First record of Encarsia formosa Gahan, an aphelinid parasitoid of greenhouse whitefly from India and its dynamics on tomato grown under protected environment

Abstract

Greenhouse whitefly, Trialeurodes vaporariorum (Westwood) is a key pest of tomato under protected environment in Himachal Pradesh. Recently, an aphelinid parasitoid, Encarsia formosa Gahan was observed to parasitize T. vaporariorum in mid-hill regions of Himachal Pradesh. It seems to be the first record of this aphelinid parasitoid from India. Population buildup of E. formosa was recorded in eight insecticide based greenhouse whitefly management modules comprising soil application of imidacloprid (0.009%) and foliar applications of spiromesifen (0.02%), thiamethoxam (0.01%) and azadirachtin (0.0003%) in tomato grown during summer cropping seasons of 2015 and 2016 under naturally ventilated polyhouse. Parasitization by E. formosa in the plants without treatment varied from 31.8 to 81.2 and 36.8 to 93.6 per cent during 2015 and 2016, respectively. The insecticidal module comprising single soil application of imidacloprid one day after transplanting followed by alternate foliar applications of azadirachtin starting 45 days after transplanting at 10 days interval proved favourable for buildup of E. formosa as compared to other insecticide based greenhouse whitefly management modules during both the seasons. Based on the observations recorded, it was observed that the parasitoid has the potential for inclusion in greenhouse whitefly management programme.