author(s)
Virendra Kumar and Swarnali Bhattacharya

abstract
The investigations on the field efficacy of some newer pesticide molecules and their combination products against major insect pests of groundnut were undertaken during the pre-summer season of 2016 on groundnut at the agricultural research farm, Institute of Agriculture, Visva-Bharati, Birbhum, West Bengal. The efficacy of seven insecticides viz; Imidacloprid 17.8% SL, Diafenthiuron 50%WP, Diflubenzuron 25%WP, Acephate 50% + imidacloprid 1.8% SP, Lambda Cyhalothrin 5% EC, Quinalphos 25% EC and Chlorpyriphos 20% EC were tested against groundnut aphid. The results of the experiments suggested that all the insecticidal treatments imposed were superior over the untreated check. The infestation of aphid (Aphis craccivora) was observed at early growth phase till the flowering phase of the crop growth. Among the seven insecticides tested, Imidacloprid 17.8% SL (0.02% a.i.) and Diafenthiuron 50%WP (600g a.i./ha) were found to be the most effective recording highest per cent reduction in aphid population as 88% and 86% reduction respectively after 10 days of spray. The efficacy of other insecticidal treatments were in the order of Lambda Cyhalothrin 5% EC (@300ml/ha>Acephate 50% + imidacloprid 1.8% SP (@1000g/ha) >Chlorpyriphos 20% EC >Diflubenzuron 25%WP (@ 300g/ha) >Quinalphos 25% EC.