Department of Biological Sciences, The George Washington University, 2029 G Street NW, Bell Hall 302, Washington, DC 20052, United States; Department of Integrative Biology, University of Wisconsin-Madison, 430 Lincoln Dr., Madison, WI 53706, United States.
Department of Biological Sciences, The George Washington University, 2029 G Street NW, Bell Hall 302, Washington, DC 20052, United States.
Mol Phylogenet Evol. 2018 Apr;121:183-197. doi: 10.1016/j.ympev.2018.01.002. Epub 2018 Jan 11.
The orchard spider, Leucauge venusta (Walckenaer, 1841) is one of the most common and abundant orb-weavers in North America. This species has a broad geographic distribution extending across tropical and temperate regions of the Americas from Canada to Brazil. Guided by a preliminary observation of the barcode gap between sequences from specimens of L. venusta collected in Florida and other North American localities, we collected across a transect through the southeastern USA to investigate the observed genetic divide. The dataset, complemented with additional samples from Mexico, and Brazil was analyzed for species delimitation using STACEY and bGMYC based on sequences from one nuclear (ITS2) and one mitochondrial marker (COI). The analyses clearly separate USA samples into two deeply divergent and geographically structured groups (north-south) which we interpret as two different species. We generated ecological niche models for these two groups rejecting a niche equivalence hypothesis for these lineages. Taxonomic changes are proposed based on these findings, Leucauge venusta is restricted to denote the northern clade, and its known distribution restricted to the USA. Leucauge argyrobapta (White, 1841) is removed from synonymy to denote the populations in Florida, Mexico and Brazil. Although the delimitation analyses suggest each of these geographic clusters within the L. argyrobapta samples represent different species, more specimens from Central and South America are needed to properly test the cohesion of L. argyrobapta populations.
果园蜘蛛，Leucauge venusta（Walckenaer，1841）是北美的最常见和最丰富的圆蛛之一。该物种的地理分布范围广泛，从加拿大延伸到巴西，横跨美洲的热带和温带地区。根据对佛罗里达州和其他北美的 L. venusta 标本序列进行条码间隙的初步观察，我们在整个美国东南部进行了收集，以调查观察到的遗传分裂。该数据集补充了来自墨西哥和巴西的其他样本，使用基于一个核（ITS2）和一个线粒体标记（COI）的序列的 STACEY 和 bGMYC 进行物种划定分析。分析清楚地将美国样本分为两个深度分化和地理结构的组（南北），我们将其解释为两个不同的物种。我们为这两个组生成了生态位模型，拒绝了这些谱系的生态位等价假设。根据这些发现提出了分类变化，Leucauge venusta 被限制表示北方分支，其已知分布限于美国。Leucauge argyrobapta（White，1841）被从同义词中删除，表示佛罗里达州，墨西哥和巴西的种群。尽管这些划分分析表明，L. argyrobapta 样本中的每个地理聚类都代表不同的物种，但需要更多来自中美洲和南美洲的标本才能正确测试 L. argyrobapta 种群的凝聚力。
