Couso-Ferrer, FranciscoArouri RabehBeroiz, BeatrizPerera, NathaliaCervera, AmeliaNavarro-Llopis, VicenteCatañera, PedroHernández-Crespo, PedroOrtego, Félix2013-05-022011-080022-0493https://riunet.upv.es/handle/10251/28389Resistance to malathion has been reported in field populations of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), in areas of Spain where an intensive use of this insecticide was maintained for several years. The main goal of this study was to determine whether resistance to malathion confers cross-resistance to different types of insecticides. Susceptibility bioassays showed that the malathion-resistant W-4Km strain (176-fold more resistant to malathion than the susceptible C strain) has moderate levels of cross-resistance (three-to 16-fold) to other organophosphates (trichlorphon, diazinon, phosmet and methyl-chlorpyrifos), the carbamate carbaryl, the pyrethroid lambda-cyhalothrin, and the benzoylphenylurea derivative lufenuron, whereas cross-resistance to spinosad was below two-fold. The W-4Km strain was selected with lambda-cyhalothrin to establish the lambda-cyhalothrin-resistant W-1K¿ strain (35-fold resistant to lambda-cyhalothrin). The synergistic activity of the esterase inhibitor DEF with lambda-cyhalothrin and the increase in esterase activity in the W-1K¿ strain suggests that esterases may be involved in the development of resistance to this insecticide. Our results showed that resistance to malathion may confer some degree of cross-resistance to insecticides currently approved for the control of Mediterranean fruit fly in citrus crops (lambda-cyhalothrin, lufenuron, and methyl-chlorpyrifos). Especially relevant is the case of lambda-cyhalothrin, because we have shown that resistance to this insecticide can rapidly evolve to levels that may compromise its effectiveness in the field. © 2011 Entomological Society of America.Reserva de todos los derechosChemical controlEsterasesMediterranean fruit flyResistance managementSynergistButyl phosphorotrithioateCyhalothrinInsecticideMalathionNitrilePesticidePhosphorothioic acid derivativePyrethroidAnimalArticleGenetic selectionGeneticsInsecticide resistanceMultidrug resistanceAnimalsCeratitis capitataDrug Resistance, MultipleInsecticidesNitrilesPesticide SynergistsPyrethrinsSelection, GeneticThiophosphoric Acid EstersCitrusDipteraTephritidaeArtículo10.1603/EC11082Cerrado