Encarsia formosa, a parasitoid of greenhouse whiteflies, is one of the first natural enemies being used. It is mainly released to control Trialeurodes vaporariorum but also Bemisia tabaci in horticoltural and ornamental crops.
The adult female is a tiny wasp, 0.6 mm long, with a black and yellow body. Once found a whitefly an egg is inserted within the host body. The host “pupa” changes its colour and turns black (T.vaporariorum) or brown (B.tabaci). After the end of larval development the adult cut a rounded hole to emerge from the host. Encarsia is one of the most reliable natural enemies when conditions are suitable having a very high searching capability. Also the host feeding is very important for the pest control as many host pupae are killed to obtain a food source.
EnPAK can be applied using bottles containing 3000 or 15.000 individuals. Introduction rates vary from 2 to 6 individuals/m2 per week, starting very early in the season as the first whiteflies is detected.