Integrati ve taxonomy of Megalomyrmex Forel, 1885 (Hymernoptera: Formicidae) for species groups delimitation
Lívia Pires do Prado, Rachelle M. M. Adams , Rogério R. Silva , Carlos Roberto F. Brandão
Laboratório de Ecologia e Morfologia Funcional de Formigas, Campus de Pesquisa de Ciências da Terra e Ecologia, Museu Paraense Emílio Goeldi; Department of Evolution, Ecology and Organismal Biology Museum of Biological Diversity, Ohio State University ; Laboratório de Ecologia e Morfologia Funcional de Formigas, Campus de Pesquisa de Ciências da Terra e Ecologia, Museu Paraense Emílio Goeldi ; Laboratório de Hymenoptera, Museu de Zoologia da Universidade de São Paulo
Higher level taxonomy and phylogeny of Formicidae have stabilized in recent years due to advances in molecular and morphological of extant and fossil taxa. Myrmicinae was the subject of a recent molecular phylogenetic study condensing the former 25 myrmicine tribes into a six tribes. The genus Megalomyrmex Forel, 1885 belongs to the tribe Solenopsidini, currently composed of 44 valid species distributed in four groups (leoninus, modestus, pusillus and silvestrii), morphologically and behaviorally characterized. The species of the genus Megalomyrmex are diverse in behavior, several are predacious, some species can be free-living or associated with fungus-farming ants, maintaining lestobiotic, agro-predatory, or xenobiotic relationships. Since the last taxonomic revision carried by Brandão (1990), more than 10 species and castes hitherto unknown have been described, as well as information on the biology and geographical distribution. Recent revisionary studies in Central America, focusing on the study of workers and males have questioned morphological limits of the species groups, due to extreme morphological variation. The aim of this study is to assess the relationships and boundaries among the species groups of Megalomyrmex combining morphological, behavioral, chemistry of venom alkaloids and molecular data. Preliminary results indicate that: (i) Megalomyrmex as a monophyletic group within Solenopsidini; (ii) a single origin of social parasitism in the genus; (iii) the silvestrii and pusillus species groups as a single species group; (iv) leoninus species group is a monophyletic and; (v) the phylogentic position of modestus group is unclear. In the next analyzes, we will use a wider geographical coverage and employ Ultraconserved Elements (UCEs) and morphology to continue the study of the relationships among the genus and investigate questions about the diversification, associations and behavior.