnini (Duges) Neumann,which very commonly attacks the ears of cattle and horses andsometimes man in the southwestern United S~ates.A fatal. otoacariasis in the cow is charged to Dermanyssus gallinaeRedi, but there is reason to question this.OCULAR ACARIASIS of the cornea may also be caused by Dermanyssusgallinae.INTERNAL ACARIASIS. CATARRHAL INFLAMMATIONwhich may produce ASPHYXIA in chickens may be caused by Sternostomumrhinolethrum Trouessart and by a Rhinonyssus in birds. BRONcHIALINFLAMMATION which may prodQ-ce asphyxia may be causedby Halarachne americani, H. attenuata, and H. halichaeri, all of whichattack seals. INFLAMMATION OF THE LUNGS, which may produceasphyxia, may be caused by Pneumonyssus simicola of the monkey.Cytoleichus nudus Vizioli occurs in the air passages of" chickens and turkeys,penetrating the tissues, and may produce asphyxia. C. sarcoptoidesHeguin also attacks the air sacs in fowls.N ephrophages sanguinarius Miyake and Scriba is a doubtful parasitepassed in bloody urine. Carpoglyphus alienus Banks has been found inpurulent urine. A case of a cyst in the testis containing Histiogasterspermaticus Trouessart is recorded from India. Cytoleichus sarcoptoidesHeguin is sometimes found in the liver and kidneys of the fowl. C, nudusVizioli is suspected of producing PERITONITIS and ENTERITIS inchickens and turkeys. C. banksi Wellman also produces an internal

DISEASES CAUSED OR CARRIED BY MITES AND TICKS 409acariasis in the squirrel. Lammosioptes cysticolQ, produces a calcareouscyst in the subcutaneous tissues of chickens.GENERAL EFFECTS OF TICK BITE. The mites in attackinga host usually attack in numbers, or if individually, will be found toburrow into the skin, but the ticks merely attach themselves to the skinand draw blood. Tick bites are very likely to caUse a PRURITIS whichin some cases will be painful for months or sometimes years. This isespecially true in the case of Argas refleX'lb8 (Fabricius) Latreille whichcauses a painful bite marked for years by a cicatrix at the site of theattack. Argas brumpti Neumann causes a pruritis the site of whichremains indurated for years. The bite of Ornithodoros coriaceus Kochis very painful; the bites are slow healing. The bite of Ornithodorosturicata (Duges) Neumann may cause dermatitis and lymphangitis. Thebite of [{Codell ricinus (Linnaeus) Latreille may cause in man abscesses,edema, lymphangitis, and fever; it may penetrate beneath the skin andproduce a tumor. The bite of [{Codes (Cerati{Codcs) putus (PicardCambridge J Neumann is painful to man. It normally attacks birds.The bite of the "conchuda," [{Codes bicornis Neumann, is sometimes fatalto infants.TICK PARALYSIS. The bite of certain ticks causes paralysis ofman and animals. The NORTH AMERICAN HUMAN TICKPARALYSIS is caused by the Same tick which Causes Rocky MountainSpotted Fever, Dermacentor andersoni Stiles (venustull Banks) 2 in thenorthwestern States, and British Columbia, but It case is recorded fromCalifornia caused by Ornithodoros coriaccus Koch. Todd has describeda typical case of paralysis in children as follows: an active and apparentlyhealthy child suddenly develops a paresis o~ paralysis of the legs;neither abnormal temperature nor any other symptoms of paralysis isconstant. After the discovery of the tick and its removal the symptomsdisappear in a few hours with a possible exception of a more or lesslocal reaction, often probably due to a secondary bacterial infection at• In view of the contention of Mr. Bishopp that tl6ntlBtua is the name of the fevertick it is necessary to give my reasons for the adoption of ander8oni.D6rmac6ntoT 1)entlBttUI Marx in Neumann (1897) is cited as an undescribed synonymof D. Toticulat'lts Fabricius.In 1905 Stiles named the Rocky Mountain Spotted Fever tick as D. and6TBo'lli,strengthening his description in 1908 lind 1910.In 1908 Banks drew up the description, liS a new specif:s, of D6rmacentoT tlenuatUB(Marx) from the Marx material, which was subsequently examined by Stiles andfound to consist of three lots of material of at least two species. Stiles definitelypicked from Banks' type material Marx No. 199 as type of species D. tJe'llwtw. Sfnceboth Marx and Banks confused more than one species an

410 SANITARY ENTOMOLOGYthe site of the tick's bite. 'In some cases which have been reported thetick was not removed and in these the paralysis progressively involvedthe whole body until reflexes and control of the sphincters were lost anddeath ensued. Abscesses following a tick bite are probably due to thehead of the tick remaining in the wound. The symptoms suggest infantileparalysis but they may be distinguished from cases of that diseaseby the invariably transitory nature of the paralysis. The tick paralysisnever leaves permanent disability. Various doctors practicing in theNorthwest have dellcribed cases, some of which have been fatal. In caseof paralysis it is always w~ll to make a thorough search of the body, especiallyin the vicinity of the spinal column, for the ticks. They are quitecommonly found in the hair at the base of the· head. The exact causeof the paralysis is unknown, but it is believed'that it is caused either bythe injection of a specific poison into the body by the tick, or by thereactions which take place, forming poisons during the presence of thetick's head in the body. The only treatment necessary is the removal ofthe tick by excision in order to make sure that the mouth parts areremoved, and the dressing of the wound antiseptically. Purgatives andstimulants should be given. Dermacentor andersoni also causes a paralysisof animals similar to that in man; in the case of sheep the effect on thebody is a loss of balance, causing the sheep to fall in places from whichthey cannot extricate themselves. H the tick is removed in time theanimal will recover.South African TICK P ARAL YSIS in animals is caused by the biteof [:codes pilosus Koch which attacks sheep principally. The effect ofthis paralysis is to cause the sheep to become very unsteady on theirfeet and to lie down frequently. They seem to recover rather rapidly,death being usually caused by their ,becoming prostrated in the open wherethey fall victims of jackals. There are no fever reactions. Dippingwith Cooper's Dip is considered a very effective control measure.HUMAN TICK BITE FEVER of Louren~o l\brqueg is' causedprincipally by the larva of Amblyomma hebraeum Koch but occasionallyby Rhipicephalus simus Koch and Boophilus annulatus (Say) Stiles andHassell 3 and B. annulatus (decoloratus Koch). The patient at firstcomplains of general weakness, muscular pains and especially of considerabledifficulty in moving his arms and legs. The glands in the neckbecome swollen in a short time, those situated in the naye of the neckI Mr. Bishopp writes that he prefers Margaropus to Boophilus for this tick and itsallies. My reasons for adopting Margaropus are as follows:1. Margaropus Karsch and Boophilus Curtice are considered by Nuttall, Warburton,Cooper, and Robinson (1911) to be two distinct genera. The type of theformer is designated by them as Margarop1lB winthemi Karsch, and of the latterBoophilllB annula.t1lB (Say) Curtice.II. Boophil1lB annulatm is a name well established in medical literature. (W. D.Pierce.)

DISEASES CAUSED OR CARRIED BY MITES AND TICKS 411being chiefly involved. The patient suffers from severe occipital headachewith considerable rigidity of the muscles of the nape of the neck, so thaI;the head may be turned to one side as in torticollis. The superficialglands in the groin and axilla are found to be enlarged and acutely painful.The acute neck symptoms begin to subside from the eighth to tenthday and recovery takes place spontaneously, but the glandular enlargementpersists a month or more after recovery. The glands become hardand painless.AUSTRALIAN HUlVIAN TICK P ARAL YSIS is caused by eitherIxodes ricinus (Linnaeus) Latreille or Ixodes holocyclus Neumann andis very similar to the American tick paralysis. Eaton considers that thereare three possibilities as the cause of the paralysis: pre-formation of thepoison by the tick, development of the infective organism in the blood, orliberation mechanically or biologically (by bacterial introduction) at thesite of the bite, of some poison subsequently absorbed.DISEASES CARRIED BY MITES AND TICKSTicks and mites are the carriers of many diseases.DISEASES CAUSED BY PLANT ORGANISMSThere are undoubtedly many cases of SEPTICEMIA due to the introductionof plant organisms at the site of the bite of the tick. These aremost likely to be streptococcal and staphylococcal infections. For instance,the bite of Argas reflexus (Fabricius) Latreille has been knownto give rise to FURUNCULOSIS caused by Staphylococcus pyogC1les(Nuttall, Warburton, Cooper, and Robinson, 1908). Ixodes ricinus(Linnaeus) Latreille may also carry infections of Staphylococcuspyogenes (Nuttall, Warburton, Cooper, and Robinson, 1911).Demodex folliculorum Simon, the blackhead mite, causes an irritationgiving rise to papules which become infected with BaciUus necrophorus.Jarvis has just published an article in which he claims that EPIZOOTIC LYMPHANGITIS is an inoculable disease through the; agency orthe ticks of the genus Amblyomma. The dis('ase is characterized by suppuration,ulceration, and necrosis. He believes that the lesions are causedby a variety of micro-organisms including the Priesz-Nocard organism,.the Cryptococcus farciminosus, the Bacillus nccrophagu8, and Staphylococci,and that these organisms are introduced through the agency of themouth parts of the ticks which are very long and pierce the whole integument,reaching the subcutaneous layers where the bacteria can easily setup lesions.Hadwen has just published an article in which he shows that ticks play

41!e SANITARY ENTOMOLOGYan important role in producing FISTULOUS WITHERS. He considersDermacentor albipictus Packard as the worst offender, but alsoconsiders D. andersoni Stiles (venustus Banks) as a cause. D. albipictusis commonly called a winter" tick and in some regions of British Columbiawhere poll evil and fistulous withers are common, horses are heavilyinfested with these ticks. The favorite ,site of attachment is along thewhole length -of the mane from the pon to the withers. At the point ofattachment there is oiten a necrotic spot if the tick has been attached fora few days. It is easy to see that these necrotic spots should be afavorite point of entrance for bacteria.It is quite probable that most of the cases of abscesses and irritationresulting from tick bites are due to secondary infections by bacteriawhich may possibly be mechanically introduced by the tick itself. Noone has given this question serious attention.DISEASES OF UNKNOWN ORICINThere are quite a number of instances of so-calledJick fever caused bythe bite of ticks, of which the exact cause is unknown. Among these areunnamed TICK FEVERS caused by Ornithodoros savignyi Audouin(Koch) and Hyalomma aegyptium (Linnaeus) I{och.•HEART WATER, a disease of sheep, caused by a filterable virus, istransmitted by Amblyomma hebraeu;m Koch.The TICK FEVER OF MIANA is caused by the bite of Argaspe18ic'U8 Oken.INTERMITTENT FEVER of Wyoming, which is possibly identicalwith Rocky Mountain Spotted Fever, is thought by Castellani and Chalmersto be caused by Dermacentor andersoni Stiles (venust'U8 Banks).ROCKY MOUNTAIN SPOTTED FEVER, a disease characteristicof the Rocky Mountains of Montana and Idaho and occasionally othernearby states, was proven by Ricketts to be transmitted by the tickDermacentor anilersoni Stiles (venustus Banks), by D. variabilis (Say)Banks and possibly by D. modestus Banks.The first scientific article in which the tick is mentioned as a possiblecarrier of this disease was published by Wilson and Chowning in 190!e.They subsequently published the reports of thcir investigations but theydid not prove that the tick was actually the transmitting agent. Anderson(1908) was so convinced that the tick was the cause of the feverthat he publishe.d an article calling it the SPOTTED FEVER or TICKFEVER of the Rocky Mountains. Stiles in 1905 did not attribute thedisease to ticks. Finally Ricketts in 1906 began a thorough investiga-

DISEASES CAUSED OR CARRIED BY MITES AND TICKS 413tion of the cause of the disease and proved transmission of the diseaseto a guinea pig by Dermacentor andersoni Stiles (occidentalis Stiles, notMarx). This preliminary report by Ricketts was followed by numerousother papers by himself on the subject, until he had definitely proven therelationship of the tick to the disease. The organism causing spottedfever has just been described. Wilson and Chowning described Piroplasmahominis as the causative organism, but their work has not been corroboratedby others. Very recently Wolbach (1919) has found bodies somewhatsimilar to the Rickettsia bodies found in typhus fever and trenchfever. He describes his organism as Dermacentro:cenus riclcettsi Wolbach,but is uncertain as to its location in classification. It is intracellularin mammal and tick, and intranuclear in ticks. Two multiplicativeforms and an infective form are found in the tick, and only the latteris regularly found in mammals. Wolbach's volume is the latest and mostcomplete treatise on all phases of the disease and is well illustrated.Mayer (1911) conducted transmission experiments and waf,! successfulin transmitting the disease by Dermacentor marginatus Banks,Amblyomma americanum (Linnaeus) Koch and Dermacentor variabilis(Say) Banks.The role of wild animals in acting as reservoirs for the disease has notbeen definitely determined although several wild mammals have been shownto be susceptible. It is probable that it is by this means that the diseaseis perpetuated. The ticks which carry the disease are normally foundon wild animals in the immature stages and the adults usually engorgeon the larger domestic animals and to some extent on the larger wildmammals. The Rocky Mountain Spotted Fever is transmitted hereditarilyby the tick. Control of the disease must be effected by destructionof the adult ticks on domestic animals, reduction of the numbers of wildhosts, and prevention of tick attack on man.TSUTSUGAMUSHI DISEASE, sometimes called JAPANESERIVER FEVER or I{EDANI DISEASE, has been proven to be carriedby the mite Leptus akamushi Brumpt (Trombidium). Kitashima andMiyajima have proven that this disease is not caused by the bite of allmites of this species, but only by certain ones, and consider that the evidenceis sufficiently strong ~o assume that the disease is caused by a nonfilterablevirus which can be inoculated by the mites only after they havebecome infected. They conducted a large number of experiments to provethe role of the mite. The field mouse, Microtus montebelli, is susceptibleand is believed to be the important natural host of the virus. (It is interestingto note that another Japanese disease, Seven Day Fever, caused byLeptospira hebdomadis Ida, Ito and Wani has the same mouse, Microtusmontebelli as its reservoir.)

414 SANITARY ENTOMOLOGYDISEASES OF ANIMAL ORIGINProtozoaMastigophora: Bmucleata: Trypa1WsomiaaeSchizotrypanum crUD Chagas, the cause of CHAGAS FEVER, whilenormally transmitted by the kissing bugs of the genus Triatoma, has beenshown by Brumpt to develop in the tick Ornithodoros moubata (Murray)Pocock, and by Neiva (1913) to develop in Rhipicephalus sanguineus(La treille) Koch. .Trypa1Wsoma sp. which is supposed to cause a reptilian disease, iscarried by Amblyomma testudinis (Conil) Neumann.Trypanosoma christophersi Novy is an organism probably nativeto Rhipicephalus sanguineus (Latreille) Koch and was originally recoveredfrom ticks fed on dog.Mastigophora: Binucleata: LeptomonidaeSome authors are inclined to separate the genera of tick organismsto form the family Piroplasmidae. These organisms do seem to form arather consistent family which contains the genera Theileria, Nuttallia,Babesia, Piroplasma, Rossiella, and Anaplasma.Anaplasma argentinum, the cause of ARGENTINE ANAPLASMOSIS of cattle, is carried by Boophilus an'fl.!lilatu8 australis Fuller (microplusCanestrini) (Lignieres 1914).Anaplasma margmaZe Theiler, cause of ANAPLASMOSIS of manyAfrican and Australian animals, is transmitted according to Theiler(1910) by Boophilus a/11/wulatus (decoloratus Koch), and according toCastellani and Chalmers by Rhipicephalus simus Koch.Babesia argentinum, cause of Argentine BABESIASIS OF CATTLE,is carried by Boophilus annvlatus australis Fuller (microplus Canestrini)(Lignieres 1914).Babesia boms Babes (Piroplasma bigeminum Smith and Kilbome),4the cause of TEXAS CATTLE FEVER which is also known as REDWATER, SPLENIC FEVER, SOUTHERN CATTLE FEVER andnnder various other names, is normally transmitted by the cattle tickBoophilus a'1llTVlilatus (Say) Stiles and Hassall in North America. Thefirst proofs of tick transmission were published by Smith and Kilborne(1893). Crawley (1915) believes the organism is pathogenic to thist.ick. The organism may also be transmitted by Boophilus annulatusaustralis Fuller (decoloratu8 Koch) in South America, Cuba, Porto Rico,• Babellia bovill and B. bigeminwm are separated by some authors as two distinctspecies, bovis causing the European disease, nnd bigemi7lum the American.

DISEASES CAUSED OR CARR{ED BY MITES AND TICKS- 415Philippines, and AustraJla, according to various authors, and by Boophilusannulatus australis (microplus) in South America (Lignieres),and B. annulatus decoloratus and Rhipicephalus capensis Koch in Africa.Carpano (1915) suspects Hyalomma aegyptium (Linhaeus) Koch to bethe carrier of Babesia annulatum, a synonym of bo'Vis which is recordedas the causative organism of MEDITERRANEAN COAST FEVER OFCATTLE.''.rhe first contributions to the life history of this organism were madeby Smith and Kilborne. It is found in the blood of the animal hosts inthe first stage, being inside the red blood cells near its margin, and isnon-motile and pale. This single body develops incompletely into twosmall roundish bodies which are partially connected by a narrow interveningstrand. In the next stage the minute, double, rounded bodiesbecome enlarged and spindle-shaped. They probably remain attached,however. The two bodies enlarge uniformly and assume a pear-shapedappearance. At this stage of the life cycle, the disease is in its mostacute form. The parasites occupy nearly one-fourth of the body of thered blood cells and from 0.5 to 2 per cent of the red cells are usuallyInvaded. The blood cells finally break up, liberating the parasites whichmay be observed as free bodies in the circulation. The parasites aretaken up by the tick, according to Koch, in the red blood cells. In thebody of the tick the parasites leave the red cell and become long andclub-shaped. From the club pseudopodia project. This club then becomesspherical and immense numbers of amoeba-like forms appear, whichare said to grow into clubs. The disease can only be transmitted byseed ticks, that is, by the first stage of the tick. The adult tick whichsucked up the infected blood drops to the ground and lays its eggs. Theorganism passes into the eggs and is transmitted to other animals by theoffspring of the tick which became infected. The disease can be givento a host almost immediately after attachment. The tick remains onthe animal throughout its development (Mohler 1905).Babesia caballi (Nuttall), the cause of EQUINE BILIARY FEVER,is considered by Marzinowski and Bielitzer (1909)' to be carried by Dermacentorreticulatus (Fabricius) Koch in Russia. According to Valladares(1914), there is a possibility that Hyalomma aegyptium (Linnaeus)Koch is the carrier in India. •Babesia canis (Piana and Galli-Valerio) the cause of a CANINEBABESIASIS, also known as MALIGNANT JAUNDICE OF DOGS, istransmitted by several ticks. The life cycle has been traced in Rhipicepkalussanguineus (Latreille) Koch by Christophers in India (fig. 78).Lounsbury proved the transmission of the disease in South Africa byHaemaphysalis leachi (Audouin) Neumann. According to various authorsDermacentor reticulatus (Fabricius) Koch carried the disease in

416 SANITARY ENTOMOLOGYFrance. Ixodes hexagonus Leach (reduvius Audouin), and I. nctnus(Linnaeus) Latreille, are suspected to be carriers. The life cycle in thedog was worked out by Nuttall and Graham-Smith (1904-7). The cycleof schizogoVY is passed in the dqg. The free pyriform parasite entersa normal re'i1 blood corpuscle and becomes rounded in shape. The parasitethrows out pseudopodia and appears as an amoeba. This stage lasts along time, at the end of which the parasite enters upon a quiescent stage.Finally the organism takes a form called the trefoil stage, in which themain mass of the chromatin, much reduced in size, lies at the base ofthe two processes. Two nuclei are formed, finally the cytoplasm dividesLIFE CYCLE Of BABESIA CANISFIG. 78.-(Pierce).and two pyriform paJ;'8sites are found lying side by side in one corpuscle.The corpuscle now ruptures and liberates the two parasites.Christophers has worked out the cycle of sporogony in the tick. Whenan adult or nymphal tick bites a dog and takes in blood containing theoval parasites, these develop in the gut into round or oval bodies whichfinally assume the form of a club-shaped body which gradually becomesookinete. In the adult these ookinetes wander into the ova, while in thenymph they simply pass into the embryonic tissues. In either case theybecome rounded and form a zygotc which breaks up into sporoblasts,and these again into sporozoites which infect the salivary glands of thelnymph and the adult of the second generation.A parent tick having gorged with blood falls to the ground and

DISEASES CAUSED OR CARRIED BY MITES AND TICKS 417lays her eggs which develop into six-legged larvae. They do not infectthe dog, which they attack as soon as possible and on which they remaintwo days sucking blood. After dropping off they in due time shed theirlarval skin and become eight-legged nymphs which again attack the dog,but do not infect it. The nymph, after dropping off, undergoes metamorphosisand sheds its nymphal skin, and becomes the sexually maturetick, which is the only form that spreads the infection, according toLounsbury (1901), and Nuttall.Babesia divergens (McFadyean and Stockman), the cause of BritishRED WATER OF CATTLE, is principally carried by I:codes ricinus(Linnaeus) Latreil1e, although McFadyean and Stockman succee4ed intransmitting the disease by means of Haemaphysalis cinmabarinapwnctata Canestrini and Fanzago (Nuttall, Warburton, Cooper, andRobinson, 1915).Babesia gibBoni (Patton), cause of BABESIASIS OF THE JACKALAND DOG, is said by Neumann to be carried by Rhipicephalus simusKoch. Patton "found infested jackals with Haemaphysalis birmaniaeSupino (bispinosa) and Rhipicephalus simus Koch but did not provethat they were infected.Babesia minenBe Yakimoft', the cause of BABESIASIS OF THEHEDGEHOG, is said by Doflein to be carried by Dermacentor reticulatus.( Fabricius) Koch.Babesia ovis (Babes), the cause of CARCEAG of sheep, is hereditarilytransmitted by Rhipicephalus bursa Canestrini and Fanzago. Thedaughter adult tick, developed from a tick which sucked the blood, isthe stage which transmits the disease. The disease has been transmittedby H aemaphysali8 cmnabarina punctata Canestrini and Fanzagoexperimentally.Crithidia haemaphY8alidia Patton is hereditary in Haemaphy8alisbirmaniae Supino (bispmo8a) in India.Crithidia hyalommae O'Farrel is hereditary in Hyalomma aegyptiwm(Linnaeus) Koch in the Sudan.Nuttallia equi (Laveran), the cause of NUTTALLIOSIS OFEQUINES, was demonstrated by Theiler to be transmitted in SouthAfrica by Rhipicephalu8 evert8i Neumann. Considerable evidence pointstowards Hyalomma aegyptiu.m (Valladares 1915).RossieUa rossi (Nuttall), the cause of JACKAL ANEMIA, is thoughtby Nuttall to be possibly carri~d QY Haemaphysalis lea chi (Audouin)Neumann.Theileria parva (Theiler), the cause of EAST COAST FEVER orRHODESIAN FEVER, has been known by Theiler (1908, 1904, 1908)and Lounsbury (1906) to be transmitted by Rhipicephalus appendicu.latu8 Neumann, R. sVmus Koch, R. evert8i Neumann, R. capen8;'8 Koch

418 SANITARY ENTOMOLOGYand De1"TlUJcmtor nitens Neumann. It is also recorded from Hyalommaaegyptiu.m (Linnaeus) Koch by Carpano (1915) and Dermacmtor reticu.latus(Fabricius) Koch (Doflein 1911). The ticks do not produce aninfection during the first two days after they have taken up the infectiveorganism. They may transmit th~ organism in the instar following thatin which they ingested the blood containing the organisms.Mastigophora: SpirodTuztacca: SpirocTUl:titIaSpiroschaudilnnia sp. (duttoni Brumpt, not Novy and Knapp), thecause of ABYSSINIAN RELAPSlNG FEVER, was transmitted byBrumpt to monkeys, rats, and mice by means of Ornithodoros savignyi(Audouin) Koch.Spiroschaudinnia anacrina (Saccharoff), the cause of GOOSESPIROCHAETOSIS, Transcaucasia, is carried by .4. rgas persicus(Oken) Fischer Von Waldheim (Saccharoff 1891).Spiroschaudinnia duttoni (Novy and Knapp), the cause of RELAPSING FEVER of tropical and west Africa, is hereditarily transmittedby Ornithodoros mouhata (Murray) Pocock. The transmissionby this tick was first proven by Dutton and Todd in 1905. Many othershave corroborated this. MoIlers in 1907 showed that infected ticks, fedsuccessively on six cleari animals, after each feed may lay a batch ofinfected eggs. The ticks hatched from these eggs are capable of conveyingthe infection to the animals they feed upon. Moreover, not onlyis the infection carried through the second generation, but also throughtheir offspring, ticks of the third generation being found to be infectiveeven though their parents have never fed on an infected animal. Schubergand Manteufel (1910) and Hindle (1911) found that about SO per centof the ticks are immune to spirochaetal infection. In man the parasiteis ribbon-shaped on transverse section and though it is in spirals, maybe simply waved. A narrow undulating membrane is sometimes present.Reproduction is by longitudinal as well as transverse fission and also bygranular formation. The latter method occurs just before the crisis,when the blood is swarming with parasites. They are then to be seencoiling themselves up in the spleen, bone marrow, and liver, and becomingsurrounded by a thin cyst \vall. In this cyst the parasite. becomes moreand more indistinct and breaks up into filterable granules.Leishman found that when the organism finds its way into the intestinalsac of the tick it loses its mobility and characteristic appearance,and chromatic masses escape into the lumen of the gut in the form ofsmall rods or rounded bodies. These multiply and pass into the cells ofthe Malpighian tubules. Hindle found the spirochaetes ahvays presentin the gut of infectelf ticks, often in the Malpighian tubules and sexual

DISEASES CAUSED OR CARRIED BY MITES AND TICKS 419organs, very seldom in the salivary glands, and not at all in the coxalfluid. Leishman in 1910 proved that the organism is voided in :M:alpighianexcrement while the tick is feeding, and, by means of an anticoagulincoxal fluid voided at the same time, is washed into the wound.Infection does not take place through the proboscis. Leishman's experimentswere completely checked and substantiated by Hindle (1911), whodemonstrated that the infection was due to the presence of the spirochaetesin the white Malpighian secretions, and entered the feeding punctureswith uninfected coxal fluid; and, furthermore, dissections provethat the salivary glands of these particular ticks were not infected, whilethe gut contents, sexual organs and Malpighian tubules were. Inoculationof these various organs gave incubation of spirochaetes in 7 to 9days.8piroBchaudinnia granulo8a (Balfour), cause of Sudanese or NorthAfrican FOWL SPIROCHAETOSIS, was proven by Balfour to betransmissible by A rga8 persicu8 (Oken) Fischer Von W aldheim.8piroBchaudinnia marchoua:i (Nuttall), the cause of Brazilian orSouth American Fe)WL SPIROCHAETOSIS, was shown by Marchouxand Salimbeni to be carried by Arga8 per8icuB. This has. been corroboratedby Nuttall, Hindle, and others. Shellack transmitted the diseaseby Argas refle:cus (Fabricius) Latreille. In experiments conducted atHamburg, Fiilleborn and Mayer transmitted the disease by Ornithodorosmoubata. Nuttall working with the Brazilian strain, found that whenthe spirochaetes first enter the tick they soon disappear from the gut;a certain number degenerate while others traverse the gut wall and enterthe coelomic cavity to circulate all over the body. They enter variousorgans, especially the cells of the Malpighian tubules and sexual organs,in which they break up into a large number of small particles or coccoidbodies which multiply by fission and give rise to large n.gglomerations.These coccoid bodies may also be found in the lumen of the gut and Malpighiantubules and in the excreta. According to Nuttall, the tick in theact of feeding occasi~ally voids excrement and exudes a few dropsof secretion from the coxal glands situated in the first intercoxal space,the fluid pouring out of a wide duct and being rapidly secreted from thefreshly imbibed blood serum. This fluid, as well as the salivary and intestinalsecretions of Argas, contains an anticoagulin. The coxal fluid dilutesthe escaped excrement and facilitates its getting into the wound inflictedby the tick. This is doubtless the usual mode of infection, the coccoidbodies in the excrement gaining access to the body of the host and afterwardsdeveloping into spirochaetes, though the latter development hasDot actually been followed. The bird begins to show symptoms after aperiod of incubation of about four days following upon the bite of theinfected tick.

4~O SANiTARY ENTOMOLOGYHindle has found fhe coccoid bodies within the Malpighian cells ofthe embryo tick. If the eggs are maintained at 87° C. the coccoid bodiesgrow out and assume a form which suggests that they are on the wayto forming spirochaetes. This indicates hereditary infection.Spiroschaudinnia neveuxii (Brumpt), the cause of Senegal FO'VLSPIROCHAETOSIS, is spread by A rgas persicus~ according to Brumpt.Spiroschaudin'Ttia 'Ttovyi (Shellack), the cause of American or ColombianRELAPSING FEVER, may be transmitted by Ornithodoros turicata(Duges) Neumann according to Brumpt, O. megnmi (Duges) Neumannaccording to Doflein, O. moubata (Murray) Pocock according to Nuttall,and Argas persicull (Oken) Fischer Von Waldheim according toDoflein.Spiroschaudinnia recurrent is (Lebert), the cause of EuropeanRELAPSING FEVER, is normally transmitted by lice and bedbugs, butManteufel found that the disease could be easily transmitted by Ornithodorosmotibata. .Spiroschaudinnia rossii (Nuttall), the causing of East AfricanRELAPSING FEVER, may be spread by Ornithodoros moubata,according to Nuttall.Spiroschaudinnia theileri (Laveran), the cause of BOVINE SPIROCHAETOSIS, was proven by Theiler to be transmitted by Boophilusannulatus decoZoratus. It may also be transmitted by Rhipicephaluseverts. Neumann. The organism is heredit~ry in B. annul(1tus (decoloratus)as proven by Laveran and Vallee. The disease appears in 14days after inoculation by a larval tick (Nuttall 1918).Telosporidia: Haemogregarinida: HaemogregarinidaeHaemogregarina (Hepatozoon) canis (James), the cause of CANINEANEMIA, has been shown by Christophers to pass its cycle of sporogonyin Rhipicephalus sanguineus (Latreille) Koch; the cycle of schizogony.i-;passed in the dog (fig. 79). Schiz.ogony appears to take place only in thebone marrow and does not take place in the liver or spleen. When atick sucks the blood of the dog it takes up the encapsuled forms whichpass into the stomach. The parasite escapes from the blood of the corpusclesbut is still inside its own envelope. By elongation and passageof the protoplasm behind the nucleus, the oval parasite becomes a vermicule.The vermicules enter young epithelial cells lining the lumen of thegut in whose cytoplasm they divide by fission, which often takes placeseveral times, resulting in the secondary formation of four to eight vermiculeslying in a pocket in the cytoplasm of the cell. Two of thesesecondary vermicules, which apparently do not differ in appearance,

DISEASES CAUSED OR CARRIED BY l\HTES AND TICKS 4~1conjugate and the nuclei fuse, and then follows a throwing out of ~wolarge masses of chromatin from the nucleus and the separation of a.port.ion of cytoplasm resulting in the formation of an oocyst with a synkaryon.The oocyst, still imbedded in the epithelial cell, grows rapidly,becoming irregular in form. Later stages of development are onlyfound in ticks which ingest vermicules during their nymphal stage. Theoocyst divides into four cysts which grow very large. These may ruptureand release into the body cavity the sporocysts which contain thesporozoites.After sucking the blood of a dog from two to four days; th!;! adultCYCLE OF SCHIZOGONYIN CA.NI! FAMILIARIS (DOl)OvCLE 0 F SPOROGONYIN RHIPICEPHAL.US SANGUI"£US(no. TICK).LIfE CYCLE OF HAEMOGREGAlM CANIS.THECAUSE OF CANtNI;: ANEMIA.(CO ... TlluanuArru D~HRlPTIO'""'ND o.."WIIII •• BY CHRlsroPHCRs)FlO. 79.-(Pierce).tick drops off never to feed again. It IS apparent then, that the adulttick taking up infected blood for the first time in this stage of its development,cannot of itself transmit the disease, as the parfisite has been shownby Christophers not to complete its development in the adult. We must,therefor~, look to the life history of the tick to find the possible methodof transmission. Christophers found that complete development in thetick only occurs when the parasite is taken up in the nymphal stage. Hedid not find any parasite in larvre fed on infected dogs. After the nymphalstage the ticks drop oft' from the host for molting. They then reattachas adults and engorge. The possibility of infecting a new' host is verygreat because of this change. of host during the development of theparasite in the tick.

