Data from: Introgression between divergent corn borer species in a region of sympatry: implications on the evolution and adaptation of pest arthropods

The Asian corn borer, Ostrinia furnacalis, and European corn borer, O. nubilalis (Lepidoptera: Crambidae), cause damage to cultivated maize in spatially distinct geographies, and have evolved divergent hydrocarbons as the basis of sexual communication. The Yili area of Xinjiang Uyghur Autonomous Region in China represents the only known region where O. furnacalis has invaded a native O. nubilalis range, and these two corn borer species have made secondary contact. Genetic differentiation was estimated between Ostrinia larvae collected from maize plants at 11 locations in Xinjiang Province, and genotyped using high throughput SNP and microsatellite markers. Maternal lineages were assessed by direct sequencing of mitochondrial cytochrome c oxidase subunit I and II haplotypes, and a high degree of genotypic diversity was demonstrated between lineages based on SNP genotypes. Furthermore, historical introgression was predicted among SNP genotypes only at sympatric locations in the Yili area, whereas in Xinjiang populations wherein only O. furnacalis haplotypes were detected no analogous introgressed genotypes were predicted. Our detection of putative hybrids and historical evidence of introgression defines Yili area as a hybrid zone between the species in normal ecological interactions, and furthermore might indicate that adaptive traits could spread even between seemingly divergent species through horizontal transmission. Results of this study indicate there may be a continuum in the degree of reproductive isolation between Ostrinia species, and that the elegance of distinct and complete speciation based on modifications to the pheromone communication might need to be reconsidered.亚洲玉米螟（Asian corn borer，学名Ostrinia furnacalis）与欧洲玉米螟（European corn borer，学名O. nubilalis，鳞翅目Lepidoptera：螟蛾科Crambidae）在空间分布迥异的地理区域内危害栽培玉米，并进化出趋异的烃类化合物作为性通讯的物质基础。中国新疆维吾尔自治区伊犁地区是目前已知唯一的亚洲玉米螟入侵至欧洲玉米螟原生分布区的区域，二者在此发生了二次接触。研究人员对从新疆11个采样点的玉米植株上采集的玉米螟（Ostrinia）幼虫开展了遗传分化评估，并通过高通量单核苷酸多态性（Single Nucleotide Polymorphism, SNP）与微卫星标记完成基因分型。本研究通过直接测序线粒体细胞色素c氧化酶亚基I与II的单倍型来评估母系谱系，基于SNP基因型的分析结果显示，不同谱系间存在高度的基因型多样性。进一步分析显示，仅在伊犁地区的同域分布采样点的SNP基因型中，预测到了历史基因渐渗现象；而在仅检测到亚洲玉米螟单倍型的新疆其他种群中，则未发现类似的渐渗基因型。本研究检测到疑似杂交个体以及基因渐渗的历史证据，将伊犁地区确定为这两个物种在正常生态互作下的杂交带；此外，该结果还表明，适应性性状甚至可以通过水平传递在看似趋异的物种间传播。本研究结果表明，玉米螟属物种间的生殖隔离程度可能存在连续渐变谱系，而基于信息素通讯修饰所形成的清晰且完整的物种形成模式，或许需要被重新审视。