ECTOPARASITES

<strong>ECTOPARASITES</strong>Various arthropods, mainly from the Insect class, are vectors for infectious diseases. When livingon or interacting with the surface of the body, they are called ectoparasites.Examples are:o Hard body ticks (Ixodes) – Lyme disease caused by bacterium Borrelia burgdorferi(Dermacentor) – tularemia caused by bacterium Francisella tularensis,Rocky Mountain spotted fever caused by bacterium Rickettsia rickettsiio Soft body tick (Ornithodoros) – Relapsing fever caused by bacterium Borrelia recurrentiso body louse (Pediculus) – typhus caused by various Rickettsia species, (Pithirus) pubiclouse– STD – the “crabs”o itch mite (Sarcoptes) – sarcoptic mange –STD - “scabies” (not a microbial infection)o mosquito (Anopheles) – malaria caused by many species of the protozoan Plasmodium.(Aedes) – dengue (viral) fever, viral encephalitiso flea (Pulex) – plague caused by Yersinia pestisThese ectoparasite vectors are in the KingdomAnimalia, generally in 2 classes---Insecta andTicks. Ticks and mites are in the Class Arachnida(relative of spiders), while the others are in theClass Insecta. Differences between the InsectsArachnids include presence of wings, main bodyparts, numbers of leg pairs, and presence ofantenna.Arachnida.andPulex (flea) – insect Pediculus (louse) -Insecthard ticks(arachnids)Dept. of Medical Entomology, Univ. of Sydneyhttp://medent.usyd.edu.au/photos/insect%20photos.htmOBJECTIVES:soft tickLearn about various vectors of infectious diseases.Identify representative ectoparasites under the microscope(use common names, not scientific names)Fall 2011 – Jackie Reynolds, Richland CollegeMATERIALS NEEDED:

prepared slides of ectoparasitesflea louse tick (hard bodied and soft bodied)bedbug mosquito head miteTHE PROCEDURES:View various prepared slides using the low power of stereoscopic microscopes.LABORATORY REPORT SHEETQUESTIONS:1. Record the views of the various parasites (on low power magnification)flealousebedbugtickmite2. How many leg pairs does the Class Arachnid have compared to the class Insecta?3. How does the body plan of Insects differ from Arachnids based on major divisions?4. Why is malaria not common in the United States?