Detection of Resistance to Pyrethroid And Neonicotinoid Insecticides in the Greenhouse Whitefly, Trialeurodes Vaporariorum (Westw.) (Hemiptera: Aleyrodidae)

Abstract

In Turkey as elsewhere, control of the greenhouse whitefly, Trialeurodes vaporariorum (Westw.) (Hemiptera: Aleyrodidae), relies extensively on the use of insecticides, which can promote the development of insecticide resistance. In this study, resistance to commonly used pyrethroid and neonicotinoid insecticides was investigated using bioassays and biochemical analyses. Full dose-response bioassays using 11 samples of T. vaporariorum from three locations in Turkey disclosed resistance up to 8.1-fold, 16-fold and 11.4-fold for the neonicotinoids acetamiprid, imidacloprid and thiamethoxam, respectively. Corresponding figures for pyrethroids were 56.5-fold for cypermethrin and 116.4-fold for deltamethrin. All samples were characterized using polyacrylamide gel electrophoresis (PAGE) and by measuring non-specific esterase and glutathione-S-transferase (GST) activity. There is no positive relationship between esterase activity and resistance pyrethroid or neonicotinoid resistance. It is thought that esterase enzyme activity seen in T. vaporariorum may be at lest partially related to the resistance to insecticides, but it cannot be responsible as a single mechanism. No relationship has been determined between GST activity and resistance to pyrethroids or neonicotinoids. The practical implications of these results for control of whiteflies are discussed.