Persistent Toxicity of Imidacloprid against Aphid, Aphis Gossypii and Leafhopper, Amrasca Biguttula Biguttula on Cotton

Laboratory studies were made to evaluate the persistent toxicity of imidacloprid (17.8 SL) against aphid, Aphis gossypii Glover and leafhoppers, Amrasca biguttula biguttula (Ishida) attacking cotton (Gossypium hirsutum) cv MCU 7. The results revealed that foliar application of imidacloprid 17.8 SL at 50 g ai ha⁻¹ showed toxicity for 29 and 31 days against aphids and leafhoppers. Imidacloprid 17.8 SL at 25 g ai ha⁻¹ registered persistence up to 25 days for aphids and 29 days for leafhoppers. Imidacloprid 17.8 SL showed longer persistence and was superior to the conventional insecticide methyl demeton, which showed toxicity up to 15 and 17 days, respectively, against aphids and leafhoppers.