Field evaluation of recommended insecticides to control bollworms on cotton aphid, Aphis gossypii glover and their side effect on associated predators

Cotton aphid, Aphis gossypii appears as serious late season pest of cotton causing severe losses in quality and quantity of lint Field experiments were conducted at Sakha Agriculture Research Station, Egypt in 2009 and 2010 seasons to evaluate the efficacy of six recommended insecticides to control bollwoms, i.e. larnbda-cyhalothrin, alphacypermethrin, deltamethrin, methomyl, profenofos and chlorpyrifos and two aphicides, i.e. thiamethoxaxn and imidacloprid at their recommended rates against A. gossypii. Side effect on associated predators was also studied. Obtained results indicated that methomyl, profenofos and chlorpyHfos proved to be very effective against aphid causing percent reduction ranged from 83.74 to 98.06 % in 2009 and from 85.57 to 94.17 % in 2010 season. The two aphicides; thiamethoxam and imidacloprid caused 93.60 % and 95.00 % reduction in 2009 season and 94.24 % and 95.32 % in 2010 season. The pyrethroid insecticides showed unpersuasive aphid control. Regarding the side effect on associated predators, with exception of thiamethoxam and imidacloprid, all the rest evaluated insecticides were ultimately toxic to the predators recording from 82.89 to 94.80 % reduction in 2009 season and from 82.76 to 92.78 % reduction in 2010 season. The two aphicides were the least toxic causing less than 50 % reduction in the two seasons of study.