Contact toxicity of synthetic pyrethroids, organophosphorus and carbamate insecticides to adults of the parasiteChelonus blackburniCameron

SUMMARYFour synthetic pyrethroids: fenvalerate, deltamethrin, cypermethrin and permethrin were evaluated as spray deposits on cotton leaves for their contact toxicity to adults of the parasiteChelonus blackburniCameron (Braconidae). Fenvalerate was found to be the least toxic of the four pyrethroids. In another study five organophosphorus insecticides (profenofos, bromophos ethyl, chlorpyrifos, quinalphos, monocrotophos), three carbamates (U.C.51762, carbosulfan, bendiocarb) and diflubenzuron were evaluated for their contact toxicity to the same parasite. U.C.51762 (carbamate group experimental insecticide) and diflubenzuron were less toxic while the five organophosphorus insecticides, carbosulfan and bendiocarb were highly toxic to the parasite.Contact toxicity of spray deposits of four synthetic pyrethroids were studied against parasitization and subsequent development of the parasiteC. blackburnion thin strips of egg cardsCorcyra cephlonicaStainton. It was observed that fenvalerate was not reducing oviposition or affecting subsequent development of the parasite and emergence from the parasitized eggs while the other pyrethroids, permethrin, cypermethrin and deltamethrin, were toxic.