18种中草药提取物对褐飞虱和甜菜夜蛾的杀虫活性分析

为了筛选对农产品和环境安全、对害虫高效的植物源杀虫剂，分别采用喷雾法和饲毒法，测定了18种中草药的3种溶剂（水、乙醇、石油醚）提取物对褐飞虱Nilaparvata lugens Stål的触杀活性和对甜菜夜蛾Spodoptera exigua Hübner的胃毒作用。结果表明，各种提取物（0.8 g/mL）对甜菜夜蛾的胃毒作用不明显，校正死亡率最高为33.33%；但对褐飞虱的杀虫活性较高，其中百部、黄柏、榧子、生山栀、鹤虱、木香的乙醇或石油醚提取物，对褐飞虱3龄若虫的24 h校正死亡率均在80%以上，其石油乙醚提取物的LC50值依次为：0.0826，0.0455，0.0145，0.0047，0.0038，0.0033 g/mL。采用系统溶剂法分析发现，木香和鹤虱的主要杀虫活性成分均在氯仿萃取物中，表明其杀虫成分易溶于较弱极性溶剂中。进一步通过活性追踪法，对鹤虱提取物的柱层析各流分的活性检测表明，其杀虫活性成分的Rf值为0.5556~0.5926。该研究为进一步纯化新型植物源杀虫物质并确定其分子结构，从而开发其应用前景及发现新的杀虫活性先导化合物奠定了基础。

Insecticidal activity of extracts from eighteen Chinese traditional herbal plants against Nilaparvata lugens St(a)l (Homoptera: Delphacidae) and Spodoptera exigua (Lepidoptera: Noctuidae)

In order to screen the environment friendly and highly effective insecticide of plant origin,we determined the contact toxicity of 52 extracts from 18 Chinese traditional herbal plants against the brown planthopper,Nilaparvata lugens Stl,by spray method and their stomach toxicity to Spodoptera exigua.The results showed that all the 52 extracts from the 18 Chinese traditional herbal plants separated with solvents of water,alcohol and petroleum ether had low activity to S.exigua,with the highest corrected mor...