J Econ Entomol. 2014 Aug;107(4):1462-70. doi: 10.1603/ec14124.
Regions of southern Florida and southern Texas (extending into Mexico) provide the overwintering source populations for virtually all fall armyworm infestations affecting the continental United States. Understanding how these migratory populations annually disperse is important to predict and control infestations by this specific pest and to more generally investigate the environmental factors that influence the long-distance movements of flying insects. The two overwintering locations are associated with differences in the distribution of certain mitochondrial haplotypes that overlap in the region near the border separating the states of Alabama and Georgia. This provided an opportunity to test the resolution of the haplotype method by comparisons between smaller geographical areas and shorter time frames than previously examined. Correspondences were found between trap-capture numbers, fall armyworm strain proportions, and haplotype ratios calculated for individual counties and within season time periods that were generally consistent with expectations, providing confidence that those population movements could be accurately inferred. The comparison of haplotype distributions identified a migratory boundary separating the Texas and Florida populations coincident with the eastern edge of the Apalachicola-Chattahoochee-Flint River basin. Calculations of strain numbers based on genetic markers revealed similarities and differences in strain population dynamics that can be applied to study the migratory behavior of fall armyworm subpopulations. The use of this methodology for the detailed mapping of migratory pathways and the identification of factors that influence the direction and extent of pest migration are discussed.
美国南部佛罗里达州和得克萨斯州南部（延伸至墨西哥）地区是影响美国大陆的秋季行军虫几乎所有疫情的越冬源种群。了解这些迁徙种群如何每年扩散，对于预测和控制这种特定害虫的疫情以及更广泛地研究影响飞行昆虫长途迁移的环境因素非常重要。这两个越冬地点与某些线粒体单倍型的分布差异有关，这些单倍型在阿拉巴马州和佐治亚州边界附近的地区重叠。这为我们提供了一个机会，即在比以前研究的更小的地理区域和更短的时间框架内，对单倍型方法的分辨率进行测试。在个别县和季节内时间段内，我们发现了诱捕数量、秋季行军虫种群比例和单倍型比率之间的对应关系，这些关系通常与预期相符，这使我们有信心能够准确推断出这些种群的迁移情况。单倍型分布的比较确定了一个迁徙边界，将德克萨斯州和佛罗里达州的种群与阿巴拉契科拉-查塔胡奇-弗林特河流域的东部边缘分开。基于遗传标记的种群数量计算揭示了种群动态的相似性和差异，可用于研究秋季行军虫亚种群的迁徙行为。本文讨论了该方法在详细绘制迁徙路径和确定影响害虫迁徙方向和程度的因素方面的应用。
