Field Efficiency of Certain Neonicotinoids Alone and Their Mixtures With Chlorpyrifos Against, Aphis gossypii, Bemisia tabaci and Their Predators Coccinella septempunctata and Chrysoperla carnea

Cotton aphid, Aphisgossypii and whiteflies, Bemisia tabaci are an important pests incotton plants in Egypt.The present work was conducted during two successive seasons 2014 and 2015 in Beni- suef Governorate on the cotton crop by spraying the tested insecticidesalone and mixtures of both acetamipridand thiamethoxam with chloropyrifos to estimate the percentage of reduction of Aphisgossypii and Bemisia tabaci and their associated predators, Coccinella septempunctataand Chrysoperlacarnea,after different intervals which include (24 hours) to estimate theimmediate effect, as well as after 3 ,7 and 14 days to evaluate the latenteffect. Results indicated that acetamiprid, thiamethoxam and chloropyrifosalone proved to reduce Aphis gossypii and Bemisia tabaci populations up to 14days after treatment throughout both seasons. Whereas, combination ofacetamiprid and thiamethoxam with chloropyrifos at half recommended rate showedthe high efficiency with reduction percentage reached to 100.0% at same exposuretime during the successive seasons 2014 and 2015. In addition, acetamiprid,thiamethoxam and chloropyrifos proved the high reduction percent to thepopulations of Coccinella septempunctata and C. carnea when these insecticides were usedalone at recommended rate at 24h from treatments. Chlorpyrifos in mixtures with both acetamiprid, and thiamethoxam athalf recommended rate showed the high effect with reduction percentage reachedto 100.0% reductions for both predators in two seasons. Results suggested that,choosing suitable insecticide to control the tested cotton pests not onlydepends on its efficiency but also its toxicity tonatural enemies. Also, these results indicatedthat the initial kill and residual effect of these insecticides washighly persistent up to 14 days. The overall results appeared promising incombination with insecticides as result of significant increasing its reductionpercent.