Sensitivity of Anopheles sinensis to insecticides

Objective To understand the sensitivity of Anopheles sinensis to DDT,malatlion,cyfluthrin and deltamethrin in Nanyang and provide scientific evidence for its control.Methods Adult mosquitoes filter contact method recommended by WHO was used to assay the mortality rate and knockdown rate,in order to determine the resistance levels.Results Anopheles sinensis in the field of Nanyang had initial resistance to malatlion,cyfluthrin and deltamethrin,for that the discriminating dose mortality rates were between 80% and 97%.And they had become resistant to DDT,for that the mortality rate was less than 80%.Conclusion The resistance is still in high level many years after the termination use of DDT.The resistance of Anopheles sinensis to pyrethroid-type insecticides is initial formation.The resistance development of the future would be the most obstacle of malaria vectors control.So it is necessary to carry out regular and effective monitoring measures timely so as to control Anopheles sinensis effectively.