Resistance to s-methoprene in mosquitoes:case report,risk assessment and analytical literature review
SU Tian-yun
Abstract：Objective To assess the risk of resistance to methoprene and resulted cross-resistance to other pesticides in mosquitoes through case report and analytical literature review and suggest the strategy and methods to combat resistance development.Methods A field collection of the southern house mosquito Culex quinquefasciatus that carried low-level resistance to s-methoprene was subjected to laboratory selection at 70％-90％ mortality for 30 generations.Bioassays were conducted every 3rd generation concurrently with a susceptible laboratory colony and unselected population to monitor the resistance development.Results The low-level resistance due to product application in the field reached to a significantly high level in response to further laboratory exposure for 30 generations,amounting to 1 167.3-fold at IE50 and 421.7-fold at IE90 as compared with susceptible laboratory colony,and 168.3-fold at LC50 and 57.4-fold at LC90 in relation to unselected population.Conclusion It was once believed that methoprene and other juvenile hormone analogs would negate the potential of resistance evolution owing to their unique mode of action.The reported occurrence,doubled with few earlier studies on other species,truly indicated the risk of resistance even cross-resistance,which warrants the needs of susceptibility monitoring before,during and after applications of methoprene products in the field.Resistance to methoprene and resulted cross-resistance to other pesticides were discussed.
Keywords：s-methoprenejuvenile hormone analogCulex quinquefasciatusmosquito controlresistancecross-resistance
Publication Date：2020-12-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 506-514 )