关键词: 淡色库蚊, 抗药性, 生物学测定

Abstract:

Objective To monitor the resistance status of Culex pipiens pallens to three kinds of commonly used insecticides in Weifang city for management of insecticide resistance development. Methods Egg rafts of Cx. pipiens pallens were collected from four districts in Weifang, and reared to larvae in insectary. The late-third-to-early-fourth-instar larvae were tested against temephos, deltamethrin and beta-cypermethrin with dipping method to determine the median lethal concentration (LC₅₀). Results The resistance ratios (RRs) to temephos ranged from 7.12 to 11.24 (LC₅₀= 0.003 466-0.005 472 mg/L); to deltamethrin ranged from 1.86 to 3.83 (LC₅₀=0.000 908-0.001 866 mg/L); to beta - cypermethrin were 0.47-1.60 (LC₅₀=0.001 798-0.006 097 mg/L). Conclusion Culex pipiens pallens has developed resistance to temephos, tolerance to deltamethrin, and remained susceptible to beta-cypermethrin. To prevent and control the development of insecticide resistance, insecticides including temephos should be used in rotation or mixture with other pesticides with different modes of action, while avoiding using single active ingredient for long time.

Key words: Culex pipiens pallens, Resistance, Bioassay