Resistance assay of Anopheles sinensis to four conventional insecticides in Feidong County of Anhui Province

Objective To determine the resistance situation of Anopheles sinensis to four conventional insecticides(DDT,malathion,propoxur and delatamethrin) in Feidong County of Hefei City.Methods Three villages (Shuangqiao,Zhaofang,and Chenxiaoying) of Feidong County were selected as the investigation spot according to historic malaria situation and the distribution of the imported Plasmodiun falciparum cases in recent years.Anopheles sinensis adults were collected by whole night cow-baited traps from July to August in 2012.WHO standard assays were used to test the resistance of Anopheles sinensis F0 generation female.Anopheles sinensis was tested for four to five test tubes,the amount of mosquitoes was larger than one hundred.The density of DDT,malathion,deltamerthrin,propoxur was 4％,5％,0.05％ and 0.1％,respectively.Acetone was used as control at the same time.Knockdown rate was calculated after one hour insecticides exposure and mortality was recorded after 24 hours of exposure.Results Totally 1 576 Anopheles sinensis were captured.The resistance to 4％ DDT,0.05％ deltamerthrin,0.1％ propoxur and 5％ malathion was all detected in the population of Anopheles sinensis in Feidong County.The average knockdown rates of Anopheles sinensis to 4％ DDT,0.05％ deltamerthrin,0.1％ propoxur were 10.86％,9.21％ and 5.73％,respectively.And the average adjusted mortality of Anopheles sinensis to 4％ DDT,0.05％ deltamerthrin,0.1％ propoxur and 5％ malathion was 36.41％,7.54％,88.83％ and 29A5％,respectively.Conclusion The main malaria vector Anopheles sinensis in Feidong County showed dominant resistance to DDT,deltamethrin and propoxur,and primary resistance to malathion. Key words: Anopheles sinensis;  Insecticide;  Resistance