植物源昆虫调控剂研究Ⅰ．茶枯等植物源调控剂的药效测定

Searching for Plant Based Insect Control AgentsⅠ.Bioassay of Six PlantExtracts Against Caterpillars

测定茶枯水及芫花、苦楝、长叶冻绿、苍耳的乙醇抽提物对卫茅尺蠖和菜青虫药效，结果表明，芫花的效果最好，可使取食量下降７５％，并又进一步降低羽化率，抽提物１０ｇ／Ｌ浓度野外有效期在５天以上；次之为苦楝叶。作用途径主要是拒食和胃毒。茶枯水亦有一定作用，它还是植物抽提物的极好湿润剂，对提高药效起重要作用。

Ethanolic extracts from six plants,namely,Camellia oleifera, Daphnegenkwa,Xanthium sibiricum,Tripterygium wilfordii.Rhamnus crenata,and Meliaazedarach,were separately applied to the hosts of caterpillars of Abraxas miranda(Lep.:Geometridae)and Pieris rapae(Lep.:Pieridae)in the lab and in the field respectively in or-der to test their effect of insect control.Results showed that the extract from D. genkwa hadthe strongest feeding inhibition and toxicity to the insects tested which took 75 percent lessfeed than did the check group,and whose percentage of emergence also dropped markedly.The controlling effect of this extract could well last more than 5 days outdoors with a con-centration of 100 g/L. The next best extract was the one from M. azedarach,followed bythe one from the residual cakes of the seed of C. oleifera.