BIOGEOGRAPHY OF HYCLEUS (COLEOPTERA: MELOIDAE): SPATIAL AND TEMPORAL DIVERSIFICATION OF A HYPER-DIVERSE GENUS

The genus Hycleus is a hyper-diverse genus of blister beetles including ~500 species with a wide geographic distribution in different biogeographic regions in the Old World, and with the highest diversity occurring in the Afrotropical Region. The phylogenetic relationships among the species and the biogeographic processes related to their diversification have never been investigated. In this study, to provide a biogeographic hypothesis that allow explaining the current diversity and the observed distribution patterns of Hycleus, we built a robust time-calibrated phylogenetic tree using mitochondrial and nuclear DNA obtained from 125 species. Phylogenetic results were subsequently used for biogeographic inference carried out with the R package BioGeoBEARS. Four main lineages were detected in our tree: A. including only Afrotropical species; B. including only Saharo-Sindian species; C. comprising Afrotropical, Palaearctic and Saharo-Sindian species; and D. comprising Afrotropical and Oriental species. According to our results, the genus Hycleus likely originated in the Afrotropical Region during the Early Miocene (~20 Mya), and subsequently spread in the Saharo-Sindian Transitional Region and in the Palaearctic Region. In the Late Miocene (~7.5 Mya) a second Saharo-Sindian group branched off from the Palaearctic lineage, whereas the Oriental Region was colonized (~7.8 Mya) following a dispersal event through the Arabian Peninsula from the Afrotropical Region.