Bioassay Studies for Testing Toxicity of Novel Insecticides against Helicoverpa armigera (H.)

Bioassay studies were conducted in the Department of Entomology, College of Agriculture, Rajendranagar, Hyderabad to determine the relative toxicity of selected novel insecticides viz., chlorfluazuron, chlorantraniliprole, spinetoram, indoxacarb, emamectin benzoate and spinosad against second instar larvae of H.armigera by topical application, residue method and surface diet method. The data on the toxicity of insecticides to H. armigera, clearly indicated that among the six insecticides tested against the second instar, irrespective of the method of application, spinetoram, indoxacarb and spinosad showed greater toxicity compared to chlorfluazuron, chlorantraniliprole and emamectin benzoate. While in the latter three insecticides, the toxicity to H. armigera was comparatively higher in topical application than other methods although in case of emamectin benzoate it was almost similar with surface diet method.