不同种类植物提取物对小菜蛾的拒食活性

摘要

The antifeedant activities of the methanol extracts of 10 plants against 3rd instar P.xrylostella were determined by leaf-dipping method in laboratory in order to seek new insecticidal plants.The results showed that the methanol extracts from Terastrocmia gymnanthera,Gordonia acuminate,Tutcheria brach ycarpa,Tutcheria hirta,Eurya chinensis had high antifeedant activity against 3ra instar P.xylostella.Their 48 h antifeedant rates were more than 70％ when the concentration reached 10 g/L.The methanol extracts from T.gyrnnanthera had the highest antifeedant activity,the antifeedant rates of 48 h was 81.48％.Secondly,they were G.acuminate(77.250％),T.brachycarpa(74.99％),T.hirta(70.52％),E.chinensis (70.51％).The other five plants had low antifeedant activities,with the antifeedant rates being below 60％.%为寻求活性较高的新的杀虫植物,采用小叶碟添加法,室内测定了10种山茶科植物甲醇提取物对小菜蛾3龄幼虫的拒食活性.结果表明:10种山荼科植物甲醇提取物在10 g/L浓度下,厚皮香、四川大头茶、短果石笔木、粗毛石笔木和米碎花48 h拒食率均大于70％.其中,厚皮香甲醇提取物对小菜蛾3龄幼虫的拒食活性最高,为81.48％00；其次是四川大头茶,为77.25％；短果石笔木、粗毛石笔木和米碎花分别为74.99％ 、70.52％和70.51％;其余5种植物甲醇提取物对小菜蛾3龄幼虫的拒食活性较低,拒食率均在60％以下.