Study on the synergistic mechanism of mixture of chlorpyrifos and emamectin benzoate.

The synergistic mechanism of a mixture of chlorpyrifos and emamectin benzoate on the larvae of brown rice planthopper(Nilapavata lugens) was studied by the analysis of interaction between chlorpyrifos and emamectin benzoate on target and Detoxicating enzyme.The result showed that the joint action of chlorpyrifos and emamectin benzoate to acety1cholinesterase(AChE),carboxy1esterase(CarE) and Glutathione-S-ransferase were stronger than independence.Taking chlorpyrifos as standard,the relative toxicity of emamectin benzoate were 0.76,1.52 and 0.75 to AChE,CarE,and Glutathione-S-ransferase respectively.However,the joint relativetoxicity of emamectin benzoate and chlorpyrifos were 10.41,11.68 and 7.28.Graphic analysis on the toxicokinetic mode of action on the acety1cholinesterase of joint treatment indicated that the mixture of chlorpyrifos and emamectin benzoate inhibited the enzyme competitively