SANITARY ENTOMOLOGYHaemogregarina (Haemogregarina) mauritanica (Sergent and Sergent),a parasite of Testudo mauritanica, is transmitted by Hyalommaaegyptium (Linnaeus) I{~ch, according to Von Prowazek.Haemogregarina (Hepatozoon) jaculi (Balfour), parasite of thejerboas (Jaculus gordoni and J. orientalis), while usually carried bythe fica, may be carried by the mite, Dermanyss'U8 gaUinae Redi, accordingto Von Prowazek.Haemogregarina fHepatozoon) leporis (Patton), a parasite of therabbit Lepus nigricollis, maybe mechanically carried by Haemaphysalisfta'lJa Neumann in India, I:\ccording to Von Prowazek.Haemogregarina (Hepatozoon) muris (Balfour) the cause of RATANEMIA, was found by Miller to pass its schizogony in the rat and itssporogony in the rat mite Lbelap8 echidninus Berlese. In sucking theblood of the rat the mite takes up the leucocytes containing the gametocytesof this organism, which are then liberated from their cells by thedigestive action of the mite's gut. They arrange themselves in coupleswhich are at first quite similar, but which later differentiate into macrogametesand microgamctes. Zygosis now takes place forming an ookinetewhich grows, and, leaving the gut by piercing the wfl.ll, forces its wayinto the body cavity and further into the sheaths of the muscles andinto the investing membrane of the salivary glands. In the tissues itencysts and becomes the oocys~ which grow.s rapidly in size and undergoesnuclear division. The daughter nuclei migrate to the peripherywhich becomes covered with 50 to 100 bud-like projections, in each ofwhich a nucleus is to be found. These buds break off from the centralmass and form sporoblasts, the nuclei of which divide to form daughternuclei which gather at the poles, while the whole sporoblast encysts.Short rod-like processes of cytoplasm, each containing a nucleus, nowbreak off from the sporoblast and become sporozoites, of which thereare on an average 16 to each sporoblast.Infection of the rat takes place by ingestion of the mitesr when thesporozoitcs are liberated by the juices of the duodenum and becomeactively motile, striated vermicules which penetrate. the intestinal villi,enter the blood system, and are carried to the liver, into the cells ofwhich they penetrate and start the cycle of schizogony. As the mitesleave the rats during the daytime, only feeding on theJ;ll during the night,it is easy to understand the manner in which the disease spreads fromthe sick to the healthy.Ha:mogregarina (Karyolysus) lacertarum (Danilewsky), a parasiteof lizards of the genus Lacerta, is recorded by Chatton and Roubaud fromnymphs of mites of the family Dermanyssidre, in which the cycle of sporogonytakes place.

DISEASES CAUSED OR CARRIED BY MITES AND TICKS 4231i.".N ..'"ML S. .... ArTA ..... H" .. II, R. ..... n.~teONo NYMP'HAL. STili. ATr .... CAs HO'I1' m.ANDo...o., O"REPI.£TE.TICKLIFECYCLE-TYPE IL"E C.,CLE 0' ARGI\S PEftSICU5,I\LSOPROIII'BLVA"f.FLElIUS.AV£S.EATILIONIS AND ..... 01MlRSP[ClES.rAAIJ4SA •• O ..'n.o._.(A .. Trlt.Nu,.TALL" '911)FIG. 80.MALE lIVtS ONFEMALE UVES ONTICKLlfECYCLE-~YPEHTil! LirE CYCle arORNITHODOROS MOUBATUND tlSAYI;NYI.(A.TC"NUT,.M ... 1911)F'G.81.

SANITARY ENTOMOI,OGYSUMMAllYA good idea of the diversity of life cycle and of the interrelationshipof the tick to its host and its parasite can be obtained by a comparisonof the life cycles of HlI!1nogregarina canis and Babesia canis, both ofwhich pass their cycle of sporogony in the dog 'tick Rhipicephalus sanguineusand their cycle of schizogony in the dog. Two charts are presentedto illustrate the life cycles .of these two parasites (figs. 78, 79).!t will be noticed that a ifi!"t~in tick, taking up both ?f these parasites inIts nymphal stage from a given dog, would collltnU!)lcate the Hremogregarinato its adult host, bt;'t tIle Babesia would not be transmitted until thetick's offspring had reached the adult stage, possibly on the third dog hostof the offspring. The best way in which to understand how ticks can carry .disease organisms is to study the types of life cycles which were worked outby Nuttall, and charts of which are presented. In the first type (fig. 80),found in various species of the genera Argas and Ornithodoros, th~leare one larval host, two nymphal hosts, and an indefinite number of adulthosts. Thus, it is apparent th~t organisms which can be taken up byanyone of these stages can be tran~mitted to quite a number of otherhosts by the same tick.In type two (fig. 81) there is no larval host but there are fivenymphal hosts and any number of adult hosts. This type is found inOrnithodoros moub'aJa and 0.· s~vignyi .. . n is therefore, apparent thatthe diseases transmitted by thcs~.ticks. can be conveyed to a number ofsuccessive hosts by the same tick.The third type (fig. 82), found in the genera Ixodes, Hremaphysalis,Dermacentor, Rhipicephalus, and Amblyomma, consists of a developmentwith just tht:ee hosts, onc for the larva, one for the nymph, and one forthe adult. Therefore, if the parasite is taken up by the nymph it maybe transmitted to the host of the adult, but ·if the parasite is taken upby the adult, it must either die or be transmitted hereditarily by the offspringof the tick.Type four (fig. 83), found in Rhipicephalu.s evertsi and HyalommalI!gyptium, consists of a development with only two hosts. The larvadevelops into a nymph on the host and the nymph drops lvhen replete.It reattaches as an adult. The possibilities of transmission are similarto those in type three, but tend more toward hJ!rcditary transmission.Type five (fig. 84), represented by the genus Boophilus, has onlyone host. The larva attaches and goes through its entire transformationon the host. It is, therefore, apparent that any organism transmittedby these ticks must be transmitted hereditarily.Type six (fig. 85) is similar in that there is but one host. It is representedby Ornithodoros megnini, which i_s on the host during its larval

DISEASES CAUSED OR CARRIED BY MITES AND TICKS 425ADUL1'5ATTACKHO'TmANDMATE.AouL. T5 ['''''IAUfAOMNYMPHALSMiNWHILE. ON GNIUNDR.r:PLD'l ~PM![MDPfllQlMHen 1TICK LIFE CYCLE-TYPE illT .. LoftC_ or I.O.U ....... _I .... ,_I._,SUIJI.H.'M.PIIYSAU. LEACH', H.PUNCTATA,D£RMAClNJDA R~.ATU" D OCCIDCNMUS.UV",,.'A BILIS.RHIP'OlPHALUS APP[N£NCLlLATUt,R. $A"'.U"IW •• R.II~US AND AMBLYOMMA HEaAAEUM.(Ann NUTTALL 1911)FIG. 89.ADULn ATTAco..HoST nANDM.TE:ADUT. E",oGt ...rOO .. NYMPHALSKIN W'''Lt 0.. G.OUNDTICK LIFE CYCLE-TYPE NTHE LIFE CVCL' or RHIP'C[PHAWS EVERTS' AND H Y"LOMMA AEGYPllUM.(AII'TE"NUTTALL. 19U)Flo. 83.

4!!6.SANITARY ENTOMOLOGYTICK LIFE CYCLE"TYPEVTH.L,rE eVeL. O,'HSOINUS BOOPHILUS(APTUI N"'T'1''''''L 1911)FIG. 84..TICK LIFE CYCLE a rYPE"lHTNt LIFE eve .. D.DRNITHaooRoi MEGNINI.(ORIGINAL.)FIG.8.?-(Pierce).

DISEASES CAUSED OR CARRIED BY MITE'S AND TICKSand nymphal stages, and does not reattach during the adult stage. Theorganism, if taken up, must be taken up by the larva or nymph andremain in the body during transfo_frnation, entering the eggs, thus to betransmitted by the offspring of the'tick.. It is quite evident from this that anyone who studies the transmissionof disease by ticks, must first take into account the life cyclesof the ticks which he is studying, in order to arrive at any understandingof the life cycles of the parasites. Perhaps we may learn a valuable lessonfrom the ticks in our search for the life cycles of parasites in other formsof invertebrates.4fl7LIST OF REFERENCESAnderson, John F., 1903.-U. S. Treas. Dept., Hyg. Lab., Bull. 14,pp. 1-41.Balfour, A., 19l!.-Parasitology, vol. 5, pp. Iflfl-l!6.Banks, N., 1915.-U. S. Dept. 'Agric., Office of the Secretary, Report lOS,153 pp.Brumpt, E., 1905.-BuII. Soc. Path. Exot., vol. 1, pp. 577-579.Brumpt, E., 1913.-Precis de Parasitologie, pp. 133, 136.Brumpt, E., 1914.-BuII. Soc. Path. Exot., vol. 7, No.2, pp. 13fl-133.Carpano, M., 1915.-Ann. Igiene Speriment, Turin, vol. fl5, No.4, pp.343-410.Castellani, A., and Chalmers, A. J., 1913.-A Manual of Tropical Medicine,flnd Edit., p. 950.Christophers, S. R., 1907.-Sci. Mem. Officers Med. & Sanit. Dept., India,n. s., No. 29. ,Christophers, S. R., 1912.-Parasitology, vol. 5, No.1, pp. 37-44, 4S.Crawley, H., 1915.-Journ. Parasit., vol. fl, No. fl, pp. S7-9fl.Doflein, F., 1911.-Lehrbuch der Protozoenkunde, p. S17.Dutton, J. E., and Todd., J. L., 1905.-Liverpool School Trop. Med.,Mem. 17, pp. I-IS.Fiilleborn and Mayer, M., 1905.-Arch. f. Schiffs- u. Trop.-Hyg., vol.12, p. 31.Hadwen, S., 1919.-Journ. Amer. Vet. Med. Assoc., vol. 54, No.6, pp.639-64fl:Hindle, E., 1911.-Parasitology, vol. 4, No.2, pp. 133-149. ContainsBibliography on Transmission of Relapsing Fever.Hindle, E., 1911.-Parasitology, vol. 4, pp. 463-477.Jarvis, E. M., 1919.-Vet. Journ., Feb.Kitashima, T., and Myajima, 1915.-Kitasato Arch. Exper. Med., vol.2, No. fl, July, pp. 91-146, PIts. 1-4; No.3, pp. fl37 for'd.Leishmann, W. B., 1910.-Lancet, vol. 177, pp. 11-14.

4~8 SANITARY ENTOMOLOGYLignieres, J., 1914.-Centralbl. Bakt. Parasit. Uo Infekt.-I(rankh., Abt.1, vol. 74, pp. I33-I6~.Lounsbury, C. P., I901.-Agric. Journ. (Cape of Goal! Hope), Nov. ~1,1901. Reprint as Bull. ·7. Dept. Agr., Cape of Good Hope.Lounsbury, 1906.-Agric. Journ. Cape of Good Hope, vol. ~8, pp.634-643.Manteufel, 1907.-Arb. a. d. kais. Gesundheitsamte, vol. 29, p. 355.Marchoux, E., and Salimbeni, A., 1903.---.-Ann. Jnst. Pasteur, vol. 17,pp. 569-580.Marzinowski, and Bielitzer, 1909.-Zeitschr. f. Hyg. u. Infekt.-Krankh.,vol. 63, pp. 17-33. .Maver, M. B., 1911.-Journ. Infectious Diseases, vol. 8, pp. 3~7-331.Mohler, J. R., I905.-U. S. Dept. Agric., Bur. Anim. Ind., Bull. 78,48 pp. -, .MoIlers, B., 1907.-Zeitschr. f. Hyg. u. Infekt.-Krankh., vol. 58, pp. ~77-~~ .Neiva, A., t913.-Brazil Medico, vol. 27, No. 46, p. 498.Neumann, L. G., 1914.-Parasites et Maladies, Parasitaires du Chien etdu Chat. Paris, p. ~93.Nuttall, G. H. F., 1904.-Lancet, vol. 167, pp. 1785-1786.Nuttall, G. H. F., 1905.-Tr. Epidem. Soc. Land., n. s., vol. ~4, pp.1~-~6.Nuttall, G. H. F., 1908.-Journ. Roy. Inst. Pub. Health, vol. 16.NuttaIf, G. H. F., r91~.-Parasitology, vol. 5, No.1, pp. 61-64.Nuttall, G. H. F., 1913.-Parasitology, vol. 5, No.4, p. ~68.Nuttall, G. H. F., and Graham-Smith, G. S., 1904-1907.-Canine Piroplasmosis,I-VI. Journ. Hygiene, vols. 4-7.Nuttall, G. H. Fo., Warburton, C., Cooper, W. F., and Robinson, L. E.,1908.-Ticks. A Monograph of the Ixodoidea. Cambridge Univ.Press, Part I.Nuttall, G. H. F., Warburton, C., Cooper, W. F., and Robinson, L. E.,1911.-Ticks. A Monograph of the Ixodoidea. Cambridge Univ.Press, Part II.Nuttall, G. H. F., Warburton, C., Cooper, W. F., and Robinson, L. E.,1915.-Ticks. A Monograph of the Ixodoidea. Part III, p. 519.Patton, W. S., 1910.-Bull. Soc. Path. Exot., vol. 3, pp. 274-281.Piana and Galli-Valerio, 1895.-Moderno Zooiatre, No.9, p. 163.Ricketts, H. F., 1906.-Journ. Amer. Med. Assoc., vol. 47, p. 358.Saccharoff, 1891.-Ann. Inst. Pasteur, vol. 5, pp. 564-566.Shellack, C., 1908.-Centralbl. f. Bakt., vol. 46, pp. 486-488.Smith, T., and Kilborne, F. L., U. S. Dept. Agric., Bur. Anim. Ind., Bull.1,301 pp.Stiles, C. W., 1905.-U. S. Treas. Dept_ ..._ Hyg. Lab., Bull. 20, pp. 1-119.

DISEASES CAUSED OR CARRIED BY MITES AND TICKS 4!t9Theiler, A., 1904.-Journ. Royal Army Med. Corps, vol. 3, pp. 599-6!tO.Theiler, A., 1905.-Trallsvaal Dept. Agr., Rept. Govt. Vet. Bact.,1903-1904.Theiler, A., 1908.-Transvaal Dept. Agr., Rept. Govt. Vet. Bact.,1906-1907.Theiler, A., 1909.-Transvaal Dept. Agr., Rept. Govt. Vet. Bact.,1907-1908.Theiler, A., 1910.-Transvaal Dept. Agr., Rept. Govt. Vet. Bact.,1908-1909.Theiler, A., 1910.-Bull. Soc. Path. Exot., vol. 3, pp. 135-137.Von Prowazek, S., I9i!-1914.-Handbuch der Pathogenen Protozoen.Valladares, J. F., 1914.-Parasitology, vol. 7, No.1, pp. 88-94.Valladares, J. F., 19I5.-Parasitology, vol. 7, pp. 88-94.Wilson, L. B" and Chowning, W. M., 190!.-Journ. Amer. Med. Assoc.,vol. 39, July 19, pp. 131-136.Wolbach, S. ~., 1919.-Journ. Med. Res., Boston, vol. 41, No.1, November,pp. 1-193, plates I-!I.

CHAPTER XXXThe Biologies and Habits of Ticks 1F. C. BiahoppThe importance of ticks as vectors of disease and as simple parasiteshas directed the attention of many workers to this group. Although thesuperfamily Ixodoidea, which comprises the ticks, is comparatively small,the species numbering about 300, the life-histories and habits of thespecies arc quite varied. Many forms exhibit a close correlation betweentheir habits and habits of their hosts. There is often also a marked relationshipbetween seasonal and climatic conditions and the presence andabundance of different species.Knowing the intimate interdependency between ticks, their hosts, andseveral serious diseases of man and animals, and also considering thefact that all important control measures are based upon the life historiesof the species concerned, we cannot too strongly emphasize the needof a thorough knowledge of host relations, distribution, and life historiesof the more important species.Stages in the Life of Ticks.-There are two distinct families comprisingthe ticks. One of these, known a,s the Argasidre, may be recognizedby the absence of any highly chitinized parts, while the other, theIxodidae, is supplied with a definite, highly chitinized scutum or shield (onthe dorsum anteriorly), and highly chitinized legs and other parts.There are usually four distinct stages in the life of all ticks. Theegg, which is more or less oval in shape and usually brown in color, thelarva or six-legged stage, the nymph or second stage (with eight legs),and the adult tick in which the sexes are well defined. In several specieswe have a second or even third nymphal stage. In the Ixodidae the malesand females are usually readily distinguished in the unengorged state.The female has a chitinized shield covering almost the entire dorsal side.In this group of ticks the female is the only one which becomes greatlydistended with blood, and being quite conspicuous when engorged, is theform usually observed by the layman. In practically all the species themales attach and imbibe some blood, but do not become greatly swollen.Habita.-There are certain general habits which are peculiar to thetwo families of ticks. Most species in the family Argasidae remain free1 This lecture was prepared for this edition only.430

THE BIOLOGIES AND HABITS OF TICKS 431from the host the greater part of the time, imbibing blood rapidly whenfavorable opportunity offers, such as when the hosts are at rest at night.The first or seed tick stage of this group of ticks, huwever, usually remainson the host for several days. The adults of this family partake of bloodmeals several times and the females deposit a number of batches of eggs.The total number of eggs deposited is usually much smaller than in thecase of the ticks in the other family.Among the Ixodid ticks we find but one species which has the habitof feeding rapidly, as in the Argasidae. In the other species each stageremains on the host for at least several days. Even in the same genus,however, we find widely different habits as regards feeding. There aresome forms in which the larvae and nymphs leave the host for molting.In several species molting takes place on the host and the tick does notdrop off until it has become replete as an adult, while in still otherinstances, the first molt takes place on the host and the second on theground. In all cases in this family the engorged females deposit a largenumber of eggs and die soon after. In most species copulation takes placeon the host. The males may remain some time after the females havedropped. In certain species of the genus Ixodes, however, it appears thatthe males never attach to the host, but remain in the places frequentedby the host and when the females drop off they are fertilized by them.A few species have been found. to deposit fertile eggs without the interventionof the male. The eggs of practically all Ixodids are deposited ina single mass in some protected place. They hatch almost simultaneouslyin a few weeks' time and the larvae or seed ticks usually crawl upon vegetationand there await the passing of a suitable host. In the case of thosespecies which drop from the host for each molt, sometimes spoken of asthree-host species, it is necessary for the ticks to secure a host on threedifferent occasions, hence undoubtedly increasing the mortality beforematurity is reached.Many species show a predilection for attachment to certain regionsof the host. Structure or habits are sometimes modified to fit the conditionsunder which the ticks live on the host. There is a tendency with allticks to choose the more tender portions of the skin upon which to attach.Hence' with many of our common forms we find groups of ticks betweenthe forelegs, on the brisket or the inguinal region. The habit of attachingin the ears has already been mentioned in connection with Ornithodorosmegnini (Duges) Neumann. The tropical hor§c tick, IDermacentor nitensNeumann, also has this habit well developed. The Gulf Coast tick, Amblyommamaculatwm Koch, is usually found in the ear but never in thedeeper portions of that organ. On small animals there is also frequentlyexhibited a tendency of the ticks to attach in the region where they areleast in danger of being destroyed by scratching or biting.

432 SANITARY ENTOMOLOGYHost Relation8.-Ticks develop upon a great variety of species amongthe higher animals. Toads, lizards, snakes, and turtles are infested to aconsiderable extent, birds are attacked by a number of species and especiallyby immature stages of forms which when mature attack largeranimals. Practically all mammals, from the small field mice to the pachyderms,ruminants, and man, are infested by ticks. In general those tickswhich remain on the host for their molts attack fewer species of animalsthan those forms which pass their molt on the ground, and nearly allticks attack more than one host, but many, species develop successfullyonly on certain related animals. These points are made use of largelyin practicing control or eradication.Relation Between Stages and Disease Transmission.-In connectionwith the transmission of disease, the infective stages of ticks vary with thespecies and the disease organism concerned. In the case of a numberof diseases, the organism passes from one generation to the other throughthe egg. This is true in the case of the cattle tick and Texas fever andalso with Rocky Mountain spotted fever. With certain diseases the

TH~ BIOLOGIES AND HABITS OF TICKS 433Pocock.-This tick is a common parasite of man in a large part of tropicalAfrica. It also feeds on domesticated animals. It lives in the hutsand is carried about by the natives in their mats, etc. As the nameindicates, it is the carrier of relapsing fcver or tick fever of man inAfrica. Thc tick hides and brccds in the cracKs, feeding at night. ThisFig. 1-( Upper left) Lanue of fowl tick under feathers of chicken.Fig. 9 (L'pper rij!ht)- Cnengorged male. Fig. 3 (Lower left)-FemaJe w' gs.Fig. 4 (Lower right)-Unengorged female.PLATE XX"I.species is peculiar in that it does not have an active sced tick stage,the first molt taking place within the egg shcll.The Spinose Ear Tick, Ornithodoros megnini (Dugcs) Neumann.This is an Amcrican spccies. It is an important pest of live stock in thesemi-arid Southwestern United States and throughout Mexico. It alsooccurs in the cars of ccrtain wild animals and not infrcquently attacksman, producing severe earache. The tick normally attacks deep in theears of the host. The first or larval stage is very active. This is the•

484 SANITARY ENTOMOLOGYstage which enters the ears. The larvre molt to nymphs within the ears infrom seven to twelve days. The nymphal stage is covered with spines,hence the common name. Engorgement in this stage requires from 81 toover 200 days. The nymphs then crawl out of the ears, hide about barns,posts, trees, etc., and molt their skins, copulate, and lay eggs, no foodbeing taken in the adult stage. The eggs are deposited in these hidingplaces and the larvae remain on the objects until brushed off by an animal.There are several other species in this genus, some of which are ofimportance as parasites of man and animals. One which is commonin the Southwest infests the burrows of prairie dogs and other wild rodentsand may attack man at nigllt. The species O. savignyi (Audouin) Kocliis widely distributed in Africa and southern Asia. It normally feeds onthe camel but often attacks man. Certain other species in the tropicsof Asia bite man, but the transmission of disease has not been definitelyconnected with them.In the family Ixodidae there are many imporr&.nt species. Only a fewwill be mentioned.The Castor Bean Tick or Black-Legged Tick, Ixodes ricinus (I,innllms).-Thisspecies is common throughout the greater part of Europeand Asia and two varieties of it occur in the United States. The mouthpartsare long, thus often producing a troublesome bite. The hostsare many, including both domestic and wild animals and man. While ithas not been connected with any disease in America, it has been clearlyshown to carry red water or bovine piroplasmosis in Europe. This tickdrops from the host to molt, the larvre engorge in from three to nine daysand molt in three to four weeks. The period of engorgement of thenymphs is practically the same as in the larvre. The nymphs require somewhatlonger to molt to adults. The females require about eight to fifteendays to become engorged, and begin depositing eggs in about two weeks.The eggs hatch in from fort." days to several months.The Genus Haemaphysalis-H. leachi (Audouin) Neumann, which iscommon in Africa, has been shown to carry malignant jaundice (Babesiacanis) of dogs. The common rabbit tick in the United States belongsto this group. Another species H. cinnabarina (Koch) punctata Canestriniand Fanzago is sometimes of importance as a parasite on catttle,sheep, and other domestic animals. All of the ticks of the group dropfor molts, and the developmental periods arc somewhat similar to thoseoutlined for Ixodes ricinus, with the exception of the species H. incrmisBirula, which occurs on deer in Europe. The immature stages of thistick engorge very rapidly, becoming replete in from IV!! to 24 hours.The Cattle Tick, Boophilus annulatus (Say) Stiles and Hassall(MargaroptUl) (plate XXVII) and Varieties of This Species.-This isprobably the most important tick in relation to live stock. B. annulatu8

THE BIOLOGIES AND HABITS OF TICKS 435proper occurs in southern United States and parts of )lexico whilevarieties of this species are present in tropical America, Africa, Australia,and other parts of the world. It is not only a species which produces heavylosses on account of its occurrence in tremendou numbers, but it is especiallyimportant on account of being the intermediate host of the piroplasmawhich produces Texas or splenetic fever in cattle.Our form is very restricted in host relations. It can complete developmentonly on cattle, horses, mules, and dccl', rarely on a few smaller animals.This habit has greatly facilitatcd eradication. The molts arePUTE XXYll.-The cattle tick, Boophilus anmllatus. Fig. 1 (Left)- Fully engorgedfemale. Fig. 9 (Right)- Engorged female depositing eggs. (Bishopp.)passed on the host. The females deposit from ~,500 to 4,500 eggs. Insummer these hatch in from ~o to 30 days, while in the fall and winterthe incubation period may extend to 200 days. The longevity of the seedtick varies according to temperature and humidity from about two toeight months, and the period from dropping of the engorged female tothe death of all of her progeny, or the nonparasitic period, ranges from28 days in summer to 279 days in cooler weather. The period of attachmentof the seed tick to the host until the engorged female detachesranges from 20 to 59 days. Both of these periods are of considerableimportance in connection with control by the so-called pasture rotationmethods.The Genus Rhipicephalus.- This group, though small, contains many

496 SANITARY ENTOMOLOGYspecies of importance. The species are most abundant in Africa whereseveral of them are connected with the transmission of disease. R. appendiculatuaNeumann is the principal transmitting agent of East CoastFever, a malignant disease' of cattle in Africa, and four other relatedspecies play some part in the dissemination of this malady. R. everts?'Neumann is credited with the transmission of Nuttallia equi, or biliaryfever of equines, in South Africa. R. bursa Canestrini and Fanzago transmitsBabesia ovis of sheep in southern Europe and R. sanguineu8(Latreille) Koch, a species which is present in extreme southern Texasand Florida and generally distributed throughout the tropical parts ofthe world, plays some part "in the transmission of babesiasis or malignantjaundice of dogs. The biologies of the ticks in this group are quite similarto that outlined for Ixodes and need not be repeated. With mostspecies the molts are passed off the host. R. bursa, the sheep tick, andR. everts;', the horse tick, of South Africa, are exceptions, the larvalmolt being passed on the host and the nymphal molt on the ground. Forthe. most part, the ticks of this group are general feeders.The Genus .A. mblyomma.-This group reaches its maximum developmentin South America. In the United States we have three species ofsome economic importance. The Lone Star tick, .A.. americanum Linnaeus,is the commonest of these. It is widely distributed through the countryand extends into South America. The females are readily recognized bythe single white spot on the scutum, from which the common name isderived. All of our species are general feeders and attack man freelybut are not known to carry disease. In tropical America, A. cajennenseFabricius is tremendously abundant and is often the cause of much annoyanceto man, the larvae and nymphs attaching to the skin by the hundredsand frequently ulcerated sores develop from scratching. The best knownspecies of this group all drop from the host to molt. Engorgement ofthe different stages is comparatively rapid, ranging from three days tothree weeks. The Bont tick, A. hebraeum Koch, a South African species,is capable of carrying the disease known as heart water of sheep. Lounsbury'sstudies indicate that the organism of this disease does not passthrough the egg but is taken up by the larvre or nymphs and subsequentlytransmitted by the following stage.The Genus Dermacentor.-This group reaches its highest developmentin North America. About half of the species drop from the hostto molt while the others pass the molts on animals. The most importantspecies economically is. the Rocky Mountain spotted fever tick, D. venustusBanks (or D. wndersoni Stiles of many authorities 2). This species drops• The editor has chosen to adopt anderBoni as the name for the Rocky Mountainspotted fever tick on the grounds of priority and absolute identification. (See footnoteon this species in Chapter XXIX, p. 409.-W~ .. p:~ie~ce.

THE BIOLOGIES AND HABITS OF TICKS 437from the host to molt and is a very general feeder in the immature stages,practically every rodent of the region being attacked. The species i"widely distributed in the Rocky Mountain and intermountain I'egion,hut the disease of man which it carries is somewhat more limited in range.In the Bitter Root Valley in Western Montana occurs the most virulentform of the disease. Investigations conducted by the Bureau there,indicate that the adult ticks develop almost exclusively on the largerdomestic animals and this point has been utilized in control. In otherregions, however, the jack rabbit plays a considerable part in the engorgingof adults. This species is commonly known as the "wood tick" andin the region where spotted fever is not known it is considered of littleimportance, although occasionally it becomes so abundant as to injurelive stock through irritation and blood loss. It also occasionally producesa form of paralysis in man and animals.FIG. 86.-The Rocky Mountain Spotted Fever Tick, Dermacentor ander80ni (Bishopp.)The larvae are comparatively short lived but the nymphs and adultslive for many months. In fact it is possible for individual ticks whichhave access to hosts in the nymphal stage to live so long as to carrythe species over three years. The larvae develop on the animals in fromthree to eight days and these molt their skins in from one tothree weeks. The nymphal engorgement is practically the same as inthe larval stage, but the molting requires from eleven days to twomonths or even longer. The females become filled' with blood in from oneto three weeks. From 4,000 to 7,000 eggs are deposited. The winter isusually passed in the nymph and adult stages, and these stages, especiallythe adult, are markedly active in the spring months. Seldom areany of the adults to be seen on hosts after the middle of July, and practicallyall cases of spotted fever occur in March, April and May. Thedisease may pass from one generation to the next through the egg andall stages are capable of transmitting the malady. However, the immaturestages are seldom found on man and only occasionally on the largedomestic animals.

438 SANITARY ENTOMOLOGYThe species is very variable in abundance, wooded or brushy4andsbeing most favorable for it, particularly when close to cultivated fields,and of course where small mammals are present upon which the immaturestages may engorge, and d.omestic animals for the engorgement of theadults.Other species of Dermacentor include the American dog tick, D. 'Variabilis(Say) Banks, which occasionally attacks man, and the Pacific Coe.sttick, D. occidentalis (Marx) Neumann, which infest various hosts, includingman, in the Pacific region. The life" histories of these species arequite similar to that of t~e spotted. fever tick." Many animals serve ashosts, especially for the immature stages.The winter tick or elk tick, D. albipictua Packard, is a representativeof the group which remains on the host to molt. This form is often aserious pest of horses and cattle and is probably the cause of the deathof many elk on account of its occurrence in great numbers on the animalsduring the winter season. The eggs hatch in the summer or late fall andthe ticks attach in the long winter coat of the host, becoming matureand detaching in one to three months.In tropical America another species of Dermacentor, D. '1litens Neumann,is often the cause of considerable annoyance to horses by itsattack of that host deep in the ears.It was first suggested that a simple scheme for the separation of themore important species by morphological characters, host, and distributionmight be desirable, but on further consideration this idea wasdropped. In the first place, it is very essential, especially in consideringdisease transmission, that the exact species of the possible vector bedetermined. This can always be accomplished best by submitting specimensto a specialist. In the second place there is a general lack offamiliarity among sanitarians and even among entomologists with ticksand the characters utilized in distinguishing different forms. sIn collecting specimens it is well to attempt to secure both sexes. Themales are usually rather smaller and less conspicuous than tbe females,especially when the latter are engorged. The specimens may be preservedin 70 per cent alcohol or 3 per cent formalin solution;BIBLIOGRAPHIC REFERENCESLiterature on ticks has become quite voluminous. Fortunately there isa very complcte bibliography availablc. This appeared in two parts,• The writer (Box flOB, Dallas, Texas) Is prepared to make determinations of the ticksof North America on short notice. In Europe there are a number of systematists inthis group. Dr. G. H. F. Nuttall of Cambridge University, Cambridge, England, wouldno doubt be glad to determine specimens sent to him. Professor L. G. Neumann,Laboratorie d'Histoire Naturelle, Toulouse, France, is a leading tick authority on thecontinent. Prof. C. P. Lounsbury, Pretoria, South Africa, is well acquainted with theticks of that region.

THE BIOLOGIES AND HABITS OF ~{S 439July, 1911, and May, 1915, as a part of "Ticks. A Monograph ofIxodoidea" by Nuttall, V\Tarburton, Cooper, and Robinson (CambridgeUniversity ~l·ess). Those who wish to go into the systematic or biologicstudies o('"'{fcks further should consult the monograph above mentioned.Three parts of it have been issued. These cover the Argasidre and thegenera Ixodes and. Hremaphysalis. Dr. Nuttall has also published ~number of important papers on habits and notes on biologies of theticks. Most of these appeared in the Journal of Parasitology. Cambridge.In South Africa, Prof. C. P. Lounsbury has done a large amount ofwork, especial1y on the bi~logies of ticks. Many of his articles appearedin the Agricultural J oumal of Capetown, in the Transvaal AgriculturaZJournal. and in the reports of the Government Entomologist, Cape ofGood Hope Department of Agriculture. A summary of Prof. Neumann's.systematic work with descriptions and tables for differentiating specieshas been published as "Ixodidae" (in Das Ticrreich. !e6 Lieferung, publishedby T. E. Schulze, in Auftrage der K. Preuss. Akad. d. W.jss., Berlin,1911. R. Friedlander & Sohn). In the United States the principal papers.are a "Revision of the Ixodoidea" by Nathan Banks, 1908, Bureau of'Entomology, Technical Series, Bulletin 15, and several papers on tickbiologies by IIunter, Hooker, Bishopp, and Wood, the most important ofthese being issued as Bulletin lQ6 of the Bureau of Entomology.

