Taxonomic Review and Phylogenetic Analysis of the genus Hylomyrma Forel, 1912 (Formicidae: Myrmicinae: Myrmicini), based on morphological and molecular data

Abstract

Ants are eusocial insects with the most ecological success and dominant in all of terrestrial ecosystems. However, the phylogenetic relationships among the main lineages represent an important source of uncertainty in the literature. This is the case of Myrmicinae; its position between Formicidae subfamilies and its internal phylogeny remain unclear. Among the 25 tribes of Myrmicinae, Myrmicini is considered as a basal lineage and has been indicated as non monophyletic. Nevertheless, there is still a lot to be investigated about the internal relationships of the tribe; the latest tribe phylogeny analyzed only two species of Hylomyrma and only Pogonomyrmex species distributed in North America, understood as sister- genera. Hylomyrma is a Neotropical genus with 13 species with cryptic habits inhabitants of leaf-litter, marked by morphological uniformity. Still, the identity of some species is challenged because they were described from a small series of individuals, no more than three. In these situations, the study of morphological variation among the species is limited. In recent years, the study of leaf-litter with Winkler Extractors, especially in the Atlantic Forest (Project BIOTA/FAPESP) and Amazon Forest, and the use of Malaise to sample Hymenoptera (Project HYMPAR/FAPESP) allowed more frequent sampling of Hylomyrma, particularly workers, but also of males and gynes. As a result of these projects and due to the deposit of ants from different places in Brasil and Latin America, the Collection of Formicidae in the Museum of Zoology, Universidade de São Paulo, has accumulated a significant material of Hylomyrma, with broad geographic representation showing extensive morphological variation of the Hylomyrma species, as well as specimens clearly distinct from already known species. In this context, this study aims to perform a robust taxonomic review and phylogenetic analysis of Hylomyrma.