Couso Ferrer, FranciscoArouri, RabehBeroiz Remírez, BeatrizPerera, NathaliaCervera, AmeliaNavarro Llopis, VicenteCastañera, PedroHernández Crespo, PedroOrtego, Félix2024-07-102024-07-102011-08-01Couso-Ferrer F, Arouri R, Beroiz B, Perera N, Cervera A, Navarro-Llopis V, et al. Cross-Resistance to Insecticides in a Malathion-Resistant Strain of Ceratitis capitata (Diptera: Tephritidae). jnl econ entom. 2011;104(4):1349-560022-049310.1603/EC11082https://hdl.handle.net/20.500.14352/105939Resistance 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-1Kλ 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-1Kλ 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.engjournal articlehttps://doi.org/10.1603/EC11082https://academic.oup.com/jee/article-abstract/104/4/1349/2199744restricted access595.77631632.95Mediterranean fruit flyChemical controlSynergistEsterasesResistance managementInsectosAgricultura2413 Biología de Insectos (Entomología)3101.07 Insecticidas