CHAPTER XXXIControl of Ticks 1F. C. BillJWppMethods of destroyiIig ticks may be divided into two general headsstarvationand destruction with insecticides. The former is much morelimited in its practical application owing to the long life of many species.of ticks and the fact that many of them are capable of developing on anumber of different hosts. Furthermore, destruction with chemical agentsappeals to most stockmen owing to the fact that they can actually seethe destruction of individuals.Knowing the ill effects produced by tick infestation, both throughblood loss and the irritation due to gross infestations and by disease transmission,one would think there would be little difficulty in inducing peopleto proceed with control or eradication measures. However, this is notthe case. In practically all parts of the world it has been found thatstockmen will attempt to destroy ticks when they become grossly abundantbut their efforts relax when the numbers arc reduced to a considerableextent. In this connection it might be well to mention some of the benefitswhich arc derived from tick control or eradication. By keeping thenumber of ticks reduced to a minimum, thc growth of animals and the milkHow in cattle are increased. Death loss through gross infestation isavoided and, by accomplishing eradication, several of the most dangerousdiseases of live stock and some of those of man would disappear. Thiswould permit of more rapid agricultural development of many regionsof the world.By following either the method of repression or eradication, the bringingunder control of the herds of livc stock is an important consideration.This is greatly facilitated by fencing and clearing of brush lands. Clearingalso has a direct influence on the abundance of ticks, as the worstinfestations in the case of many species are to be found in lands more orless covered with woods and brush.It is important in many instances to maintain effective quarantinesto prevent the uncontrolled movement of stock and the consequent spreadof the ticks which transmit disease. The effectiveness of this procedurehas been fully demonstrated by the result of the quarantine maintained on1 This lecture was prepared especially fDr ihis edition.440

CONTROL OF TICKS 441tick-infested cattle in our Southern States. This has prevented the ravagingof the non immune cattle of the Northern Stat::; by this disease, andalso has the effect of hastening the eradication of the tick in the South.In South Africa quarantines are doing much to reduce the losses producedby East Coast fever, but there the control of the movement of man frominfected to uninfected areas is also needed, though not easily enforced.The infected ticks may also be shipped in hay cut on infected meadows.With many species of ticks which have the habit of developing in oneor more stages on wild animals, the question of the destruction of suchhosts is at once apparent. Fortunately in the case of our cattle tickin the Southern States these wild animal hosts playa very unimportantpart in the maintenance of an infestation, and, in the instance of theRocky Mountain spotted fever tick and a number of ticks concerned intransmitting East Coast fever of Africa, and other species, much can beaccomplished by the systematic treatment of domestic animals with littleattention being given to the destruction of native hosts. However, withthe majority of species the control, and especially eradication, can befacilitated by the destruction of wild hosts.Since the procedure necessary to accomplish the destruction of ticksmust be varied according to the habits of the species concerned, the discussionwill now be taken up by species.The Cattle Tick, Boophilus annulatus, and Varieties of the Species.The accomplishment of our own Department of Agriculture in the eradicationof this tick in the Southern States is especially notable and presumablyfamiliar to all. In this eradication work, which has been carriedon by the Bureau of Animal Industry, the dipping of cattle has beenrelied upon almost exclusively. However, since it is both possible andpractical to accomplish eradication of this species by the starvation planand since this method may be utilized in a practical way, in combatingother species, those concerned with tick control should becoms familiarwith the principles involved. The system is dependent essentially upon theproper division of the farm by fences usually placed 10 or 15 feet apartto avoid infestation from one field to another, and the knowledge of thetime required both for ticks to complete development on the host and forthe seed ticks to die from starvation under different seasonal conditionswhen proper hosts are not prt'sent for them to feed upon. By variousmodifications of the plan the cattle and certain fields on the farms maybecome tick free in from 4% to 9 months. The entire farm will be tickfree in from 13% to 15 month.s.Destruction of ticks by the use of chemicals has been practiced formany years and hand dressings with various decoctions have been resortedto in reducing gross infestations. Spraying is practiced where but few,....-unimals are treated, but dipping must be relied upon if large numbers of

442 SANITARY ENTOMOLOGYanimals are to be treated, or if complete destruction of ticks is to beaccomplished.Dipping vats of various designs and built of several kinds of materialhave been utilized. The- size of course is dependent somewhat on the numberof animals to be treated. The question of "at construction is discussedin several bulletins of the Department and theselshould be consultedby those contemplating "at building. ,In the early days of tick control work crudc petroleum was utilizedalmost entirely against the cattle tick, but this had many disadvantages.At present arsenicals are relied upon exclusiyely. These consist of eithersodium or potassium arsenite. The usual formula used in making upthe dip is as follows: Sodium carbonate (sal soda) 24 pounds, arsenictrioxide (white arsenic) 8 pounds, pine tar one gallon, and water to make500 gallons. Under certain conditions a stronger dip, consisting of 25pounds of sal soda and 10 pounds arsenic, is used. A concentrated orstock solution is made by dissolving the sal soda in about 25 gallons ofwater, adding the white arsenic and boiling until it is all combined; thenafter cooling the dip to about 140° F. the pine tar is slowly added whilestirring.Several modifications of this dip and methods of making it have beenintroduced, among them the addition of caustic soda to produce the combinationof the arsenic and sal soda without boiling. The self-boileddip is prepared in two parts which should not be combined except in thediluted condition in the vat. These are the arsenic stock and the tarstock. The ARSENLC STOCK is made as follows: Caustic soda (at least 85per cent pure, dry, granulated) 4 pounds, white arsenic (99 per centpure) 10 pounds, sal soda (crystals) 10 pounds. In a large metal containerplace the 4 pounds of caustic soda, add one gallon cold water andstir until the caustic is practically all dissolved. Immediately begin addingwhite arsenic, a pound or two at a time as fast as it can be dissolvedwithout causing boiling. If the mixture begins boiling stop stirring andcool slightly before adding more arsenic. If the proper kind of chemicalsare used a clear solution, except "for dirt, should result. When thesolution is cool add cold water to make 5 gallons.. This stock solutionmay be used immediately or kept indefinitely. The TAR STOCK is preparedby dissolving % of a pound dry caustic· soda in 1 quart of water, add1 gallon pine tar and stir until a uniform fluid resembling molassesresults. It should mix perfectly with watcr. In filling the vat, first addthe necessary amount of water then add the concentrated dip in a thinstream in various parts of the vat. The tar stock should be mixed withseveral times .its volume of water before being added to the vat. Stir themixture in the vat thoroughly.Another modification of this diJ? which should be mentioned is the

CONTROL OF TICKS 443addition of soap and kerosene oil. This was devised by Watkins-Pitchfordfor the frequent dippings necessary to destroy ticks in South Africa. Ithas been utilized also by the Bureau of Entomology in the weekly dippingof animals against the spotted-fever tick. The destructive eirectof the material on the tick is increased and the caustic action on thehost is reduced by this addition. This formula is as follows, English measure:Arsenite of soda (80 per cent arsenious oxide) 8¥2 pounds, softsoap 51;2 pounds, paraffin (kerosene oil) 2 gallons, water 400 gallons.It is important that the proper strength of the solution be maintainedat all times, both to secure efficiency in tick destruction and toavoid injury to the stock. A simple outfit has been devised by the U. S.Bureau of Animal Industry for determining the percentage of arsenicpresent.To accomplish the eradication of the cattle tick the frequency ofdipping is important. It should never be longer than the period requiredfor the ticks to become mature and drop from the host. This is about20 days. Usually it is safer to dip at intervals of two weeks. Eradicationmay be accomplished if systematic dipping of all stock is kept up for aperiod of about six months in the summer, or sufficient time to allow all ofthe seed tick~ which have not. gained access to the host to die ~f starvation.Thorough dipping of every individual is important; the animalsshould be completely submerged.Owing to the poisonous effect of arsenicals, both when taken internallyand under certain conditions when applied externally, the following precautionsshould be exercised in dipping live stock. Have the bath of theproper strength, water the animals a short time before dipping, avoidheating the cattle by long drives or otherwise just before or after dipping,dip during the cool part of the day or provide shade when convenient.The latter point is not nearly so important in connection with the use ofarsenicals as with oil dips. The poisonous effect of arsenicals has beenmentioned in dealing with the control of cattle lice. It need not be dweltupon further here. It is certain that dipping in arsenical solutions isthe most satisfactory method of destroying ticks and lice of all kinds oncattle and horses, and the experience of stockmen in the South in cOnnectionwith the cattle tick eradication indicates that, if the properprecautiCJns are exercised, thousands of cattle may be dipped without theloss or injury of even a single animal.The Rocky Mowntailn Spotted Fever Tick.-As was pointed out inthe lecture upon the biologies of ticks this species has the habit of droppingfrom the host for each of its molts. It also develops on a largenumber of different species of animals, but the adults, especially in theBitter Root Valley where the disease is the most virulent, practically allengorge on the larger domestic animals. This species appears to be

444 SANITARY ENTOMOLOGYsomewhat more resistant to arsenical dips than the cattle tick, and it,vas found best to add kerosene emulsion to the arsenical, following theWatkins-Pitchford formula. In order to prevent the dropping of repletefemales, the dipping must be practiced at weekly intervals. Fortunatelythe spotted fever tick confines its activity in the adult stage to the springmonths, so that it is not necessary to continue the dipping later thanabout the first of July.Since practically' all of the immature stages of this species developon small rodents, notably the ground squirrels, wood rats, pine squirrels,rabbits, etc., the importance of rodent destruction, both from the standpointof tick control and protection of crops, is apparcnt. In much ofthe territory where the spotted fever tick abounds, it is, however, impracticableto reduce the number of rodents to a very low point. In othel;words, in the scheme of eradication dipping of live stock should comefirst and the destruction of rodents be taken up as a secondary step.Aside from the destruction of this tick on animals, it is necessary forman to protect himself against its attack. This can be accomplished tosome extent by avoiding cut-over woodlands or brushy areas, by wearingclothing calculated to exclude the ticks arid by examination of one'sperson at frequent intervals. It was found by Dr. Ricketts that a tickmust be attached to a guinea pig for one hour or longer to produce thedisease, thus it would seem that there is li,ttle danger of infection in manif the ticks are removed promptly. Since no successful remedy for thetreatment or prevention of the disease has been devised, the importanceof exercising care in preventing infection by keeping free of ticks can notbe too strongly emphasized.The Spinose Ear Tick.-We are concerned with this species both onaccount of its injurious effect on horses, cattle, dogs, and other animals,and the frequency of its attachment in the ears of man. Furthermore weshould be familiar with this tick since a considerable part of our militaryactivities in this country have been and will probably continue to be inthe Southwest where the species abounds:It is probable that by exercising some care in locating camps and inchoosing places for sleeping, some degree of immunity from attack willresult. The seed ticks are, of course, concentrated about feed lots,corrals and watering places of live stock and these should be avoided inchoosing a camp site.The effect on animals of heavy infestations of this species is verymarked. The ears are droopy, the hair rough and the animal presentsan unthrifty appearance. Fattening is difficult if not impossible, andunder range conditions the loss by death is not infrequent. In horses andmules there is' a marked shyness on the·part of the animals when attemptis made to touch the ears or put _on a bridle. This is sometimes so extreme

CONTROL OF TICI{S 445that it is almost impossible to halter or bridle an infested animal. Inman there are seldom more. than one or two ticks present, yet the pain isdescribed as excruciating at times, and a sensation of tickling, ringing,and fulness at others. The ticks are usualc.'j so far in the ear that theycan not be discerned readily from the outside and hence frequently theyare overlooked for weeks.In man the removal of the ticks with forceps will usually give completeand permanent relief. In horses and cattle mechanical removal with arather blunt instrument may be practiced, but in general it is better todepend upon the application of some material to destroy the ticks.Unfortunately the dipping of live stock in the ordinary tickicides will notreach or destroy this species, hence we must depend upon individual treatment.The Bureau of Animal Industry (Farmers' Bulletin 980) hasfound that a mixture of pine tar and cottonseed oil (~ to 1) will destroyall ticks if properly worked into the ear. It may be applied with a longspoutedoil can or hard rubber syringe, the base of the ear being manipulatedas the material is injected. About one-half an ounce is requiredfor each ear. It also has the advantage of protecting the animals againstreinfestation for about a month.The Chicken Tick.-Although this is an important poultry pest, thecomparative freedom of man from its attack will not justify a lengthydiscussion here. While spirochaetosis of fowls, known to be carried bythis species, appears not to be present in the United States, it is a sourceof considerable loss in many other parts of the world, in the tropics andsubtropics. In this country the main loss is due to the weakening ofthe fowls by the loss of blood and irritation. This often is sufficient t.ocompletely stop egg production, reduce the fowls in flesh, and sometimescause death. •Owing to the resistance of this species to the action of chemicals, andon account of the habits of the species, it has been found best not toattempt to destroy the larvae while attached to the host but to proceedagainst the infested roosting or nesting places of the fowls. In oneinstance only is it necessary to give consideration to the individuals, andthis is in protecting an un infested yard or premises from introduction ofthe tick in the seed tick !!tage on poultry. Fowls brought in should bekept in quarantine in a crate or small yard for about ten days. Duringthis time all of the seed ticks upon them will have become engorged andhidden in the roosting places and may there be destroyed by fire or somematerial as recommended for treating roosts.It usually pays to destroy heavily infested houses lvhich are of littlevalue. In other cases, the houses should be thoroughly cleaned andsprayed with the wood preservative knolvn as carbolineum, or with crude

SANITARY ENTOMOLOGYpetroleum (plate XXVIII). It is usually best to thin each of these substanceswith one-third kerosene. Following this treatment a simple roost(fig. 87) should be constructed, preferahly supported by four posts driveninto the ground or attached to the floor, the roost poles being held inplace by notches on cross bars resting in similar notches in the supportingposts. None of the roosts or supports should touch the walls. One ortwo applications of the carbolineum or petroleum to these roosts with abrush will usually sufficc in destroying the infestation, although it isadvisable to make frequent examinations to determine if all of the tick",are destroyed. The chicken mite De'T"TTUJlTt'!l88ul1 gallinae is controlled bythe same procedure.Other American Species of Ticks.-There are several other kinds ofI II "\ ,':1,/~FIG. 81.-:\lodel chic·ken roost (Bishopp)ticks of economic importance in this countr~T. Among them should bementioned the Lone Star tick which is frequently met with in the South,East, and Central States; the Gulf Coast tick which produces considerableirritation by attacking the inside of the external ear of horses andcattle in the coastal region; the tropical horse tick which is to be foundonly in extreme southwestern Texas, usually attached deeply in the carsof horses and mules; and the widely distributed American dog tick whichis sometimes sufficiently abundant to greatly annoy man and other animals.All of these species except the tropical horse tick, drop for their molts andare therefore rather difficult to control. Dipping in arsenicals, especiallyif carried out at weekly intervals, will of course reduce their numbersconsiderably. In regions where dipping vats are not generally available,hand picking or the application of kerosene emulsion, some of the creosotestock dips, or arsenical dips with a rag or spray pump are advisable.The treatment of dogs should receive special attention. The tropical

CONTROL OF TICKS 447horse tick reqUIres local treatment similar to that for the spmose eartick.South African Ticks.-In South Africa the so-called blue tick, avariety of our common cattle tick, carries bovine piroplasmosis and probablyother diseases and may be controlled by the same procedure outlinedfor our species. However, in South Africa this is not considered the mostPLATE XXVlII.-Spraying chicken house with oil by means of knapsack spray pump.(Bishopp).important tick pa"&asite of live stock, since certain species of Rhipicephalusca-rry the much more deadly disease, East Coast fever. Since theimmature stages of the brown tick (R. appendiculatus), the principalagent in the dissemination of the disease, become engorged and leavethe host in three days or less, it becomes necessary to dip at vcry shortintervals to prevent the escape of specimens which may infect otheranimals. The larvae or nymphs which engorge on cattle infected withEast Coast fever are the only direct source of propagation of the diseasein other animals, hence the main attack must be directed against them.

448 SANITARY ENTOMOLOGYWatkins-Pitchford found that these stages can be killed with dip muchweaker than is necessary to destroy the adults. He thus determined on astrength which would destroy these young stages with one dipping andyet produce no injury fo the -host if applied at three-day intervals. Theadults are subjected to two dippings, as they remain on the host 7 days.This was found to give 100 per cent destruction. The formula (Englishmeasure) for this dip is: 4 pounds arsenite of soda (80 per cent arsenic),S pounds soft soap, 1 gallon paraffin, 400 gallons water. The majority ofstockmen, however, do not resort to either the three- or five-day dippingexcept when in fear of an outbreak of the disease. There is no doubtthat by dipping at weekly intervals during the warmer period of theyear and at intervals of two or three weeks through the cooler weather,if practiced consistently for two or three years, the ticks can be reduced.to a negligible quantity, if not eradicated.African Relapsing Fever Tick.-While this species has received considerableattention from the disease transmission and biologic standpoint,little work has been done on control practices. No doubt control of thetick in native huts will be very difficult on account of lack of interestand cooperation on the part of the natives; however, it would appear tobe comparatively easy to protect the houses of white inhabitants frominfestation, and for the traveler to avoid attack. The latter could beaccomplished best by avoiding infested huts and improvising methods ofisolation either in hammocks or otherwise. In native villages the free useof strong tickicides on the floors, and cleaning and airing of mats wouldundoubtedly reduce infestation and of course the provision of somesort of isolated bedsteads, which suggestion would probably not be takenup by the natives, would also prevent attack.The Control of Ticks in Other Parts of the JV orld.-In Australiamuch progress has been made in the destruction of the cattle tick, but inother parts of the world outside of the United States little systematicwork has been done against ticks. The hand application of insecticidesor hand picking of adult ticks has been the principal method followed.No doubt many of the control practices put into effect in this countrycould be adapted to European and Asiatic conditions.Treatment of Tick Bites.-There are many references in literatureand popular ideas regarding the painfulness and poisonous nature of bitesof various species of tick. Literature contains references to deaths withina few hours following the bite of some tick in the region of Persia. In:Mexico there is also an opinion entertained that certain species of Ornithodorosproduce very painful, if not deadly bites. In the experience ofthe writer and various other workers, most of these reports appear to beunfounded or exaggerated. No doubt the effect varies in different individualsand possibly there is a relationship between the symptoms pro-

CONTROL OF TICKS 449duced and the kind or health of the host upon which the tick has beenfceding previously. Certainly some species of ticks produce forms ofparalysis, authentic cases having been recorded as resulting from thebite of the spotted fever tick, and in the case of certain other ,speciesin South Africa and Australia. It thus appears important that tickbites be avoided as far as possible, and should paralytic symptoms develop,a search of the patient for ticks, especially around the occiput,should be made immediately.In regions where tick-borne diseases are known to occur, it is advisableto treat the bite with iodine or some other antiseptic. In the absence ofa physician, this may be done by inserting the point of a sharpened toothpick or match after it has been dipped in the iodine, in the place where theproboscis entered. Before treatment, examination should be made to besure that the mouth-parts arc completely removed, as they sometimesbreak off when pulling out the tick.LIST OF REFERENCESChapin, R. M., 1914a.-Arsenical Cattle Dips. U. S. Dept. Agr., Far~mers' Bull. 603, 16 pp.Chapin, R. M., 1914b.-Laboratory, and Field Assay ,of ArsenicalDipping Fuids. U. S. Dept. Agr., Bull. 76, 17 pp. -Cooley, R. M., 1911.-Tick Control in Relation to Rocky MountainSpotted Fever. l\lontana Agr. Expt. Sta., Bull. 85, fl9 pp.-Graybill, H. W., 191fl.-Methods of Exterminating the Texas Fever Tick.U. S. Dept. Agr., Farmers' Bull. 489, 4~pp.Hunter, W. D., and Bishopp, F. C., 1911.-The Rocky Mountain SpottedFever Tick. U. S. Dept. Agr., Bur. of Ent., Bull. 105, 47 pp.Theiler, A., 1909.-Diseases, Ticks and Their Eradication. TransvaalAgr. Journ., vol. 7, pp. 685-699.Theiler, A., 1913.-Inquiry into Dips and Dipping in Natal. Agr. Journ.Union of South Africa, vol. 4, pp. 814-8fl9 (19a); vol. 5, pp. 51-67,fl49-fl63.Watkins-Pitchford, R., 1911.-Dipping and Tick-Destroying Agents.Agr. Journ., Union of ,South Africa, vol. fl, pp. 33-79, with figs., July.

CHAPTER XXXIIFlies and Lice in Egypt 1H. A. BallouEgypt, among its other characteristics, is a land of flies. Whetherthey have been abundant there ever since the days of the plague of fliesof Moses and Rameses may be open to argument, but there can be no •doubt that in these times the abundance of flies is one of the things thatstrikes the visitor to the land of the Pharaohs.I had the good fortune to live in a smaH village where flies were notvery troublesome, and that, in spite of the fact that a fairly large veterinarycamp was situated in the village. This camp was in charge ofBritish Army officials and the village itself had been planned and builtby a company, most of the stockholders and officials of which wereBritish subjects, if not indeed actually natives of Great Britain.The native villages in the agricultural districts and the native sectionsof all the large cities and towns are, and "1 suppose always have been,infested with swarms of flies. This state of affairs results from themanner of living of the people, the nature of their religion and theirsuperstitions. As to the first of these points, the Egyptians have alwaysbeen an agricultural people, that is to say, they live on the land and bythe land. Most of them are peasants or small proprietors, a comparativelyfew are wealthy. In the past few years Ii fairly large number ofthem has become well-to-do.Egypt is Ii country practically without a rainfall. Within presentgeological time it has never been forested. The people throughout thewhole of their history have been accustomed to live in dirt and dust, andthey have not had wood for building houses or for fuel. They live inhouses of sun-dried mud and they burn for fuel the manures of theirdomestic animals.The space available for village sites is limited to slightly elevatedspots, which are generally too high to be irrigated and are thus uselessfor planting, and they are to some extent above the reach of flood andinfiltration of water. Very often these mounds are the covered-down ruinsof forgotten cities or towns. The houses are close together, often• This lecture was presented to the class Oct. 7, 1918. It was written ImmedIatelyafter Dr. Ballou's return from Egypt and gives a ~ood idea of an unsanitary nation.450

FLIES AND LICE IN EGYPT 451there are no proper streets and the villages are walled about as a protectionagainst thieves and robbers. There are usually no barns or sheds forthe animals and these are sheltered in the houses with the family or onthe house top.The dung for fuel is mostly made up into small cakes and these aredried in the sun and stored in the houses, often in an ornamental parapet.For making these cakes the dung of cows and the water buffalo is used.This. is mixed with leaves, straw, etc. Horse or donkey manure is usedby itself, mostly as a fine dry dust to produce a quick fire for baking. Itwill be seen from this that the Egyptian has no idea that manure isunclean as we understand it. In the absence of rain, the Egyptian villageis always dusty and the dust is a mixture of soil, manure, and anythingthat can be dried by the fierce sun into dust.The Egyptian has no idea of sanitation. It is one of the commonestsights in all parts of Egypt where I have been, to see in the morninghours tllC men squatting in the open for their morning relief. The verywealthy and the residents in the larger towns and cities may have someform of privies, but the open field is the habitual scene of operation forthe great bulk of the people. They have no more idea of the properdisposal of garbage of any sort than of the manure of theh- animals andtheir own ordure.The moisture necessary to maintain all life in these situations comeS"from irr.igation canals supplied by the waters of the Nile. Every villageis situated on or near a canal which supplies drinking water, serves as aplace for washing clothes, for bathing, and as a place for disposing ofanything that is to be thrown away, from a dead calf to a broken water,'essel.As to the second point. One of the tenets of the Mohammedan religionis that the good Muslem is not allowed to take life, not even of the leastof God's creatures.In connection with the third of these points, it need only be statedthat the Egyptians are very superstitious about the Evil Eye. Thisapplies particularly to the children, who must not on any account beadmired or called pretty. It would be difficult to keep them clean, butnobody wants them to be clean.It is unnecessary to give details as to the degree of fly infestation thatmay be seen in a native village or in the native quarters of the townsand cities. TIle relations of flies and children may be mentioned.Very young children are often to be seen with their faces so coveredwith flies that it is difficult to tell the color of the child's skin. Theyswarm in the eyes, nostrils and mouth, and cover the whole face. I haveoften seen a small child b~ing held or tended by another not much bigger,raise its hand to brush away the mass of flies on its face and be prevented

452 SANITARY ENTOMOLOGYfrom doing it. They are from the earliest childhood accustomed to thepresence of these insects, and after being prevented from disturbing themduring the early months of life they do not seem to mind them.As a result of this coitdition of things, eye diseases are very prevalentin Egypt. I should not think there could be any place in theworld where bad eyes are so often seen as in Egypt. The natives are oftenshort-sighted. For instance, very few of 'them can read their newspaperswithout bringing them up to two or three inches of their eyes and then itis obvious that only one eye is used in reading. It is a curious sight tosee these people reading in the trains and other public places.This condition is probably the result of some form of ophthalmia andis quite different from the one-eyed condition so often seen in Egypt inconsequence of wilful mutilation of an eye for the purpose of evadingmilitary conscription or the payment of the small sum required to purchaseexemption.THE SULTAN'S FUNERALOn the day of the funeral of the late Sultan, His Highness, HusseinKamil Pasha, in October, 1917, a party of us gained admission to abalcony overlooking the street in the business part of Cairo. When wearrived, there were a number of people already there. They seemed tobe Italians or perhaps Syrians, we couldn't tell. They spoke French.Among them were a number of children, six or seven in number,the eldest being about 16 or 17 years and the youngest some 7 or 8 yearsof age. After a time I noticed in the hair of the eldest, a girl of the brunettetype with very dark hair, a whitish streak across the side of thehead from near the forehead well back to where the hair was gathered intothe long braid which hung down her back. This white streak must havebeen about an inch and a half to two inches in width and some five or sixinches long. I saw that the whitish appearance was due to the presence ofmasses of nits of the head louse. I then noticed the heads of the otherchildren there and found that they were all the same. Every head wasfull of nits.I actually saw the lice crawling about in the hair of these children,and though I watched them pretty constantly for about two hours,except for a few minutes wheit some parts of the funeral procession werepassing, I did not once see anyone of them attempt to scratch or in anyway take notice of the irritation which must have been caused by the lice.The general appearance of thest! children was one of a fair degreeof neatness and cleanliness, and yet they were so inured to the attacksof these parasites that they paid not the slightest attention to them.I have never seen anywhere such a heavy infestation of these vermin.

CHAPTER XXXIllInsects in Relation to Packing Houses 1E. W. LaalceBefore the meat packing establishments of the United States wereplaced under government inspection, there was very little attention paidto insects and their control in such establishments, unless there wasa direct loss to the packer, and even then only such methods as werenecessary to meet the immediate situation, rather than the requirementsof permanent sanitation, were employed. During the first years followingthe institution of inspection by the Bureau of Animal Industry underthe law of 1906, packing plants were remodeled or rebuilt according togovernment specifications, and conditions were vastly improved from asauitary standpoint, although the insect question was not handled vigorouslyuntil during the past few years. The importance of safeguardingfrom contamination and infection the millions of tons of meat and meatproducts prepared by the numerous packing houses in the United Statesis indeed a task worthy of attention, especially during the present timewhen our products are so direly needed at home and abroad. That insectsplayas great a role by contamination or actual destruction of meatsand meat products as they do in other branches of agricultural industries,is easily demonstrated when one becomes familiar with the ravages ofthese pests in the numerous establishments in our country.Flies are the principal cause of annoyance and loss around packinghouses. The house fly is probably of first importance: It is especiallytroublesome around the loading docks, in sausage kitchens and in markets.The blow flies are often very abundant, especially in departments handlinginedible materials. In this country the black blow fly, Phormia reginaMeigen, is probably the most important. The greep. bottle flies, Luciliascricata Meigen and L. caosa.r (Linnaeus), rank second, and in the southernhalf of the United States the screw worm fly, Chrysomya macellaria(Fabricius), is the predominant species in the summer months. Othersconcerned are the bluebottle flies, CaUiphora spp. and Cynomyia cada'Dorina Robineau-Desvoidy; flesh flies, Sarcophaga spp.; Muscina stabulanaMacquart, M. assimilis Fallen, Ophyra spp., Chrysomyza spp., and the• This lecture was read July ~9, and issued August 8, 1918, and is now reproducedpractically in its original form.453

454 SAN"iTARY ENTOMOLOGYskipper fly Piophila casei Linnaeus. Hide and ham beetles, mostly of thefamily Dermestidae, are of local importance, especially as destructive tohides. The three common cockroaches are to be found, especially theAmerican roach and the Croton ~ug.Associated with all the larger packing houses are large stock yards,horse and mule barns, rendering plants, and thickly populated districts,all of which are prolific insect breeding places. These furnish part oftheir millions of flies, with those produced on the premises of the packingplants themselves, to constantly attack th~ fresh products of the estab·lishments. Sanitation throughout the establishments and premises undergovernment inspection, and in railway cars and other vehicleS' used intransporting meats, is rigidly enforced, but government inspectors haveno jurisdiction over sanitary matters beyond that, no matter how badthe existing conditions may be.With efficient city health departments a great deal can be done cooperativelywith the sanitary force of the packing establishments, but this isnot always possible and as a res.ult the production of myriads of fliesgoes on constantly in the immediate neighborhood of the plants and thetask of protecting meat products and controlling flies at packing housesbecomes proportionately more perplexing. In our Southern States thisis an aU-year-round work, due to the fact that our winters are rarelysufficiently severe to cause the death of immature stages and during warmdays numerous adults emerge and seek food ·and protection in the con-. '·stantly heated tankage and blood-drying rooms or other favorabledepartments. Here they also find large stores of excellent breedingmaterial and can develop to maturity in a comparatively short time duringthe winter months. The breeding of blow flies in large accumulations oftankage and blood in drying rooms, as it is found in many packing houses,may take place during the winter even in the more northern latitudesas there are many species of blow flies that are quite resistant to coldand have the advantage of many warm, protected places during severewinter. .That flies are carriers of many different diseases is well known. Thegerm-laden flies can easily contaminate many diff~rent cured meatproducts which are sometimes consumed without being cooked, or contaminatefresh meat products with putrefactive, non-pathogenic and path·ogenic bacteria, in this way hastening decomposition, and rendering themeat unfit for food. There is also loss of much meat that is "blown"with eggs or damaged by skipper fly Iarvre.Next in importance to flies in meat paeking establishments are cockroaches.Although they arc not as numerous as flies, they are presentin almost all establishments just as they are more or less plentiful indwelling houses. The damage done by cockroaches is due not so much

INSECTS IN RELATION TO PACKING HOUSES 455to what they actually consume, which is necessarily a small amount, butto losses of portions of food ,vhich are contaminated and renderednauseous. The presence of roaches leaves a fetid odor which is persistentand foods so tainted are almost beyond redemption. This odor comeschiefly from a dark-colored fluid excreted through the mouth of the insectand perhaps also from the scent glands occurring between certain segmentson the bodies of both sexes, from which an oily liquid of a disagreeableodor is secreted. Favorable conditions for the existence of cockroachesare found with{n all packing houses, namely, abundant food suppliesof all kinds, good protection in the winter, and many good breedingplaces.Skipper larvae and hide beetles are often found by the millions in thebone storage houses, especially in stores of bones collected at large in thecountry, where pieces of dried muscular tissue and skin are attached.These insects are not so often found in the department of edible suppliesof the packing plants, as the packers are well aware of the damage doneby them, especially in cured and dried products, and a constant watch iskept to prevent their appearance or to quickly exterminate them when'they do appear in such departments.INSECT-BREEDING PLACES AND THEIR TREATMENTThe importance of proper construction and arrangement of abattoirsand packing plants with a view to eliminating insect breeding places andprotecting the food products from insect contamination can not be overestimated.In plants already in operation many bad fly-breeding placescan be permanently eliminated by construction work. For instance muchfuture trouble can be avoided by constructing concrete catch basins, pavingdocks, loading tracks, and stock pens, providing adequate driers forbones, fertilizers, etc., and ample dry storage facilities for inedibleproducts. Excellent breeding media of both vegetable and animal matterare almost constantly present and are often found in hnge quantitiesin various places on the premises of establishments or on "dumps" nearthe plants. Too often thes(' large accumulations arc neglected for somecause or other, and insects, especially flies, have ample time to developand emerge by the millions, and many such places, especially those notunder government supervision, are constant producers of myriads offlies throughout the warmer seasons of the year.The undigested food of cattle, called paunch manure, and the contentsof hog stomachs, together with the horse manure and stable cleaningsfrom the horse barns, partly blood-saturated sawdust from the meatcoolers and sediment from catch basins saturated with bloody water, areusually hauled to a general dumping ground. These dumps are thusV

456 SANITARY ENTOMOLOGYrendered very attractive to house and blow flies and nearly all of thismaterial is wet when it is dumped and must have a day or two of hotweather in order to dry sufficiently to burn well. If it remains as long asfour days before burning, which is often the case during rainy weather,fly larvae have sufficient time to develop before the material becomes dryenough to be burned, and migrate to a nearby place where they enterthe ground and complete their life cycle.For the destruction·of paunch manure, etc., incinerators of varioustypes are used by some packing plants and stock yards. At Omaha,Nebraska, the Stock Yards Company has erected a huge incinerator ofa special type that contains sixteen large cells equipped with water pipesthroughout. As the contents of some of the cells are slowly burning, thewater pipes are heated and the hot circulating water dries the contentsof the freshly filled cells which are later also slowly burned. The ashesand charred material are then removed, mixed with finely ground, dry,sheep manure and sold for fertilizer. At least six men are constantlyemployed filling the cells and removing the charred contents and thereturns realized from the fertilizer are said to be sufficient to pay for alllabor and pay a reasonable amount of dividends on the investment o.f theincinerator plant, which was erected at a cost of $40,000.Other types of incinerators in use, which are operated mostly by packingplants for the disposal of paunch manure and refuse of all kinds, aresingle and double cell bridk structures where everything is completely consumedand the ashes are used for fillers of various fertilizers. At Chicagoone plant hauls all its paunch manure and refuse on railroad cars a shortdistance away to an incinerator made of a series of old discarded ironrails which slope from the top of the track embankment to the ground,leaving a considerable air space below. Here a fire is constantly keptburning and consuming the manure and waste piled on the rails above.Ashes filling the space below the rails are removed when necessary and aremixed with other fertilizers. At a few large plants the paunch manure isloaded daily on railroad cars and is shipped out two or three times aweek to places in the country where the manure is sold to truck farmers.The trackage beneath the cars along the loading docks is paved withconcrete to prevent full grown larvre from escaping from the loaded carswhen they are held over several days. The paving extends well aroundand beyond the length of the cars and near the outer edge it is providedwith a narrow, deep gutter filled to half its depth with water where it isconnected with the sewer. This arrangement carries off the excesswater and traps the maggots as they endeavor to migrate to a place forpupation.When treatment of infested dumps is necessary, borax solution orcrude oil is mostly used. Spent fuller's earth, a waste product from oil

