Leaf‐cutting ants (genera Acromyrmex and Atta) are the most important herbivores in the Neotropical region. Within the genus Acromyrmex, the species and subspecies Acromyrmex striatus, Acromyrmex silvestrii subsp. silvestrii and Acromyrmex silvestrii subsp. bruchi are morphologically similar to one another but differ from the rest of their congeners. Recent studies have suggested that Ac. striatus belongs to a currently undescribed leaf‐cutting ant genus. Herein, we propose a new phylogenetic hypothesis for leaf‐cutting ants based on five nuclear genes (wg, LW Rh, EF1αF1, EF1αF2 and Top1) and describe a new genus. We used colonies of Ac. striatus, Ac. silvestrii silvestrii and Ac. silvestrii bruchi collected from Brazil, Argentina, Uruguay and Bolivia, covering most of their known distribution. We constructed a molecular phylogenetic hypothesis for these three taxa using sequences from the mtDNA COI gene. The retrieved phylogenetic tree reveals that Ac. striatus, Ac. silvestrii silvestrii and Ac. silvestrii bruchi form a well‐supported clade (P.P. = 1). Through analyses of molecular phylogenetic and morphological data, we propose a new genus of leaf‐cutting ant, Amoimyrmex Cristiano, Cardoso & Sandoval, gen. nov., redescribe the species Amoimyrmex striatus (Roger, 1863) comb. nov. and Amoimyrmex silvestrii (Emery, 1905) comb. nov., and elevate Ac. silvestrii bruchi to the level of species as Amoimyrmex bruchi (Forel, 1912) comb. nov. et stat. rev.. We also provide information on the geographic distribution of Amoimyrmex, an illustrated identification key for its taxa and descriptions of all the known castes of each species, including diagnostic characteristics, high‐quality images and distribution maps. We believe that the results of this study contribute substantially to taxonomic knowledge of leaf‐cutting ants and reaffirm the complex evolutionary history of the group.

中文翻译：

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Amoimyrmex Cristiano，Cardoso和Sandoval，gen。十一月 （膜翅目：蚁科）：通过多位点分子系统发育和形态学分析揭示的一种切叶蚁新属

切叶蚁（Acromyrmex和Atta属）是新热带地区最重要的草食动物。在Acromyrmex属中，Acromyrmex striatus的种类和亚种，Acromyrmex silvestrii亚属。silvestrii和Acromyrmex silvestrii子亚种。布鲁奇在形态上彼此相似，但不同于其余同类。最近的研究表明，Ac。纹状体属于目前未描述的切叶蚂蚁属。本文中，我们基于五个核基因（wg，LW Rh，EF1αF1，EF1αF2和Top1）提出了切叶蚁的新系统发育假说，并描述了一个新属。我们使用了Ac的菌落。叶蝉，交流。silvestrii和Ac。silvestrii bruchi收集自巴西，阿根廷，乌拉圭和玻利维亚，涵盖了大多数已知分布。我们使用来自mtDNA COI基因的序列为这三个分类群构建了分子系统发育假说。检索到的系统发育树揭示了Ac。叶蝉，交流。silvestrii和Ac。西尔维斯特里·布鲁奇形成支撑良好的进化枝（PP = 1）。通过对分子系统发育和形态学数据的分析，我们提出了切叶蚁的新属，Amoimyrmex Cristiano，Cardoso＆Sandoval，gen。十一月 ，重新描述物种Amoimyrmex striatus（Roger，1863）梳子。十一月 和Amoimyrmex silvestrii（Emery，1905）梳子。十一月 ，并提升Ac。silvestrii bruchi达到与Amoimyrmex bruchi（Forel，1912）梳理的种类相同的水平。十一月 等统计。转速 。我们还提供有关Amoimyrmex地理分布的信息，其分类单元的插图识别码，以及每个物种的所有已知种姓的描述，包括诊断特征，高质量图像和分布图。我们认为，这项研究的结果大大有助于切叶蚁的分类学知识，并重申了该群体的复杂进化史。