5种常用杀虫剂对尖喙库蠓的毒性测定

以野外采集的尖喙库蠓成虫为试验对象,通过滤纸接触法,测定了毒死蜱、敌敌畏、溴氰菊酯、高效氯氰菊酯和高氯·甲维盐等5种常用杀虫剂对尖喙库蠓的毒杀效果.结果表明:5种杀虫剂对蠓的毒性差异显著,毒力大小依次为溴氰菊酯毒死蜱高效氯氰菊酯高氯·甲维盐敌敌畏,试虫接触药剂1 h的LC50分别为0.060、0.588、1.741、99.670和600.496 mg·L-1;试虫经药剂处理1 h后在恢复筒观察24 h,其在各种药剂不同处理浓度下增加的死亡数不同;以溴氰菊酯为标准药剂,其相对毒力指数最大.

Toxicity of 5 insecticides to Culicoides oxystoma Kieffer (Diptera:Ceratopogonidae)

Field-collected Culicoides oxystoma were exposed to different concentrations of commercial insecticides, including chlor-pyrifos, DDVP, deltamethyrin, beta-cypermethrin and beta-cypermethrin??emamectin benzoate via filter paper method, so that the toxicity effects of different insecticides on C.oxystoma were determined. Results showed that toxicities varied significantly among insec-ticides. Biting midges were the most susceptible to deltamethyrin (0.060 mg??L-1), and followed by chlorpyrifos (0.588 mg??L-1), beta-cypermethrin (1.741 mg??L-1), beta-cypermethrin??emamectin benzoate (99.670 mg??L-1), DDVP (600.496 mg??L-1) in a descending order. After exposed to insecticides for 1 h, tested midges were transferred to recovery chamber and observed for anoth-er 24 hours, increased mortality within this period was different under the different concentrations of each insecticide. Relative toxic-ity index was maximal when using deltamethrin as standard reagent.