INSECTS IN RELATION TO PACKING HOUSES 457and lard refineries at packing houses, is also used at some plants withfairly good results, if the earth is thoroughly mixed with the paunchmanure and waste, or is used as a covering. Spent fullerts earth, whenit is discarded at the refineries, contains about 8 per cent of oil and actsas a larvicide besides being a repellent for several days. In experimentsat a Dallas packing house a saturated solution of arsenic was also foundto be very effective for killing larvlE in paunch manure.Many other llreeding places of importance exist around the plants,such as the hog hair, tankage, blood cooking, and drying rooms; in fertilizerbuildings; along fertilizer loading docks where pulverized tankageand blood and hone meal accumulate on the ground under the docks; andalong car tracks where the soil becomes moistened by rain or by opensewage disposal lines, quite often found under such docks. Often the soilso covered with moist animal matter is found to be heavily infested with,blow fly larvae. Borax treatment for such infestations is very effective hutmust be repeated frequently as fresh material is always accumulating andis readily reinfested. Crude oil or fuller~s earth applied heavily on suchbreeding places packs the soil down well and also renders it less attractivefor flies for a much longer period. It has repeatedly been observed bythe writer that where enough oil or funer's earth had been applied therewas no fly breeding going on. When the capacity of a packing plant isovertaxed, or when labor is short, large stores of bones and hog hair do notget thoroughly dried in the hot air driers and these then become heavilyinfested with blow fly and skipper fly larvae. The same condition is alsooften found in storage houses containing bones, hair, blood, and tankagethat have been thoroughly dried, but again moistened by water leakingthrough a bad floor or bad roof above. To prevent fly breeding in anyof this material it must be thoroughly dried and then stored in an absolutelydry place.Another common source of fly production found at packing plants isunder and around stick-water vats where the glue stock is manufactured.Steel and wooden vats are used for boiling stick-water and sooner orlater these vats may become leaky or are heated to such an extent thatthe stick-water boils over and saturates the soil below. Prolific By breedingthen takes places. Borax solution or crude oil treatment for suchinfestations is very effective. In the stock yards the hog pens are usuallyall paved and the manure is washed into sewers leading to a nearby stream.In many instances the sewer outlet is not directly into the water and th~manure is deposited in large qua'ntities along the banks of streams where itbecomes heavily infested with fly larvre which develop in the moist manure,thence migrating to dry places for pupation and emergence. The manuremixed with hay and straw from cattle pens is usually hauled to nearby

458 SANITARY ENTOMOLOGYdumping grounds and is th-ere allowed to decompose, or is occasionallyburned over, but very seldom incinerated.Cockroaches arc found in the blood and tankage rooms, dressingrooms, and other departments that are not under refrigeration. Modernsteel and concrete construction has much to do with eliminating theseinsects. The use of steam and hot water in cleaning up the machinery,walls and floors of all the departments and rooms containing edible goodsdestroys most of them that come in during the night and do not returnto their better protect~d hiding places i~ the departments of inedibleswhere there are also good breeding places. Where steam and hot watercannot be used freely against roaches, the dusting of sodium :fluoride isvery effective. About four pounds of sodium fluoride, applied with a dustgun by the writer in a dry salt cellar and tankage drying room at acertain packing house, killed over 5,000 roaches and thoroughly cleanedaway the pest. A thorough inspection of these same departments monthslater revealed only a few roaches which probably came in from otherdepartments of the plant that were not treated.When skipper fly larvae are found in cured meats the products infestedare trimmed and the storage rooms thoroughly cleaned, or if the infestationis severe, the meat products are rendered for inedible purposes, theuninfested products removed and the storage rooms fumigated.PROTECTION AGAINST INSECTSThat flies can be kept out of packing houses to such an extent thatthey are not objectionable is well demonstrated in some of the largeplants at Kansas City, Missouri; Davenport, Iowa; Omaha, Nebraska;Milwaukee, Wisconsin, and Topeka, Kansas; which are completely andthoroughly screened and remain remarkably free from flies on the insidealthough flies are plentiful on the outside.For the protection of meats against skippers it is necessary to screenclosely with twenty-mesh wire. It is also necessary to keep the storeroomsdarkened. The use of fly traps around packing plants is fullyjustified. Even though everything possible is done to eliminate breedingplaces on the premises, great numbers of flies come from the surroundingdistrict to the attractive con(litions which are to be found around packingestablishments. Our investigations have shown that flies quickly come toslaughter houses when liberated at nearly a mile distant. No doubt theyoften travel much farther to such establishments. Traps of variousmodels are used extensively at packing plants and where traps are wellhandled great quantities of flies are captured. Accurate records kept bysome plants show that as high as !!85 pounds of flies were captured in

INSECr_rS IN RELATION TO PACKING HOUSES 459one week with 65 traps of the conical hoop type. This type is by far themost efficient all-round fly trap of some twenty different kinds tested atpacking plants.The most attractive bait for blow flies is the mucous membrane whichis freed from intestines after it has become sour. At packing plants thie.material is known as "gut slime" and when it becomes warm it fermentsrapidly, giving off a very obnoxious odor that is especially attractive toblow flies and_also a very good bait for house flies. However, on accountof its bad odor it cannot be used in departments of edible foods or onloading or shipping docks. Sugar or molasses, one part, to three partsof water, makes a very good bait, especially for house flies. A cheap, blackmolasses mixed with three parts of water and allowed to stand a day ortwo before it is used to bring it to fermentation is a very cheap andeffective bait.Fly paper used extensively in screened rooms catches practically allflies that have gained entrance through doors which are necessarily openedand closed where much trucking is done. Screening of some doorwayswhich are constantly in use by in and outgoing trucks is not practicable asflies light on trucks and follow them through the doors, and soon congregateon the inside of such rooms or departments.To exclude flies from entrances of such doorways a rapidly revolvingceiling fan or rotary blade fan operated at a high rate of speed has beenfound to expel flies very effectively. When they enter the air current,which should be directed down and outwardly, they are driven outthrough the entrance.Where breeding places are reduced to a minimum, where the plant iswell protected by thorough screening, and where flies are effectivelytrapped, there is very little loss of meat or meat products, and the plantis in a sanitary condition from an entomological standpoint.A BIBLIOGRAPHY OF LITERATURE DEALING WITH SANITATION OF MEATPACKING ESTABLISHl!olENTSAllen, R. M., and McFarlan, J. W., 1913.-The Municipal Abattoir.Kentucky Agr. Exp. Sta., Bul. 173.Anon, 1913.-The Protection of Meat from Flies. Australian MedicalGazette, vol. 33, No. 18, May 3.Bishopp, F. C., 1915.-Flies Which Cause Myiasis in Man and Animals.Some Aspects of the Problem. Journ. Econ. Ent., vol. 8, No.3,pp. 317-3~9.Bishepp, F. C., 1916.-Flytraps and Their Operation. U. S. Dept. Agr .•Farmers' Bulletin '734.

460 SANITARY ENTOMOLOGYBishopp, F. C., 1917.-Some Problems in Inse9t Control About Abattoirsand Packing Houses. Journ. Econ. Ent., vol. 10, No.2, pp. 269-277.Bureau of Animal Industry, 1906.-Regulations Governing the MeatInspection of the United States Department of Agriculture. OrderNo. 137.Bureau of Animal Industry, 1912.-Service Announcements, June.Bureau of Animal Ind~stry, 1914.-Regulations Governing the Meat Inspectionof the United States DepartIp.ent of Agriculture, Ordt!r No.211.Bureau of Animal Industry, . 1915.-Service and Regulatory Announcements,March.Farrington, A. M., 1908.-The Need of State and Municipal Meat In·spection to Supplement Federal Inspection. Bureau of Animal Industry,Circular 154.Melvin, A. D., 190B.-The Federal Meat Inspection Service, Bureau ofAnimal Industry, Circular 125.:Melvin, A. D., 1912.-State and Municipal Meat Inspection and MunicipalSlaughterhouses. Bureau of Animal Industry, Circular 185.Parks, G. H., 1911.-Tlle Sanitary Construction and Equipment of Abattoirsand Packing Houses. Bureau of Animal Industry, Circular173.Shaw, Geo. H., 1914.-The Federal Meat Inspection Service and Sanitationof Packing Houses under Its Supervision. American Journal ofPublic Health, vol. 5, No.3, pp. 236-245.

CHAPTER XXXIVInsect Poisonhg and Miscellaneous Notes on the Transmission of Diseasesby Insects .W. Dwight PierceIn the various lectures which have preceded this one, most of thelarge groups of disease-carrying insects have been discussed in full butthere are a number of cases of carriage of disease by insects of othergroups and there are many cases of insect poisoning which have not beencovered. As a matter of fact the majority of species of insects whichare chargeable with poisoning have not been mentioned.In the present course of lectures, for convenience, all arthropods havebeen considered under the popular term insects. 'rhe general public doesnot discriminate between a spider, a scorpion, a mite, a tick, and aninsect as far as the general nomenclature is concerned. In fact the diseaserelationship in these different groups are so similar that any discussionof them from a sanitary standpoint should include all of the groupswhich belong to the Phylum Arthropoda. The scorpions belong to theorder SCORPIONIDEA, the spiders to the order ARANEAE, and themites and ticks to the order ACARINA, all in the class ARACHNIDA,characterized by eight legs. It is also well to consider the very nearlyrelated class CHILOPODA, which includes the centipedes and millipedeswith one or two pair of legs to each segment. The insects all belong tothe INSECTA, characterized by six legs.SCORPION PO,SONINGThere is great popular fear of the sting of the scorpion. Thesecreatures are found largely in semitropical and tropi~al countries andare possessed of a tail with a sting at the tip. The effect of the poisoningis more or less severe and in some cases is fatal. The method ofstinging is to bring the tail forward over the body so that the curvedspine on the last segment penetrates the skin and inflicts the wound.On either side of this curved barb is an opening from which the ductfrom the poison gland discharges the venom. Very little has been dopeon the toxicity of the poisons of the various species of scorpions. Castellaniand Chalmers have summarized in a few pages the subject of scorpion461

462 SANITARY ENTOMOLOGYvenom. In the majority of cases when a person is stung by a scorpion,they fail to retain the specimen or to have a scientific identification madeso that the records of actual species causing scorpion sting are verysmall, only twelve species having come to the attention of the writer.The purpose of the scorpion venom is not necessarily as a means ofdefense, but rather as a method by which it kills its prey, which usuallyconsists of small animals. In man the symptoms depend upon the sizeand nature of the scorpion.The small European scorpion, Isometrull europaeus Linnaeus, causesonly pain, redness, and local swelling. Some of the larger tropical scorpionscause intense pain of a burning character radiating from the skin,associated often with violent convulsions, mental disturbances and hallucinations,profuse perspiration, secretion of saliva, and perhaps vomit- •ing. The pulse is weak and quick and the respiration is hurried andshallow. ,These symptoms gradually diminish in three to eight hoursand by about nineteen to twenty hours the person usually is normal.Death may ensue due to collapse or stoppage of respiration which ismore apt to happen in children than in adults. Wilson states that themortality in children under five is 60 per cent for Butkus quinquestriatu8H. & E., a species of Upper Egypt and the Sudan. Fatal poisoning isalso charged against Buthus maurus and other North African scorpions.Cararoz has stated that as many as two hundred persons die annuallyfrom scorpion sting in the neighborhood of ])urango, Mexjco. The specieswhich is responsible for this is Centrurull etclicaude Wood. In additionto the species already mentioned, Buthus martensi Karshi of Manchuria;Butkus occitanus Amour of South Europe and North Africa; Buthus aferLeach, Prionurus citrinus. P. amoureuni Savigny, Androctonus funestusEhrenberg, and Heterometrull maurus, all of South' Africa, have beenrecorded as causing severe poisoning. Kubota found the Durango scorpionmany times more toxic than the lVlanchurian. The common southernspecies in the United States, Butkus carolinianus Beauvois, which rangesfrom the Southern Atlantic States into Texas, north into Kansas, inflictsa very severe sting which hurts for many hours.Castellani and Chalmers recommend as treatment for scorpion stingthe application of a proximal ligature and incision and treatment of thewound with permanganate of potash in the same manner as used forsnake bite. C. V. Riley in 1887 recommended the use of ammonia appliedover the sting, or a small dose of ipecacuanha. Simpson recommendsthe local application of a paste' of ipecacuanha. Colonel Duke recommendsthat 5 to 10 minims of a 5 per cent solution of cocaine be injectedsubcutaneously, close to the sting, for adults, and 1 to 5 minims for infantsand children. Murthy (1919) considers that larger quantities ofa weak solution of cocaine hydrochloridg_ are better than smaller quantities

INSECT POISONING AND MISCELLANEOUS NOTES 468of stronger solution. He has used successfully a dosage of ~o to 80minims of a solution of ~o grains cocaine to the ounce, injected exactlyon the sting. A number of different writers have prepared antivenomsor serums which are capable of neutralizing the venom. Villala.reports the preparation of an antiserum in Brazil which was successfullyused in the case of a child affected with a very severe scorpion poisonmg.SPIDER POISONINGThere is more or less general fear among the public, due to manylegends which have been passed down, as to the severity of spider poisoning.The majority of spiders are not poisonous but there are certainspecies which are extrcmely poisonous. The spiders rhost feared inAmerica are the tarantulas, large hairy spiders. The tarantulas, likeother spiders, have poison jaws for killing or paralyzing their prey.There are very few scientific records of tarantula poisoning in America.Vorhies has cited four without mentioning the species. The Americantarantula which has been regarded as poisonous is Phidippus auda:cHentz. In Europe" tarantula poisoning is caused by Lycosa tarantulaLinnreus, L. narbo1Umsis Walckenaer, Epeira diadema (Moritz-Herold)Walckenaer, and Troc1wsa singorUmsis (Laxmann). Epeira diadema isthe common garden spider of Europe and is not as large as the Americanta,rantula. The bite of Lycosa tarantula produces wheals surrounded byred areola but no general symptoms result.The evidence against the hour-glass spider, Latrodectes mactansFabricius, and its allies is far more convincing and there is no doubtthat these are dangerous spiders. This species is coal black and markedwith red or yellow or both. It is quite variable in markings. Thefull grown female is about a half-inch in length and its globose abdomenis usually marked with one or more red spots on the dorsal line. Thisspider occurs in old buildings, stables and wood piles. It spins an irregularweb which is composed of very coarse, silk threads. It is an exceedinglyaggressive spider. Severe and sometimes fatal poisoning follows.the bite. Kolbert has isolated a substance from the poison gland(Arachnolysin) which is a powerful hemolysin. Dr. E. H. Coleman, LosAltos, California, has conducted quite a series of experiments withArachnolysin and with a toxalbumen which occurs throughout the body ofthe insect. He dissected the poison glands and made various triturationsfrom which he prepared powders which he took himself and noted theeffects upon himself after each dose. After taking twenty-five powders,.his heart rate was reduced to 48 and his temperature was 99. He experienceda severe headache, clonic spasms of the thoracic and abdominalmuscles, marked distress about the heart with radiating pains extending

464 SANITARY ENTOMOLOGYto the left arm pit and down to the elbow. He had no bowel action fortwo days and the pupils were markedly dilated. His symptoms appearedto him a perfect picture of angina pectoris. The symptoms subsided andin three days he felt normal. lfe repeated this experiment twice with thesame results.Doctor Coleman had a patient aged 54 years suffering from anginapectoris. During an attack he gave him a powder of one of the triturationsof the spider venom and in ten minutes the symptoms passed leavingthe patient more comfortable than after any previous attack.At least one case of death is recorded from the bite of this species andseveral cases of severe poisoning have come to the attention of the.Bureau of Entomology.Houssay gives quite a description of the symptoms and literature.He counsels the usc of morphine, bromide, or camphor oil. He citesalso the use of chloral and as cardiac tonics, caffein, and acetate ofammonia, aiding any of these by milk diet and theobromine.Doctor Coleman records treating a case by hypodermic injections ofstrychnine 1/40, followed in ten minutes by nitroglycerine 1/100, andlocal applications to the site of bite of crystals of potassium pennanganate.By repeated injections of strychnine the heart rate was increasedto 45. He then substituted the use of brandy hypodermically. Heatwas applied to the feet and back. Nine and one-half hours after theattack the heart rate had been increased to' 55 and the pains were stillsevere. A 1,4 morphine with 1/150 atropine was given. The pains easedup and the patient dropped asleep. The next day he was covered with afine rash. The heart rate was 60. This rash disappeared in four days.He suffered from insomnia for several days and a stubborn constipationthat took a very active purge to affect. After three years his heart ratewas 64, he was troubled with insomnia, and a marked bulimia.Fatal spider poisoning has been recorded as caused by LatrodectcsgcometricUB Koch in California, L. hasseltii Thorell (8celio Thorell) (the"katipo") in New Zealand, Therapho8a javanen8i8 Walckenaer in Java,Chiraco;ntkum 'fIIUtriaJ Walckenaer in Europe. Theridium 13-guttatwmFabricius in France and Italy, and T. lugubrc Koch ("kara kist") in.Russia.CENTIPEDE POISONINGThe centipedes, on account of their large size and many sharp legs,have given rise to numerous popular legends as to their poisonous nature.It is a common saying that when a centipede grips hold of a person, theimpression made by each claw gives rise to a sloughing of the flesh. This-opinion is quite erroneous as the centipede has only one pair of poisonglands, located in the head, having their ~xternal opening through a pail'

INSECT POISONING AND MISCELLANEOUS NOTES 465of venom claws which are large-clawed appendages lying beneath thehead. The opening of the venom duct in Ethmostigmus spinosus, whichhas been carefully studied by Cornwall, is on the dorsal surface of theclaw a little way from the apex and somewhat near the external side.There is one venom gland in each of two venom claws. This species isnocturnal in habit and is not naturally vicious and will not bite unlesshurt or worried. A centipede's bite may be merely a snap, but once he findshis fangs sink into the fine tissues his main idea, if other portions of himare not being mistreated, seems to be to eat. To this end he digs as manylegs as he can apply into the subject, the posterior ones to obt.ain It firmhold, and the anterior ones to knead the tissues. 'The venom claws areworked in and out and with the help of the first pair of legs the skin ofthe subject is pushed into the mouth. In five minutes a centipede willthus consume a length of rabbit skin nearly one centimeter long. Themain function of the venom claws is to hold the food tightly against themouth-parts to facilitate mastication. The slow but regularly continuedFIG. 88.-A centipede, ,scolO'[JtJ1ldra mOI'BitUiIUI (Bradford).relaxation and closing of the venom claws is designed to permit the :flowof venom into that part of the food which is to be taken into themouth. The toxic action is so slow that the venom would be practicallyuseless for destruction or defense. Cornwall believes therefore that thevenom principally serves as a digestive juice.Other species of centipedes which have been recorded as venomous areScolopendro, cingulo,to, Latreille, S. gigantca Linnaeus, S. moraitana Linnaeus(fig. 88), S~ heros Girard, and Geophilus similis Leach.The centipede bite may cause some local pain, swelling, and erythemalasting a few hours. The general symptoms are great mental anxiety~vomiting, irregular pulse, dizziness, and headache. When severe localinflammation follows a centipE:de bite" it is chiefly due to septic infection.A large c.entipede which has secured a firm hold of the skin by digging inits fangs and legs can almost be torn in half before it can be induced to letgo, and in delicate skins each leg can, under such circumstances, make Ii,punctured wound which will ad~it infective organisms. The use of dis",infectants to prevent infection by outside organisms is therefore necessary.Vorhies has described two cases of Arizona centipede bite, in both.of which the pain was severe and prevented sleep.

466 SANITARY ENTOMOLOGYCastellani and Chalmers recommended for centipede ~bites the bathingDf the parts with a solution of ammonia (1 in 5, or 1 h_.40). After bathingapply a dressing of the same alkali, or if there is much swelling andredness, an ice bag. If necessary give hypodermic injections of morphiato relieve the pain.CENTIPEDES IN NASAL CAVITIES AND ALIMENTARY CANALThere are in literature quite a number of references to the occurrenceof small centipedes in the nasal cavities and in the alimentary canal.In the nasal cavities they have been charged with causing considerableinflammation and in the alimentary canal have caused pain, cramps, andnausea. Very little is known of the cause of this attack but presumablyit is more or less accidental, probably when the person is asleep out ofdoors. The following species have been recorded from the nasal cavities:·Geophilus carpophagus Leach, G. electricus Linnaeus, G. cephalicusWood, G. similis Leach, Lithobius forficat1lA Linnaeus, L. melanaps Newport,Scutigera coleoptrata Linnaeus, Clwetechelyne vesuviana Newport,PoZydesmus complanatua Latreille, lulus terrestris Linnaeus, 1. londinensisLeach, Himantarium gervaisi, Stigmatogaster subterraneus (Leach).'There is no evidence that these parasites cause any inflammation by theirvenom. They are generally expelled from the nose in attacks of sneezingor spontaneously. The best method of making them leave the nostrilsis the use of snuff, Eau de cologne, or turpentine, but in someinstances surgical operations are necessary.This subject has been more fully treated by Blanchard in vols. 1 to·6 and 14 of the Archives de Parasitologic.LEPIDOPTEROUS LARV.lE POISONINGIt is not uncommon for persons to be more or less badly poisoned bythe barbed hairs of lepidopterous larvre. In some cases these hairs containminute drops of poison. The most famous poisoning of this kind is knownas "BROWNTAIL RASH" which, when it attacks the eyes, is calledOPHTHALMIA NODOSA. This is caused by the browntail mothEuproctis c1trysorrhoea Linnaeus. There have been numerous cases ofbrowntail rash in New England. The stinging hairs sometimes penetrateinto the lungs, as well as entering the eyes. This is most likely tohappen at the time the caterpillars are molting and the air is filledwith hairs. Entomologists working in laboratories where this species isbeing studied have suffered considerably from this poisoning. The larva isprovided with four rows of setigerous tubercles which bear barbed hairs,larger at the apex than at the base. These hairs are connected with

INSECT POISONING AND MISCELLANEOUS NOTES· 467poison glands, one of which lies beneath each papilla or tubercle. Thepoison is liberated in the blood through the sharp basal point of thehairs when they come in contact with the human skin. One case of deathhas been reported. The structure of the poison glands and hairs isdiscussed by l\:[iss Kephart.~!lingham has described poison hairs on the larva of Porthesia simili8FueSlf':'~, the swan moth.'l'he processionary caterpillar Cnethocampa pit yo campa Borowaki,according to Beille, is provided with poison-secreting, setigeroustubercles which are divided into four areas by two bands \vhich crossthe tubercles at right angles to each other and which are free fromhairs. The four sectors thus made are covered with chitinous papillawhich bear poison hairs and which are connected with the subjacent partsby pore canals in the cuticle. The glandular part exists only underthe sectors covered with hairs. These glands are unicellular and in theform of very elongate pears. These poisonous hairs, when they comein contact with tIle flesh, cause an urtication.In a similar manner the larva of the nun moth, Lymantria monacha(Linnaeus); the gipsy moth, Porthetria dispar (Linnaeus), the 10 mothAutomeri8 io (Fabricius), Hemileuca maia Drury, Lasiocampa pini (Linnaeus),JJfacrothylacia rubi (Linnaeus), Sibi'1le stimulea Clemens, are providedwith poisonous hairs. Lagoa cri8pata Packard and JJfegalopygeopercularis (Smith and Abbott) are known as flannel moths, and arecovered with long, silky hairs and do not look like caterpillars. Interspersedamong the long hairs are numerous short spines connected withthe underlying poison glands. These hairs are capable of producing amarked nettling effect when they come in contact with the skin.Riley and Johannsen present a very interesting discussion of nettlinginsects and suggest for treatment the application of weak solutionsof ammonia or a paste of ordinary baking soda. In the browntail district,one remedy which is commonly used was recommended by Kirkland:Carbolic acid ........ ,................... 112 gramZinc oxide .........................•..... % oz.Lime water ........... ~ .............•.... 8 oz.llEE, WASP, AND ANT STINGSMany species of bees, wasps, and ants are capable of inflicting painfulstings. These insects sting by means of the ovipositor. Only the femaleis capable of inflicting injury. All persons who have handled bees arefamiliar with the sting of the honey bee, Apia mellifera Linnaeus, andmost boys are familiar with bumble bee (Bombua spp.) stings.

468 SANITARY ENTOMOLOGYThe wasps most likely to sting are species of Vespa and Polistes.The most aggressive stinging insects in America are the TexasAgricultural ants of the genus Pogonomyrmex, especially P. barbatuaSmith and P. califor;nicus Buckley. These ants will attack anyone whocomes in the vicinity of their ]JJ.rge nests or who stands in their path.The immediate effect of their sting is a paralysis of the limb affected.The pain is very severe, and it is recorded that the sting of these antsis fatal to young pigs.HONEY POISONINGIn South and Central America one very frequently sees the stinglesshoney bees of the genera Melipona and Trigona at meat. The honey ofthese bees is eagerly collected by the natives for food. According toWheeler and Von Ihering there are numerous cases of poisoning from·eating this honey. This poisoning is manifested by intestinal disorders,sometimes causing paralysis an9 vomiting, while the honey of other speciescauses eczema and skin diseases and death has been recorded.Wheeler states that Trigona bipunctata Lepeletier, T. amalthea(Olivier) Jurine, and T. ruficru8 (Latreille) Jurine make the waX ofmoist earth collected along streams and drains or from the feces of animalsand man. He noted T. ruficru8 at Gatun, Canal Zone, visiting garbagebarrels in great numbers in company with house flies and blow flies.He has observed T. bipunctata at Guatemala collecting human excrementin open latrines and along railway tracks, and T. pallida Latreille wasnoted at Gatun collecting crude black oil used as a mosquito larvicide.According to Von Ihering the honey of T. limao Smith is frequently ifnot always poisonous, causing vomitin.g, convulsions, pains, and weakeningof the joints. He cites several cases. Von Martius claims that thereis a bee whose honey causes tetanus. He may have referred to this orrelated species. The cerumen or wax of this bee is sometimes 80 liquidthat it mixes with the honey.It is easy to see that there are abundant opportunities for contaminationof the honey of this group of bees. In fact it is not uncommon tosee our own honey bee at excrement and there is a possibility that attimes it may contaminate its honey.Dr. Kebler has recorded cases of poisoning in New Jersey from eatinghoney. Honey may also be poisoned by nectar gathered from poisonousplants, of which Morley lists several.ANAPHYLAXISHadwen and Bruce have contributed to medical entomology anothertype of disease caused by insects in showing that bot larvm when crushed

INSECT POISONING AND MISCELLANEOUS NOTES 469may cause anaphylaxis in an animal. Anaphylaxis essentially consistsin the development under r"l.1"tain circumstances in an animal of a hypersensitivenessto foreign alt-uminous materials which in themselves are notessentially toxic. The larvre of the hots Hypoderma bovis DeGeer, H.lineata DeVillers, and Oestrus ovis Linnaeus are not normally toxic althoughby living in an animal they produce a sensitiveness. Whencrushed in the animal or when the protein material contained in thelarvre is injected into the jugular vein of a sensitive animal, anaphylacticshock results. Both in natural and experimental anaphylaxis death mayresult. Recovery from the reaction gives i~unity for varying periods."-POISONING FROM EATING INSECTSCornelius (1919) reports an instance of eleven cases of acute nativepoisoning in India following a feast on cooked garden bugs, Aspongopusnepal81Mis Westwood, which were collected from under stones. Recoverytakes place in from three to ten days. Continued consumption is said bythe natives to immunize against poisonous effects. TIle bug gives off anodor resembling sulphuretted hydrogen, but when cooked is regarded as adelicacy.KISSING BUGSVarious species of reduviid bugs have been charged with inflictingsevere injury with their bite. The species of Triatoma have been discussedin Chapter 28. The black kissing bug, Melanolcstcs picipcs inflictsa very painful bite. Probably foreign matter is often introduced bythe bite.DERMATITIS CAUSED BY BEETLESA number of species of beetles have been recorded as excreting anirritant liquid which causes a dermatitis to the skin which they touch.As an example we may cite Paederuofl colwnibimtus Lap. of Brazil, whichcauses an acute dermatitis, a species of Staphylinid of the Belgian Congowhich causes a vesicular d~rmatitis, and the Meloid beetles, Ca;ntharisflavic(Jrnis Dufour and C. vestitUofl Dufour. The substance secreted byCantharis is sometimes used as a cauterizing agent.BEETLES AS CARRIERS OF DISEASE GERMSWe are not apt to think of beetles as carriers of disease, hut there area number of ways in which beetles may readily be concerned in diseasetransmission. There are quite a number of species of beetles whichbreed in carcasses and which can readily carry disease germs from one

4,70 SANITARY ENTOMOLOGYcarcass to another, thus 'enabling the flies and other insects which visitfood to further distribute the germs. Proust found quantities of livingDerme8te8 'tJulpinu8 Fabricius in goat skins taken from anthracic animals.He found virulent anthrax bacillus in their excrement and alsoin their eggs and in the larvae. Heim also had occasion -to examine someskins which were suspected of having caused anthrax in persons engagedin handling leather. He found the larvae of Attagen'U8 pellio Linnaeus,A nthren'U8 mU8eorum Linnaeus, and Ptinus also fully developed insectsof the latter species on the skins. All these insects had virulent anthraxbacillus (spores) on their bodies and in their excreta.The greater proportion of the cases of beetle transmission of diseaseare those in which the beetle serves as an intermediate host of a parasiticworm. In most of these cases the beetle larvre are found in excreta. TIreyingest the eggs of the worms and the transformation takes place withintheir bodies. The worms are then eaten by animals and the infection iscarried on. Since Doctor Ransom, in his lecture, has summarized 0.11 ofthe evidence, it is unnecessary to repeat at this time.We are not apt to associate the transmission of prant diseases byinsects but the cases are strongly analogous. Just recently F. B. Randhas demonstrated the transmission of cueurbit wilt, which is caused byBacillus tracheiphilu8, by means of the cucumber beetle, Diabrotica 'tJittataFabr. He has found that the beetles take up the bacillus in eatingan injured leaf and has been able to demonstrate the presence of thebacillus in the body of the insect by dissection and culture with subsequentinoculation. He has conclusively proven that the disease can betransmitted only by means of this and closely related beetles. He hasfound also that the normal bacillus content of the abdomen may, in alarge proportion of cases, destroy the wilt bacillus. It is quite probablethat infection in this case is similar to that caused by the house :By, inthat the infected excreta come in contact with the recently eaten surfacesof the leaf as the beetle moves forward.It has been found that beetles can transmit mosaic disease of tobacco.It is not at all out of the way to expect that we will find ultimately asimilar transmission in this case and in many other plant diseases.LIST OF REFERENCESCastellani, A., and Chalmers, A. J., 1915.-l\fanual of Tropical :i\{edicine.Cornelius, H. B., 1919.-Indian Med. Gaz., vol. 54, No. ~,pp. '7!e, '73.Cornwall, J. W., 1916.-Indian JOUI'D. Med. Research, vol. 3, pp. 5fl-5'7, and 540-55'7.Ellingham, E. H., 1914.-Tr. Ent. Soc. Lond., 1918, pt. 8, p. 423.

INSECT POISONING AND MISCELLANEUUS NOTES 471Heim, F., 1894.-Compt. Rend. Soc. Biol., Paris, pp. 58-61.Kephart, Cornelia F., 1914.-Journ. Parasit., vol. 1, No. ~, pp. 95-10!.Morley, M. W., 1915.-The Honey Makers. A. C. McClurg & Co.,.Chicago, pp. 188-194.Murthy, S. S., 1919.-Indian Med. Gaz., vol. 54, No. !, p. 78.Proust, A., 1894.-Bull. L' Acad. Med., vol. 84, pp. 57-66.Riley, C. V., 1887.-Hand Book of Medical Science, vol. 5, pp. 741-760.Villela, E., 1917.-Brazil Med. Journ., vol. 81, No. 48.Von Ihering, H., 1904.-Revista Mus. Paulista, p. 11.Vorhies, C. T., 1917.-Poisonous Animals of the Desert. Arizona Agr.Exp. Sta., Bull. 88, pp. 373-39!.Wheeler, W. M., 1914.-Journ. Trap. Disealles and Prevent. Med., vol. !,.pp. 166-167.

479lSANITARY ENTOMOLOGYSUMMARYThroughout this course of lectures my main object has been to showthe diverse manner in which insects may cause patliological conditions ormay transmit pathogenic organisms. Unquestionably the majority ofspecies which carry disease organisms have not yet been recorded in thisrBle. In the past we have attempted to minimize the possible rBle of theinsect as a carrier of 'disease. In the future it would be wise to take thestand that insect transmission of a disease should be one of the firstmethods of transmission investigated and that the investigation shoqldbe carried out on logical lines suggested by the habits of the insectsconcerned. It is to be regretted that a large part of the study of insecttransmission of disease has been aimed at proving or denying transmissionby means of the bite of the insect. We have seen from the evidencepresented that a large proportion of the cases of insect transmission arenot by the bite but rather through the feces of the insect. We maytherefore consider that many of the conclusions that insects are not involvedin the transmission of certain diseases are unwarranted and thatthe cases should be reopened and studied more scientifically.Any insect which visits excreta or which visits food or the person ofman or animals is to be considered a suspicious object in a diseasetransmission inquiry. Naturany we will look to the blood-suckers asthe first means of transmitting disease of which the organism is found inthe blood, but when the diseases are of the intestinal or genital organs,we are more apt to find that the disease is carried by insects which becomecontaminated by contact with infected excretions. Another unexploredfield of study is the determination of toxins in foods, produced by contaminationof insects feeding therein.If through this series of lectures we have succeeded in interesting afew investigators to look into the subject of transmission of certaindiseases more.thoroughly, we shall feel that we have been'successful in ourefforts.

