Evaluation of Newer Insecticides for Management of Cotton Mealybug, Phenacoccus solenopsis

In vivo and in vitro experiments were conducted against cotton mealybug, Phenacoccus solenopsis Tinsley (Pseudococcidae: Hemiptera) with a view to have a wide range of potent insecticides to mitigate mealybug population on cotton. In vivo baseline toxicity experiments revealed that the insecticides imidacloprid 17.8 SL and acetamiprid 20 SP recorded highest toxicity against P. solenopsis at 4.8 ppm and 5.6 ppm, respectively. In per cent mortality study, imidacloprid 17.8 SL @ 0.4 ml/l and chlorpyriphos 20 EC @ 4ml/l recorded cent per cent mortality in 72 h after treatment followed by acetamiprid 20 SP @ 0.1 g/l., recorded 97.1 per cent mortality. Foliar application of imidacloprid 17.8 SL @ 0.4 ml/l on cotton registered lower mean population of mealybugs viz., 3.2 and 3.0 per 5 cm apical shoot of cotton plant with 92.7 and 91.7 per cent population reduction and increased the yield of 47.0 and 64.2 per cent in first and second field trials, respectively.