野桑蚕对溴氰菊酯抗性品系的筛选

目的]通过溴氰菊酯对野桑蚕进行抗性品系的筛选，探明该药剂的抗药性发展情况，为科学施药和抗性治理提供依据。方法]室内饲养繁殖来自3个不同地区的野桑蚕，点滴法测定其亲代对溴氰菊酯的敏感性。分别以半数致死量左右的剂量通过点滴法逐代处理其幼虫，统计幼虫死亡情况，建立毒力回归方程并计算抗药性倍数及其提高倍数。结果]在桑叶育条件下，经3代室内筛选，启东野桑蚕（YQD）F4代抗药性倍数为14.26，较F0代提高了0.2倍；苏大桑园野桑蚕（YSD）F4代抗药性倍数为16.48，较F0代提高了0.9倍；在人工饲料条件下，经6代室内筛选，吴江野桑蚕（YWJ）F6代抗药性倍数为18.67，较F0代提高了0.2倍。结论]相同剂量筛选下，YSD比YQD抗药性倍数提高快；YWJ在人工饲料饲育和杀虫剂筛选双重选择下，抗药性发展较慢。

Selection of Deltamethrin Resistant Strain of Bombyx mandarina Moore

Objective] The aim of the study was to explore the resistance development of deltamethrin through selection of deltamethrin resistant strain of wild silkworm(Bombyx mandarina),thus providing the basis for scientific pesticide application and resistance management.Method] The wild silkworms collected from three different regions were reared indoors,and the sensitivity of their parents to deltamethrin was detected by topical application.The larvae in each generation were treated with deltamethrin in median lethal dose or so by topical application.The mortality of larvae was analyzed for the establishment of toxicity regression equations and the calculation of the multiple or increased multiple of deltamethrin resistance.Result] After the Qidong Bombyx mandarina(YQD) fed with mulberry leaves were selected for three generations indoors,the multiple of deltamethrin resistance of F4 was 14.26,1.2 times as great as that of F0;after the Bombyx mandarina from mulberry garden of Soochow University(YSD) fed with mulberry leaves were selected for three generations indoors during six generations,the multiple of deltamethrin resistance of F4 was 16.48,1.9 times as great as that of F0;after the Wujiang Bombyx mandarina(YWJ) fed with artificial diets were selected for three generations indoors during six generations,the multiple of deltamethrin resistance of F6 was 18.67,1.2 times as great as that of F0.Conclusion] With the selection in same dose,the resistance multiple of YSD increased more rapidly than that of YQD;with double selection with artificial diets and insecticide,the resistance multiple of YWJ increased more slowly than that of YQD.