Encarsia

Encarsia is undoubtedly the most successful genus of whitefly natural enemies, followed closely probably by Eretmocerus. Against diaspidid scales it is probably second only to Aphytis in terms of its effectiveness. Many species of Encarsia have been used in successful biological control projects for both whiteflies (Aleyrodidae) and armoured scale insects (Diaspididae).Important SpeciesE. auranti is virtually cosmopolitan, and known from all continents. Highly polyphagous, recorded from more than 50 Diaspididae hosts, E. aurantii is one of the best-known and most distinctive of the diaspidid parasitoids. It has been recorded from many species including: Aonidiella aurantii, Aonidiella orientalis, Chrysomphalus aonidium, Hemiberlesia lataniae and Quadraspidiotus perniciosus.E. berlesei is a widespread parasitoid, most commonly recorded from the white peach scale, Pseudaulacaspis pentagona. It has been used commonly for biological control of this pest (Clausen, 1978), as has its close relative E. diaspidicola. Both species belong to a larger group of very closely related and morphologically extremely similar species.E. citrina (=Aspidiotiphagus citrinus) is a cosmopolitan parasitoid attacking a very wide range of hosts. It can be distinguished from its close relative E. lounsburyi using the key by Compere (1936).E. clypealis is a widespread parasitoid of Aleurocanthus woglumi (citrus blackfly), and has been introduced into much of its present distribution as a biological control agent of this pest. It also attacks other species of aleyrodids, including Aleurocanthus spiniferus, the spiny blackfly (Clausen, 1978).E. elongata is a widespread parasitoid of Lepidosaphes gloverii, and has been used several times in the biocontrol of this pest.E. formosa is the best known biological control agent of aleyrodids, having been introduced virtually worldwide, in particular into glasshouses against Trialeurodes vaporariorum, the greenhouse whitefly. Alternative hosts include Aleuroglandulus malangae, Aleurotrachelus trachoides, Aleyrodes lonicerae, A. proletella, A. spiraeoides, Bemisia tabaci complex, Dialeurodes chittendeni and D. citri (Polaszek et al., 1992).E. guadeloupae is a widespread parasitoid of spiralling whitefly, Aleurodicus dispersus, and is found so far wherever this currently invasive species occurs, including the Caribbean, Hawaii, South-East Asia and West Africa. It is often found together with the species currently known as Encarsia sp. nr haitiensis.E. hispida is widespread in Central and South America, and exists as thelytokous populations in Western Europe. It is most commonly recorded from the Bemisia tabaci complex (Polaszek et al., 1992).E. inaron (=E. partenopea) is an originally Palaearctic species which also now occurs commonly in South America, and was recently successfully introduced into North America (Gould et al., 1992) against Siphoninus phillyreae (ash whitefly), though it also commonly attacks the Bemisia tabaci complex. E. inaron has many alternative hosts, including Acaudaleyrodes citri, Aleyrodes lonicerae, A. proletella, A. singularis, Asterobemisia carpini, A. paveli, Bulgarialeurodes cotesii, Siphoninus immaculatus and Trialeurodes vaporariorum (Polaszek et al., 1992; Manzari et al., 2002). Published records from Coccoidea, for example Eulecanium coryli; Lepidosaphes ulmi; are almost certainly based on misidentifcations.E. lahorensis has been widely and successfully used as a biocontrol agent of citrus whitefly, Dialeurodes citri. Originating in India, it has been introduced widely into the USA and southern Europe (Viggiani and Battaglia, 1983; Nguyen and Hamon, 1985).E. lutea is a virtually cosmopolitan species, having been introduced, perhaps accidentally, into the New World. It is most commonly reared from species of the Bemisia tabaci complex, but also attacks a wide range of aleyrodid hosts (Polaszek et al., 1992). E. lutea is known from more than 60 whitefly hosts, but was recorded in error from eggs of Lepidoptera (misidentification of Encarsia sp. near porteri).E. luteola (=E. angelica, E. deserti) is probably the most widespread parasitoid of the Bemisia tabaci complex occurring in North America (Polaszek et al., 1992; Schauff et al., 1996).E. nigricephala is one of the more common parasitoids of the Bemisia tabaci complex occurring mainly in the Neotropical region, with an anomalous record from Réunion. It is a distinctive, easily recognized species (Polaszek et al., 1992; Schauff et al., 1996).E. pergandiella is a very common, widespread species, probably originating in the New World, but now common also in Europe and recorded from Hawaii.E. perniciosi is best known as a widespread parasitoid of Quadraspidiotus perniciosus and has been used in biological control. It is also frequently recorded from Aonidiella aurantii.E. porteri is a central and south American species which is of considerable interest as the females are commonly recorded as primary parasitoids of whiteflies, in particular of the Bemisia tabaci complex, while the males of E. porteri develop as obligate parasitoids in the eggs of Lepidoptera (Polaszek et al., 1995; Williams and Polaszek, 1996).E. smithi is most commonly recorded from the citrus pests Aleurocanthus spiniferus and A. woglumi, and has been used repeatedly as a biological control agent of these pests (Clausen, 1978). E. smithi is almost certainly a complex of closely related, but biologically distinct, species.E. sophia is possibly the most common Encarsia species associated with the Bemisia tabaci complex in the Old World (especially common in Africa), though also occurring in North and South America. It has a broad host range given by Polaszek et al. (1992). Recent studies strongly suggest the existence of a species-complex within E. sophia. Records from non-whitefly hosts probably all represent hyperparasitic male development.E. strenua: many published records of E. strenua, particularly from the 1990s, are based on misidentifications of E. protransvena. See Heraty and Polaszek, 2000, for a correct interpretation of E. strenua and related species.E. tabacivora was synonymised with E. pergandiella by Polaszek et al. (1992) although unpublished studies by Johnson and Woolley (Texas A and M University) suggest that they are distinct.E. tristis is invariably associated with the sorghum and sugarcane pest Neomaskellia bergii and is widespread in India and South-East Asia.