两种寄生蜂对几种农药的敏感性测定

就平腹小蜂、荔枝蒂蛀蛾白茧蜂对几种常用农药的敏感性进行了测定.结果表明：生物性农药的印楝素、定虫隆、灭幼脲对2种寄生蜂均较安全;Bt对平腹小蜂的毒性较小;杀虫双对平腹小蜂的影响较小,但对蒂蛀蛾白茧蜂有较高毒性（2 h内死亡率70%）;拟除虫菊酯类农药对平腹小蜂有一定的毒性,而对蒂蛀蛾白茧蜂有很高的毒性（2 h内死亡率均为100%）;2种寄生蜂均对有机磷杀虫剂如敌百虫、辛硫磷、敌敌畏及氧乐果等极度敏感.表明蒂蛀蛾白茧蜂比平腹小蜂对化学杀虫剂更敏感.因此在综合防治中,尤其是当田间释放平腹小蜂时应合理选择使用杀虫剂,应以生物源性农药为首选,避免使用菊酯类农药,尤其要禁止使用有机磷类农药,以减少对平腹小蜂等寄生性天敌的杀伤.

Indoor toxicities of several insecticides to 2 parasite wasps

The indoor toxicities of some insecticides to Anastatus japonicus and Phanerotoma sp.were tested.The results showed that,(1) biological insecticides including Azadiractin(plant derivative),chlorfluazuron and dimilin (insect growth regulators) were all safe to the 2 wasp species;(2) Bacillus thuringiensis had low toxicity to A.japonicus;(3) the toxicity of dimehypo was low to Ajaponicus but high to Phanerotoma sp.(mortality rate reached 70% within 2 h after treatment);(4) synthetic pyrethroids were moderately toxic to A.japonicus,but highly contact toxic to Phanerotoma sp.(mortality rates all reached 100% within 2 h after treatment) and(5) the 2 wasps were both extremely sensitive to the tested organophosphorus insecticides such as trichlofon,phoxin,omethoate and dichlorvos.Compared with A.japonicus,Phanerotoma sp.was more sensitive to chemical insecticides.To reduce the negative effects,especially while releasing A.japonicus,biological insecticides should be considered first in IPM and chemical insecticides especially organophosphorus insecticides should be tried to be avoided.