几种植物叶粗提物对淡色库蚊幼虫的毒效

目的 :了解柑桔、樟树、柚子、雪松、柳杉、柏树、桂花和牡荆等 8种常见植物叶粗提物对淡色库蚊幼虫的毒杀效果 ,为寻找新的杀蚊化合物打下基础。方法 :用无水乙醇浸提植物叶粉 ,然后用水稀释粗提物 ,并测定其对淡色库蚊Ⅲ龄幼虫的毒效。结果 :在试验浓度下 ,各植物叶粗提物对淡色库蚊Ⅲ龄幼虫均有一定的毒杀效果 ,其中以雪松、柏树和桂花的毒杀能力最强。与对照相比 ,各处理存活幼虫的平均发育历期延长、蛹重减轻 (柳杉叶处理除外 )。结论 :柏树叶粗提物对淡色库蚊Ⅲ龄幼虫有良好的毒杀效果 ,其杀蚊幼作用值得进一步研究

Toxic Effects of the Ethanol Extracts of Several Garden Plants Against the Third Instar Larvae of Culex pipiens pallens

Objective:To test the toxic effects of the leave extract of Citrus reticulata Blance, Cinnamomum camphora Presl, Citrus grandis Osbeck, Cedrus deodara Loud, Cryptomeria fortunei Hooibrenk ex Ottoet Dietr, Cupressus funebris Endl., Osmanthus fragrans Lour., and Vitex negundo var. Cannabifolia Sieb. et Zucc.against the larvae of Culex pipiens pallens, so as to provide the basis for the study of new chemicals for mosquito control. Methods:The dry leave powders of several plants were extracted with ethanol (analytic pure) for 20 days. Then extracts were diluted with distilled water with suitable amount of Tween-80, and bioassay was done with the third instar larvae of Culex pipiens pallens. Results:At the tested concentration, the leave extracts of all plants tested had different degree of toxic effects on the third instar larvae of Culex pipiens pallens. Among them, the leave extracts of C.deodara, C.funebris, and O.fragrans had the best toxic effects.Compared to the larvae of control, the larvae survived from treatment had longer developmental period. After pupation,the average pupa weights were lighter than that of control exception the treatment of C.fortunei leave. Conclusion:In all plants which were tested, the effects of the extracts of C.funebris leave against the third instar larvae of Culex pipiens pallens were largest. The toxic effects of this plant on mosquito larvae deserve to be further studied in the future.