Primary Host Discrimination and Elimination of Supernumeraries in the Facultative Autoparasitoid Encarsia tricolor (Hymenoptera: Aphelinidae)
Artigues, Miquel; Avilla, Jesús; Sarasúa, Maria José; Albajes, Ramon
Primary host discrimination Trialeurodes vaporariorum (Westwood 1856) is examined in the facultative autoparasitoid Encarsia tricolor Forster 1840 during female lifespan at low (5 nymphs per arena) and at high host densities (25 nymphs per arena) and supernumerary elimination ♀♀ of E. tricolor, a solitary endoparasitoid of whiteflies, are able to avoid selfsuperparasitism of the primary hosts during their whole lifespan. This behaviour does not need to be learnt and is shown from their first day of oviposition. Host discrimination is detected at low and high host densities. Supernumerary immature stages are eliminated mainly by physiological suppression of the development of eggs. Sometimes two or more larvae hatched at the same time, but only one successfully develops to pupa.