A study on resistance of adult Aedes albopictus Guangdong Province in 2023
Objective To study the resistance levels of adult Aedes albopictus to commonly used insecticides in Guangdong Province,and to provide the scientific basis for coping with the resistance development of Ae. albopictus and improving the control effectiveness of dengue vector. Methods The resistance of adult Ae. albopictus to common insecticides at different monitoring sites was measured by the diagnostic dose method,and the results of resistance of dengue vector Ae. albopictus in Guangdong Province in 2023 were compared. Results In 2023,a total of 49 monitoring sites across 17 cities were tested for the resistance of adult Aedes albopictus to three pyrethroids (permethrin,cypermethrin,and deltamethrin). Of these,85.71% were resistant populations,and 14.29% were possible resistant populations. A total of 45 monitoring sites in 17 cities assessed the resistance of adult Aedes albopictus to two types of carbamate insecticides:propoxur and bendiocarb,with 6.67% being resistant populations,53.33% possibly resistant populations,and 40.00% sensitive populations. Furthermore,the resistance to two organophosphorus drugs,malathion and fenitrothion,was measured at 38 monitoring sites in 7 cities,with 92.11% being resistant populations,5.26% possibly resistant populations,and 2.63% sensitive populations. Conclusions In the monitoring sites of resistance of adult Ae. Albopictus in Guangdong Province in 2023,all adult Ae. Albopictus mosquitoes developed resistance to pyrethroids,widespread resistance to organophosphorus insecticides,and less resistance to carbamate insecticides. Mosquito vector control works should focus on environmental control,and mosquito breeding site disposal,with the scientific selection and use of insecticides. In the chemical killing of adult mosquitoes,the use of single-agent pyrethroids and organophosphorus insecticides should be reduced,and strategies such as combining and rotating insecticides should be adopted to delay the development of mosquito resistance and improve control efficiency.