TOXIC AND RESIDUAL ACTIVITIES OF SELECTED INSECTICIDES AND NEEM OIL AGAINST COTTON MEALYBUG, PHENACOCCUS SOLENOPSIS TINSLEY (STERNORRHYNCHA: PSEUDOCOCCIDAE) UNDER LABORATORY AND FIELD CONDITIONS

Laboratory and field studies were carried out during Kharif 2009-10 and 2010-11 to evaluate the efficacy of Commando (97% DF), Confidor (20% SL), Lannate (40% SP), Actara (25 WG) at field recommended doses and neem oil at 1.5 and 2.0% concentrations against cotton mealybug, Phenacoccus solenopsis on cotton. Under laboratory environment Commando at recommended dose resulted into 95.2% mortality of the 2nd instar nymphs of P. solenopsis 72 hours after exposure period. Commando, under laboratory and field conditions, was found not only more toxic but also persisted longer in its efficacy than the rest of the trialed insecticides. Under field conditions, Commando caused 80.6% mortality of the mealybug that was significantly higher than that caused by Confidor (73.29%), Lannate (70.93%), Actara (74.36%) and neem oil @ 1.5% (43.48%) and 2.0% (52.97%) concentration. Neem oil at both concentrations was less toxic than the rest of the synthetic insecticides; however, it significantly reduced the population of mealybug and remained effective up to more than 72 hours at both concentrations.