Resistance surveillance of Culex pipiens pallens in Jining in 2024
XU Haoyuan
ZHANG Huihong
LI Wenxuan
CHENG Peng
WANG Haifang
GUO Xiuxia
LIU Lijuan
GONG Maoqing
ZHANG Chongxing
Abstract：Objective To investigate the current status of insecticide resistance in both larvae and adults of Culex pipiens pallens in Jining,Shandong Province,and analyzed their resistance levels,so as to provide theoretical evidence for scientific and rational use of insecticides.Methods Field-collected larvae of Cx.pipiens pallens from six counties(cities,districts)in Jining were reared in the laboratory to F1 generation during August to October 2024.The immersion method and contact cylinder method were employed to assess insecticide resistance levels of larvae and adults,respectively.Results Larvae of Cx.pipiens pallens from all counties(cities,districts)in Jining exhibited high levels of resistance to cypermethrin and deltamethrin.The resistance ratios to cypermethrin in Rencheng,Liangshan,Wenshang,Jiaxiang,Weishan,and Qufu were 207.50,254.30,139.00,158.20,276.50,and 287.60,respectively,while the resistance ratios to deltamethrin were 298.00,111.70,39.05,100.85,117.25,and 122.80,respectively.For propoxur,with exception of Jiaxiang(exhibiting moderate resistance with resistance ratio of 11.67),the larvae from other regions demonstrated low resistance.The larvae from all counties(cities,districts)showed moderate resistance to dichlorvos,with resistance ratios ranging from 12.23 to 17.80.However,they were sensitive to Bacillus thuringiensis israelensis(Bti),with resistance ratios close to or below 1.00.Adult of Cx.pipiens pallens from all counties(cities,districts)also exhibited high resistance to cypermethrin and deltamethrin.In Rencheng District,there was a suspicious level of resistance to propoxur,while no resistance was observed to other insecticides.Generally,adult mosquitoes were sensitive to dichlorvos.Conclusion Cx.pipiens pallens in Jining has developed high resistance to pyrethroid insecticides,relatively lower resistance to propoxur and dichlorvos,and remains sensitive to Bti.It is necessary to continuously strengthen the monitoring of cypermethrin and deltamethrin resistance of Cx.pipiens pallens in this area,adopt scientific and precise prevention and control strategies in mosquito control work,and suggest scientific and rational use of insecticides to delay the development of insecticide resistance.
Keywords：Culex pipiens pallensinsecticide resistancesurveillancecontrol strategies
Publication Date：2025-06-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 240-245 )