CHAPTER XXXVA Tabulation of Diseases and Insect TransmissionW. Dwight PierceIn VIew of the fact that a very large number of diseases have beenmtmtioned in these lectures, and that the same disease has often beenmentioned in several lectures, it was thought desirable to prepare atabulation of the information presented in this volume in the most concreteform possible. In the fourth column under method of insect transmission,I have drawn frequent conclusions as to the probable mode oftransmission, based on analogy. In each such case a modifying wordmakes it clear that the statement is not proven. Unquestionably we mustdraw such conclusions and test them out, for by such methods we cangreatly facilitate progress in investigation. Unquestionably in many ofthe diseases cited below, insect transmission is not the most importantmode, but on the other hand, I am just as confident that insect transmissionwill prove to be the most important mode in other diseases nowconsidered to be carried otherwise. In no wise in this entire course do Iclairn responsibility for proving insect transmission, nor am I able tojustly repudiate the claims made by others. The evidence is presentedfor what it is worth and occasionally with theoretical suggestions bymyself, but each reader must seek the original evidence and weigh it himself.Undoubtedly there are many inaccuracies of fact in this tabulationand in the chapters on disease transmission. Soml' of them may have beencorrected but overlooked in compiling the present work.There is always a danger that people will accept a tabulation asaqthoritative. It is not, in this case at least, a critical compilation.473

474 SANITARY ENTOMOLOGYDisease Causative organism Imect transmitter Metbod of inseet Nature oftransmissions insect rilleAcariasis, human and animal D ..':"!:ny..... g~~nis Same ... preceding Direct att...,k Parasite.(acarine dermatosi.) column. in akin.Holoth.vrus cOccinellaLiponys.us bacotiTetranycbus teJariUlAcariasis. internal (parasitism Carpol!~bus alienus Same as preceding Direet attack Par ... ites.of l!ver, kldne,v~, etc., I!"!'- Cytole. us baDksi colUMn. in various indUClJJ,lpel'ltoD1tll, entel'ltil. " nudus ternal organ •.purulent urine. etc.) .. s&rCOptoidesH'lBtiogaster spermaticusLaminosioptes cysticolaNephroph_ ."nguin.riusAcari ..;" see also Chiggers.D'lr.lwninll mite, Gonoue.In ammatioD i,_broDohial,lung., oatan al), Itch,l\I&IIg8, Ocular acariasis.Otoacariasis, Par a I y 8 i •(tick), Scabiea, Sealy leg.Ainbum DermatopbUus penetranl. Dermatopbilul pen- The Ilea bur- Direet attad

TABULATION OF DISEASES AND INSECT TRANSMISSION 475DiseoseAnemia, owl (Syruium aluco)Anemia. owl' (Syruium alucoand Glaucidium uoctUII!)CaUllltive arlBDismHaemoproteus .yruiiLeUcocytoZOOD daoiIewakyiInsect transmitterCuliseta anuulata.CuI"" pipieus.Anemia. palm IQuirrel (Fu- HlI!molllegarioa fuoambuli Ha!matopinul sp.DAmbulus penuatii)HlI!IDOgregarina lepori.HlI!maphysaiis flavaAnemia. rat HlI!mogreprina muria Lelaps echidwnus.HlI!mogregariua mauritaDiea Hyalomma oeg)'p-tium.Auemia, turtle (T... tudo mauritaDiea)Anthru. animal and humanBacterium anthr.ci.A.cariaai. Aoearis lumbricoid .."Babea!a.ais. bovine. ArgentineBabe.i .. arll'lntinUIDChrysop. rGlCUtiensHII!m&topota pluvialisMpel'O!lia irritansStomollYl calcitrausTabanu. atratus.. bovinusu ItriatusAedes _ylvestrioPllorophora lay)Callipboraer~hrocephalaCalliphora vomitoriaLucifiac_arSarcophOfl& carnariaAntbrenU't mUleorumAttagenul pellioDermesteo vulpio ...Ptinuolpp.Blat.ta orieotali.Bo.boruo punelir.ound to carry theeDuil have beeaeggs.Boophilus """Illatu.australis.Method of in_ttransmislionaNature ofIDJeet r(lleTran.mil.ion Intermediateby bite of host.mOlquito.Transmission:;'.q~~. ofIutermediat.host.Transmission IntermedjRt.not worked host.out but probablytbroughsereta.TransmissionprobablY mechanicalbutnot-proven.Taken up inblood bymites. Infee-~i~~ ~f :::1:.-by rats.The manner oftraDsmiuioDis not determined.Probably me-chaniCa! carrier.Traosmi •• ioDby bite of fly.Transmillionby bite, ex ..p.rimental.Iusecto .wallowbacilli in feedingon car ..casses orwounds and11~r.°;:~~:on ""undo.Beetle. inr.':t~':~~l:on carcassesand 'kins.Paaoeath ... "ghiDte. tinaltract in tact.Infection bycontamination.Larva. .wallowtbe eggs. Flie.might depo.it:~;d~'Fn.e~~transmissioni. Dot regardedlUI important.Tt1LDsmitted bybite of ti~k.probably intbe aamemaDDer AIcattle fever.Mechanicalcarriers.Intermediatehoat.Intermediateholt.Mechanicalcarrier.IIfechanicaiand pos.ibIYbiologica1carriemMechanicalcarrier.lIlecbaoic:a1earrier.Mechanicalcarrier. NointermediatehOlt is neceslarv·Intermediatebost.

476 SANITARY ENTOMOLOGYDiseaseBooesi ...... """i". < .... alian .... tjau""ioe)Babeoiaais, eaniDe ad jackalBabesiasi ••See alto .Bili817 fever(equine). Car

TABULATION OF DISEASES AND INSECT TRANSMISSION 477Di.e_ Causative orlanism Imect tr8llllmitterMethod of insecttransmiBSionsNature ofiDsect r6JeChiggers Cred bugs) (acarine Allotrombidium fuliginOllum Same as precediog Direct attack Paraaite,dermatoai.), Leptus akamushi column, iIl.kin,See also Gonone .- americanum- irritansMetatrombidium porieep.Miorot~mbidium J'..'\".:!l.",,~teTrombidium autumnali.batata"holo.erieeum..ino_pinatumItnaticepaCholera, Asiatic Spirillum cboler ..., Cal_liphora yomito- Taken u~ from Mec:hBDica1n •. .tools Y'1ar- ClU'rier.Eri.tali. teDu:. val and adultMusca domeotica. fli .., depositedin feces orOn food.Periplaneta ameri- May be carried M.chan .... lCBD •• In the roach carrier.body lor atleut GO minuleaand depositedin viablecondi.tioll in its feces.Cholera, fowl Bacterium choler ... gallin' Blatta orientalis. P ..... through Mechamcalarum. inte.tinal eameJ'.tract Intact.Infection bycontaminatioa.Cholera, hog Filterable virna. Musca domeotica. Taken up by:r MechamealFannia caniculari •• from &Dim carrier.manure Wases:perimental ..ly trawmit.ted by contactwithwound. andb;y Inocul ....tlon ofcrushed flies.Stom~ c:alcitr&IUI Experiment:!!! Mechanicaltransmit earrier (?)by inoculationofcru.hed infectedflie ••Colitis Bacillus coli. CalliP.hora vomitoria Flies or JaryIB MechanicalLucJlia CESar take up from carrier.Musca domestica ltools. De-Sarcopbaga carnaria po.ited intheir fecea onfood.Blatta orientalia. Pas_ through M •• banical: n.teltia8J carrier.tract intact.Infeotion hycontamination.Conjunctivitil Bacillus of Koch-Weeb. Microneurum fani- Insect t&kea Ul! MeohBDiealcola. fromey.ana carrier.earri .. to eyeConjuDctiviti.s, phlyctenular VarioU! bacteria. Pedieulus humBDUI Deposited in Meohanieallouse feces, earriel.carried to eyeby handa.Deerfly levet!(See plague, rodent/Dengue Filterable viras. Aed •• argenteu! TraDemitted IntermediateCulm: quinquef.· bl mosquito hoat.ciatUl.bite.

478SANITARY ENTOMOLOGYDiseaseCausative organismNature ofinsect .aleDeplumiDB mite, chickenDermatitis, beetleCnemidocoptes gallin"'.Cantharis f1avioorniLU VestitUIPrederus rolumbinulotber Meloid andStapbylinid beetles.Cnemidoeoptes galliDie.Same as precedingcolumDoDirect attackat baae 01feather •.The.. beetles:rl~~~r~:tliquids wbichth ey emitwhen attacked.Parasite.Producers of irritautseeretiolU.Diarrhea, fowlSpirillum meiehnikovl.Blatta orientali ••Passes throughintestinaltract intact.Infection bycontamination.Mechanicalcarrier.Diarrhea, infantileDiarrhea, Bummer.~f:m~aracolitis,PoisoningBaciUus of Morgan.MUlCa domestica.Tr'::a uP bfr.,~.tools. Survivesthroughmetamorphosis.De-J:~::' foo~~Mechanicalcarrier. Possiblyalso biologieal.DiphtheriaDourineDysentery, ammhieDysentery, bacillaryDy""ntery, lamblianBaeiDul diphtherie.CastellaneUa equiperdum.Liisehia biBtolytica.BaciUuI dysenterie.Giardia intestinalis.Musca domestic •.Fliea tah upfrom sputumand depositin feces onfood.Mechanicalcarrier.Stomoxys caleitrans Experimental MechanicalAtylotus tomentosus transmi .. ion carrier (n~a~=~~~t-CaUiphora erythrocephalaMusca domestica.Musca domestica.MUllca domestica.Taken up fromstools in en ..B':~:i~~feces on food.Taken up bylarvie from8tool8. Survivesthroughmetamor ..phosis. Depositedin feceson food.Taken up fromstools in en ..">'Sted .ta~.Deposited Infeees on food.Mechanicalcarrier.Mechauicalcarri ....Mechanicalcarriw.Eaat Coast fever(Rhodesian fever)Theileria parva.Rhipicephalus simu8II aPla~~!cu-U evertsi.1 capenli.Hyalomma .. gyptiumDermacentor uti ..culatWl.Dermacentor niteDsTransmitted hythe tick inthe inst .. followinj!thatin whlch takenup. or byDest generation.Intermediatehost.Eczema.ElepbantiaaiB.see Filariasis (human)Enteritis.See Aeariasia.Pediculus corpori ••Pediculus corporis.Direct attack.External paralite.

TABULATION OF DISEASES AND INSECT TRANSMISSION 479ErysipelasFavus Cporrigo)DiseaseFevers, tick ·Ci.clllding tickfever of Miana and intermittentfever of Wyoming)Filariasis, canineFilariasis, canineFilariasis, ~anineFi1ariasia. humanFilariuis, human(elepbantiasis)Causative organismStreptococcu. pyogenel.Achorion schoenleini.Exaet cause of the fever UDknown.A"t:!~ocheilonema reeondi-Dirofilaria immitis.Dirofilaria repens.Acanthocbeilonemaste •.Filaria buncrofti.Amblyoma hebrreum Inoculation byArgas perlicu. bite of tick.Dermacentor 8Dder-BoniHyalomma "'BYPtiumOrnithodoros lavignyiper-Musca domestica.Insect feeds onorganism. Dere8!~:0~t:-.voonda.Pediculus humanus. Manner of ear ..riage Dot demonstrated.CteD"'7.PhaiUS ~!H~sPulex irritaol.Anopheles maculipenniaAnopbeles bilu_tUl.. algerieDl!lis.. sinensis.. su~rpictusCulex penioUaris" malarieII pipien8.. quinquefascistUBAedes vex-auU argenteus.Aede. argenteus.Partial developmentrpcorded in ManIUlDioides africanusAedes sugensAedes argenteu8Anopheles costalis~:'i~~~~~~~sfuscopennatu8Ornithodoros moubataoComplete developmentinAn~pbel .. ::~:w.Culex pipiens... quinquefasciatusAedes pseudosentellarisAedes argenteu8MaDsoDioides alrieanuaMansonioides uniformieIncomplete developmentinAD~phel::~i=iris:: :i:r~~=isPossibly taken~r.,~.r.fie4~:method 0 ftransmi8llioDis unknown.Insect. take upin blood.Worms migratefromin-ci:t, Ib~~'r':itime of bite.Insect. take upin blood.Worms migratelromin-::t,~:t':ttime of bite.Transmissionby bite ofmosquito, theexact manneris not described.Transmissionby' mosquitobIte.Natul'1l ofiuaeet r6leMecbaniealcarrieJ'.Mechanicalcarrier.Uncertainwhether asparasite o.&I carrier.Possibly intermediatehostIntermediatehost.Intermediatehost.IntermediatehOlt mIntermediatehost.

480 SANITARY ENTOMOLOGYDiseaseI CallBQ.live organism Inseet transmitter Method of insect Nature oftransmissions insect r6leFilariasis. buman (cont'd) Mamonioides anuu ..(elephantiasis)lipeoMansonia pseudotitillan.Culex micro.nuulatusCui." geliduB, .. sitiensAedes perp]ezullU BcutellarisScotomyia a1bolineataTaeniarhynchus domesticus.Filariasis. human Filaria demarquayi. Partial development Insee! takes up Probably inte ....iB rec()rded ID in blood but mediateAedes argentous transmission hosts.Anoph.e!es muuli .. is not proven.pennI'Anopheles a1bimanusFilariasis, human Filaria (Loa) loa Culex quinquefasci- Inseet takes + Intermediateatos in blood. In .. host.Chrysops tenturionis oculates at.. dimidiata time of biting." silaceaP,,:rtial developmentInH",matoJl

TABULATION OF DISEASES AND INSECT TRANSMISSION 481Disease Causative organismI llUIect transmitter Method of insect Nature oftransmbsioIlS insect rOleImpetigo, tropical Diplococcus pemphigi con .. Pediculus .l\Ianner of car- Mechanicaltagiooi. ryingnotdem- carrier.o ns t l' atedhut prohablythrough lousefeces.Inflammation, bronchial and Hala~~achDe americani Same as preceding Direct attack of Parasite.lungs, in animals (internal attenuata column. mites in airacariasis)..halich .... i passages pro-Pneumonyssus aimicola aueing a 11-Cytoieichul nudusphyxia.u lIarcoptoides ..•Inflammation, catarrhal (in Sternootomum rhinolethrum. Stemo.tomum Direct attack of Parasite.chickens) (internal acariasis) I'hinolethrum. mite B inthroat andnose producingasphyxia.Itch, bicho-colorado Tetranychus molestissimul TetranychuB mol .. - Direct attack in Paraaite.(acarine dermatosis) tiL!lsimull. akin.Itch, cborid!tic, animal Chorioptes equi Same &I preceding Direct attack in Parasite.(acarin. .rmatolis) .. symbiotel. column. skin.Itch, coolie (ground) RhyzoglyphuB paraaiticu •. Rb:r~oglyphus par ... Direct attack in Parasite.(acarine dermatosis) IltieuS. .l!lkin.Itch, < irritaDS. }leen ezperi- host.mentallytransmittedby fie ... butthe e"actmethod i. notproveD.K edani disease.See Tlutsugamuahi disease-.....L eprosy Bacillus lepr ... Musca dom .. ti .... Taken up from Mechauicallesion. and carrier.probBblf dey:tedID fly

48! SANITARY ENTOMOLOGYDisease Causative orgaDism Insect transmitter Method of insect Nature oftransmissions insect rilleLwroay (cont'd) Pediculus humanus. Organism has Mechaniculbeen found in carrier.lice. Transmi.sionwould be effectedthrough feces.Lossi •.See Filariasis (human)LeishmaniBlis.See Kala 88 .... , Sore {Bagdad,Diskra, and Orienta JCimez lectularius. The bacilli may Mechaniculbe taken up carrier.by the bull",but transmIssionhas notbeen provenalthough it issuspected. Itwould takepJact. by fecalcontaminatioDofwounds.Lymphangitis, epizootic C'7PtOCOCCU8 farcimiDOIus Amblyomma spp, Inoculated by Mechanical{animal} Pri_-Nocard organislll bite of ticlt, eanier.Bacillus Decrophaguzprobably byStaphylococci. contamina ..tionaMacula> """,u1ese Phthirus pubis, Phtbirus pubis. Direct attack. Edernal parasite.Mal de cad .... Castellanella equlnUJD. Triatoma. iDfestan& ExperimeDtal IntermediateCimez lectularius. transmi.lion host.by bit .. ofbugs.Malaria, avian Plasmodium damlewBkyi. Culez quinquefuci- TraDsmiBsion Intermediateatus bl' mosquito hoat.Culex pipiens bIte.A~es nemor08U8argenteus.Malaria, canary P1umodium relictum. Culex pipieno. Transmission Intermediatebl' mooquito hoot.hlte.Malaria, pigeon Hremoproteus columb., Lynchia maDra Transmission Intermediatef. hrnnea.. by fly bite. host.Malaris, quartan Plasmodium Illalariae. An'?P:!.~~.geriensi. Transmission Intermediatebl' mnsquito bost.n culicifaciel b,te.,. fuliginosus•• fnneltaII maculipeDD.i •.. myzo~aciesIII qUadrimaculatusII l'08Iii.. sinensia" .tepheDBi.. theobaldi.Malaria, 81lbterl.ian Laverania falciparum. Anopheles albim"ul18 Tra.namitted by IntermediataII annuHpes bite of mos- host.quito.::t:h~~:!:n costalis•• Cl'uciaullII culicifacies•• formos&enai. n•• fuliginoBUB"lunestus.. maeulatus

~TABULATION OF DISEASES AND INSECT TRANSMISSION 483JDisease Causative organislIl Insect transmitterMethod 01 in.ecttraDBIDisaioDIMalaria .ubtertian (cont'd)Malaria, tertianPlasmOdium vivas,Anopbeles maculipalpisindiensllU maculipenniaII minimul BCOni ...tooII pseudo~uDctipcDD11II punctipennil.. quadrimaculatooII rosIn.. sinensisII tanimaculatWi.. theobaldi•• turkhudiII umbrosus.~~~hir!!~~anU8If bifurcatul•• costalilII cruciansII cuJicifaciesII fuliginOluR'I·lnDest&.II intermedium::fr:~~fil.. maculo.tus.. maculipRlpia•• maculipennil'.,1 me

484SANITARY ENTOMOLOGYDisealeMange, demodectic(Seborrhea, blepharitis,blackheads)(acarine dermatosis)Mange, p"oroptic(AcarlDe dermatosis) (sheep• cab, Texas itch, etc.)MboriMeaslo.Mediterranean coast fever ~See Cattle feverMelanodermiaMeningitis, eerebrospinalKiana. tick fever.See Fevers (tick)Murrina, equineMyiasis, blood .. ucking larvaeMYIasis of the bead pasaageoMyiasis intestinal and urogenitalMyi .. i ... ubdermal (trulv parasitic)(human, animal)Causative organismDemode.: folliculorumIt ~~~!oidesPIO'9ptes coMl]1unis ::~IU II equi.Castellanel!a evansi IDbon,Vlru ••Pediculus corporisPhtbirus pub ...Diplococcus iutracellul .. rismeningiticiis.Castellanella hippi.um.Auchmeromyia luteolaCh",romyia boueti.. .hmrophag"lI[yd"", piciP ..... rom:via heterocba:taPhormia azurea.. ::fi3!~h"'"C.phalomyia maculata Same as precedingCepbenomyia phobif •• column.U pratti.. trompe.OestrID ovisRhio .... t.us hipp!!potalDi.. nasalisI. purpureulAntbomyi. disgordiensi. Same as precedingAphiocb",tll fo .. ugio •• column.Cobboldia ebrysidiformis.. elepbantisloxOdontisEriat.lis arbustorum

TABULATION OF DISEASES AND INSECT TRANSMISSION 485Di!JeBSeCausative organismInsect transmitterlIIethod of insecttralUlmisaioWlNature ofinsect rOleMyiaai., subdermal (cont'd)Myda::a anoDlalao. to~ueD8Neoculerebra squamosaOedemagena tarandi.Dermatobia hominia.The mosquito P.orophoralutzi ca:rri.. the fly eggs tothe host.• ''; fly larvae- .... atcli whilemosquito i IsncklDg bloodand enterbody, developinllin skinand emergingtherefrom.~~.:.~~~and carrieaa lI .. b paraaite.lllyiasil of tbe ti.lues (includIng attack aD eye. ear I nose,woundsj screw worms, blowIIi .. , wool maggots) (humananimal)Anastellorhina a~1'Aothomyio. pluvialisCallir.hora dux• erythrocephalaChrysomya ma.cellar.a.. rufifaciesCynomyia spp.Lncilia argyrocephalB... eaeso.r.. lJereniuima.. Berieaia.. tumanieD.l.isMicrocalliphora varipesUl\fWlicina stabulamNcopolleniB stygia~~::~ian;~;inadomestic.PYCDosoma bezzian.•• chloropyga.. ilavicep.sII margiJinJeIe meg~hala.. putoriumSa~phaga ~::~:ri:'-II hll!lllorrhoidalia.. lambens.. pY0l!hila•• regularisWohlfabrtia magnifica.Same as precedingcolumn.Deposition 0 feggs in tis ..lUes andwound •• Laryedevelopat the exIlense of thetissues.Scavenger andUasue deBtroyer.NaganaCasteUanel1a bruceiG10Wna morsitansI. brevipalpil•• pallidipe.!!It t.a.chinoidesU fmC&Aty]otWi nemarali.Tabanul !poStomoxys CalcitransU glauca.Mansoni.IP.Cimex lectularius.Transmis.ionbl bite oflI.e ••IntermediatebostsTransmission Mechanical (P)by bite experimental.Ezperimentaliytransmitteilby bite ofbUfll.Nematode, bovineGongylonema scutatum.Aphodiul coloradenlis" fimetariul.~ femoralis,. granarius.. vitt.tullOnthophagus hecate•• pennsylvanicUiBlattella germanica(e>:perimentallInsect ..... aDoweggs. Awmalsswallow insects.Intermediatehosts.

486 SANITARY ENTOMOLOGYDi ......Caus.,tive orlanismInseet tra.nsmitterIIlethod of insecttransmi.lioDSNature ofinsect rilleNematode, canineSpirocerca aanguinolentaNematode, equine (granulomCL) Hahronema megastoma.Nematode, equine (granulo",CL) Hahronema micro.toma.Nematode, equineNematode. fowlNematode. fowlNematode hedgehogHabronema muo.,.,.Acuaria Ipiralis.Filaria gallinarum.Gongylonema mueronntum.Nematode, hedgehog (fo:

TABULATION OF DISEASES AND INSECT TRANSMISSION 487Di ....... Causative organism Insect traDlmitterIMethod of i",ecttrausmisuoDSN .. tu .... ofi_ot rilleOcular aeariuia Dermanyssus gaIlime. Dermanyslus gal- Direct attack P""asite.liDIe.OD. cornea.O"htbalmia nodosa.See Poisoning (Lepidoptera)Ophthalmia, purulent Musca domestics. From eye to eye. Mechanicalearrier.Otoacariasi •• bumanand animal Acamp.is Dlericourti Same RI preceding Direct attack Parasite.Cheyletus .ruditus column. on ear.Demodex foUic:ulorum8:!~::ro:: ::~~:iOtodectes eyDotiaPloroptea cUDiculiRbYlOglypbu8 parasiticUl.Pappataci fever Filterable virul. PblebotomUl papa- TraDlmissioD Intermediatetasii. by bite of fly. hOlt.Nem .. tode, rodeot Ptotospirura muds. Te.oebrio molitor Iosect .w&IIOWl IntermediateXenopoyUa cheopia. egg. AuiDlal hosto.Iwallows insect.N uttolliosi., equine Nuttalli .. equi. Rhipicephalus . Traoomitted by Intermediateevertal bite of tick. host.and possiblyHyalomma "",yptium.Paracoliti. (lumDler diarrha>al BaclUus paraeoli. MUlea domestica. Taken up by Mechanic:olflie. from carrier..toola. De-Paral~i.1i inf .. ntile.See Po . omyeliti.C:~~fo!d~P~~i tick (human and Am~omma hebr",um Same RI preceding Attachment of Par.lite.Boo,P 'IUI ""Dulatos column. tick causesannulatua deco-paralysisloratu.tDermacentor andersonibod .. hoIoeyelusU p'i1osus=!:'er::rRemoval oftick head byU ricinus m::cisioD ter-Ornithodoros coriaeeulminates par-Rhipicepha.luo .imos.alysis.Paratyphoid rever (A and B) BacillDl paratypbosus (A MDI ... dom.stica. Taken up by Mecba.oicaland Bl. flie. from carriers..tool••Der::::'f;.J.PeUagra Unknown cause. Simulium :r.' No positive evi-Slomoxy. akau . di:nce.have beell IUSpected.Peritonitis.See Acariaoi.Pinworm. equine Oxyuri. curvula (probably) Musca nebulo. LarVal 1.&1- Pouibly Interlow"lIP of mediate bOlt.worms.PiropIaomooio.See Cattle FeverPityriasis Malauuia Ip. PediculDl corpori •• HaDDer of car- r.lechanicalriagenot dem- . carrier.onatrated.

4BBSANITARY ENTOMOLOGYDisease C81lSative organism Insect transmitter Method ot iILSect Nature oftra.nsmissions Insect rOlePlague, bubonic BacillUII pestis. CeratophyUus The b&ciilu. i. Mechanicar..acutu!I laken up carrier..fasciatus from thesilantiewi blood by theCtenocephalu8 canis flea. and maybe transmittedby regur-{fJ!;fr~~:D~u.culi~giop.yna aha.l .... gitatioIL atenopsylla cheopi •. the time ofbiting. or byinocula tonthroughBClBtching inof infectedfeces.Musca domestica.. Taken up by Mechanicalfl i •• from earner.010010. Derositedinece. andfood.Pediculus corporis. EIperimental Mechanicaltransmission carrier.obtained bysubcutaneousinocu\a.tion of~rushed lice.Plague. rodent (Iometimel bu- nacterium tulareDSe. Ceratophyllus aClltusUlan, 1.1 Deerfly fever, Pah.The baclIlus i. Mechanicalvant Valley Plague)taken up from carrier.tbe blood. Exr.eriDlentalinewonhasbeen obtainedby inoculationof crushedf1eao.Musca domestic •. Taken up from Mechanicalcarcass. carrier.Stomoxys calcltranll. Experimental Probably me.ttllon awission chanical cal ..only has rier.heen obt.ain-od by bite oflIy and by inoculationofetu.bed flies.Cbrysops sp. Inoculatidb by Mechanicalbite of fly I. carrier.suspected.Plica polonica PediculuB hummus. Pedicu111ll hum.a.nul. Direct attack of External papaliceon the site.sca.lp.Poisoning. bee, wasp and ant Api. meUifera Same as preceding The poison i. Direct attack.Bambus ow. column. injected b.,P0tr.nomyrm"" barbatussting 01 OVl-Po ISles spp.positor.V ~r:Di~tberants, beesand ... asps.Poisoning. bug (used lIS food) AapoD80pul nepalensis Aspongopu8 nepa .. Tbe bugs are T,?xic poiaonlemie.cooked and IDg.eaten asa delicacybutcause Bevererigon.Pq~loniDI, centipede EthlDo.ti~u!l spiuosu! Same as preeeding The poison is Direct attack.Geophil ... simms oolumn. injected fromScoloeendra angulata!!laods locat-~ganteaed in the headIf eros and havingu morsiC8.IUI. their openi~iDapairolvenom clswa~ntbeneathe ead.

TABULATION OF DISEASES AND INSECT TRANSMISSION 489DiseaseCausative organismInsect transmitterMethod of insecttransmissionsNature ofInsect rillePoisoning, food (summer diarrh",a)Bacillull suipestifer.Musca domestica.Taken up fromstools. De·ro~~ted onMechanicalcarrierPoisoning, honeyPoisoning, kissing hugPO!~I~D('~~~t:nt;.:h.1 o~:thalmia nodosa)Poisoning,. scorpionPoisoning, spiderPoliomyelitis(Infantile paralysistf~iip,::~~i~:-;.Trigona bipunctataOf amaltbeaU ruHeru!II limBoMelanolestes pidpe ••Automeris ioCnethocampa pityocampaEuproctis chrysorrhc:eaHemilellCB. maimLa~a erispataLasJOCanlpa piniLymantria monachaMacrotbylacia rubi~~~f~e~r:~~1i~rculariaPorthetna disparSibine stimulea.Androclonus funeatulButbus arerU carolinianusU martensimautu!It occitanUBC~trur~~i:](lk-::!~:tUlHeteromelrus maurulIsometrus europarusPriunurus amoureuni.. citrinusChiraeanthum DutrixEpeira diademaLatroc!ectes ra::mr cusU mactlUUlLycosa narbonensis.. tarantulaPhiddipus aud""~t:~iJi~:i~:b~:Dsi8.. 18---j!uttatumTrochosa singonensisFilterable virus,Same as precedingcolumn.The honey ofthese bees iscontaminatedby poisonsderiveil fromtheir foods,and may oftencontaindisease 0 r -g_Bn ism II.Honey poisoningis oftenfatal to thenatives ofCentral Amer·ica.The r6le of tbebee i. that ofcontaminat-~~~~:obe!comes foodof mao.Melanolestes picipes Bite of inoect. Dirert attack ~Same aa precedingcolumn.Same as preeedingcolumn.Same as precedingeolumn.l\lusca domestica.CimeJ[ lectularius.StomOJ

490SANITAR~ENTOMOLOGYDiaea.seCa.usative organislDNature 01Imect rOlePo~.See FavusP.eudoedema. 'malignantBacilluR "lIleudoedema maligno"Cao.Blatta orientali ••P ..... thronghinte.stinalbact intact.Infeetion bycontamination.Meehanicalcarrier.P.eudop .... asiti.m of nasal andalimentwy PBII_ by centipedesPyodermiaR edWBteJ" 01 eatt1e. BritishChaeteclJel;yne veIIuvianBGeophilus carpoJ:!halruo• ~baljcu8.. eJectriClJS.. aimiliaHimant&rium .rvailiJ ulus londinenoi.U terrestrisLithobiua forlieatul.. melanopaPol;ydeomuo compIanatusScutigera coleoptrataStigmatogB8ter lubterraneuoPediculu. corporis.Babesia divergeno.Same .. preceding.Pediculul corporis.In8ammatioDis caused. inthe nasal andslimen taryp .... ages dueto the accidentalentranceof centipedes.proba61yduringsleep or infreoh vegetablefoodS.Direct attack.Direet. attack.-External par ....ite.bod .. ricinus TrBDllmitted by Intermediateg"""aphyoalio cin- bite of tick. hoot.Ila.barina punctata.Redwater.See Cattle FeverRelapsing fever. AbyssinianSpiroschaudinnia 01'.Ornithodoros oavignyiExperimentaltransmissionb}' bite oftick. Transmissioni.probably bythe washinginto th ewound of the~~r;hi!':.excrement.Intermediatehost.Relapling fever, AmericanSpiroschaudiDDia Dovyi.OrnithodorosturieataII megniniIImou.~ta.Arll" persicua arelUOPeCte

TABULATION OF DISEASES AND INSECT TRANSMISSION 491Disease CaUlative organilm Natura ofIaaect rbleRelapoiug fever, Europe&ll Spiroschaudinwa re'llrrenti. Cim"" lectulariua. Taken up by Intermediatebug from hoot.Relapoing fever. North AfricanRelapoing fever, Tropieal AfricanRhodeoian Fever.See EBlt Cout FeverRocky Mountain SpottedFeverPScah.See Mange (demodemc)Scahi .. (oarcoptic itch), (Acarinedermatosis of man andaoimalo)SpiroschBudinniB berherB.Spiroschaudinnia duttoni.Dermaceatrozenus ricketbi·Sarcopteo acabiei homin;'u u crustosmII auchenim.. bovi,III' canis:: d:~medariiII. ~uileoniaIII. ovia., auilNot~~rea -:'t'cati... muriahlood andre::.~ i~o~~lation byscratching atsite of bite.PediculWl corporis Infection by IntermediatePolyp"'" spinuloous scratcbing in bOlt.(""perimental). leceo or bod,yof louse.Ornithodoros moubat••Pediculus.corpori ••Ornithodoros moubataoPolyp"'" apinulolWl(sperlmental).Dena_toranderaoniII variabilisII modestusII marginatulAmblyo::eriea.num.Euily trans.i.i!t:~ed '1.!t~ably taken u~~r.:~:j~~~.ed in Mal·pighian excrement.to bew""bed intowound bycoxallluids.Intermediatehoot.Infection by Intermediatescratching iq hDlt.feceo of louse.Taken up hy Intermediatethe bite of tlie hOlt.tick and maybe tranomit·ted in Bubse ...quent attach·ments 01 theadult, or ofthe aecondand even thet~~J~;;?~~fcf:3i~:the Malpig.man excre'"ment andwuhed intothe bitewound.Rat infected Intermediateexperiment. hoat.aU7.::t ti"Jand transmit.,ted by bite ofnen generation.T't~:Intermediatehoat.Same BI preceding Direct attack of Parasitic.column..mites in akin.

49! SANITARY ENTOMOLOGYDiseaae Causative organism I""ect trausmi~terMethod of insecttransmission.Nature ofi".ect raleSeal,. leg. chicken CneDlidocoptea mut.".. Cnemidocoptes Direct attack of Parasite.(aca:rine derma.toais) mutana. mites on legs ..Searlet fever Viru •• Flies suspected. Flies migllt car- Jl.feclJanicairy virus fromlore to IIOre.carrier.Seborrbea.See Mange (demodectic)SeptiClelJliaStapbylococeu. pyogenes v ..... r:~ir.:=::mitoria In.ects take up MecbanicalBlbua; aureul. citreus. frOIll 'bus. car- carriers.Musca domesticu. ryin od},orSarcopbo.ga carnaria on 1Clt". e-TabanlH .p..posit m fecesou wounds.Septicmmia StrepmcocCUl. Swmo:ryB calcitrano. Found in body Jllecbanicalof fly. camel'.Septi .... mia. rabbit Bacillus cuniculicida. Musca dODleltica. Flies take up lIecbanicalfrom rabbIt carrier.f ...... and d;'-tribute i Dtbeir fecea.CastellBneUa gambiense. Glossina paJpalis Transmitted by IntermediataSJ~fi=k'::'TNigerianpali>ali. 0)' bite. host.fuscipesmonitansfuscB.. J0:w.~nnisgall ipes.. ~E:ta!: .SwmUYI calcitrBDlI.Sleepilll lickn .... Rhodeoian Castellanella rhodeoienoe. Glossina mOlsilaDs Transmitted b,. Intermediate.. C:pali• fly bite. bost... revipalpis.Aedes argenteuo. Experimental lIIeclJanicai (?)transmissionb~ mosquitobIte.Smallpox Virus. Flies. Flies have been Mechanicalfound breed- carrier.inc in openlesiOns andcan probabl,.transmit theviru... :'roughtheir feces.Sore. Bagdad Leishmania tropics. Aed .. argenteus. MosquitO! wok Uncertain..¥:a::ni!i:~un.uccessful~Sore. Bilkra Leishmania tropica. Phlebowmus minu- Transmission lIIechanicaltn! africanus i. by bite of fly. carrier (1)suspected.Sore, Orienta' Lei.hmania tropica. Cimex leclulariua Taken up by..Experimentalhemipterus . bug from IntBrmediatablood Bnd bost.capableofcomplete developmentingut. No suecessfultran ....misaion.Transmissionis probablyelfected b yfecal motam ..ination.MllSCB domestica.Can probablybe taken upby f1i .. fromsores and depositedintheil' feces ODwound. ormucousmemb,aDe.Mecbanicalcarrier.

