川楝素与青虫菌等农药混用对菜青虫增效作用的试验

川楝素分别与苏芸金杆菌(B.t. Var.galleriae)、青虫菌6号、雷公藤根粉乙醇抽提物以及化学农药乐斯本混用,对保护作物避免菜青虫(Pieris rapae L.)幼虫的取食为害有明显的增效作用,而且对幼虫的化蛹及蛹重都有明显的仰制作用,具有理论和实际意义.

THE SYNERGISTIC EFFECT OF TOOSENDANIN IN ADMIXTURE WITH BACILLUS THURINGIENSIS AND OTHER INSECTICIDES AGAINST THE CABBAGE WORM PIERIS RAPAE L.

Results of laboratory and field experiments with mixtures of toosendanin, Bacillus thurin-giensis (B. t.), B. t. No. 6 (containing 0.05% cypermethrin), etlianol extract of the root-bark of the thunder-god-vine (Trypterygium tvilfordii Hook f.) or chlorpyrifos showed marked synergistic effects in controlling the damage of the cabbage worm. It was found that although the conventional organic insecticides such as cartap, chlorpyrifos exhibited a rapid toxic action against the. cabbage worm, yet those survived the treatment fed and developed normally, and the weight of the pupae was similar to that of the unreated larvae. With botanical insecticides, however, either applied alone or in admixture with other insecticides, the percentage of pupation was significantly decreased in the larvae which survived the treatments and interestingly, the weight of the pupae was found to be markedly lighter, than the untreated control. This discovery seems to indicate that the toxic principles of the botanical insecticides, such as toosendanin and Trifterygium alkaloids would possess growth disrupting properties against the cabbage worm and furthermore it may have far-reaching importance in studying the mechanism and genetics of insecticide-resistance. .