植物源杀蚊驱蚊物质的筛选及效果观察

Screening and observation of the plant-derived mosquito repellent substances

目的筛选对媒介蚊虫有驱蚊灭蚊活性的植物资源,进行驱蚊灭蚊效果研究,对蚊虫进行防治,为植物源杀虫剂和趋避剂的开发研制提供基础。方法浸泡提取植物中的活性成分,过滤浓缩后测定提取物对蚊虫幼虫的杀蚊活性和对成蚊的趋避活性,对于效果好的植物,研究提取物复配对蚊虫的毒杀和趋避效果。结果所选植物提取物对淡色库蚊幼虫有杀灭活性,24 h杀灭淡色库蚊Ⅳ龄幼虫超过50%的有9种,48 h超过50%的有21种。6种植物的乙醇提取物24 h对淡色库蚊Ⅳ龄幼虫的致死中浓度(LC_(50))<1 mg/ml。部分植物乙醇提取物两两复配对淡色库蚊Ⅳ龄幼虫24 h死亡率有增效作用,其中有明显效果(增效值>40)的有6组。8种植物的乙醇提取物对人手趋避白纹伊蚊持效时间超过2 h,5种复配持效时间超过6 h。结论很多植物具有杀蚊驱蚊作用,有些两两复配具有良好的增效作用,植物提取物可以作为杀虫剂和趋避剂进行研究和使用。

Objective To screen plant resources with the effects of mosquito killing and repelling abilities and to study on its effects for controlling mosquitoes,so as to provide the basis for the development of botanical insecticides and repellants. Methods The active components of the plants were soaked,extracted and filtered to determine the mosquito-killing activity and the repellent activity against mosquito larvae and adult mosquitoes respectively. The mixtures of different effective extracts were compared for further studying of its effects. Results The extracts of the selected plants had an insecticidal activity against the iv-instar larvae of Culex pipiens pallens. There were 9 extracts which killed more than 50% of the iv-instar larvae in 24 hours,and 21 species more than 50% in 48 hours. The lethal concentration( LC50) of the ethanol extract of 6 plants on the 4th instar larvae of Culex pipiens pallens was <1 mg/ml. Some plant ethanol extracts had a synergistic effect on the 24 h mortality of Culex pipiens pallens larvae,and there were 6 groups with obvious effects( >40). The ethanol extracts of 8 plants lasted for more than 2 hours to prevent Aedes albopictus,and the 5 mixtures of different compounds lasted for more than 6 hours. Conclusion Many plants have the biological activity of killing and repelling mosquitoes,and some of the mixtures have better synergistic effects. Plant extracts can be used as insecticides and repellents for researching and using.