Biopotency and toxicity of diverse group of insecticides under laboratory condition against sunflower defoliator Spilarctia obliqua (Walker)

Abstract

The biopotency and toxicity of two groups, conventional and newer insecticides [eight commercial insecticides] were determined against Bihar or Common hairy caterpillar (BHC) Spilarctia obliqua (Walker). Experiment carried out in the laboratory by exposing BHC larvae to insecticides. Biopotency was measured at different time intervals from 12-72 h after insecticidal application showed that all of the insecticides outperformed the control. At 48 h after imposing, the highest mortality percentage (100) was observed on spinetoram 11.7 SC and chlorfenapyr 10 SC, which are comparable to cyantranaliprole 10.26 OD, followed by chlorantraniliprole 18.5 SC, λ-cyhalothrin 5 EC and chlorpyriphos 20 EC, with the lowest mortality percentage observed on tolfenpyrad 15 EC (66.67 %). In chlorantraniliprole, cyantranaliprole, spinetoram, tolfenpyrad, fipronil, chlorfenapyr, λ-cyhalothrin and chlorpyriphos, respectively, the toxicity level of insecticides was calculated based on median lethal concentration (LC50) values of 0.36, 0.48, 0.52, 0.50, 0.69, 0.98, 1.43 and 3.82 ppm. The overall conclusion of this trial was that spinetoram 11.7 SC and chlorfenapyr10 SC are the best chemicals for controlling the early stages of BHC larvae. In comparison to traditional insecticides, new insecticides have the highest level of toxicity