TABULATION OF DISEASES AND INSECT TRANSMISSION 498Di,ease Causative organism Insect transmitterMethod of insect Nature 01trWl8miasiom iusect.vleSouma Dutton"lIa eazalhoui. G109Sina r.,a,:palis Transmitted by Intennediate•• ongipaipis fly bite. hOlt.•• morsltans.. ta.cbi~oidesStomoxys calcitrans.. nigraT .. baaUlf bigrexcrement.S pirochEtosi •• fowl, of Senegal SpiroschaudiJULia neveuxii. Arg ... peIBieus. Transmitted by Intermediatebite 01 tick, host.C~!':~~h~~into the:i°~:rl(!N:':-the MalpighianeKcrement inwhich it isvoided.Snirochetosis, fowl, of South Spi>oscbaudinniallllU"Chow

494 SANITARY ENTOMOLOGYDi.., .... Ca\l8alive organiSJll, IlISeet tranamitter Method of inaect Nature oftranamilsiolll iDsect rOleSpirochEto"; •• gOOie SpirosohaudiDDia an •• riDB. Argas penicu •.Sp!rocbsctosl •.See Relapsing fe\O ••Tr~~m~~tii~{.TraD8IUilsioDi. probablytbe "Bobinginto thewound 01 tb.QrKanism inMalpighiaDUCl'e.Q1e.ut.IDterlDediat.bOlt.SpleDic fn'er. "See Cattle leve."eeD pusSuppura\in~ .. ound. (blut- Bacillus procyaneu,. Muoca dome.tiea.T~:=..: ':'':1carried towonnd •• DerOlitedilleee. onwOllDd •.Meohanicalcarrier.Surra Castellan.11a e.ansi. ElIPe.imentally Trallimitted by Intermediatetransmitted by lIy bit •• bost.St_osy. calcitran.u~DieuJatulU nigr •.Strobg aUlpieioDpoint. toTabanul tropicUl•• Itrlatu.linoolafumilerpartitul..vagulminiJDulTb.followin, ... al-Ia luspected:klraros1a winotaEmatoD13"ia eras·Biroltri,LYperoaia ""igoa.,MUllica domestic •.T~~n~ ~~':ltranlltlittedto wound!!.Mechanicalcarrier.A.de. argentoul. Mosquitoe. e"- Meohaaicalperimenta.Uy ea.rrier.took up organi.mwhichce .. isted fo.our •.Tahaga eel dedBb, zoualana) C ... tellanolla BOudanenoe. Stomo:r,. ... I.itrano T ... nami •• ioll IntermediateIt niRra by hiteDr lIy host.At,o!~tus nemoraliltomentosuse""perim"ntBI).Tapeworltl. canine and buman Dipylidium caninUID. Trichodectes latul In.ect ."Bllow. IntermediateCtenocepbalul eBni. .,go. Ani- host... feli •• mals .wallowPul"" irritan •• in.ectJJ.Tapeworm. cattle and man T .... ia oagiDatll. :&Juaca domestica. Insect s .. allowl Mechanical~. DeI101- earrieJ'.itt on fooo.Tapeworm. fowl ChOBnot"",ia infundibulum. Mu.ca domestica. Insect Jarva:: Intermediate• "a110" "gill. h ... t .chicken ."RI-10 ... fly.Tapeworm. fowl Davaio.a ceaticillu. Muaca domestic •• In.ect s"allowa Poosibly inter-Daf"aiDea tetragons. "gsa. Chicken mediate boll."a110 ... 8y.

TABULATION OF DISEASES AND INSECT TRANSMISSION 495DiseaaeCaUlatiVe organismInsect uanlmitter IMetbod ",f !n.... ttr&IUJID1!1SlonsNature oriDlect rIBJeTapeworm, fowl.Tapeworm. bumanTapeworm, rat and bumanTapewarm, rodent aDd!inmanTetanuoThorn beaded worm. rodentaDd humanThorn headed worm. pig aodmaoToaemi.TracbOlDaTrench feverHymenolepi. carioca.. DavaiDea mlMiagaseaneuis.lIynIenolepi. DaDB.Hymenolepis diminuta.Daeill ... tetanUI.Moniliformi. moniliformis.Macraeantborbyncbul hirudiu8CeUI.Pediculus corpori.Pbtbiru. pub, ••Stomozyo ealcitraoo Insect owallow. Po •• iblY interellllB.Cbicken mediate hootaWallows fly.Blatt.. orientali..Ceratopbylluo faleiatu8.XenqPlylla choop;'.Ald •• pinosaAoisolabi. annulip ..Aaopia tarinali.Fontaria virginienlilJulu. 01'.S~aurus ItrialoaTenebrio molitor.Ceratophyllus fasciatus.Ctenocol'balu. canisPules irritansXenoPlylla cheapis.The cy.ti .. rcus Mechanical carhalbeen rier orfound in tb .. e ~";bl:v bioroach...logical.IDsect .wallowae_. It theinsect ita thetrue interme ..diat. bootthen inlectioni. probabl):by tbe animBIswallowingiosect.Inlect swallowa~ggs. animal.w.l\o",. in ...sect.The Ilea larvaow"lIows theegg. whichperli8latbrough metamorpho.h.The animal isinfected byeatins t betlea.In term ediatebo.t (po..ibly. but notproved).Intermediateboot.Intermediateboot.Derm"topbilul pen- The attack of MethanicalWaul. this Bea Ire- carrier.quently lead.to attack. oftetanu •.Cetonia .urataDilohoderu •• bderu.MeloloDtha vulgarisPhyllophBg" &reuataPediculno corppri.Phthirul pub, •.MUll •• dom .. ti ....Filterable vi,uI.Pedicul ... corporis.Poolibly Rickett,ia quintan"CastellaneOa dimorphon.The larv"latage Intermediateha. beeD hoat ••found intbes.insects.BII.J>I: mucronat"Periplaneta &meJ"icana.Inlecto awallowellllB. Animalseat in ...lecto.Direct attack.Intermediateboots.Erleraal para&it ••FrOID eye to eye. :t.leebanical~rier.Orsamam i. der.eceo 0litedinof lice.IntermediatebootTraD.mi,aioD Intermediateby fly bite. boot.Tqpanolomi •• i •• batTr1panosomi •• i., bovineTrypanoooma velpertilioDi.. Cimez pipiotrelli.M • D D e r 0' Intermediatetransmission hOlt.Dot demon ..auated.Duttonell. nanum. Glouina J?&lpalioand pouil:i~Tranlmi .. ion Intermediateby fly bite. boot.Glossina monltaus.

496SANITARY ENTOMOLOGYDiseaseCausative organismInsect traumitterMethod of inseettraDsmission.Nature ofiDiect rSleTrypanosomiasis, bovineTrypanosomiasis, boviDe andovineTrypan08oDliasis, crocodileTrypa,nosomiuis, equineTrypano!loDliasi •. fowlTrypanosomiasis. goatTrypanosomiasis, rabbitTrypauosOlQiasiB. rodent'Trypanoaom.iaais, rodentTrypanosollliasis, rodentTrypaD080QJ.iasis, ro8.entTrypanoloJl1iasis, limimDuttonella uniform ••Duttonella vivBX.Trypanosoma Bray!.Castellaaeila. al1D&tbense.TrypaMsoma (.ens. fat.)gallinarum.Duttonella capr ....Trypanozoon nabiQi.TrypanOlloon blancbardi.TrypaDOloon duttODi.Trypanoloon rabillowitschi.TrypanolOoD lelf'iai.Duttonella simie.GlossinB paJpBlio.GIOBSiDB ~hjDOjdesand pl'obabLvGlossina palpa"liJ;II morsitaDs.Glossina palpali,t. brevipalpiB.T .. banid ..Hippoboscid'"are suspeCted.Glo •• iDa pBlpalio.Glo~ina ~:;;~i.oCtenocephalul JeJM?risSpilopsylluslepcri ••CeratopllYUus Javorani.CimOlt l~ctuIariu •.Ctenocephaluo canisCeratopbyllusfasciatua,. hirundiniaIeluciferCten~halu. canisCleaoplitb"lmusagyrtes~~i::lb~!iii:~:uli.. irritansXenopsylla choopb.Polypi"" spinulosuo.Cimes lectularius.Glossina. morsitanl., brevipalpis.TrBnamiuioDby bite.Tranami'liODby bite.Tranamissionby bite.Trt,nlmh.ionby bite.Transmissionby biteTransmissionby bite.Taken up bythe JJea fromthe blood.l1::::bg~~~the feceo ofthe 00&.Taken up bythe Ooa lromthe blood.Licked up bythe rodent inthe Ieee. 01the Oea.Taken up bythe Ilea fromthe blood.Licked up bythe rodent inthe fee .. ofthe Ilea.Expe.imentallyfed to bed-~~gre "':1 de:velopmenttherein.Take .. up bythe flea fromthe blood.Licked up bythe rodent inthe Ieee. 01the 8oa.Taken up by. the 8ea fromtheblood.Licked up bythe rodent inthe feces ofthe 0 ...Rat is infectedby licking upir;:rsect·sdejeC! ..lIOhS.Experimentallyfed to bullSand complet.-.ed development.Inocu ...la.tion of rectalcontenuproduced diseaae.TrADImitted byby bite.Intermediatebost.IntermediatehOlt.Intermediatehost.InterW

TABULATION OF DISEASES AND INSECT TRANSMISSION 497DiseaseCausative organismNature ofinsect r61eT~tmA~~::i-;!ieri,Ch~asfever, Dourine. Horse sick·Dess (Gambian), Mal de caderas,N &gaDa. Sleepingsickness. 5oumB, Surra, Ta ...hagaTsubugamushi disease (lap.aneserivafner, KedaDj disease)TuberculolilTumon, lebaceolD (in birdsand animal.Typhoid feverTyphuo feverllrticariaIT rticariasi. (pain itch. ery·thema urticaria) (aearinedermatosis)UtaVauillismuo(acarine dermatoois)Verruga peruviaDs(Carrion'. diseue)Volhynian feverWhipwormWithers. fistuloUI (equine)W~~:,~~!!t(~~Lt)tent fever.YawsYellow feverFilterable virul.Bacillus tuberculosi ••Harpyrynchu8 longipilusPsorergates simplex museu-. linusMyobia musculi.Bacillus typhoous.Filterable viruo.Possibly Rickettsia prow&zeki.Pediculus corporis.Pediculoidea ventricosusTarsonemus uncinatus inteclusCrithoptes mODuDguicul&tus.Leishmania uta.Aleurobius I.rinreJ,)'roglyph us airoHistiogaster entomophagus.Bartonella bacilliformi. (P)Rickettsia pediculi possiblyTrichuris trichiura.Treponema pertenue.Leptospira icteroidesLeptUl akamuobi.Musca domeltics.Blatt. oriental;'.Same II precedingcolumn.Musca dom .. tica.Pediculul corporis.Same as precedingcolumn.Forcipomyia ut~... townsendiar

Abscess, 69, 108, 115, 409Acanthocephala, 79, 889Acanthocheilo1Ulma grallrii, (Filaria.), nematode,75, 76, 80, D4perBtanB, (FilariG), human nemato,de, 74,75, 80, 81, 82, 89, 90, 91, 92, 93, 95,96, 261, 479reconditttm, (Filaria.), dog nematode, 76,80,89, 92, 94, 857, 479A eanthomys spp., rodents. 9SSAcariasis, 474.internal, 408ocular, 408sense organ, 408Acarina, ticks, mites, SS, S9, 403-429, 461Acarine dermatosis, 403Acaropsia mericottrti, mite, 408, 487Achorion 8choenleini, fungus, !'l89, 479Activity, zone of, 99Acuaria BpiraliB, fowl nematode, 66, 67,S9,486Adenitis, 69Aedes arglJntettB (calopra, faseiatllB), yellowfever mosquito, 70, 7!'l, 74, 75, 80,89, 248, 249, 250, 251, 259, 260, 261,262, !'l66, 267, 269, 270, 27fil, 279. 477,479, 480, 482, 492, 494, 497graciliB, mosquito, 70, 80nemOrOBttII. mosquito, 259, 48filperple:eulI, mosquito, 262, 480pB6ttdoBeutellari8, mosquito, 26!i1, 479BeutellariB, mosquito, 70, SO, 262, 480BugenB, mosquito, !'l61, 479l1Y't'e.triB, mosqu'ito, 249, 475'lJe:ea1l8, mosquito, 261, 479A.elchna. sp., dragon fly, 59, 87African relapsing fever tick (sec Omithoa07'olJ'1Iloubata)Agamome7'mia culdcis, mermithid. i62Aggrippina bona, gregarine, 855Aggrippinidae, 355Agrion sp., dragon fly, 59, 87Ainhum, 92, 878, 474Aino, 214, 474Akis goryi, beetle, 61, 62, 84, 486spinosa, beetle, 4S1, 54, 84, 495Aleu7'oWu. fa7'inae, mite, 405, 497A lloc7'eadiwm iIlOPOrwm, fluke, 59, 83, '87A Zlot7'ombidi'Um fuliginosum, mite, 404,477Amblyomma spp., ticks, 411, 424, 482amerieawum, Lone Star tick, 413. 436,491INDEXA.mblyomma spp., ea;6111U11186, tick, 436h6b7'a6wm, tick, 410, 425, 436, 479, 480,487maculatum, Gulf Coast tick, 431t6Btuddnia, tick, 414Amoebiasis, 474Amoebidae, 116, 117, 388Amoebina, 116, 117,388Anabolia 'I",,",oBa, caddice fly, 59. 83Anaphylaxis. 468. 469Anaplasma spp., piroplasmids, 414a7'gentilllUm, piroplasmids, 414, 474ma7'U'inwle, piroplasmids, 414, 474Anaplasmosis, 414, 474Argentine, 414A1I4Btellorhina. Q/Ugur, fly, 181, 485AneyloBtoma duodenal6, hook worm, 122,480Ancylostomida~, l!il!i!Androctonull fun68tUl, scorpion. 469. 489Anemia. avian, 249, 250canine, 420, 421,474equine infectious, ill, 228. iSO. 474jackal, 417, 474jerboa, 296, 355, 474owl, 475.palm squirrel, 297, 475rabbit. 475rat, 422, 475turtIe, 475Anesthetic zone, 98. 10lJAnillolabia annulipe., earwig, 42, 54, 88.495Annoyance caused by insects, 20, ilAnopheles sp., mosquito, !il5Stnear ekwigeT, 251aitkeni, mosquito, 253. 489albimawus. mosqu1to, 72, 2115, ilS6, 257.i58, 26i. iSs, 479, 48(), 48i. 483albipB' (see A. albimawua)albiro8t7'ia (see A. minimtl. aeonitua)algeriena1l1. mosquito, 253, 255. 257, 261,479, 48!i1, 483annulipeB, mosquito. 255, 48iapicimaculata, mosquito, 253, 483ambieMII. mosqll~'to, 253. 255. 483arde7UIia, mosquito, !il53. 483a7'gyrota7'sia, mosquito, 255, St56, 262, 479,481lbarbi7'oBtrla (Myzorhynchw). 70, 80, Sl55.Sl57, i62, 479, 489, 483bifureatw, mosquito. 7S. 80, 257, Sl61.479,41i13499

500 INDEXAMphele, sp., boU1IienBis, mosquito, !il/iS,488braziliemiB, mosquito, 25S, 483cla1liger (see A. ma.c •.zipenni8)coh/U8'US (see A. mimmua acl»lit'IUI)c08taniB (Pyretophof"U8), 70, 8d, fl55, g57,!116I, 479, 482, 483cO'UBtani, mosquito, g/i4, 483C7"1IC;an8, mosquito, fl55, 256, fl57, fl58,266, 267, fl68, 270, 271, fl72, fJ73, 489,483c'I.llicifacieB mosquito, fliiii; 9/i7, 482, 48S,ergentii, 254, 483fa1'OlUt;, mosquito, 954, 483febnfer (see A. mini_)fo1'mosaensis I (see A. m4.,.lmnu acOft"tm)II, mosquito, $l5/i, 482f1'agiliB (see A. aitken.i)franeiBcaniUB (see A. p8oodopun.cti,..pennis)fu1i.QinoS'U8, mosquito, $l55, fl57, 258, 48g,488fune8t'UB, mosquito, 255, 257, 258, 482, 483grablurnn.ii, mosquito, 954, 483intermedium, mosquito, 258, fl59, 483jameaii, mosquito, 254, 48SjeBoena;8, mosquito, !lI58, 488jeypo1'enai" mosquito, 254,483karwari, mosquito, 2M, 483li8toni, mosquito, 2/i8, 483(utlll" (see A. bolillienais)maculat'UB, mosquito, fl56, 258, 48$l, 488maculipalpi8, mosquito, $l/i8, 483indienBi.!, !liM, 483maculipen-niB, mosquito, 59, 72, 73, 75, 8(),g51, !lI56, 257, gS8, !il59, 261, 479, 48(),48!il,483maculip88, mosquito, 254, 483martini, mosquito, liI54, 483mauritianu8, mosquito, 254, 483paludis, fl54, 483mediopul1ctatuB, mosquito, !il58, !il/i9, 488m4nimus, mosquito, 254, 255, 258, 48SaccmituB, mosquito, !1156, 483chriJrtopherli, mosquito, 254, 488mifllUt'l.l' (see A. sinensis)myzomyifacie8 (see A. turkhudi myzomyifacie,)nigllrrimu, (see A. linensis)nimba, mosquito, 254, 483peditaeniatu, (see A. sinensis)pOO1'oen8;8, mosquito, 258, 483pitchfordi, mosquito, 254, 483p,eudomacuEipe8, mosquito, !1158, 259, 483p'Budopunctipewni8, mosquito, fl56, liI66.271, 27$l, $l74, 488punctipenniB, mosquito, !il56, 258, 259,fl66, 268, fl7l, fl7fl, 274, 483punct1l-1ata, mosquito, $l54, 483pu1'8ati, mosquito, $l54, 483qua.drirno.culatUB, mosquito, $l1i6, £J7,fl58, !1159. !1166, fl67, !117l, 27!l1, fJ7 4, 482,488Anoph616, sp., rhode.ienai8 d'thali, mosquito,254, 483rOB';; (Myzom.yiG), mosquito, 59, 'I'(), 81.fl56, $l57, 2/i8, !lI60, 261, 479, 48$l, 483linen9is (Myzorh.1J1IchUl), mosquito-, 70,81, fl56, 257, fl58, $l62, 479, 48$l, 4838intJMia peditaematu8, mosquito, 70, 81sinen';B plleudopict'UB, mosquito, 73, 81,$l55, 261, 262, 483Itephensi, mosquito, !1151, $l57, !IIS8, 482mperpict'UB (Myzc:mY'La). mosquito, 73,81, ~S5, fl61, 479, 483taraimaculatu8, mosquito, !1156, fJ85, 483theobaldi, mosquito, fl5i.~57, $l58, 4813,4SSturkhudi, mosquito, 256, 258, 483chOlUdoyoi, mosquito, 255, 483hispaniola, mosquito, $l58myzomyifaci68, mosquito, $lii5, 257, 482,483umbroBw" mosquito, liI56, 4831Iincenti, mosquito, fl55, 483willmori, mosquito, 255, 483ziemanni (see A. mauritianu.)Ant bear. 196Antelope (see TragelaphuB ,pekei)Anthomyia diBgordiensiB, fly, 193, 484plu1Iiali" fly, 180, 485Anthrax, 49, 109, 110, 115, 209, $l10, $l28,230, !1149, 384, 470, 475A.,.th1'e'111U8 m'UBeorum, beetle, 470, 475Aphaniptera, fleas, 79, 80Aphiochaeta ferruginea, fly, 192, 484.&.phodiu8 colo1'OOen8is, beetle, 6!il, 84, 485femoraliB, beetle, 62, 84, 485{innetarim, beetle, 6fl, 84, 485granari""" beetle, 84, 485rufm castan6'UB, beetle, 64, 84, 4861IittatuB, beetle, 62, 84, 485Api.! mellifera, honey bee, 467. 468, 488,489Apoxeraenosis, 98. 101Aquaria, 282Arachnida, 461Araneae, 461A 1'duenna strongylina, pig nematode, 64,84,85,486Arga8 spp., ticks, 424brumpti, tick, 40!,)miniatu8, tick, 439per8ic'UB, fowl tick, 418, 400, 4fJ3, 445,446,479,490,493,494 ,refleanul, tick, 409, 411, 419, 4fJS. 482, 480,4931IespertWoniB, tick, 4li!3Armadillo, 393Army diseases carried by insects. 48-48Anny sanitation, 43-48Arsenic dip, 44!11Arsenic wash, 837Ascariasis, 121, 1$l2. 475Ascaridae, 121A,ca,.iB lumbricoideB, human nematode, 68,96, 106, 121, 475

Ascomycetes, 289.A.opia farina1iB, meal moth, 4.i!, 54, 83, 495Asphyxia, 408AspongopuB nepale16li8, bug, 469, 488AteieB pentadactyl1Ul, monkey, 302A teuchu. Bacer (see S carabaeua).Attagenw pellio, beetle, 4'10, 475A tylotuB spp., horseflies, lil98n6morali8, hdrsefly, 914, 217, 485,494rujidooJl, horsefly, 211, 474tomentoJlUJI, horsefly, 215, 217,478,494.Auchmeromyia spp., flies, lil!i!8luteola, Congo floor maggot, 195Automeris ,i.o, moth, 467, 489Babe8ia spp., piroplasmids, 414arg(Jntrinum, piroplasmid, 414, 475bigeminum, piroplasmid, 414, 475bovis, piroplasmid, 414, 415, 475caballi, piroplasmid, 415, 475canis, piropfasmid, 415, 424, 434, 475divergen8, p'iroplasmid, 417, 490gibBoni, piroplasmid, 417, 475minenB6, piroplasmid, 417, 475ovil, piroplasmid, 417, 436, 47.5Babesiasis, bovine, Argentine 414, 475canine, 415, 417, 476hedgehog, 417, 475jackal, 475Bacillw of Koch-\Veeks, bacterium, 109,477of Morgan, bacterium, 109, 418A of Ledingham, bacterium, 109acid.a lactici, bacterium, 109aerogenea capBulatw, bacterIum, 109, 480ant"-"acia (see Bacterium)cloacae, bacterium, nocoli, bacterium, 110, 384, 885, 881, 477coli anaerogenea, bacterium, 110coli comm'Unior, bacterium, 110coli communi., bacterium, 110col' m'Utabilill, bacterium, 110coli8limile, bacterium, 110c'Unioolicida, bacterium, 110, 492diphtheriaIJ, bacterium, 111, 478dyaentenae, bacterium, 478dysenteni.ae, Flexner, bacterium, 111dYllentlJriae, Shiga, bacterium, 111dYBenteriae Y Hiss and Russell, bacterium,IIIooteritidil, bacterium, 111fecalis alkaUgeneB, bacterium, 111/loorellcenB liquifacienB, bacterium, 111,884jlooreacen, nonlique facie"" bacterium,Ill, 885gaaoformans, nonliquefaciens, bacterium,Il2griinthal, bacterIum, 112icteroide" bacterium, 260lactill acidi, bacterium, 11lillact;, aerogene" bacterium, 119leprae, bacterium, lISI, 392, 481mallei, bacterium, 112INDEX 501Bacilltua megatherium, bacterium, 8SSneapolitanfl8, bacterium, 112necrophaguB, bacterium, 48~necrophoTUs, bacterium, 411, 475o:cytOClllt perlllicios'UB, bacterium, 112paracoii, bacterium, 11~, 487pa'l'adya6nteria(J, bacterium, IIIparatyphollU8 A, bacterium, 112, 481paratyphos'UB B, bacteri~, 11~, 487pe8till, bacterium, 119, 350, 351, 360, 892,898,488prodigiosu8, bacterium, Il!ilproteillimile, bacterium, 386prot6'UB mirabilis, bacterium, 118profe'Us v'Ulgaris, bacterium, 113prote'UB zenkeri, bacterium, U3p8eudoedema maligno, bacterium, 886.490'P!I0cywne1Ul, bacterium, 113, 494-radiciformis, bacterium, 118, 886rober kielensiB, bacterium, 118,chafferi, bacterium, lIS,ept

50!e INDEXBinucleata, 117-119, ~1~-~19, ~49-f159, 5194,359-355, 388, 893-898, 4.14Bird lice, 988Blab6TU11 sp., cockroach, 876Blackheads, 407, 411, 475Blapll sp., beetle, 63, 84, 486sp., near apfI6ndiculata, beetle, 69, 84app611diculata, beetle, 69(lmon.di, beetle, 62, 84mortuaga, beetle, 55'lJllUcronata, beetle, 71l, 84, 495IItrQlUchi, beetle, 62, 63, 84, 486Blatta sp., cockroach, 388oriontalill, cockroach, 55, 60, 69, 63, 88,376, 377, 378, 379, 383, 384, 385, 386,387, 388, 389, 475, 477, 478, 486, 490,4.95, 497Blatt(llla geTmfMJica, cockroach, 55, 62, 63,88, 316, 371, 318, 384, 388, 989, 4.85.486lapponica, cockroach, 388Blepharitis, 288, 407, 475Blood-sucking fly larvae, 195, 196Bodonidae, 117Body louse (see P6ditmlw corporill)Bomb'!", spp., bumble bees, 467, 488Boophiltl.B spp., ticks, 4914, 4.26tmfW,lat1.lll, cattle tick, 4.10, 4-14-, 4940, 486,441, 476, 487a7ltlllUiat1.lll a'lLlltralill, cattle tick, 4014, 474,4.75, 4-76, 4098annulat1.lll d6colorat'ILII, cattle tick, 415,400, 474, 476, 487micropl'lUl (see B. IlIIt4W1atw a1UItralis)Borax, 881Borborw puonctipe1lflill (Limolli'lla) , fly,lSI, ISS, 475, 497Bots, 189-186Bouba, 219, 251Bovine trypanosomiasis, ~17, 218Bronchial inflammation, 408Browntail rash, 466, 475Bubonic plague (see Plague, Bubonic)Buffalo gnats (see Svmtl.dium spp.)Bug-borne diseases, 89~Bugs, 891-4OiBursarinidae, 388Buthull af6r, scorpion, 469, 489caroli'llliamu, scorpion. 469, 489martonai, scorpion, 462, 489tnaUI'U8, scorpion, 46!i!, 489occitanw, scorpion, 462, 489quinq'U88triatW, scorpion, 469, 4.89Cabbage snake (see Mermitbidae)Caddice flies (see Trichoptera)Calliphora spp., flies, 177, 453dt.ui:, fly, 179, 4856rythrocephala, fly, 105, no, 111, 117,180, 181, 1:12, 140, 148, 147, 148, 151.180, 475, 478, 485flomitoria, fly. lOS, 108, 109,110, 111,119,118, 114, n5, 120, ISO, lSI, ISS, 140,148, 148, 386, 4.75, 477, 489CalopteryQJ 'Vit'go, dragon fly, 59, 87Camel, 405Camel head bot (see Oephalom'glio. maculllta.)Camel trypanosomiasis, 215Canary, fl59Candy factories, 41Oam. aU'I'61U', jackal, S56familiarill, dog, 260, 844, ~7S, 405, 408,414, 415, 416, 420, 4511, 486Canthariasis, S2Cl4ntharid'in, 49Oantharis (lavicomill, beetle, 469, 478'V6I1tit'UlI, beetle, 469, 478Capybara, 393Oar

INDEXCephenomyia spp., phobifer, bot, 194, 484pratti, bot, 194, 484trompe, bot, 194, 484CeratophylT!ua aC$tm, flea, 351, 360, 368,365,488anu1UI, flea, 360, 864fasciatus, rat flea, 54, 55, 56, 79, 94, 350,351, 859, 3;0;4-, 355, 357, 860, 861, 864,488,495galU:nae, fiea, 863hirm"dini8, flea, 359, 496lavorani, flea, 352, 496Tiucifer, flea, 35~, 855, 496silantiowi, flea, 351, 365, 488Ceratopogon spp., midges, 994Ceratopogoninae, ~93Cesspools, 282Cestoda, tapeworms, 53-57, 88, 297Cestoidea, tapeworms, HlO, 355, 356, 357,389Cetonia aurata, beetle. 79, 85, 495Chaetechelyne V6Su,viq,na, centipede, 466,490Ohaetopterya: "ilIasa, caddice fly, 59, asChagas fever, 393, 414, 475Cheest bacteria, 113maggot (see Piophila clUfIi)Chelidon 'Ilrblica, bird. 952Ohtlyletm erwiitu8, mite, 408, 487Chicken (see also Fowl), 405, 406,407, 408house and yard, 173, 174, 445, 446, 447roosts, 445, 446tick (see Argas persWus)Chiggers, 92, 404, 477Chigoe (see Dormatophihtl ptnUltran8)Children, protection from insects, 37Chilopoda, 461Chiracanthum wutria:, spider, 464, 489Ohironitis irroratu8, beetle. 63, 85, 486Chironomidae, 223Ckironomus plwmo8'U8, midge, 59, 81Chlorocyanogen, 395Chlorpicrin, 824, 326Ohoanotaenia infundibulum, fowl tapeworm,58, 56, 57, 8'1, 1>10, 199, 494Choeromyia spp., flies, 229bousti, :fly, 196, 484ch06rophaga, fly, 196, 484Cholera, 49Asiatic, 115, 387, 477fowl, 884194, 296, 391, 399,893, 394, 395, 396, 397, 398, 399, 400,476, 481, 489, 485, 489, 491, 49'1, 496pipi$tl'elli, bedbug, 395, 400, 495rotundatm (see O. hemipte'1'U8)Cimicidae, 399Cisterns, '182OitelT!ua boeche!/li, ground squirrel, 351City sanitation, 39-41Clayton gas. 325Olepauu'ina blattMWm, gregarine, 888serpentu,la, gregarine, 388Climate and life, 97-104Clinostomum sp., trematode, 260Cl'i.pping of hair of cattle. 334-Oloeon diptof'um, mayfly, 59, 87Onemidocopte8 gallinae, mite, 478'm'Utan8, mite, 405, 406, 407, 492(Jnethocampa pitllocampa, moth, 467, 489Cobboldia chrysidiformi4, bot, 193, 484eleplumtia, bot, 193, 484loa:odonfAis, bot, 193, 484Coccaceae, 107-109, lillO, 911, 989, 290, 883.384Coccidiidea, 888Cockroach control, 380-882Cockroaches, 51, 874-390, 458Coleoptera, beetles, 59, 84, 85, 86, 469, 470Colitis, 477Columba livia, dove, 9f2, 213, '119Comfort stations, 39Cono'1'ltin'lls spp. (see Triatoma)Conchuda (see Ia:orUs bicorni.B)Con.junctivitis, 109, 115, 477phlyctenular, 290, 477Cootie (see Pediculus cO'1'po'1'i.)OOP'1'iB hispanu,8, heetle, 61, 85,486Coprophagous insects, 51, 52Cordulia sp., dragon fly, 59, 87CO'1'dylobia anthf'opophaga, fly, 188, 189.004,484f'odhaim, fly, 189, 198, 484Cow pasture, 233Crab louse (see Phthirus pubis)Creolin, 336Cricetus spp., rodents, 354

