麻疯树种子提取物对几种害虫的杀虫活性

在室内测定并比较了3种麻疯树种子提取物对同翅目、鳞翅目和鞘翅目害虫桃蚜、菜青虫和米象的杀虫活性。结果显示种子油、种子乙醇提取物和石油醚提取物对3种害虫都具有一定杀虫活性，对桃蚜的触杀活性LC50分别为5．1154、2．0796、13．9882g／L；对米象的杀虫活性LC50分别为8．0243、3．0701、24．3458g／L；种子油和乙醇提取物对菜青虫的胃毒活性LC加分别为18．1043、3．0796g／L，此外这2种提取物对菜青虫也显示出较强的拒食活性；而种子石油醚提取物对菜青虫无明显胃毒活性，拒食活性也很弱。麻疯树种子提取物对3种害虫的相对毒力顺序为乙醇提取物〉种子油〉石油醚提取物。

Insecticidal activity of Jatropha curcas seed extracts against several insect pest species

Laboratory studies were conducted to determine and compare insecticidal activity of three different Jatro- pha curcas seed extracts against Homopteran (peach aphid), Lepidopteran (cabbage butterfly), and Coleopteran (rice weevil) insect pests. Seed oil, ethanol extracts of seeds, or petroleum ether extracts of seeds all showed activity against the three insect species, with peach aphid (Myzus persicae) contact LC50 values of 5.12, 2.08, and 13.99 g/L, respectively, and rice weevil (Sitophilus oryzae) insecticidal LC50 values of 8.02, 3.07, and 24.35 g/L, respectively. Seed oil and ethanol extracts of seeds exhibited stomach poison activity against the cabbage butterfly (Preris rapae), with LC50s of 18.10 and 3.08 g/L, respectively, and showed strong antifeedant activity as well. However, petroleum ether extracts of seeds showed no significant stomach toxicity against the cabbage butterfly, with only weak antifeedant activity. Relative insecticidal activity of the three Jatropha curcas seed extracts against the three pest species was as follows: ethanol extracts of seeds > seed oil > petroleum ether extracts.