EVALUATION OF INSECTICIDES AGAINST FIRST AND THIRD INSTAR NYMPHS OF MEALY BUG, Phenacoccus solenopsis TINSLEY UNDER LABORATORY CONDITION ON Bt COTTON

摘要

In laboratory experiment, among ten insecticidal treatments, against the first instar nymphs of P. solenopsis the maximum mortality was obtained when nymphs were treated with profenophos 0.05 per cent and imidachloprid 0.005 per cent were recorded 99.49 per cent mortality within 48 hours of its application then the rest of treatment. The insecticidal application of triazophos 0.04, thiamethoxam 0.01, acephate 0.075 and dimethoate 0.03 per cent was recorded viz., 99.49, 95.18, 89.96, 98.96 per cent mortality, respectively and found as effective against P. solenopsis within 72 hours of treatment. In case of the third instar nymph of mealy bug, P. solenopsis was observed that the profenophos 0.05 per cent was found superior and gave 83.61 percent mortality within 48 hours of its application. The insecticidal application acephate 0.075, triazophos 0.04, imidachloprid 0.005 and thiodicarb 0.03 percent was recorded viz., 83.62,79.97, 76.78 and 76.78 per cent mortality, respectively against P. solenopsisafter 72 hours of application.