504 INDEXCrickets, 78Orithidia callilphorruJ, leptomonid, 117cttmOphthalm', leptomonid, 354.fallciculata, leptomonid, 251haBmaphysalidi" leptomonid, 4.17hyalommae, leptomonid, 4.1'7hystrichopsyllae, ieptomonid, 354.melophagia, leptomonid, 219mUBcruJ-dome8ticae, leptomon'id, 117nycteribiruJ, leptomonid, 219pangonia.8, leptomonid, 219puliciB Porter, ieptomonid, 354.puliciB Wenyon, leptomon'i'd, 354.tewui8, leptomonid, 219Orithoptes 'I1W1IunguiculosUB, mite, 4.04., 497Crocodile trypanosomiasis, 218Crossbill,408Crow, 259Cryalgesia, 100Cryesthesia, 100OryptocOCCU8 farcimi'fl,OBUB, micmllrganism,411,482Otenocephalus canis, dog flea, 63, 64, 65,76, 79, 80, 351, 852, 854, 855, 856, 857,360, 362, 363, 479, 481, 488, 494, 495,496feli8, cat flea, 53, 76, 80, 355, 357, 360,863, 479, 494leporis, rabbit flea, 353, 496Ot(J'l/,Ophthalmus agyrtes, flea, 352, 354, 355,360, 865, 496aIIsimma, flea, 854Otenopsylla. musculi, flea, 359, 355, 864, 496Culex sp., mosquito, 249, 251, 261, 268albopictus (see A ede8 8C'Utellania)cantator, mosquito, 249ciliaria (see O. quinquefallCltatUB)fatigan8 (see C. quinquefa8ciatUB)gelidulI, mosquito, 70, 81, 262, 480jenningsi, mosquito, 269ludlo'Wi, mosquito, 250malariae, mosqnito, 78, 81, 261, 479microannulatus, mosquito, 262, 480nigrithoraw BkuBei (see C. q'IJJ.mquefa,ciatUII)plmicillari8, mosquito, 73, 81, 261, 479pipien8, mosquito, 70, 78, 82, 93, 248,249, 250, 251, 252, 259, 261, 284, 475,479,48.i1quinquefaBciatu8, mosquito, 59, 70, 72, 82,248, 250, 251, 252, 259, 260, 261, 262,266, 267, 270, 272, 273, 477, 479, 480,482mtieR8, mosquito, 70, 82, 26g, 4808011icitan8, mosquito, 249, g6!il, 273taeniatus (see AedeB argenteUB)vtnJan8 (see AedeB)Culicidae, !il19, !il28Culicoidelt spp., midges, 2.i14CuliBeta anwulata, mosquito, .249, 476Outerebra e'ffl4Bculator, bot, 187, 484fontinella, bot, 187Cyanide fumigation, 3$15, 326Cyclophyllidea, IlIO, 5147, 355, 356, 357Cyclopodlia sykeBi, fly, .219Cynomolgus cynocephalUB, monkey, 295Cynomyia spp., flies, 177,485cadallerina, fly, 132, 453Cyprinodon variegatu8, fish, 282Cyprinoid fish flukes, 59Oypselu8 alfiniB, s,wift, 7!'JCytoleichua baMBi, mite, 408, 474nu.d1tB, mite, 408, 474, 481Barcoptoides, mite, 408, 474, 481Da'llainea cesticillus, fowl tapeworm, 57, 82,89, 120, 489'ffl4dagascariensiB, tapeworm, 388, 495tetragona, fowl tapeworm, 57, 8!il, 89,120,494Deer fly fever, 209, 477, 488Deer head bots (see Oeph6nomyia)Defecation, 39Delousing, 814-816Demodew b01liB, mite, 407, 484folliculorum, mite, 407, 408, 411, 476,484, 487phylloid68, mite, 407, 484Dengue, 49, 948, !'J62, 477Depluming mite, chicken, 478D6'I'macentor spp., ticks, a.24albipictus, tick, 412, 436, 497Dermacentor anderBoni, Rocky Mt. spottedfever tick, 22, 409, 410, 412, 413, 4S6,437, 438, 4.43, 479, 48.7, 491marginatuB, tick, 413, 491modestus, tick, 412, 491"itena, t'ick, 418, 431, 486, 478occidentalis, tick, 419, 425, 436reticulatUlt, tick, 409, 415, 417, 418, 4.$15,476,478variabili8, tick, 412, 418, 4!'J5, 436, 491venustus (see also D. andet·sotll') , 409,491Dermacentroreenu8 rickettsi, microOrganism,413, 491Dermanyssidae, 4!'JliIDermanys8UB gallinae, mite, 404, 408, 49!ol,474, 487hirundiniB, mite, 404, 474Dermaptera, 88Dermatitis, liI86, !'J90, 469beetle, 478equine g,·anular, 121, 122Dermatobia sp., fly, 175cyanillentnu, (see D. hominis)hominill, fly, g2, 187, 197, 199, 904, 486nowialia (see D. homi'1l1u,)Dermatophilus penetl·at18, clligoe, 22, 360,366, 373, 474, 495Dermatosis, 2!'J, 403papular eczematous, 404DermesteB vulpinUlt, beetle, 470, 475Diabrotica vUtata, beetle, 470Diarrhea, 49fowl, 387, 478infant'il

INDEX 505Diarrhea, summer, n2, 114, 478Diloboderua abdel'Ull, beetle, 79, 84, 495Dip, 442, 443Diphtheria, 111, 115, 478 .Diplobacillm e:llcmthematte'US, bacterium,!il92Diplococcus sp., microorganism, 29flg01l()rrhoeae, microorganism, 108, 480intra-ceUulariB meningitidis, microOrganism,108, 989, 484pemphigi conta9'wBi, microorganism, 289,481DiplocyatiB achneideri, coccidian, 888DipodiUuB campeBtris, jerboa, 63Diptera, flies, 59Dipylidium cani7IIIWI, dog tapeworm, 53,54, 80, 86, 297, 355, 356, 494Dirofila1"ia immiti8, nematode, 73, 80, 81,89, 89, 261, 479replnUl, dog nematode, 74, 76, 80, 89,261, 479Disease, how carried by insects, 19-24transmission, how fo prove, '25-38Diseasc& carried or caused by beetles, 469-470carried or caused by bugs, 392-399carried or caused by caterpillars, 466,467carried or caused by cockroaches, 883-390carried Qr caused by fleas, 350-359carried or caused by flies, 104-125, 209-222.carried or caused by lice, 286-360carried or caused by mites, 402-400carried or caused by mosquitoes, 247-265carried or cllllsed by ticks, 402-429carried to food by insects, 22carried to wounds by insects, 28inoculated by insects, 28DiBpharaguB naa'UWB, nematode, 68, 94Ditching, 276, 277Dog (see Oanis familiariB, and canllne)Dog flea (see Ot61Wcephalua caniB)lfluse (see Trichodectes latu8)nomatode (see AcantllOcheilonema grrulIii)nematode (see Acanthocheilonema rectnirditum)nematode (see Di.rofilaria immitiB)nematode (see Dirofilaria repenll)nematode (see Spirocerca Banguinolenta)Donkey nematode (see PhYBoc8phaim B8{calat'UII)Dourine, 1115, 228, 230, 478Dragon flies (see Odonata)Drainage, 37, 39, 277-279Dromedary, 405nematode (see PhYBocBphalua aea:alqtu.)trypanosomiasis, 217. iJl'osopkila c_tuBa, fly, 117, lI8DruBuB trifid'UB, caddice fly, 59, 83Dry cleaning, 320, 321D'Uttonella. caprae, trypanosome, 217, 496D'UttOft6lla. cazalboui, trypanosome, 217, 493cazalboui, pigritia, trypanosome, 217, 493congole'nB6, trypanosome, 917, 480nanum, trypanosome, 217,495p6cor'Um, trypanosome, 218lIimine, trypanosome, 218, 496'Unifof'm6, trypan(tsome, 218, 496vivtw, trypanosome, 218, 496Dysentery, 49amoebic, 117, 478bacillary, 111, 115, 478Lambllan, 117, 478East Coast fever, 417, 436, 447, 478Echidnophaga gallinaceus, flea, 360, 865,366Echinorhynchus sp., worm, 91Eczema, 281, 290, 478Effective temperature, 99-104Eimeriidae, 388ElaBsoma zona tum, fish, 282EI dedab, 217Elephant bots, 193foot bot (see Neoout61'ebl'a squamosa)Elephantiasis, 69, 261, 478Elk, 436Endamoeba. blattae, amoebid, 388coli (see LOBchia)EnneacanthuB glol'josus, fish, fl82ob 68'UB, fish, 282Enteritis. 115, 408, 478Entomophobia, 20Epeira. diadema, spider, 463, 489Ephemel'a 'fJulgata, mayfly, 59, 78, 87Ephem6"i.da.e, mayflies, 59, 87Epimys spp., rats, 353, 360Epitheca sp., dragon fly, 59, 87Equine biliary fever, 415trypanosomiasis, .914-Ennac6us algiruB, hedgehog, 61, 63, 64.EriBtaliB spp., flies, 191, 197arbuBtomm, fly, 192, 484dimid.iat'UB, fly, 19iJ, 484t6na:ll, fly, lIS, 192, 477, 484.EI'th6Bina tullo, bug, 895Erysipelas, 95, 108, 115, 479Coast, 77Erytbema urticaria, 404..Ethmostigmua BpinosuB, centipede,. 465, 488Euprocti8 chrgBorrl106a, brown tall moth,466,489Excitability, caused by insects, 20, 21Excreta disposal, 161F'annia canicularn, lesser house fly, 116,117, 135, 136, 139, 149, 143, 144, 192,197, 477. 484Bcalari" latrine fly, 117, 118, 135, 144,199, 197, 484 .Farm, insanitary, 85, 36Farm sanitation, 36-38Fasciol'idae, 260, 261Favus, 989, 290, 479

506 INDEXFebris quintana, 294Fevers, tick, 479Field mouse (see MicrotU8 mon.tt/belli)Filaria bancrofti (noctw-na), human nematode,69, 70, 71, 80, 81, 82, 93, 261,479 .cYP8eli, nematode, 7il, 86, 91demarquaii (see F. demarquayi)demarquayi, nematode, 80, 93, Sl6Sl, 480diurna (see Filaria (Loa) lea)ephemeridarwm, nematode, 7S, S7gallinarum, fowl nematode, 68, 87, 96,486geotrupill, nematode, 77, 85grall8ii (see Acanthocheilcmema)immitill (see DirofllaTia) .juneea, nematode, 71labfuto-papilloaa (see Setaria)loa (see Filaria (Loa) lea)(Loa) loa, human nematode, 71, 81, 93,95, 2Sl0, 480martill, rodent nematode, 73, 88nocturna (see F. bancrofti)ozzardi, nematode, 71pflrBtana (see Accmthocheilonema)phtlippine'1Ul1ia, human nematode, 72, 89quadri8pina (see F. martill)rytipleuriteB Deslongchamps, nematode,6Sl, 91rytiplmtriti8 De Magalhaes, nematode,78, 88Banguilllia hominill, nematode, 93BtomozeoB, nematode, 7S, S9tucwmana, human nematode, 72, SO, 90FilariaSis, 4S, 69, 70, 71, 7'ft, 261, 26!i!canine, 261, 479human, 290, 4078, 480Filariidae,. 220, 261, 26fl, 351Finch, fl59Fish,2811Five day fever, 294Flea abundance, 3b6, 361bite treatment, 370, 371, 373control,367-371trapping, 869, 810Flea-borne diseases, 350-859Fleas (see also A phaniptera ), 850-373Flesh fly (see Wohlfahrtia magniflca)Flies (see Diptera)bloodsucking, 208-285FlIes, non-biting, 105-208Flies in Egypt, 450, 451, 452Floor maggot (see AuchmeromY'iD. luteola)Flower vases, 28>1Flukes (see Trematoda)Fly attack, avoidance, 203baits, 164, 002control, 158-114paper, 164poisons, 202repellents, 165sprays, 164traps, 162, 163, 178, fl09Folliculitis, 290Fomaria IJirgi'1llienaill, myriapod, 54, 55, 88,495Food protection, 89, 40, 41, Sl06Foot-and-mouth disease, 180, 480Forcipomyia to'WnBendi, midge, 219, 497utae, midge, 219, 2114, 497Forficula auricularia, earwig, 55Fountains, drinking, Sl82Fowl (see also chicken), 866lice, 889-843nematode (see Acuaria BpiraliB)nematode (see Filaria gallinarum)tapeworm (see Ohoanotaenia i""fundibulitm)tapeworm (see Da1Iamea ceBticillm)tapeworm (see Da1Iainea t6tragona)tapeworm (see Hymenolepis carioca)tick (see Argaa perBiCU8)trypanosomiasis, 218Fox (see also Vulp6B "IIulp6B atlantica),405Frenzy caused by insects, 20, 21Frog flukes, 59Fumigation, 3>14, 3S0Ji'unambulm pennatii, palm squirrel, iJ97.475F'Ilndulull chrysOtUII, flsh, 28S1diaphanuB, fish, 2SSId,iBpar, fish, iJ82majali8, fish, 289notatuB, fish, 282flottti, fish, 28S1'imilill, fish, 98gFungi, 107-115, Sl09, 210, 211, 249, 2S9,fl90, 350, 851, 383, 387, 39>!, 393Furunculosis, 290, 411, 480Gall sickness, bovine, 218, 480GambUBia alftni8, top minnow, 282GamocyBtiB tenaal, gregarine, 388Gangrene, 480gas, 109, 1I5Garbage, 31, 89, 40, 41, '160, 2051, 2851Garments, louse-proof, 328Gastroenteritis, 115GfUltrophilm haemorrhoidaliB, horse nosefiy, 188, 190, 196, 205, 484intestlnaliB, horse bot, 182, 188, 184, 185,190, 191, 205, 484'nfUlaliB, horse chin fly, 190, fl05, 484GedoelBtia spp., flIes, 195Goophilull carpophagUII, centiipede, 466, 490cephaliooB, centipede, 466, 490eloctricU8, centipede, 466, 490s£miliB, centipede, 465, 466, 488, 490Geotrupo8 douei, beetle, 61, 63, 64, 85, 486BtercorariU8, beetle, 78,.85Gerbillua ·indicUB, jerboa, 296, 414GfurcUa mte8tinaliB, protozoan, lI1, 478Gigantorhynchid .. e, 389GiroBtigma spp., flies, 193Glanders, 211GlCllUcidiium fWctuao, owl, il49, 250, 251, 475GlamorU limblltll, myriapod, 57, 58

Glossina sp., tsetse fly, 219brevipalpiB, tsetse fly, fl14, fl16, fl17, 218,485, 492, 496fUBea, tsetEe fly, 214, fl16, 485, 49!lIongipalpi8, tsetse fly, 214, 216, fl17, 476,485, 498, 495longipe'1l'1liB, tsetse fly, fl14, fl16, 474, 492mor8itQ/1l8, tsetse fly, fl14, 916, !l17, 218,IJ84, 476, 480, 499, 498, 495, 496pallidipBs, tsetse fly, 214, 916, 499palpaliB, tsetse fly, 71, 77, 214, 915, 216,917, !il18, 220, 984, 476, 480, 492, 498,495,496palpaliB f'Ullcipes, tsetse fly, 215, 492tachinQldeB, tsetse fly, 214, 216, 917, 218,476, 485, 499, 498, 495, 496Glossininae, 284.Glyeiphag'UII pruno1"1lm, mite, 405, 481Goat, 873, 405lice, 346, 347trypanosomiasis, 217Goldfish (see CarassiuB aurat'UII)GO'1lgylonema sp., nematode, 78breviBpic'Ul'Um, nematode, 68, 84, 486muoronatwm, nematode, (i9, S5, 86, 4861I6oplaatiC'Um, nematode, 63, 86, 88, 91,389,486pulchrum, nematode, 889, 4868C'Utatwm, nematode, 69, 84, 86, 88, 95,389,485Gonococcus (see Diploeo'CC'IUl gonorrhoeae)Gonone, 404, 480Gonorrhoea, 108, 115, 291, 480Gordiacea, horse-hair worms, 78Gordius aquaticUB, horse-hair worm, 78• chilens'8, horse-hair worm, 78robustus, horse-hair worm, 78Gorgodera cygnoide8, fluke, 59, 87!lIagenBtecheri, fluke, 59, 87.rsovwnBiB, fluke, 69, 87dla, 313.... nary beetle (see Tenebrio moUtor)weeVil (see Sitophilu8 granariu8)Granuloma, equine cutaneous, 480Grasshoppers, 78Grease-traps, 161Gregarina blatta'l"llm, gregarine, 388.16geri, gregarine, 388Gregarinida, Gregarinidae, 355, 388Ground squirrel (see Citell'llB beecheyi)Grouse, red, haemoproteasis, 213Gmnea pig, 63, 959Gulf Coast tick (see Amblyomma maculatum.)Gutters, 289Gymnoasceae, !il89Gymnopl6'U'I"IUl mop8'U8, beetle, 63, 85, 486sturmi, beetle, 61, 63, 85, 486HabrO'llema &PP., nematodes, 77, 129megastama, horse nematode, 66, 67, 89,121, 486microBtama, horse nematode, 66, 67, 78,89, IfJl, 486INDEX 507Habronema spp., mUBooe, horse nematode,65, 66, 67, 82, 95, 121, 486Habronernic granulomata, 90Haemaphysalis spp., ticks, 424birmaniae, tick, 411biBpillosa (see H. birmaniae)Clinnabarina pUllctata, tick, 417, 434, 480,490{lava, tick, 4fJ9, 475leachi, tick, "415, 417, 495, 434, 474, 416punctata, tick, 425Haematobia e3!igua (see Lypero.ia)irritans (see Hyperolw,)8anguiBuge1l8, fly, 982H aematomyidium spp., flies, 2240Haematopin'U8 spp., lice, 297, 415aIIIW, horse louse, 847eurYBterflUB, cattle louse, !il88, 881, 382piliterus, dog louse, 344BUis, hog louse, 844, 345vituli, cattle louse, SSfJHaematopota spp., horseflies, 998cordigera, horsefly, 220, 480duttoni, horse1ly, 219italica, horsefly, 219perturba1l8, horsefly, 917, 493pluvialis, horsefly, 210, 416trisbiJI (see Chrysozona piu"iatiliB)vandenbrandeni, horsefly, 219Haomato8iphofl, inodora, bug, 400Haematozoon sp., worm, 92H aemogrega'l'ina sp., protozoan, 220francao, protozoan, 219gracilis, protozoan, 293(/Iaemogr6garina) maurittmica, protozoan,4911, 475(Hepatozoofl,) ca1lA8, protozoan, 490, 491,494,474(Hepatozoon.) funambuli, protozoan, 296,475 •(Hepatozoofl,) gerbilU, protozoan, 296,474(Hepatozoofl,) jaouli, protozoon, 355, 499,474(Hepatozoon) leporiB, protozoan, 422,475(Hopatozoofl,) muri8, protozoan, 492, 475(Karyo!Y8UB) laceTtarwm, protozoan, 422Haemogregarinida, Hemogregarinidae, 219,220, 996, 291, 355, .490, 4fll, 492Haemoproteidae, 219-214, fJ49H aemoprot6'U8 coiumbae, protozoan, 212~482danil6wBkyi, protozoan, 249ma1l8&n4, protozoan, 913, 480'/I.octuao, protozoan, 249, 251Byrnili, protozoan, 949, 475Halaraehne americani, mite, 408, 481att6'lllUata, mite, 408, 481halicham, mite, 400S, 481Halipeg'llB ovocaudat'llB, fluke, 59, 87Hallucinations caused by insects, 21Haplometra cyli'lldracea, fluke, 59Harpyrynch'llB lonfJIipilUB, mite, 408, 491

508 INDEXHead louse (see Pediculus It'llvza_a)Heartwater, 436, 480Hedgehog (aee also Erinaceua algirus), 417nematode (see Gonuylolumm 1!'ucronatum.)IIelopltilua pomfulinua, fly, 192, 484Homileuca maia, moth, 467, 489Herpeatea ich1UlWm0'lt, mongoose, 62ilerpetomonas spp. (see Leptomonas)Heterandria formoaa, fish, !il89Ileterometrua mauruB, scorpion, 462, 489Heterotricha, 388Hide beetles, 454, 455IIimwnta'1ium gen·aiai, centipede, 466, 490IIippoboBca spp., files, 235 .maculata, fly. 218rufipos, fly, 218, 480Hippoboscidae, 214, 218, 2SS, 496III.ppocentrum trimaC'Ulatwm, horsefly, 290,480Hippopotamus head bot (see RhinoestruahippopotQ/1Tli)Hiss-Werner disease, 294ilistiogaater entomophagus, mite, 405, 497spermaticua, mite, 474.Hodotermes pretorienBis, termite, 68, 87,486Hog (see also pig), 389, 408louse (see Ilaematopiwu8 BUis)Hog-feeding trough, 171, 179Holothyrus coccinella, mite, 404, 474Homalomyia corvina, fly, U8Honey poisoning, 468Hookworms (see Ancylostomidae)Hoplopsyllua anomalua, flea, 360, 365Horse (see also equine), 373, 405, 412bot (see Gastrophilu8 intsBtinaliB)chin fly (see Gaatrophilus naaaliB)diseases, 119, 122head bot (see Rhinoestru$ purpureu8)lice, 347, 348nematode see Gongylonoma Bcutatum)nematode (see Habronema megastoma)nematode (see IIabronema microstomu)nematode (see IIab,"onema muscae)Horse nose fly (see Gaatropl~iluB haemorrhoidal;s)sickness, Gambian, g17, 480trypanosomiasis, 215, fH6, 217Horse-hair worms (see Gordiacoa)Hospitals, 328Hot air delousing, 324House fly (see Musca domeRtica)Human flea (see Pu16~ irnitans)nematode (see Acanthochttilonema per-BtCMUl)nematode (see A8caris lumbricoideB)nematode (see Pilaria bancrofti)nematode (see Pilo,ria demarquayli)nematode (see Pilaria (Loa) loa)nematode lsee Filaria philippinensis)nematode (see Flilaria tucumana)nematode (see Oncocerca caecutiena)nematode (see Oncocerca 1I0111ulus)Human tapewonn (see Dipylidium c(J1li-'1Ium)tapeworm lsee Hymenolepis ciAimiwuta)tapeworm (see Hymenolepis nana)tapeworm (see Taenia Baginata)thorn-headed worm (see Macracatnthorhynchu8hirudinaceu8)thorn-headed worm (see Moniliformismoniliformia)Humidity, 97-104Hyalomma aegyptium, tick, 4H~, 415, 417,41!:l, 422, 424, 425, 475, 478, 479, 487IIydrocampa nymphaeata (see Nymphula)Hydrocyanic acid gas, 325, 326, 380H ydro-taea meteorica, fly, 192, 484Hygranesthesia, 98, 101Hygronochel'ia, 98, 101Hygroplegia, 98, 101Hylemyia nidicola, fly, 195Hymenolepididae, 120, 356, 357, 889IIymenolepis carioca, fowl tapeworm. 57.82, 92, 495dim;nuta, rat tapeworm, 49, 53, 54, 55,79, 80, 83, 84, 86, 88, 94., 856, 495microatoma, mouse tapeworm, 4g, 86nana~ dwarf tapeworm, 53, 55, 56, 79, 80,91, 357, 495Hypercryalges'ia, 100HYp6rchiria ;0, moth, 22Hyperthermalgesia, 100Hyphomycetes, 289Hypoderma bOllia, bot, 197, 469, 484liMata, ·bot, 141, 182, 184, 186, 197, 469,484HyBtrichopBylla talpae, flea, 854Ilybiua fuliginoB'Us, beetle, 59, 85Immigrant inspection, 314, 315Impetigo contagiosa, 289, 290, 480tropical, 289, g90, 481Impromptu delousing, 326, 327Inactivity, zone of, 98, 99, 101Incineration, 158Incinerators, 45, 46, 456Industrial sanitation, 41, 42Inflammation, bronchial, 481catarrhal, 481Insanity caused by ipsects, 21Insomnia caused by inseC'ts, 21Insect breeding, 32, 83stings, 467. 468Insecta, 461Intermittent fever, 4i2[somett"us 6uropaeu8, scorpion, 462, 489Isopoda, sowhugs, 89Isoptera, termite3, 87Itch, bicho-colorado, 403, 481chorioptic, 405, 481coolie, 405, 481copra, 405, 481grain, 405grocer's, 405, 481ground, 405guano, 408, 481

Itch, Norwegian, 405psoroptic, 40"'sarcoptic, 405Texas, 405lzodea sop., ticks, 494bicornia, tick, 409(Cerati:l:odeB) put'UII, tic}.!:, 409hezago1llUll, tick, 416, 41'lJ, 476holocycl'UII, tick, 411, 487. piloB'UB, tick, 4.10, 4.87reduvw8 (see I. he:l:agon1l8)ricinua, castor-bean t'ick, 73, 88, 89, 409,411, 417, 425, 434, 476, 487, 480,490Jackal (see CamB aure'UII), 417Jaculua gordoni, jerboa, 355, 422, 474orientalia, jerboa, 355, 4jl2, 474JanthinoBoma lutzi (see PBorophora)Japanese river fever, 413Jaundice, canine malignant, 415, 416, 417,4.36, 475infective or epidemic, !lI96, 481Jerboa (see DipOd4UuB conrvp6Btria)(see Gerbillu8 indic'U8)(see Jaculu., spp.) ~Jinja, !lI50J ohannBl11IIwlla spp., midge~, !lI!lI4.JuJUB sp., myriapod, 54, 55, 88, 495guttulat'U8, myriapod, 68, 88londi1l8nBiB, myriapod, 466, 490terreBtria, myriapod, 466, 490Kala azar, !lI62Indian, 251, 294, 395, 396, 397, 398, 481infantile, 354, 481Kara kist (see Theridium lugubre)Kat'ipo (see Latrod6cteB haB8 eltii)Kedani disease, 413, 481Keratitis, phlyctenular, 29QKerosene emulsion, 336Killifish (see Fundulw spp.)KirkioeBt1"1l8 spp., bots, 195Kissing bugs, 469Labideathell ~icC'UluB, :fish, ii!82Lacerta spp., lizards, 42!l1Laehnolterna spp. (see Phyllophaga)LaelapI echidnin'UB, mite, 422, 475Lagoa; sp., moth, !lI2criapata, moth, 467, 489LagopuB 8cotieull, red grouse, !lI14Lakes, 276Lwmblia inteBtinaliB (see Giardia)LwminoBiopteB eY8tlicola, mite, 409, 474.Lark. 249Larvicides, !lI79, !lI80Lasioeampa pini, moth, 461, 489Latrines, 45, 47, 48, 282Latrodec~ell geometricuB, spider, 464, 489hasBeltii, kaUpo, 464, 489mactana, hour-glass spider 463,. 4898calia (see L. hasBeltii)Laundry, 319, 3£10INDEX 509Laverania falciparwm, plasmodid, 253, 255,256, 481i1malariae (see L. faleiparwm)Lecithodendrilwm ascidia, fluke, 59, 81, 87,88chiloBto1WUm, fluke, 59, 83Leiothinae, biru lice, 7fil, 73, 86Leishmania sp., leptomonid, 395brasilien8iB, leptomonid, 219, 5151donovani, leptomonid, 251, 294, 395-398,481infantum, le-ptomomd, 354, 4.81tropica, leptomon"id, 118, 219, iilSl, 398,49ii1uta, leptomonid, 219, 497Leishmaniasis, 482oral, 219, iil51Lepidoptera, moths, 59, 83Lepidopterous larva poisoning, 466LepomiB cyanelT!ua, fish, 282gibboll'U8, fish, 5182Leprosy, 112, lIS, 392, 481, 482Leptomonas sp., leptomonid, 354algeriena6, leptomonid, !lISIblattarum, leptomonid, 388calliphorae, leptomonid, 117ctenocephali, leptomonid, 354.ctenophthalmi, leptomonid, 355ctenoplyllae, leptomonid, 355CUliCliB, leptomonid, !lI52debreuili, leptomonid, 355dro3ophilae, leptomonid, 117homalomyiae, leptomonid, 117lineata, leptomonid, 117luciliae Roubaud, leptomonid, 117luoiliae StrickJan.d, leptomonid, 111mBBnUi, leptomonid, 117minuta, leptomonid, 219m'UBca6-domo8ticae, leptomonid, 117'(Iattoni. leytomonid, 355pediculi, leptomonid, 294phlebotomi, le-ptomon~d, 219pycno8offlae, leptomonid, 118roubaudi, leptomooid, 118sarcophagae, leptomonid 118lIimuliae, leptomonid, iil198oudallemia, leptomonid, 1188tratiomyiae, leptomonid, 118aubula!a, leptomonM, 219Leptomonidae, 117, 118, 219, 251, 25ii1, 294,354, 355, 388~ 395~9B, 414-418LeptopBylla musculi, flea, 351, 488LeptoBpira- hebdomadi8, spirochaete, 413icttJrohaemorrhagiao, spirochaete, 296,481 .ictel"oideB, spirochaete, flS9, 260, 497Lept'UB akamuBhi, mite, 404, 413, 477, 497american'UB, mite, 404, 477irritanB, mite, 404, 477Lopull spp., r.abbits, 853nigricolliB, rabbit, 4:il1il, 476Leucocytozoidae, 214, 250Leucocytozoon danu6'WBkyi, protozoan, flSO,Sil5l, 4.75

510 INDEXLtI'Ucocytozoo'n lavati, protozoan, !il14LtI'UoopluUJo. sp., cockroach, 376L6Wiso{l,6lla spp. (see Trypanozoo'n)Lice, ~6-348ani~ T. 980-848in lli.;ypt, 459Lif~ ~'P .. s of temperature and humidity,9B-to",Limnophifua fiavicorniB, caddice fly, 59,88gris6'IUI, caddice fly, 59, 83liu'lULt'UII, caddJ."'ce fly, 59, 83 .f'hombic'llB, caddice fly, 59, 88LimoBi1UL p'Unotiponni8 (see BOf'b01"Ull)Linognath'UB podaliB, sheep foot louse, 845BtOllOPBiB, goat louse, 346, 347vitul'i, cattle louse, 288Linseed oIl for cattle lice, 334, SS5Lion, S7S, 405Lip0'1llJl8B'UB bacoti, mite, 4M, 474Lipoptena ctlf'1)i, fly, 935Lithobi'U8 forficat'IU, centipede, 466, 490melanopB, centipede, 466, 490Liv'ing quarters, S27Lizards, 2fl6Llama, 405Loaais,48!ilLone Star tick (see Amblyomma amencanum)LOBChia coli,. a.moebid, 116hiBtolytica, amoebid, 117, 478Louse, body (see PediC'UIiuB corporis)crab (see Phthi'I"UII pubw)control, SI2-S29head (see PediC'U1iuB hu.ma'IIIUB)ravages, S12, 31SLouse reservoirs, 313, S14Louse borne diseases, !il86-297Louse-ulcers, 287L'Uco.nio. parva, fish, 28211e1llUBta, fish, !lSflLucilia spp., flies, 117, lI8af'gyrocfJphala, fly, 180, 48/)callBar, green bottle fly, 105, 108, 109,110, 111, 119, lIS, 114, 139, 133, 140,177, 179, 180, 181, 453, 475, 477, 485,49!JnobiliB , fly, 149BeroniBBima, fly, 117, lI8, 180, 480, 485Benicata, green bottle fly, lSI, 139, 140,143, 148, 149, 177, 179, 180, 181, 453,485sylva'I"Um, fly, 139tasmani91l8i8, fly, 181, 485Lungs, inflammation of, 408LycoBa narbo'nfJ'lUIu, spider, 463, 489tamnt'Ula, spider, 463, 489Lymo.ntria. monacha, moth, 467, 489Lymphangitis, 69, 409opizootJic, 411, 482Lymph-scrotum, 69Lynchia spp., flies, 935bruntJa, fly, !J19, 482maura, fly, !!l19, !illS, 919, 489Lypef'oltia sp., fly, !!l14, 918ea:igua, horn fly, 915, 939, 494irritans, horn fly, 169, 910, 939, 983, 984,475minuta, fly, !il15, 494MacracanthOThynchua h~'l"Udinace'UB, thornheadedworm, 79, 85, 86, 495Macmthylacia 'l"Ubi, moth, 467, 489Maculae coeruleae, 288, 482Mal de caderas, 393, 482Malacotylea, 120, 121Malaria, 48, 962aestivo-autumnal, !!l5S, 955, 9S6avian, 259, 489canary, 482malignant tertian, !J58, g55, g56pernicious, 25!ilpigeon, 212, 213, 482quartan, !il53, 256, 257, 489subtertian, !il5S, !il55, 256, 489, 483tertian, 25S, 957, 258, 259, 483unclassified, 253, 254, 955, 489Malass8zia spp., fungi, 989, 41;17Mallophaga, bit'i.ng lice, 86Mange"" 405demodectic, 407, 484pscroptic, 484 .Mansonia~., mosquito, 250, 485pso'Udotilla1l8, mosquito, 969, 480McmBO'1Iioiitdo8 africa1lllUl, mosquito, 961,262, 479annulip8B, mosquito, 70, 89, 26!i1, 4801IIIUifOf'miB-, mosquito, 70, 8!J, 250, !J62, 479Manure, 158-160bin, 157broadcasting, 156clean-up, 158collection, 156hog, J. 72, 173incineration, 158inspection, 158, 160loading platforms, 156~ 158piles, 159scraper, 159shipment, 158spreader, 157Margamp'll8 'Wintheml. ti'rek, 410Mannoset (see Midas spp.)Mastigophora, 117-119, 919-919, 249-260,294-296, 35>1-355, 888, 393-399, 414-490Mastophorua 6chi'U'l"UB, nematode, 78, 86globocaudat'lls, nematode, 78. 85Mayflies (see Plectoptera)Mbori, !il!J8, 251, 484-Meal moth (see Asopia fari1l41i8)Measles, 116, 192, 484Mediterarnean Coast Fever of cattle, 415,484 •Megalopygs operculari8, moth, 467, 489Melllnodennia, 987, 288,484MelanoleBt6B picip68, kissing bug, 469, 4891l£elipo'l'l.a spp., bees, 489Meloidae. 469. 478

Melolontha melolontha, June beetle, 79, 85,495vulgaria (see Melr>lrmtha melokmtha)Melophagu8 OViMUl, sheep tick, 9HJ, 219,23.5, 346Meningitis, cerebrospinal, 108, 115, 289,5190, 484MeningococcUil sp., mi('roorganism, 289MeITurial ointment, 337M erion68 spp., rodents, 55!)Mertnithidae, 78, 262MesogoniatuB chaetodoo, fish, 282Metatrombidiwm poricepB, mite, 404, 477Metazoa, 220, 000, 297, 355, 389, 390Miana tick fever, 484Mice, 355, 395white, 393Microcalliphora domeBtica, fly, 485varipeB, fly, 181, 485MicrococCUII sp., microOrganism, 299ftav1lB, microOrganism, 108melitensis, microilrganism, 248nigrofasciens, IiJlicroilrganism, 383tetrageMUl, microilrganism, lOSMicrofilaria dmrna (see Filaria (Loa)loa)perst_ (see Acanthocheilo7b6'TRa)Microneurwm fUnJiJCola, fly, 109, 477Microtrombidi-um pwrillwm, mite, 404, 477tlalBahuate, mite, 404, 477wichmanni, mite, 404, 480MicrotuB spp., mice, 352montebeUi, field mouse, 413Midas geoffroyi, marmoset, 259oedipw, marmoset, 959Midges (see Chironomidae)Milk bacteria, 112, 115Minnow, top (see Gambmia alftniB)Mites, 403-4&9MollieniBia latipinna, fish, 289Mongoose (see H erpesteB ichnewmon)MoniliformiB mOlllUiformiB, thorn-headedworm, 79, 84, 88, 389, 495Monkey, 291, 408(see AteleB pentadactyTAu)(see Cynomolg'UB cynocep1uJ,/;u6)Morbus errorum, !i!87Mosquito control, 275-gs5repellents; 284sources, 276sta5.ns, 976traps, 283Mosquitoes, 69, 70, 71, 247-285Mouse, 408nematode (see ProtoBpilf'U'I'a mu.riB)tapeworm (see Hymenolepi8 diminuta)tapeworm (see H ymenolepiB mi('rostoma)tapeworm (see HymenolepiB nana)Municipal boarding houses, 41Murrina, 119, 122, 484Mus spp., mice, 552, 353mUBculuB, mouse, 118, Sil94Mwca sp., fly, 118bezzii, fly, mINDEXollMtUlca sp., conl1e:rifron8, fly, 200cO'l'Vina, fly, 229dome,tica, house fly, Frontli:spie

