摘要
本文选用8种常用治螟药剂,对玉米螟幼虫的主要天敌—螟虫长距茧蜂进行室内触杀毒力研究。结果表明,对螟虫长距茧蜂的毒力大小顺序为:对硫磷>辛硫磷>巴丹>久效磷>溴氰菊酯>杀灭菊酯>甲胺磷>杀虫双。对硫磷和久效磷两种药剂,随着浓度的增高茧蜂死亡率增加较快。溴氰菊酯和杀灭菊酯两种药剂处理的茧蜂,中毒后有明显的复苏现象。茧蜂成虫的LC_(50)与3龄玉米螟幼虫LC_(50),比值都小于1,说明这8种药剂在防治玉米螟时,对其天敌长距茧蜂很不安全。
Results of the laboratory tests showed that the contact tqxicity of eight commonly used insecticides to M. linearis tanked in the following order: parathion > phoxim > padan > monocrotophos. > deltamethrin > fenvalerate > methamiophos > dimehypo. The selectivity ratios, (i.e. LC50 of the adults parasite/LC50 of the 3rd instar larvae of the host), of the eight insecticides tested were all less than 1. It indioates that chase insecticides are highly harmful to the parasite, and should be used judiciously when the parasite.is abundant in the field.
关键词
长距茧蜂
玉米螟
杀虫剂
毒性
Macrocentrus linear is Ostrinia furnacalis insecticides contact toxicity
