author(s)
VN Tidke, US Kulkarni and SR More

abstract
The present investigations on “Screening of insecticides against fall armyworm, Spodoptera frugiperda (J. E. Smith)” were conducted in the toxicology laboratory of Department of Entomology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, and Akola (M.S.) during the year 2019-20. The insecticides used as a treatments included, Thiamethoxam 12.6% ZC + Lambda cyhalothrin 9.5% ZC, Chlorantraniliprole 10% + Lambda cyhalothrin 5% ZC, Pyriproxyfen 5% EC + Fenpropathrin 15% EC, Beta cyfluthrin 90 + Imidacloprid 210 OD, Spinetorum 11.7% SC and Quinalphos 20% EC + Cypermethrin 3% EC along with untreated control. For mass rearing of fall armyworm, S. frugiperda method described by Sisay et al. (2019) was followed with slight modifications with respect to rearing materials and food. The results on relative toxicity studies at LC₅₀ values revealed that Spinetorum 11.7% SC is highly toxic to the third instar larvae of S. frugiperda than rest of the other insecticides tested. At LC₅₀ level the results on relative toxicities of six insecticides can be summarized in decreasing order of toxicities as [Spinetorum 11.7% SC] > [Chlorantraniliprole 10% + Lambda cyhalothrin 5% ZC] > [Pyriproxyfen 5% EC + Fenpropathrin 15% EC] > [Beta cyfluthrin 90 + Imidacloprid 210 OD] > [Quinalphos 20% + Cypermethrin 3% EC] > [Thiamethoxam 12.6% ZC + Lambda cyhalothrin 9.5% ZC]. The results on relative toxicity studies at LC₉₀ level revealed that Spinetorum 11.7% SC is highly toxic to the third instar larvae of S. frugiperda than all other insecticides tested. At LC₉₀ level the results on relative toxicities of six insecticides can be summarized in decreasing order of toxicities as [Spinetorum 11.7% SC] > [Chlorantraniliprole 10% + Lambda cyhalothrin 5% ZC] > [Beta cyfluthrin 90 + Imidacloprid 210 OD] > [Quinalphos 20% + Cypermethrin 3% EC] > [Thiamethoxam 12.6% ZC + Lambda cyhalothrin 9.5% ZC] > [Pyriproxyfen 5% EC + Fenpropathrin 15% EC].