Study on the Screening of Optimum Toxicity Ratio of Azadirachtin and Imidacloprid against Uroleucon gobonis(Matsumura) and Their Field Control Effects

[Objective] The aim was to explore the optimum ratio and control effect of azadirachtin and imidacloprid against Uroleucon gobonis.[Method] The synergism of mixed ligand of azadirachtin and imidacloprid against U.gobonis and their optimum ratio were studied by leaf immersion.[Result] The toxicity indoor result showed that the synergism of mixed ligand of azadirachtin and imidacloprid against U.gobonis was obvious.When the ratio of azadirachtin and imidacloprid was 104∶1 according to effective components,the synergism of the mixed ligand was more obvious,and then the co-toxicity coefficient reached 142.179 3.Field test result showed that 10% imidacloprid WP diluted 2 000 times had efficient and fast effect on U.gobonis,and its control effect exceeded 91% in 1 d and that exceeded 94% in 7d.The control effect of 0.32% azadirachtin EC diluted 500 times was lower and its control effect reached 75.13% in 7 d,but when it was mixed with imidacloprid according to 104∶1 of effective component,the control effect of mixed ligand diluted 600 and 800 times exceeded 97% in 7 d.[Conclusion] The research provided basis for establishment of harmless integrated management technology for U.gobonis.