阿维菌素与杀铃脲对舞毒蛾幼虫的联合作用机制

Synergy Mechanism of Abamectin and Triflumuron on Lymantria dispar Larvae

【目的】通过舞毒蛾幼虫解毒酶活力、保护酶活力测定,研究阿维菌素和杀铃脲对舞毒蛾幼虫的联合作用机制,为上述2种农药的混用提供理论依据。【方法】人工饲料中添加不等量的9 000μg·mL^(-1)阿维菌素丙酮溶液和25 000μg·mL^(-1)杀铃脲丙酮溶液,分别配制成含有阿维菌素、杀铃脲的单剂和复合剂混毒饲料。饲料中药剂含量:低浓度处理组单剂阿维菌素0.50μg·g^(-1),单剂杀铃脲8.30μg·g^(-1),复合剂阿维菌素0.50μg·g^(-1)、杀铃脲8.30μg·g^(-1);高浓度处理组单剂阿维菌素1.10μg·g^(-1),单剂杀铃脲16.60μg·g^(-1),复合剂阿维菌素1.10μg·g^(-1)、杀铃脲16.60μg·g^(-1)。采用含毒饲料处理3龄舞毒蛾幼虫,24 h后统计幼虫死亡率,测定存活幼虫解毒酶CarE和GST活力以及保护酶SOD、POD、CAT和PPO活力。【结果】对照组、阿维菌素和杀铃脲单剂处理时舞毒蛾幼虫死亡率为0,低浓度复合剂处理的舞毒蛾幼虫死亡率为1.15%,与对照组、单剂处理组无显著差异;高浓度复合剂处理的舞毒蛾幼虫死亡率为4.11%,与对照组、单剂处理组有显著差异。阿维菌素和杀铃脲单剂处理、复合剂处理的幼虫CarE和GST活力均高于对照组;阿维菌素和杀铃脲单剂处理时,幼虫CarE和GST活力显著高于对照组,复合剂处理与对照组无显著差异。阿维菌素和杀铃脲单剂处理及复合剂处理时,幼虫SOD、CAT和PPO活力均高于对照组,而POD活力均低于对照组;复合剂处理SOD、POD和CAT活力均高于单剂处理,而复合剂处理PPO活力则均低于单剂处理。【结论】阿维菌素和杀铃脲联合作用主要是通过抑制舞毒蛾幼虫解毒酶CarE和GST活力,再辅以抑制保护酶PPO活力,从而提高毒杀效果。

【Objective】The combined use of abamectin and triflumuron has synergistic effect on the control of gypsy moths,but the synergy mechanism of abamectin and triflumuron is still unknown.In order to clarify the synergy mechanism of abamectin and triflumuron,3rd-instar Lymantria dispar larvae were treated with abamectin and triflumuron alone or their combination,and then the activities of detoxification enzymes and protective enzymes were determined,which would provide theoretical basis for the mixture use of the two pesticides.【Method】Abamectin acetone solution of9000μg·mL^-1or triflumuron acetone solution of25000μg·mL^-1,and the two combination were added to the artificial diet for preparation of poisonous feed for L.dispar larvae.In a low concentration group,the content of drugs was0.50^μg·g^-1abamectin or8.30^μg·g^-1triflumuron in single pesticide treatment group,and0.50^μg·g^-1abamectin plus8.30μg·g-1triflumuron in mixed pesticide group.In a high concentration group,the content of drugs was1.10^μg·g^-1abamectin or16.60^μg·g^-1triflumuron in single pesticide treatment group,and1.10^μg·g^-1abamectin plus16.60^μg·g^-1triflumuron in mixed pesticide group.The third instar L.dispar larvae were fed with the poisonous artificial diet for 24h.Survivors were counted following activity determinations of detoxification enzyme and protective enzyme.【Result】Mortality analysis showed that all larvae of the control group,single abamectin treatment,and single triflumuron treatment survived from this experiment.The mortality of mixed pesticide treatment group was1.15%at a low concentration,and 4.11%at a high concentration.There was no significant difference between low concentration group and control,but there was significant difference between the high concentration group and control.Detoxification enzyme activities analysis showed that the activities of CarE and GST of larvae treated with abamectin or triflumuron were significantly higher than those of the control group,while there were no significant differences in the enzymes activities between the mixed pesticide treatment and the control group.Protective enzyme activities assay showed that activities of SOD,CAT and PPO of larvae treated with abamectin,triflumuron,and the two combination were higher than those of control group,however POD activities of treated larvae were lower than that of the control.Meanwhile,activities of SOD,POD and CAT of larvae treated with the mixed pesticides were higher than that treated with either single pesticide,while the case for PPO activity was opposite.【Conclusion】It is concluded that the combined effect of abamectin and triflumuron on Lymantria dispar larvae is mainly through inhibiting the activity of the detoxifying enzymes CarE and GST,and supplemented by inhibiting the activities of protective enzymes PPO,so as to improve the toxicity effect.