Residual toxicity of insecticides against thrips of chilli

Residual toxicity and persistence studies of different insecticides viz., Fipronil 0.5 SC, Imidacloprid 70 SC, Dimethoate 30 SC Spinosad 45 SC, Lambda-cyhalothrin 5 SC, Acephate 75 SP Tolfenpyrad 15 EC, Spinetoram 11.7 SC Chlorantraniliprole 18.50 SC, Broflanilide 300G/L SC, Diafenthiuron 50 WP, Flonicamide 50 WG, Cyantraniliprole 10.50 OD, Spinosad 45 SC, Flubendamide 20 WG, Profenophos 50 EC, Emamectin benzoate 0.5 SG, Novaluron 10 EC in spray schedules were carried out against thrips S. dorsalis and black thrips parvispinus. The entire plant was covered while application of insecticides. The required numbers of leaves receiving application of insecticides were tagged for investigations on residual toxicity of insecticides. The numbers of dead or moribund test insects were counted after 24 h of exposure. Similarly control mortality of test insects were also observed by releasing them on untreated leaves of chilli plant. The values of LT₅₀ (time required to give 50% mortality) for different insecticides applied on chilli plants was calculated by using software of probit analysis. Results showed highest PT and LT₅₀ values in broflanilide 300 G/L SC. Residual toxicity of these insecticides declined with lapse of time and provided prolonged protection up to 14 days.