桑树不同季节施用杀虫剂虫螨腈对家蚕的残留毒性调查  

Survey on Residual Toxicity of Insecticide Chlorfenapyr to Bombyx mori After Spraying in Mulberry Field at Various Seasons

作　　者：佘柳涛 薛卫东 陆琴 钱小兰 

机构地区：[1]如皋市蚕桑技术指导站,江苏南通226500

出　　处：《蚕业科学》2012年第3期565-570,共6页ACTA SERICOLOGICA SINICA

基　　金：江苏农业三项工程项目[No.SX(2011)224]

摘　　要：虫螨腈因其对家蚕的低毒性而成为桑树害虫防治药剂之一。为了确保桑园施用虫螨腈对家蚕的安全性,分别于春、夏、秋季对桑树喷施虫螨腈后,调查药剂对家蚕的残毒性及家蚕的中毒情况,结果表明不同季节桑树喷施虫螨腈对家蚕的残毒性差异较大。夏季以24%虫螨腈悬浮剂3 000倍稀释药液喷施桑树后3 d采叶饲养对3龄期家蚕基本安全,1000、2000倍稀释药液喷施后5d采叶饲养对3龄期家蚕已无致死性;春季3种浓度药液喷施后7 d采叶饲养仍造成3龄期家蚕100%死亡。夏蚕期3龄期家蚕饲喂1000倍稀释药液喷施后1h的桑叶后即出现中毒死亡,而中秋蚕期、春蚕期的3龄期家蚕食下相同毒叶分别在1、3d后才出现中毒死亡现象。此外,调查虫螨腈对不同龄期家蚕的残毒性,表明对5龄期家蚕的残毒性明显低于3、4龄期的家蚕,因此建议在家蚕4龄期之前尽量不用虫螨腈防治桑园害虫。Chlorfenapyr is one of the main pesticides for control of mulberry pests due to its low toxicity to silkworm, Bombyx mori. In order to assure the security of spraying chlorfenapyr in mulberry field to silkworm, the residual toxicity of chlorfenapyr to silkworm larvae and poisoning symptoms of silkworm larvae were investigated after spraying chlorfenapyr in mulberry field in spring, summer and autumn. The results indicted that the residual toxicity of chlorfenapyr to silkworm were greatly different in different seasons. The 3000 times diluted solution of 24% chlorfenapyr product was generally safe to the 3rd instar silkworm larvae on the 3rd day after spraying in summer, while the 1 000 and 2 000 times diluted solutions had no lethality to the 3rd instar silkworm larvae on the 5th day after spraying in summer. Mulberry leaves sprayed with the above three concentrations could still cause 100% mortality of the 3rd instar silkworm larvae on the 7th day after spraying in spring. In summer rearing season, dead larvae of the 3rd instar were observed at 1 h after feeding on mul- berry leaves treated with 1 000 times diluted solution of chlorfenapyr, while dead larvae appeared at 1 d in mid-autumn and 3 d in spring respectively after feeding on mulberry leaves from the same treatment. In addition, the residual toxicity of chlorfenapyr to the 5th instar silkworm larvae was obviously weaker than that to the 3rd and 4th instar larvae. Therefore, it is suggested not to use chlorfenapyr for controlling mulberry pests before the 4th instar of silkworm larvae.

关 键 词：桑园杀虫剂 虫螨睛 家蚕 残毒性 季节 龄期 

分 类 号：S888.7[农业科学—特种经济动物饲养] S884[农业科学—畜牧兽医]