Resistance of Culex pipiens pallens larvae to 7 insecticides in parts of Jiangsu province

Objective To determine the resistance of Culex pipiens pallens larvae to commonly used insecticides in parts of Jiangsu province, providing the guidance on proper administration of mosquito control agents. Methods Using 7 common chemical pesticides, the resistance of Cx. pipiens pallens larvae in Nanjing, Nantong and Huaian regions of Jiangsu province was measured by larval impregnation. Results Compared with the laboratory susceptible strain, the Cx. pipiens pallens larvae from Nanjing, Nantong and Huaian each had the highest resistance to dichlorvos, while the populations from Nantong and Huaian had the lowest resistance to permethrin. The Nanjing population had the lowest resistance to bioallethrin, and similar resistance to permethrin. Conclusion Suitable insecticides should be used for prevention and control of mosquito larvae, taking into account the regional resistance. To properly apply insecticides, dichlorvos, propoxur, and temephos which mosquitoes are highly resistant to should be gradually replaced by pyrethroids.