以辽细辛精油为研究对象,以小菜蛾为靶标害虫,采用叶碟法、试管药膜法、改良的熏蒸盒法、改进的夹毒叶片法等研究了辽细辛精油对小菜蛾3龄幼虫的杀虫活性的影响。结果表明:辽细辛精油对小菜蛾的综合毒杀效果最好,LC50为1 407.7mg/L;其次为触杀作用>熏蒸作用>胃毒作用>麻醉作用;从拒食作用可以看出,辽细辛精油对小菜蛾幼虫的选择性拒食作用强于非选择性拒食作用。说明辽细辛精油对小菜蛾具有较好的杀虫活性,且作用方式多样,可以通过毒杀、触杀、熏蒸、麻醉、拒食等途径作用于害虫,该研究可为小菜蛾的防治和植物源农药的开发提供参考依据。 Loxia asarum essential oil as the research object, the diamondback moth as the target pest, the leaf dish method, the test tube membrane method, the improved fumigation box method, Effects of insecticidal activity on larvae. The results showed that asarum essential oil had the best killing effect on the diamondback moth, the LC50 was 1 407.7 mg / L, followed by contact action, fumigation, stomach toxicity and anesthesia. From the antifeedant effect, The selective antifeedant effect of Xin essential oil on Plutella xylostella larvae was stronger than that of non-selective antifeedant. The results showed that Asarum essential oil had good insecticidal activity against Plutella xylostella and varied in a variety of ways and could act on pests through poison killing, contact killing, fumigation, anesthesia and antifeeding, which could be used for the control of Plutella xylostella and plant sources Pesticide development to provide a reference.