Comparative Toxicity of Selected Insecticides against Cotton Aphid, Aphis Gossypii Glover

Experiments were conducted in the laboratory to evaluate relative efficacy of eight insecticides viz, endosullan, deltamethrin, profenofos, trizophos, thiodicarb, imidacloprid, spinosad and thiomethoxam against totton aphid Aphis gossypii Glover. On the basis of LC₅₀ values of insecticides and taking that of thiomethoxam as unity, the order of toxicity of insecticides was deltamethrin > spinosad >imidacloprid > thiodicarb > endosullan > profeeofoo s trizophos with their relative toxicity values being 1.00, 0.20, 0.11, 0.09, 0.06, 0.05 and 0.04, respectively. However, at LC₉₀ it is variable and the order of toxicity is deltamethrin > thiomethoxam > spinosad > imidacloprid > thiodicarb > endosulfan > triazophos > profenofos.