Primary study on resistance of Anopheles pseudowillmori to deltamerthrin in Chayu County, Xizang Autonomous Region

Objective To determine the resistance of Anopheles pseudowillmori to deltamethrin in Chayu County,Xizang Autonomous Region.Methods Anopheles pseudowillmori adults were collected by cowbaited trap from villages of Rima and Tama in Xiachayu Town of Chayu County in July of 2011.Anopheles pseudowillmori F1 generation was raised from the eggs layed by the blooded meal adults and WHO standard assays were used to test the resistance of Anopheles pseudowillmori to deltamerthrin with blank control.Acetone was selected as solvent in both groups.No insecticide was contained in blank control test paper,while 0.05％delatamethrin in experiment group.KT50 was calculated after 60 min exposure and mortality was recorded after 24 h of exposure.Results The knockdown rate of Anopheles pseudowillmori to deltamethrin in Rima and Tama village were 96.4％ and 97.5％,respectively with adjusted mortality were 100％ and 100％ respectively.Conclusion The predominant anopheline Anopheles pseudowillmori in Chayu County showed sensitivity to deltamethrin.Deltamethrin can be as vector control insecticide to Anopheles pseudowillmori in Chayu County. Key words: Anopheles pseudowillmori; Deltamethrin; Resistance; Xizang Autonomous Region