联苯肼酯与毒死蜱对二斑叶螨联合毒力

Co-toxicity of Bifenazate and Chlorpyrifos to the Two-spotted Spider Mite(Tetranychus urticae Koch)

【目的】寻找控制二斑叶螨的药剂，延缓对联苯肼酯抗性的产生。【方法】采用玻片浸渍法研究了联苯肼酯与毒死蜱对二斑叶螨的联合毒力。[结果]联苯肼酯的毒力明显高于毒死蜱，24、48、72h的LC50值分别为10．9277、5．1543、3．3894mg／L，毒死蜱LC50值分别为433．2953、206．7985、69．0944mg／L。两药剂混用时，在1：1-1：80混配范围内具有增效作用，以1：1比例混配增效作用最明显；随着毒死蜱用药量的提高，共毒系数呈现下降趋势。【结论】联苯肼酯与毒死蜱混用对二斑叶螨具有明显的增效作用。

[Aims] This study aims to find effective acaricides to the two-spotted spider mite Tetranychus urticae. [Methods] Co-toxicity of the bifenazate and chlorpyrifos was tested using slide-dip method. [Results] The results showed that the bifenazate had higher toxicity to two-spotted mite than chlorpyrifos. The LC50 values of the bifenazate at 24, 48 and 72 hours after treatment were 10.927 7, 5.154 3 and 3.389 4 mg/L, respectively, while those of chlorpyrifos were 433.295 3, 206.798 5 and 69.0944 mg/L, respectively. When the bifenazate and chlorpyrifos were mixed, they showed an addition of toxicity with a mixing ratio of 1 ： 1 to 1 ： 80 （bifenazate ： chlorpyrifos）. The highest co-toxicity coefficient was present at the ratio of 1 ： 1, the co-toxicity coefficient decreased with the increasing of the propertion of chlorpyrifos. [Conclusions] There is synergism of toxicity between bifenazate and chlorpyrifos on the two-spotted spider mite.