拟除虫菊酯对松林内几种天敌的毒性测定

<正>本研究用拟除虫菊脂(2.5％溴氰菊脂及20％杀灭菊脂)对松林内常见的6种马尾松毛虫天敌进行了室内毒性测定。试验结果表明:20％杀灭菊脂(40,100ppm)对异色瓢虫幼虫、成虫有较高接触毒性,但对蠋敌若虫、成虫及黑大蚁的接触毒性较低,且均低于80％敌敌畏(200,400ppm)。两种菊脂的常量喷雾对天敌有较高毒性,而超低容量喷雾除对龟纹瓢虫、寄蝇外毒性均较低。两种菊脂对黑大蚁及异色瓢虫3龄幼虫的选择性比值远小于1,说明它们对马尾松毛虫4龄幼虫具有高毒性,而对黑大蚁及异色瓢虫幼虫则相对较安全(LC_(50)毒性相差13.6～75.1倍; LC_(90)毒性相差62.8～164.7倍)。

DETERMINATIONS OF THE TOXICITY OF PYRETHROID TO SEVERAL IMPORTANT NATURAL ENEMIESIN THE PINERY

Tests were conducted to examine the toxicity of pyrethroid to several species of pinery natural enemies in the laboratory during 1983~1985. Following are the results so far as the contact poisoning is concerned, 20% S-5602 are serious to the adults and larvae of Leis axyridis but mild to the adults and larvae of Arma custos and Camponotus japonicus. Its toxicity is even lower than that of 80% Dichlorphos (DDVP). The full-coverage spray of pyrethroid is highly toxicant to all the natural enemies, while the ULV spray less toxicant to natural enemies. The selected values of 20% S-5602 and 2.5% NRDC-161 to Camponotus japonicus and to the 3 instar larvae of Leis axyridis are below one, so pyrethroid is highly toxicant to the 4 instar larvae of Dcndrolimus punctatus, but less toxicant to Camponotus japonicus and to the 3 instar larrae of Leis axyridis.