Co-toxicity of destruxins with chemical pesticides against Frankliniella occodentalis（Pergande）

Toxicity of several insecticides，i.e. emamectin benzoate，imidacloprid，acetamiprid，nitenpyram， spinosad and destruxins against the second instar Frankliniella occodentalis were tested by leaf-dipping method in laboratory，and the optimum combination and proportion were determined by the Horsfall-method and co-toxicity coefficient. The results showed that toxicity order of the insecticides against the second instar F. occodentalis was that destruxins > spinosad > emamectin benzoate > acetamiprid > nitenpyram > imidacloprid. The most obvious synergistic effect was observed in the mixture of emamectin benzoate and destruxins with about 1∶4.