RT Journal Article
T1 Tracking malathion resistance in spanish ceratitis capitata populations: prevalence of resistance alleles/haplotypes before and after the withdrawal of malathion
A1 Couso-Ferrer, Francisco
A1 López-Errasquín, Elena
A1 Arouri, Rabeh
A1 Beroiz Remírez, Beatriz
A1 Perera, Nathalia
A1 Sánchez, Lucas
A1 Ortego, Félix
AB BACKGROUND: Field resistance to malathion was reported for Mediterranean fruit fly (medfly), Ceratitis capitata, populations collected in Spain in 2004 and 2005, when medfly control mainly relied on malathion bait sprays. The mutation G328A in the acetylcholinesterase (AChE) gene (Ccace2) was then identified as the main resistance mechanism in a field-derived resistant strain. However, outdoor plant protection products containing malathion were withdrawn from the European Union in 2009 and other insecticides gained importance, such as spinosad and pyrethroids, though other organophosphates were occasionally used for medfly control for a few years.RESULTS: We have: (i) provided evidences of a novel malathion resistant mechanism in Ceratitis capitata, mediated by a heterogeneous duplication of the Ccace2 gene (RS haplotype, one of the copies bearing the mutation G328A and the other copy nonmutated); (ii) found that individuals bearing the G328A mutation (R allele) and/or the RS haplotype were widely distributed in Spanish medfly populations during the years that malathion was used; and (iii) showed that malathion resistance reverted in field populations when analysed 8–13 years after malathion was withdrawn, but the frequencies of the genotypes containing the RS haplotype remained stable (RS/RS) or declined less (S/RS) than those containing the R allele (R/R, R/S, R/RS).CONCLUSION: This represents a scenario where the R allele and the RS haplotype are present in the field at low frequencies, but resistance may rapidly evolve if malathion or other organophosphates were used in the absence of appropriate management resistance strategies.
PB Wiley
SN 1526-498X
YR 2025
FD 2025-03-11
LK https://hdl.handle.net/20.500.14352/122447
UL https://hdl.handle.net/20.500.14352/122447
LA eng
NO Couso‐Ferrer, F., López‐Errasquín, E., Arouri, R., Beroiz, B., Perera, N., Sánchez, L., & Ortego, F. (2025). Tracking malathion resistance in Spanish Ceratitis capitata populations: Prevalence of resistance alleles/haplotypes before and after the withdrawal of malathion. Pest Management Science, 81(7), 3921-3932. https://doi.org/10.1002/ps.8761
NO This work was supported by the Grants: AGL2007-63388/AGR funded by CICYT, and PID2022-137142OB-I00 funded by MICIU/AEI/10.13039/501100011033 and by ‘ERDF/EU’; and by Predoc Fellowships to Francisco Couso-Ferrer (BES-2005-9406) and Rabeh Arouri (BES-2008-006863) funded by Ministerio de Ciencia e Innovación, Spain
NO Ministerio de Ciencia, Innovación y Universidades (España)
NO Agencia Estatal de Investigación (España)
DS Docta Complutense
RD 27 dic 2025