萜类化合物对小菜蛾幼虫的拒食活性

采用叶碟浸液法测试从松节油合成的26个不同结构萜类化合物样品对小菜蛾Plutella xylostella(L.)4龄幼虫的拒食活性。结果显示,编号为2,4,8,13,27,31的6个化合物,即诺卜醇、诺卜丙基醚、内型异莰烷基甲醇丙酸酯、4-(1-甲基乙烯基)-1-环己烯-1-乙醇丙酸酯、羟基香茅醛丙酸酯、羟基香茅醛1,2-丙二醇缩醛具有较高的拒食活性。处理有效成分为0.01g/mL时,这6个化合物24h拒食率为70%～100%。其中2,4,8号3个化合物拒食活性最高,处理有效成分为0.01g/mL和0.001g/mL时,24h拒食率分别为98.33%,99.80%,100.00%和85.60%,83.90%,66.97%;并且持效性较好,72h拒食率分别为92.67%,89.97%,98.73%和63.20%,63.30%,45.93%。

Antifeedant activity of terpene compounds against larvae of the diamondback moth, Plutella xylostella

The antifeedant activities of twenty six terpene compounds synthesized from turpentine were tested with 4th instar larvae of diamond back moth,Plutella xylostella(L.),using dipped cabbage discs.Six of these compounds,numbered 2,4,8,13,27 and 31,namely nopol,nopyl propyl ether,endo-isocamphanyl methanol propionate,4-(1-methyl ethylene)-1-cyclohexenyl-1-ethol propionate,hydroxycitronellal propionate and hydroxycitronellal 1,2-propanediol acetal,showed rather high antifeedant activity,and compound 2,4 and 8 displayed the highest.Compounds 2,4 and 8 held 98.33%,99.80% and 100.00% antifeedant rate respectively 24 hours later,and 92.67%,89.97% and 98.73% 72 hours later when the leaf discs were treated at the dosage of 0.01 g/mL.While the dosage was 0.001 g/mL,the antifeedant rates were 85.60%,83.90% and 66.97% 24 hours later,and 63.20%,63.30% and 45.93% 72 hours later respectively.The results also showed that the antifeedant activity went high with the dosage increase,down with the time going.