6种低毒药剂对核桃楸大蚕蛾的毒力测定与林间防效

为有效控制核桃楸大蚕蛾幼虫并尽量减少对环境的危害，对6种低毒、无公害的植物源和生物杀虫剂开展室内毒力测试和林间防治试验，筛选出更适合杀灭核桃楸大蚕蛾幼虫的药剂。结果表明，室内48 h毒力测试时不同药剂对核桃楸大蚕蛾2龄幼虫的毒力依次为:阿维菌素>甲维盐>阿维·灭幼脲>烟碱·苦参碱>阿维·杀铃脲>灭幼脲。用药后的1、2 d，烟碱·苦参碱的防治效果最好；用药后3 d，阿维菌素、烟碱·苦参碱、阿维·杀铃脲的防效都达到100.00%，阿维·灭幼脲防效为99.69%，甲维盐防效为98.50%，这5种药剂的防效均无显著差异，且都显著大于灭幼脲的防效28.08%。阿维菌素、烟碱·苦参碱和阿维·杀铃脲都能作为林间防治核桃楸大蚕蛾2龄幼虫的药剂，防治时可以根据不同药剂的市场售价和稀释倍数择优选择。灭幼脲对核桃楸大蚕蛾幼虫的林间防效较差，用药后7 d防效达到77.29%，不可单独使用作为防治药剂。林间打药防治核桃楸大蚕蛾幼虫应在幼虫3龄以前集中时进行，以达到事半功倍的效果。

Toxicity and Field Control Efficacy of 6 Low-toxic Insecticides to Dictyoploca japonica

In order to control Dictyoploca japonica and to minimize its damages to the environment,6 plant originated pesticides and biological pesticides were examined by indoor toxicity measurement and field test to select optimum pesticides.The results showed that the toxicity sequence of the pesticides were abamectin > emamectin-benzoate > abamectin-dimilin > nicotine-matrine > avermectin-triflumuron > chlorbenzuron in the test of 48 h preliminary toxicities to the second instar of D.japonica larvae.The control effects of nicotine-matrine were the best 1 d and 2 d after the application.Three days after the application,the control effects of abamectin,nicotine-matrine and avermectin-triflumuron were 100%,99.69% for abamectin-dimilin,and 98.50% for emamectin-benzoate.There were no significant differences in control effects among 5 pesticides that were all greater than that chlorbenzuron (28.08%).Abamectin,nicotine-matrine and avermectin-triflumuron could be used to control the second instar of D.japonica larvae.The control effect of chlorbenzuron was poor in the field test,the control effect was only 77.29% 7 d after spraying,indicating that it could not be used alone to control the insect.To achieve a better control effect,pesticides should be sprayed before the gathering of third larvae.