Safety evaluation of natural products and insecticides to Encarsia formosa Gahan, an endoparasitoid of Trialeurodes vaporariorum Westwood

Abstract Encarsia formosa Gahan (Hymenoptera: Aphelinidae) is one of the most efficacious natural enemies used as biological control against Trialeurodes vaporariorum Westwood. Insecticides have a negative impact on non-target species such as natural enemies. Therefore, present studies were conducted to evaluate cattle bye-products based natural products namely, Agniastra, Darekastra, fermented butter milk, Tamralassi and vermiwash at 10%, biopesticide (azadirachtin @ 0.00045%) and chemical insecticides, spiromesifen (0.02%) and imidacloprid (0.005%) for the safety to adults of E. formosa. Dry film method of bioassay was deployed under laboratory conditions. Results revealed that Agniastra, Darekastra, fermented butter milk, Tamralassi, vermiwash and azadirachtin resulted in 23.15, 13.66, 17.36, 15.74, 15.74 and 30.22% adult mortality, respectively being harmless, whereas, spiromesifen and imidacloprid resulted in 53.27 and 58.83% mortality, respectively being slightly harmful to E. formosa.