Ecological life table and relative toxicity of insecticides against leaf eating caterpillar, Spodoptera litura Fab. on groundnut

The life table and key mortality factors of Spodoptera litura Fabricius revealed that the mortality in the younger group larvae was 1.56 per cent due to bacterial infection and unknown reasons. Mortality in the older group larvae was 19.8 per cent due to diseases like NPV, N. rileyi, B. bassiana and parasites like Cotesia spp., and Tachinid maggot. Mortality in the pupal and adult stage was 7.98 & 2.15 per cent due to NPV and unknown reasons, respectively. Generation survival (SG) was worked out and it was 0.70. Value of trend index (I) was calculated to the tune of 0.018. Comparative relative toxicity of some modern insecticides against S. litura revealed that Emamectin benzoate was the most toxic and effective insecticide as its LC₅₀ value was 0.000954, however, Spinosad was found to be the least toxic in which the LC₅₀ value was worked out to the tune of 0.0158 in comparision to Chlorpyriphos, Flubendiamide, Rynaxypyr and Novaluron.