关键词: 小菜蛾, 辣椒碱, 产卵忌避作用, 拒食作用, 谷胱甘肽-S-转移酶, Na+, K+-ATP酶

Abstract: The repellent activity of capsaicin against Plutella xylostella, and the effects of capsaicin on activities of glutathione-S-transferase and Na⁺, K⁺-ATPase in the 3rd instar larvae of the moth were tested in the laboratory with conventional methods. The results showed that capsaicin had strong oviposition deterrence and antifeedant activity against P. xylostella. At a concentration of 6.25×10⁴ mg/L, the nonselective oviposition deterrence rate was 96.55% 24 h after capsaicin application, while the selective oviposition deterrence rate was 84.30%. At the same concentration, the nonselective antifeedant rate and selective antifeedant rate was 81.47% and 69.69% respectively 48 h after capsaicin application. In addition, glutathione-S-transferase and Na⁺, K⁺-ATPase activities fluctuated after P. xylostella was treated with capsaicin for different hours. When P. xylostella was treated with 1.25×10⁵ mg/L capsaicin, the highest GSTs and ATPase activities were found at 18 h and 1 h after treatment, respectively. These results suggested that capsaicin can disturb the oviposition and feeding of the moth, and influence some enzymes in its body.

Key words: Plutella xylostella, capsaicin, oviposition deterrence, antifeedant activity, glutathione-S-transferase, Na+, K+-ATPase