Study on Roles of DDVP and Propoxur for Non-Specific Esterase (NSE) and Acetylcholinesterase(AChE) of Culex pipiens pallens

Objective: To explore the roles of DDVP and propoxur for NSE and AChE of Culex pipiens pallens and to improve biochemistry assay for determination of insectieidal resistance in mosquitoes. Methods: We tested the activity of NSE and AChE of individual mosquito with microplate assay. Results: DDVP and propoxur could inhibit the activity of NSE and AChE of Culex pipiens pallens , and the activity of NSE returned to normal level of pre-treating after treating 72 h. The sensitivities of AChE of anti-DDVP and anti-propoxur strain of Cx. pipiens pallens were lower than that of sensitive strain, the insensitivity of anti-propoxur strain being high compared with anti-DDVP strain, and the inhibition action for AChE with propoxur being larger than that of DDVP. Conclusion: The NSE should be determined after treating 72 h if mosquitoes have been treated with OP and carbamates insecticides, and propoxur should be selected as inhibit agent when testing AChE insensitivity for resistance of mosquitoes.