土荆芥精油对5种杀虫剂毒力的影响

Effect of essential oil from Chenopodium ambrosioides L.on toxicity of five insecticides

【目的】研究土荆芥精油对5种杀虫剂毒力的影响,为合理开发利用杂草资源研发环保农药助剂,进而促进害虫持续控制提供依据。【方法】以小菜蛾幼虫为供试昆虫,采用微量点滴法、浸叶法和夹毒法分别测定不同用量土荆芥精油对5种杀虫剂触杀和胃毒作用的影响。【结果】土荆芥精油对敌百虫、氟虫腈和甲氨基阿维菌素苯甲酸盐的触杀毒力表现出较好的增效作用;10 mg/g土荆芥精油对联苯菊酯增效作用最好,增效比可达9.13,而30 mg/g土荆芥精油对联苯菊酯则表现为拮抗作用;土荆芥精油对灭多威均表现为拮抗作用。夹毒法毒力测定结果表明,土荆芥精油对灭多威、氟虫腈、联苯菊酯的胃毒毒力均表现出较好的增效作用;对甲氨基阿维菌素苯甲酸盐和敌百虫均表现为拮抗作用。浸叶法毒力测定结果表明,土荆芥精油对氟虫腈、联苯菊酯、甲氨基阿维菌素苯甲酸盐和敌百虫胃毒毒力均表现出很好的增效作用,对灭多威表现出拮抗作用。【结论】土荆芥精油对氟虫腈和联苯菊酯(10 mg/g土荆芥精油)均有良好的增效作用,可显著增加其杀虫毒力,是提高杀虫剂药效的优选助剂。

【Objective】This study investigated the effects of essential oil of Chenopodium ambrosioides L.on toxicity of five insecticides to provide basis for rational development and utilization of weed resources to develop environmental protection pesticide additives and promote sustainable pest control.【Method】Using Plutella xylostella larvae as experimental insects,the effects of different concentrations of C.ambrosioides essential oil on contact and stomach toxicity of five insecticides were determined by microdrop method,leaf-dip method and leaf-sandwich method.【Result】The essential oil of C.ambrosioides had good synergistic effects on contact toxicity of trichlorfon,fipronil,and emamectin benzoate.The synergistic effect on low concentration of bifenthrin(10 mg/g)was the best with synergistic ratio of 9.13.The essential oil also showed antagonistic effect to high concentration of bifenthrin(30 mg/g)and to different concentrations of methomyl.The toxicity assay showed that the essential oil of C.ambrosioides had good synergistic effect on stomach toxicity of methomyl,fipronil and bifenthrin by leaf-sandwich bioassay.The essential oil of C.ambrosioides showed antagonistic effect on emamectin benzoate and trichlorfon.The leaf-dip bioassay showed that the essential oil of C.ambrosioides had good synergistic effect on fipronil,bifenthrin,emamectin benzoate and trichlorfon,but certain antagonistic effect on methomyl.【Conclusion】The essential oil of C.ambrosioides showed good synergistic effects on fipronil and trichlorfon for control of diamondback moth,which could significantly increase the efficacy of insecticides as preferred additive.