Plutella xylostella has developed resistance to most commercially available insecticides, resulting in an urgent need for novel insecticides. It was found in our previous study that (S)-(-)-palasonin (PLN) has great value in the management of P. xylostella. Extracted from Butea monosperma seeds, (S)-(-)-palasonin has been discovered to have stomach and contact toxicity against P. xylostella larvae. However, it is not clear whether PLN has other modes of action. In this study, (S)-(-)-palasonin had strong stomach and fumigation activity against P. xylostella adults with an LC₅₀ (48 h) values of 50.50 and 16.49 mg/L, respectively. The selective antifeedant rate and non-selective antifeedant rate of (S)-(-)-palasonin at 25 mg/L were 92.86 % and 97.27 % respectively. Normal growth and development of P. xylostella larvae was inhibited by (S)-(-)-palasonin. The larval weight and weight gain were significantly inhibited, the relative growth inhibition rate was increased, and the instar stage was significantly prolonged. The larval survival rate, pupal weight, pupation rate and adult emergence rates were significantly reduced. Wing deformity in P. xylostella adults was observed. And the life span of adults was shortened. These results show that (S)-(-)-palasonin has various modes of action in P. xylostella and can be used as a potential new botanical insecticide for the control of P. xylostella.

Plutella xylostella已对大多数市售杀虫剂产生抗药性，因此迫切需要新型杀虫剂。我们之前的研究发现，(S)-(-)-palasonin (PLN)在小菜蛾的治理中具有很大的价值。从Butea monosperma种子中提取的 (S)-(-)-palasonin 已被发现对P. xylostella幼虫具有胃毒性和接触毒性。但是，尚不清楚 PLN 是否具有其他作用方式。在这项研究中，(S)-(-)-palasonin 对小菜蛾成虫具有很强的胃和熏蒸活性，LC 为₅₀(48 h) 值分别为 50.50 和 16.49 mg/L。25 mg/L(S)-(-)-palasonin的选择性拒食率和非选择性拒食率分别为92.86%和97.27%。(S)-(-)-palasonin 抑制小菜蛾幼虫的正常生长发育。幼虫增重和增重受到显着抑制，相对生长抑制率增加，龄期显着延长。幼虫成活率、蛹重、化蛹率和成虫羽化率均显着降低。观察到小菜蛾成虫的翅膀畸形。成年人的寿命缩短了。这些结果表明 (S)-(-)-palasonin 在小菜蛾中具有多种作用模式可作为一种潜在的新型植物源杀虫剂防治小菜蛾。