The olive fruit fly (olf) Bactrocera oleae is the most damaging olive pest. The intensive use of organophosphates (OPs) to control it, led to an increase in resistance in field populations. This study assesses the presence and distribution of three mutations at the ace gene related to target site insensitivity to OPs in Spain. Samples from other Mediterranean countries were included as external references. Resistance-conferring alleles (from exons IV and VII of the ace gene) reached almost an 80% frequency in olf Spanish populations. In total, 62% of them were homozygous (RR/RR), this being more common in eastern mainland Spain. High frequencies of RR/RR individuals were also found in North Mediterranean samples. Conversely, in Tunisia, only sensitive alleles were detected. Finally, the exon X mutation ∆Q3 had an extremely low frequency in all samples. The high frequency of genotype RR/RR in Spain indicates high fitness in an agroecosystem treated with pesticides, in contrast to ∆Q3. At exon IV all flies carried the same haplotype for the allele conferring resistance. The sequence analysis at this exon suggests a unique origin and fast expansion of the resistant allele. These results provide evidence that OPs appropriate use is needed and prompt the search for alternative methods for olf pest control.

中文翻译：

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西班牙橄榄果蝇种群中有机磷抗性ace等位基因的系统志：在全球变化背景下的地中海视角。

橄榄果蝇（OLF）实蝇油橄榄是最具破坏性的害虫橄榄。大量使用有机磷酸盐（OPs）来控制它，导致田间种群的抗药性增加。这项研究评估了ace基因上三个突变的存在和分布，这些突变与西班牙目标地区对OP的不敏感性有关。包括来自其他地中海国家的样品作为外部参考。赋予抗性的等位基因（来自ace基因的第IV和VII外显子）在西班牙olf人群中的频率达到近80％。总共有62％是纯合子（RR / RR），在西班牙东部大陆更为常见。高频率的RR / RR在北地中海样本中也发现了这些个体。相反，在突尼斯，仅检测到敏感等位基因。最后，外显子X突变ΔQ3在所有样本中的发生频率都非常低。西班牙的RR / RR基因型频率很高，这表明与ΔQ3相比，在经过农药处理的农业生态系统中具有很高的适应性。在第4外显子上，所有苍蝇均具有相同的单倍型，从而赋予了抗性等位基因。该外显子的序列分析表明抗性等位基因的独特起源和快速扩增。这些结果对替代方法提供的证据表明，需要有机磷农药合理使用和及时搜索OLF防治病虫害。