Invasion of organisms into new ecosystems is increasingly common, due to the global trade in commodities. One of the most complex post-invasion scenarios occurs when an invasive species is related to a native pest, and even more so when they can hybridize and produce fertile progeny. The global pest Helicoverpa armigera was first detected in Brazil in 2013 and generated a wave of speculations about the possibility of hybridization with the native sister taxon Helicoverpa zea. In the present study, we used genome-wide single nucleotide polymorphisms from field-collected individuals to estimate hybridization between H. armigera and H. zea in different Brazilian agricultural landscapes. The frequency of hybridization varied from 15 to 30% depending on the statistical analyses. These methods showed more congruence in estimating that hybrids contained approximately 10% mixed ancestry (i.e. introgression) from either species. Hybridization also varied considerably depending on the geographic locations where the sample was collected, forming a ‘mosaic’ hybrid zone where introgression may be facilitated by environmental and landscape variables. Both landscape composition and bioclimatic variables indicated that maize and soybean cropland are the main factors responsible for high levels of introgression in agricultural landscapes. The impact of multiple H. armigera incursions is reflected in the structured and inbred pattern of genetic diversity. Our data showed that the landscape composition and bioclimatic variables influence the introgression rate between H. armigera and H. zea in agricultural areas. Continuous monitoring of the hybridization process in the field is necessary, since agricultural expansion, climatic fluctuations, changing composition of crop species and varieties, and dynamic planting seasons are some factors in South America that could cause a sudden alteration in the introgression rate between Helicoverpa species. Introgression between invasive and native pests can dramatically impact the evolution of host ranges and resistance management.

中文翻译：

---

棉铃虫和玉米穗虫之间的杂交和基因渗入：适应桥梁。


由于全球商品贸易，生物体入侵新生态系统变得越来越普遍。当入侵物种与本地害虫有亲缘关系时，就会发生最复杂的入侵后情况之一，当它们可以杂交并产生可育后代时，情况更是如此。全球性害虫棉铃虫于 2013 年在巴西首次被发现，并引发了一波关于与本地姐妹分类群玉米棉铃虫杂交可能性的猜测。在本研究中，我们利用现场采集的个体的全基因组单核苷酸多态性来估计巴西不同农业景观中棉铃虫和玉米须虫之间的杂交。根据统计分析，杂交频率从 15% 到 30% 不等。这些方法在估计杂种包含来自任一物种的大约 10% 的混合祖先（即基因渗入）时显示出更多的一致性。杂交也根据收集样本的地理位置而有很大差异，形成一个“马赛克”混合区，环境和景观变量可能会促进基因渗入。景观组成和生物气候变量都表明，玉米和大豆农田是造成农业景观高水平渗入的主要因素。多次棉铃虫入侵的影响反映在遗传多样性的结构和近交模式上。我们的数据表明，景观组成和生物气候变量影响农业区棉铃虫和玉米的渗入率。 有必要对田间杂交过程进行持续监测，因为南美洲的农业扩张、气候波动、作物种类和品种组成的变化以及动态的种植季节等因素可能会导致Helicoverpa物种之间的渗入率突然改变。入侵害虫和本地害虫之间的渗入可以极大地影响寄主范围的进化和抗性管理。