512 INDEXNematode, mongoose, 486rodent, 486, 487Neocuterebra 8quamo8a, bot, 190, 485Neopollenia BtYUia, fly, 181, 485Neosporidia, lil1, 388 .Nephrophagel1 Banguinariua, mite, 408, 474-Nervous exhaustion, caused by insects, 20,91N61lroctena aniliB, 1I.y, 118Neuroptera, 59, 89 •Nicotin wash, 837Nigua (see Dermatophi1JuB pen""etram)Nochelic subzone, 98, 102Nose protection, lil05NOBema apia, protozoan, 120N osemidae, 1lilONotemigonm crYBole'UCaB, flsh, 982Notidobia ciliariB, caddice fly, 59, 83NotoedreB cati cati, mite, 405, 491mum, mite, 491Nuttallia spp., piroplnsmid, 414equi, piroplasmid, 417, 436, 487Nuttalliosis, equine, 417, 487Nycteribiidae, 235Nyctotheru8 ovaliB, ciliate, 888Nymphula nymphaeata, moth, 59, '83OctoBporea m01WBpora, protozoan, 120Ocular acariasis, 487Odonata, dragon flies, 59, 87Oedqmagena tarandi, reindeer bot, 188,485OeBtruB ovis, sheep bot, 176, 198, 198, 207,469, 484Oilers, 281Oiling, 980Oils for treating cattle, 3S4, 835Olethric zone, 98, 10lilOligo'fU!'Urtia rh6'1latna, mayfly, 78, 87Oncooerca sp., cattle nematode, 77caecuti6'1lB, nematode, 77lienalis, cattle nematode, 77volvulus, human nematode, 77OnitiB irroratuB (see Ohironitia)Onthophag'UB spp., beetle, 62, 64, 85, 486bedeli, beetle, 68, 64, 85, 486hecate, beetle, 62, 86, 4851IebuWBuB, beetle, 64, 86, 486pennBylvanie'UB, beetle, 62, 86, 485Ophthalmia, purulent, 116, 12lil, 487nodosa, 466, 487Ophyra spp., flies, 4531Iigra, fly, 181, 485OpiBthioglyphe ra8tell'UB, fluke, 59, 83, 87Optimum temperature, 10QOrganisms carried by insects, 27, 28, 29Ornithodoros spp., ticks, 4lil8, 424coriaceua, tick, .4C9, 487meg1lli.ni, tick, 408, 420, 4lil4, 426, 431,433, 434, 444, 445, 487, 490moubata, African relapsing fever tick,79, 74, 75, 89, 96, 414, 418, 419, 420,423, 4lil4, 482, 433, 448, 476, 479, 490,491,493Ornithodoro8 spp., Bavignyi, tick, 412,418, 423, 424, 484, 479, 490turieata, tick, 409, 420Omithomyia spp., flies, fJ35lagopodiB, fly, 218, lil14, 480Orthoptera, 88OBoimiB pallipes, gnat, 119, 497Otoacariasis, 408, 487Otodecte8 cynotiB, mite, 408,487Otomyiasis, 149Ovine trypanosomiasis, 218Owls, 249Oxyuridlle, 121, 889, 390OeyuriB blattaeorientali8, worm, 889bulho6si, worm, 889CU'I"V'Ula, worm, 121, 487dAie8in!Ji, worm, 889kunckeli, wOl'm, 889vermicularis, worm, 12iPacking h~se insects, 40, 453-460Paedeyua columbi1llUB, beetle, 469, 478Pahvant Valley plague, 209Palm squirrel (see, Fllnambu1JuB pennatii)Panama larvicide, 280Pomgonia spp., horseflies, 228PanopliteB sp., mosquito, 75, 82, 479africa1llUB (see Man8onioid(8)Pappataci fever, 49, 211, 226, 487flies (see PhkbotofWUB spp.)Parachordode8 pustuIo8'UB, horse-hair worm,79toluaaWU8, horse-hair worm, 79Vtiolace'UB, horse-hair worm, 79Paracolitis, 487ParagordiIuB tricuapidat'UB, horse-hair worm,79varluB, horse-hair worm, 78, 79Paralysis, Australian human tick, 411infant'i:le (see also Pollomyelitis), 116,487insect, 22North American human tick, 409, 410South African tick, 410tick, 487Parapla8ma ftavigenum, protozoan, 959Paratyphoid A fever, 112, 115, 487B fever, 112, 115, 487Partridge, 9.59PasBer dome8tic'UB, English sparrow, 25lilPa88eromY'ia heterochaeta, fly, 196, 484Pasture rotation, 441Pannch manure, 456Pecilothermal, 101PediculoideB ventricOB'UII, mite, 404, 405,497Pediculosis, 22capitis, 286, 287corporis, 286, 287Pediculus spp., lice, 481capitis (see P. hu.mamIB)ConsObrinu8, monkey louse, 800

Pedk'Ul'Us spp., corporis, body louse, 286,289, 290, 291, !il9il, 003, 294, 296, 301,302, 304, S05, 306, 307, 308, 309, 310,317-28. 478, 479, 481, 484, 487, 488, 490,491, 495, 497hwman'U8, head louse, liI86, 289, 290, 294,295, SOl, 30lil, 306, 316, 317, 477, 480,482, 488, 491'Vestimen.ti (see P. cO'1'poriB)Pellagra, 21li1, 225, liISO, 487Periplaneta sp., cockroach, 37/Jam61'icana, 63, 78, 79, 88, 316, 378, 879,383, 387, 388, 389, 477, 486, 495a'U.stmlaaiae, 376, 380Peritonitis, 408, 487Perlidae, stoneflies, 59Personal prophylaxis, 315Pharyngobol'U8 african1U, bot, 198, 484Phidipp'U8 auda:n, spider, 463, 489Philaematomyia c1'aBBi1'OBtria, fly, liI15, 494'iIn8igniB, fly, 200Philaematomyinae, ~Phlebotomus fever, 211minut'U8, fly, liI19, 226, 492mi_t'Us africamu, fly, liI19papatasii, pappataci fly, 2n, 226, 487"1I7'1'UCa7'Wnl, fly, lilli, 926, 497Pho'l'mia OZ'U1'ect, fly, 195, 484metallica, fly, 1951'egina, black blowfly, 132, 138, 135, 141,177, 178, 179,459, 485Bort:Uda, fly, 195, 484Phosohorus, 382Phrygama sp., caddice fly, 59, 83grandiB, caddice fly, 59, 83Phthiriasis, 286, 287, 288Phthiy'U8 mgui1laliB (see P. pubis)pubi.a, crab louse, 286, 301, 302, 316, 475,476, 482, 484, 495Phyllophaga a1'cuata, June beetle, 79, 86,49.7PhVlloBtom'UB sp. (bat), 251Physocephalus 8e~at'Us, nematode, 64, 66,78, 85, 86, 95, 486Pi'g (see also hog), 373, 405nematode (see A1'aU6nna stt-ongyUtna)nematode (see Phylocephallus B6zalat'U8)pens and pig lots. 170, 171, 172, 178thorn-headed worm (see Mac1'acanthorhynchuBkit"Udi'IUICe'U8)Pigeon lice, 343Pin itch, 122Pink eye, 109Pinworm, equine, 487Pinworms (see Oxyuridae), un, 989, 990Piophila caaei, cheese maggot, 192, 454,484.Piroplasma spp., protozoa, 414bigemin1im (see Babesia)hominiB, protozoan, 4.13Piroplasmidae, 414Piroplasmosis, 487Pityriasis, 289, 990, 487Plague, 49INDEX5ISPlague, bubonic, 112, 115, 350, 351, 360,365, 392, 893, 488rodent, 114, 115, 209, 230, 351, 488PlanorbiH eZ'U8t1U, snail, 260Plasmodidae, 25!i1, 259Pla8moditwm sp., malaria organiSm. 252,489oonu6wllk'!/';" malaria organism, 259, 482falcipa1"Um (see La'Verania)malariae. malaria organism, iil59, 257, 4811f'eliGtwm, malaria organism. 259, 482,,"'am. malaria organ'ism, 259, iil57, 258,liI59,489Platybelmia. 120, 121, 260, 261, 555, 356,557,989Plecoptera. stoneflies, 59, 88Plectoptera, mayflies, 59, 87PZ6urogen61t claviger, fluke, 59, 86medinnls, fluke, 59, 86, 87Plica polonica, 987, 488Pli.atophora sp., protozoan, 988p61'ipZwneta, protozoan, 988Pneumococcus septicaemia, 289, 000Pnewmonoec6B Bimili.a, fluke, 59, 87Pneumo"1lBBUB Bimicola, mite, 408, 481Pogonomyrm6z barbat'U8, ant, 468, 488calif01'1lic'U8, ant, 468Poisoning, bee, wasp and ant, 488bug, 488centipede, 464466, 488food, 111, 114, 115, 489honey, 468, 489insect, 21, 22, 461-471kissing bug, 489lepidopterous larvae, 466, 489scorpion, 461-469, 489spider, 46S, 464, 489Poliomyelitis, 116, 12ii1, 211, 1i112, 290, 248.249, 993, 489Poli.at6B spp., wasps, 468, 488Pol/e,da I'udis, fly, 118, 199, 484-villosa. (see Neopollenia stygia)Polydesmus compla.nat'U8, centipede, 466,490Polymastigidae, 117Polymastigina, 117,388Polyneuritis, 291PoZyplaz Spi_IOIl'US, rat louse, 294, 296,491,496stephefUoi, jerboa louse, 296, 474P01'c6Uio lafI'D;", sowbug, 68, 89, 486Porrigo, 2!l9, 490PortheBia similis, moth, 467, 489Porth6tria' di.apar, gipsy moth, 467, 489Pot-holes, 277Practicotatum,.98, 100, 101, 109Priesz-NQC8rd organism, 411, 482Prionuf"U8 am&ureuni, spider, 462, 489oitrimu, spider, 462, 489Prisoners, inspection, 41Privies, 37, 89P1'OBOtOC1Uf conf'U8us, fluke, 59, 86, 87Protection of body against mosquitoes.289,284

.514 INDEXProtomonadina, 117Protollpint,ra mum, rodent nematode, 60,78, 80, 86, 99. 957, 487Protozoa, 116-120, 212-220, 249-260, 2940-297, 952-855, 988, 993-999; 4140-423ProwtU6kia sp., protozoan, 117Prurigo senilis, 287Pruritis, 287, 288, 409Pseudoedema, malignant, 386, 490Pseudoparasitism of nasal passages, etc.,400PBeudopyrellia cOrwU:ina, fly, 136, 169Psorergates simplea: 'IllJU8C'l.dmm, mite, 408,497Psorophora lutzi, mosquito, 188sayi, mosquito, 249, 475Psoroptes ctnn'11llUnis bovill, mite, 405, 484cullliculi, 408, 487equi, mite, 405, 484Ollis, mite, 405, 484Psychodidae, 226, 228Ptinus spp., beetles, 475PulilrD bra.sili61laU, flea, 352, 496irritan8, human flea, 53, 54, 55. 16, 80,951, SS2, 954, 355, 356, 957, 960, 969,963, 479, 481, 488, 494, 495, 496Pupipara, 935Pus, green, 113, 115Pustular dermatitis, 287Pycnosomo bezzia-na, fly, 180, 485chloropyga, fly, 485, ftafJicBpB, fly, 180, 485mar.l1Iinale, fly, 180, 485mdgacephala, fly, 180, 485putoriwm., fly, 118, 180, 485rufifacies (see OhryBomya)Pygiopaylla ahalae, flea, 351, 365. 488Pyodermia, 287, 288, 490Pyrethrum powder, 381, 389Rabbit, 63fleas, 358lice, 343, 944Rain barrels, 282Rat (see also rodent), 389, 395, 404, 492fleas, 350, 951louse (see Polyplax spinulosa)nematode (see Gcmgylonema n.eoplaaticum)'nematode (see Protoapirura mut1is)tapeworm (see Hymenolepi8 dimi'IIIUta)tapeworm (see Hymenolepis n.tma)thorn-headed worm (see MonIliformiBmoniliformis)Rat-tail maggots (see E'llLBtalis .pp.)Raven, 249Red bug, 404grouse (see LagopfUI .coticua)Reduviidae, 399Redwater, 414British, 417,490Reindeer· bot (see Oephenomyia trompe)(see Oedemag61!a tarandi)RelapSing fever, 48, 400Relapsing fever, Abyssinian, 418, 490Amer'ican, 420. 490Asiatic, 295, 490East African, 420, 490European, 296, 313, 398, 999, 420, 491Manchurian, 296North African, 295, 296, 398, 491Tropical African, 296, 398, 418, 491Rhiganesthesia, 98Rhligonochelia, 98, 100Rhigoplegia, 98, 101#Rhinoceros bots, 193Bh:noeBtrus hifJpOPOtCllmi, bot, 195, 484nasalill, bot, 194, 484purpur6'UB, bot, 194, 198, 207, 484BhipicephalUB spp., ticks, 424, 435appendiculata, tick, 417, 425, 436, 447,478burBa, t!ick, 417, 486, 476caprmB'iB, tick, 415, 417f1IJ6rtsi, tick, 417, 420, 494, 425, 436, 478,487,493aanguin6'UB, tick, 74, 76, 89, 414, 415, 420,4S11, 424, 4S15, 486, 474, 476riculuc, tick, 410, 414, 417, 4S15, 474, 476,478,487Bhi=oglyphul paraaitiCUII, mite, 405, 408,481,487Rhodesian fever, 417, 491BhodniuB prolWtu, bug, 394, 476Bhyacophila 'lllUbila, caddice fly, 59, 83BhY1U!hoidomonas luciliae, protozoan, 118Bhyr.oglyphUB paraaiticu8 (see Rhi=oglyphUB)BickettBlia m61ophagi, microorganism, 212pediculi, microorganism, 29S1, 294, 491prowtUBki, microorganism, 29~, 497quintana, microorganism, 293, 495Robin, 195Rocky !\fountain spotted fever, 403, 412,491tick (see Dermacentor andBrBoni)Rodent trypanosomiasis, 294B.oBBieUa spp., protozoa, 414rOBBi, protozoan, 417, 474Sanitation, entomological, 34-42Sarcina alba, microorganism, 383aurantiaca, microorganism, 108, 384lutea, microorganism, 884Sarcodina, 116, H7, 388Barcophaga spp., flies, 119, 458, 484, 497aurifrtmll, fly, 181, 485camaria, fly, 105, 108, 109, 110, 111, 112,113, 114, 180, 475, 411, 485, 492haemorrhoidaliB, fly, 118, 180, 191, 4P4,485lcrmbenB, fly, 179, 485'llLUrwl, fly, 118pyophila, fly, 179, 197,485regulam, fly, 180, 485robu8ta, fly, 185,ruftcorniB, fly, 180.araceniae, fly, 117, 132, 186

Sarcophaga spp., telllMllJ, fly, lSi.tuberoaa aarracellioidea, fiy, ISflSarcophag'idae, 141, 144, 150, 161, 177Sarcoptea aucheniae, mite, 405, 491b01JiB, mite, 405, 491cani" mite, 405, 491caprae, mite, 405, 491dromedarii, mite, 405, 491equi, mite, 405, 491le01llLB, mite, 405, 491o"i" mite, 405, 491Bcabi6i cr'UBtosae, mite, 405, 491Bcabiei homilli8, mite, 405, 491Buia, mite, 405, 491"ulpi.8, mite, 405, 491Sarcoptidae, 405Sawdust, oil-soaked, 281Scab, 491sheep, 405Scabies, 48, 405, 491Scaly leg, 405, 406, 407, 492Scaraba6'U8 (Ate1tchet'UB) tlarioloB'UB, beetle,61, 64, 86, 486(A teuch1tB) ,acer, beetle, 61, 63, 64, 65,86,486Scarlet fever, 116, IfJ!i1, 492Scatophaga £Utaria, fiy, 118Scaurua 8triatu" beetle, 4i, 54, 86, 495Schistosoma manaoni, worm, liO, IfllSchistosomiasis, liDSchistosomidae, liD, IiISchizomycetes, 107-115, i09...Qll, i49, 289,i90, 350, 851Schizotrypanum cruzi, trypanosome, 893,894, 895, 414, 475Scholeciasis, i2Schonga8tia tlandet",andei, mite, 404, 480School children, inspection, 40Scolopendra cingulata, centipede, 466, 488gigantea, centipede, 465, ·481'1heros, centipede, 465, 488mot",itanB, centipede, 465, 488Scop, gin, owl, i49Scorpion poisoning, 461-463Scorpionidea, 461Scouting for mosquitoes, 275Screening, 162, i06, SilB3of food, 39of houses, 36Screw worms (see Ohryaomya macellaria)Scutigera coleoptrata, centipede, 466,490SC'Utomyia albolineata, fly, 70, 80, 262, 480Sebaceous tumor, 408Seborrhea, 407, 492Seepage water, Sil77Sense organ injury, 21Septicaemia, 108, 110, Ill, 115, 211, 230,Sil89, 290, 411, 49iSerbian barrel disinfector, 822Setaria labiato-papillo,a, cattle nematode,77,82,94Seven-day feRr, 413Sewage, 40, 41, 161INDEX 515Sewers, 282bheep, 873, 405, 410bot (see OeBtf"'UB avis)lice, 345, 346Sheep maggots, 181nematode (sec Gongylonema Bcutatwm.)tick (see M elophagm 01li1l1tB)Shrew tapeworm, 57Sialis lutaria, dobson fiy, 59, 8>1Sibine 8timulea, moth, 467, 489Simian trypanosomiasis, 218Simuliidae, 224, 225, 226Simulium spp., buffalo gnats, il>!, 2fl4,225, 226, 487bracteatum, buffalo gnats, 2!il7columbaczenae, buffalo gnats 219ditnelli, buffalo ~ats, 77 'jenningsi, buffalo gnats, 927pictipes, buffalo gnats, 2>17lIamboni, buffalo gnats, 77"en'UBtum, buffalo gnats, 227•",it tatum, buffalo gnats, 2i7SIphonaptera (see Aphaniptera)Sitophilm granariu" beetle, 4!i1Sleeping sickness, >169Gambian, 915, 280, 250, 499Nigerian, 215, 492Rhodesian, 217, >150, 492Smallpox, 116, 122, 291, 499Soaps, 318Sodium fluoride, 341. 84!i1, 848, 381Sore, Bagdad, 118, 919, 226, 49~Biskra, 219, 49~Cambay,118non-ulcerating oriental, 395Oriental, 118, 251, 398, 492tropical, 269Souma, 217, 928, 930, 493Zambian, 917, 493Sowbug (see Porcellio la6tlis)Sparrow, 249, 259Spider poisoning, 463, 464Spilopayll'UB leporis; flea, 85S, 496Spinose ear tick (see Ornithodoros m(Jgnini)Spirillaceae, 115, 887Spirillum (Vibrio) cholerae, microOrganism,115, 387, 477metchnikcmi, micrOOrBl8Dlism, 387,478Spirocerca ,anguino lenta, dog nematode,60, 65, 84, 85, 86, 88, 91, 486Spirochaeta gallica, spirochaete, 993Spirochaetacea, 219, 259, 960, 295, 296 355898, 418-4!i10 ' ,Spirochaetidae, 119, 919, 259, 960, 995-SiI96,355, 398, 418-490.Spirochaetosis, 49bov'ine, 4~0, 498goose, 418, 494North American fowl, 498Senegal fowl, 490, 493South American fowl, 493Sudanese fowl, 419

516 INDEXBpiropttJra obtlllla (see Protollpirura mum)(Filaria) Banguinolenta (see Spirocerca)(Gongylonema) neoplaaticWm (see Gongylonema),Bpirollchaudin1lJ6a spp., spirochaetes; 296,.418,490anserina, spirochaete, 418, 494b,rbe,.a, spirochaete, 295, 898, 491carleri, spirochaete, 295, 490ctenocephali, spirochaete, 855culicis, spirochaete, 259dutton,i, spirochaete, 296, 898, 49iduttoni, Brumpt, spirochaete, 418duttom, Novy and Knapp, spirochaete,418,419ea:anthematotyphi, spirochaete, 292glollllinae, spirochaete, 219granulata, spirochaete, 419, 498marchouxi, spirochaete, 493neveuan.i, spirochaete, 420, 493novyi, spirochaete, 420, 490,.eCUl"f'entill, spirochaete, 295, 296, 898,420,491rOllllii, spirochaete, 420, 490theilBri, spirochaete, 420, 493Spirura gaBtrophila, cat nematode, 60, 61,84, 85, 95, 389, 486Spiruridae, 121, 357, 389Splenic fever, 414, 494Sponge baths, 318Sprays for cattle, 835, 886Squirrel, 355, 409bot, 187Stable fly (sec StomoXYII calcitrana)Stables, 39, 40Staphylinidae, 469, 478Staphylococcull spp., microorganisms, 489pyogen611, microorganisms, 411, 480pyogenes albw, microOrganisms, 108, sno,fl89, 384, 480, 49fl .pyogonea aU,.eu8, microorgan!isms, lOS,fHO, 289, 384, 480, 492pyogonoll citreulI, microorganisms, 108,492Stcll:m, enclosed, 32fl, 3fl3live, 81l1lsterilization, 391-323BtfJgomyw. calopus (see Aedell argentlJUa)fatlciata (see Aedes ar!Jenteus)graciliB (see Aedea)ingfl1lll, mosquito, 251Sterilization, steam, 321-323.BtemoBtom'llm rhinolethrum, mite, 408, 481Stigmatogaate,. Bubte,.ran6us, centipede,466,490Stomoxydinae, 229, 230, 232, 233Btomoeyll spp., flies, it17, 218caloit,.ana, stable fiy, 57, 66, 67, 77, 78,8fl, 126, 139, 140, 143, 145, 146, 209,210, 211, 212, flI4;, 215, 216, 217, fl20,221, 230, 231, 232, 474, 475, 476, 477,478, 485, 487, 488, 49!i!, 493, 494, 495genicula tUB, fly, !ilI5glauca, fly, fl14, 485Strnrw'Z!}s spp., nigra, fly, 215, 216. St17, 220,476, 498, 494Stoneflies (see Plecoptera)Btratiomyia chameloon, fly, 118potami.da, fiy, 118Straw, 231, 23l!Streams, clearing, 276Streblidae, fl35St,.eptococcus sp., microorganism, 211, 492equi1lllUl, microorganism, 107fecaliB, microorganism, 108pyogenoB, microorganism, 108, 479aaliva,.full, microorganism, 108Strickeria jilrge:1£8Ii, protozoan, 292Stria: flalfr.:~!!9a .. owl, 249Submarine !.8WS, 277Submersible automatic oil bubbler, 281Sulphur fiowers, 843, 382fumigation, 381gas, 3!i!4, 325Suppurating wounds, 113, 494Suppuration, lOSSurra, 119, l!i12, !il15, fl!i!8, 230, 250, 494Swamp fever, 211Swamps, 276Swift (see Cypaelus ofliniB)Swine (see hog)Syphilis, 291Syrnium alueo, owl, 249, fl50, 475Syrup factories, 41Tabanidae, 211, !i!U, !U8, 219, 228, 236-!il46, fl5t, 496Tabanw .spp., horseflies, 210, 214, 217,219,!i!!i!8, 485, 492atrat'U8, horsefiy, 210, !il15, 475biguttatuB, horsefly, flI5, 217, 484, 498bovinuB, horsefiy, 210, 475Ch1"!}8UI"'UII, horsefly, 211, 474coram, horsefly, 289, 240aitaeniatw, horsefly, 287, 242, 243, 246faaciatulI, horsefly, 220fumife,., horsefiy, !ilI5, 494hilanll, horsefly, Sl19kingi, horsefiy, 237, 240, 1142, 246laBiophthalmUB, horsefly, 248, 244lineola, horsefly, 215, 494minimw, horsefiy, fllS, 494par, horsefly, 220, 297, 240, 24!i!partit'UB, horsefly, 2lS, 494phaenopll, horsefiy, 236, 237, 239, 240,241, 242, 243, 245p'Unctife,., horsefiy, 286, 237, 288, 239,240, 241, !i!48, 245BfJcedena, horsefiy, 220Bocialia, horsefly, 220striatuB, horsefly, 210, fllS, 219, 240, 241,24l!, 243, fl44, 245, 246,475, 494Iltygiw, horsefly, 239, 244, 245taeniat'UB, horsefiy, 215, 217, 484, 498tatJniola, horsefly, 237tergeBtinw, horsefiy, 219trigemi1llUB, horsefiy, 211, 474trigO'fI.'UII, horsefiy, 211, 474

INDEX 517TabafWU spp., tropic'llll, horsefly, S1l5, 494"ag'llll, horsefly, 915, 494vivaz, horsefly, 242TtUln-ia cucumerina, tapeworm, 94nana (see IIymenolepis) ,(TtUllIIiar'hynchus) saginata, beef tape-worm, 120, 494Taeniidae, 120, 297, 355, 356Tae1lWrhynchuB domestiCUB, mosquito, 70,82, 262, 480fuscopennatuB, mosquito, 261, 479Tahaga, 217,494Tapeworm, bovine, 494canine, 494fowl, 494, 495human, 494, 495rodent, 495Tapeworms (see Cestoda)Tarsonemidae, ~04TarSOnflmUS in-toctus, mite, 404., 497uncinatus. mite, 404Teichomyza fusca, fly, 118Telosporidia, 219, !!lOO, 355, 388, 4!lO-42!illemperature, 97-1Q4.and louse development, 804, 306, 807,309,310Temperatures, absolute fatal, 98, 101Tenebrio molitor, granary beetle, 42, 54,55, 57, 60, 68, 78, 86, 486, 487, 4,95Tflrs6Bthell torrens, fly, 224Telltudo mallritanica, turtle, 4.22, 4.75Tetanus, 378, 4,95Tetramitidae, 888Tetranychidae, 404Tetranychus mO{6stissimus, nfrte, 404, 481teiariU8, mite, 474teiaritls t'Us8eol1u, mite, 404Texas fever of cattle, 403, 414Thallophyta, 107-115, 209, 210, 211, 249,1189, 290, 850, 351, 383-387, 392, 393Theileria spp., piroplasmids, 414parva, piroplasmid, 4.17, 478The!ohamia ovata, protozoan, 120Thelohaniidae, 120, 388Theobaldia an7llUlata, (see auliBeta)Thoraphosa 3avanensiB, spider, 464., 489Theridium !ugv,bre, kara kist spider, 464.,48913-gllttatv,m, spider, 464, 489Thermalgesia, 100Thermanastas'is, 99'1'hermanesthesia, 98, 101'Thermesthesia, 100Thermohyperesthesia, 100Thermonochelia, 98, 100'Thermophilic, 100Thermophobia, 101Thermophylic, 100Thermoplegia, 98, 101Thermopnigia, 100Thermopolypllea, 100Thermopractie zone, 98, ~9. 10~Thermosystaltic, 101Thermotaxis, 101Thermotropism, 101Thorn-headed worms (see Acanthocephala)Three-day fever, !!lUTick bite, 409bite fever, human, 410bite trl'atment. 448, 4.49control, 440-449dip, 4411fever of Miana, 419fevers. 412paralysis (see Paralysis)Ticks, 403-4029Tile dra~nage, !!l77, 978Tin can dumps, 9agTQilet flushing box, 282Town, insanitary, 38sanitation, 38, 39Toxemia, 287, 288, 495Toxins, insect, 97Trachoma, 116, 122, 495Tra,gelaph-uB spekei, antelope, 215Train diSinfection, 32!!lTmps in sinks, 989Trash, 41Trematoda, flukes, 1'>7, 58, D9, 81, 82, 83,88, 120, 121Trench fever, 48, 999, 298, 994, 312, 818,495Trepo1lema. perte7llUe, spirochaete, 119, 497Triatoma spp., kissing bugs, 414, 469cha,gasi, kiSSing bugs, 394" 476qenic1l1ata, kissing bugs, 394, 476""'fortans, kiSsing bugs, 893, 482megillta, kissing bugs, 394, 399, 400mbf'ofasciata, kissing bugs, 399, 400BanguiBUga, kissing bugs, 4008ordida, kissing bugs, 894, 476TrichodecteB camB (see T. lat1l8)climaa:, goat louse, 346hermsi, goat louse, 346mtw, dog louse, 53, 86, !!l97, 344, 355,494parwmpiioBU8, horse louse, 8478calarill, cattle louse, 288, 322, 838Bphaerocephalw, sheep louse, 346mbro8trat'II.B, cat louse, 344Trichomonas orthopterwTn, protozoan, 388Trichoptera, caddice flies, 59, 83Trichosomidae, 1112Trichllri$ trichilura" Whipworm, 12!il, 497Trigona sp., honey bee, 29amalehea, honey bee, 468, 489bipWItCtata, honey bee, 468, 489limao, honey bee, 468, 489fOUfiCt'UB, honey bee, 468, 489TrochoBa 81lngoriensi8, spider, 463, 4891'rombidium akam'II.Bhi (see Lept'II.B)Imtumna!i$, mite, 404, 4.77batatas, mite, 404, 477holo8erico'Um, mite, 404, 477inopinatv,m, mite, 404, 477IftriaticepB, mite, 404, 471Troughs, water, 282

518 INDEXTrypanoBoma sp., trypanosome, 914, 951,414spp. (see Ol18tellanella, DuttO'MUa,Schizotf'!}pa'IIIUffl, TrypafWzoon)chriafopher8i, trypanosome, 414fra"."i, trypanosome, 918gallinarwm, trypanosome, !nS, 496grayi, trypanosome, §l18, 496noctuao, trypanosome, !lI51theileri, trypanosome, SH8, 480tullocm;, trypanosome, 218'V8Bpe"tilwnia, trypanosome, 395, 495ziemanni, trypanOBome, S51TrypanosomiasiS, 49animal; 495bat, 395, 495bovine, 495, 496crocodile, 496equine, 496fowl,496goat, 496ovine, 496rabbit, 496rat, 395rodent, 496simian, 496Trypanosomidae, lI9, !lI14-!lI18, S94, 8.52-854, 898-395, 4l4oTrypanozoon blanchardi, trypanosome, 852,496duttoni, trypanOBome, 8511, 395, 496lewid, trYPanosome, 294, 352, 353, 895,496twbil18i, trypanosome, 353, 496rabinowitBchi, trypanosome, 354, 496Tsetse fly (see Glo88!ina spp.)Tsutsugamushi disease, 413, 497TuberculOSis, 114, 115, 387, 497Tumbu fly (see Oordylobia anthropophaga)Tumors, 389Bebaceous, 497Turkey, 408lice, 843TydeUB moleBtUB, mite, 408, 481Tylench'IU sp., worm, 89Typhoid fever, 49, II4, 115, 1190, 291, 887,393,497Typhus fever, 48, 1191, 2911, 312, 313, 497Tyroglyphidae, 405TyroglyphUB IOll~ioT caBtellanii, mite, 405,481Biro, mite, 405, 497Urine soakage pit, 48Urticaria, 286, 497Urticariasis, 404, 497Uta, 219, 224, 497Vagabond's disease, 987Vanillismus, 405, 497Verdu Cayor (see Oordylobia a'fIthropophaga)Vermicides, 31S, 819Vermij~lly, .816Vermin problem in armies, 45Verruga peruviana, Sll, S26, 497Vertical drainage, 278V 8Bpa spp., wa.sps, 468, 488Volhynian fever, S!94, 497VUlpB' 'Vulpe. atlantica, fox, 61WarNes .. treatment, 204, 205Watfhog, 196Wa.ste disposal in armies, 44-48W her beetles, 59, 86gates, 978, 979holes, 216pitchers, 289Weed-tilled bays and lakes. !il77Weep-holes, fJ77Weil's disease, 296Wells, 87Whipworm (see Trich'Um trickitura)Withers, fistulous, 412, 497WOhlfahrtia magnifica, flesh fly. 175. 178,179. 180. 198, 480,485Wolf neplatode (see Spirocerca BtmUlIifwlenta)Wood owl (see Syrnw,m allUJo)Wool blowflies, 181Worms, paraslitic, 5()"'96Worry caused by insects, 20, 91Wound treatment for myiasis,!'.!04Wristlet method of breeding lice, 80SWyoming intermittent fever, 497Xenopsylla cheopia, flea, M, 56, 60, 80, 850,851, 35!'.!, 855, 357, 860, 474, 481, 48b,495,496cleopatrae, flea, 854. 855BcopulifBr, flea, 860, 366Xeranesthesia, 98, 101Xeronochellia, 98, 101Yaws, 119, 199, 497Yellow feyer, 48, 259, 260, !lI62, 497Zero ot' effective temperature, 99Zousfana. 917

ENTOMOLOGY

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