Data from: Genetic analyses reveal cryptic diversity in the native North American fire ants (Hymenoptera: Formicidae: Solenopsis)

The native North American fire ants (Solenopsis) comprise a difficult group taxonomically that has undergone multiple revisions in the past century yet remains in a state of taxonomic uncertainty. In this study, we utilized a large set of microsatellite markers to conduct the first robust genetic analysis of the nominal species. Our approach used a variety of methods to test operational criteria commonly employed in species delimitation, including genotypic clustering, reproductive isolation/cohesion, and monophyly. We conclude from our results that the recognized North American fire ant species represent evolutionarily independent entities and, moreover, we confirm the presumed sister status of the desert fire ants, S. aurea and S. amblychila. However, the presence of at least two genetically divergent populations within the nominal species boundaries, including a western form of S. xyloni and a distinct population of S. aurea endemic to the Coachella Valley of California, suggests that the current taxonomy does not fully capture the species-level diversity in this group. Our study provides the molecular foundation for future integrated studies of the taxonomy and evolution of this scientifically and economically important group of insects.

原产于北美的火蚁属（Solenopsis）昆虫是一个极具挑战性的分类学类群：尽管在过去一个世纪中已历经多次分类修订，其分类地位仍处于不确定状态。本研究利用大量微卫星标记（microsatellite marker），首次对该类群的名义物种开展了严谨的遗传学分析。研究采用多种方法，对物种界定中常用的操作标准进行验证，包括基因型聚类、生殖隔离/生殖凝聚以及单系性（monophyly）分析。结果表明，当前公认的北美火蚁物种均为演化上独立的单元；此外，本研究证实了沙漠火蚁（S. aurea与S. amblychila）被推测为姊妹群的分类关系。然而，在名义物种的分类范围内已发现至少两个遗传分化显著的种群：包括分布于西部的S. xyloni类群，以及仅分布于美国加利福尼亚州科切拉谷的特有S. aurea种群。这说明当前的分类系统未能完全涵盖该类群的物种级多样性。本研究为该兼具科学与经济重要性的昆虫类群的分类学与演化综合研究，奠定了分子生物学基础。