息半夏皮乙醇提取物对小菜蛾的杀虫活性

为探索息半夏皮中的生物活性物质在小菜蛾防治上的应用。采用叶片浸渍法和浸虫法测定息半夏皮干粉95％乙醇提取物对3龄小菜蛾幼虫的拒食活性、触杀活性和胃毒活性。结果显示：在选择性拒食试验中,95%乙醇提取物对试虫24 h和48 h的拒食中浓度(AFC₅₀)分别为30.89 mg/mL和38.71 mg/mL；非选择性拒食试验中,对试虫24 h和48 h的拒食中浓度(AFC₅₀)分别为24.63 mg/mL和6.54 mg/mL；同时,息半夏皮95%乙醇提取物对小菜蛾的触杀和胃毒作用显示,100 mg/mL粗提物72 h对其校正死亡率分别为63.54%和70.2%。息半夏皮乙醇提取物对小菜蛾幼虫的拒食和胃毒作用较为突出。

Insecticidal Activity of the Extract from Pinellia Tuber Peels Against Plutella xylostella

In order to explore the application of the extraction of Pinellia ternate peels in the prevention and control of Plutella xylostella. The bioactive substances of P. ternate peels was extracted by Soxhlet extractor method. The effects of laboratory bioassays of the extract to 3rd instar larva of P. xylostella were investigated by the dipping leaf method and dipping insect method. The results showed thatthe 95% ethanol extract had good insecticidal activity against P. xylostella larvae. In the selective antifeeding experiment, the antifeedant concentration (AFC₅₀) of the extract against the 3^_rd instar larvae at 24 h and 48h was 30.89 mg/mL and 38.71 mg/mL, respectively. In the non-selective antifeedant experiment, AFC₅₀ of the 3^_rd instar larvae at 24 h and 48 h were 24.63 mg/mL and 6.54 mg/mL, respectively. Treatment with 100 mg/mL for 72 h, the extracts also had very strong contact and stomach toxicity against P. xylostella with corrected mortality of 63.54% and 70.2%, respectively. The ethanol extract of Pinellia ternata peel had certain antifeedant effect and good gastric toxicity on P. xylostella.