Molecular phylogeny and biogeography of the West‐Palaearctic Velia (Heteroptera: Gerromorpha: Veliidae)

We investigated the systematics and biogeography of the West-Palaearctic water cricket genus Velia Latreille based on a phylogenetic analysis of five molecular markers obtained from 79% of all known taxa of the subgenera Velia (s.s.) and Velia (Plesiovelia) Tamanini. The results revealed a sister-group relationship between Velia (Plesiovelia) and the monotypic subgenus Velia (s.s.), and showed that the former is divided into three major clades. All taxa of Velia (Plesiovelia) were recovered as monophyletic, except for V. (P.) serbica Tamanini, which was paraphyletic with respect to V. (P.) mancinii mancinii Tamanini. Our results also indicate the existence of several unrecognized species. Molecular dating based on fossil data and COI rates indicates that the split between Velia (s.s.) and Velia (Plesiovelia) occurred between 40 and 22 Ma. An ancestral area reconstruction suggests that the latter originated in southeastern Europe, from where it radiated to the west and east, along the Neogene archipelagos of Europe and Asia Minor. Northwestern Africa served as the second most important diversification centre of the subgenus. The low genetic variability in the widespread V. (P.) caprai caprai Tamanini and V. (P.) saulii Tamanini implies a rapid postglacial colonization of Europe, whereas high diversity within the lineages of V. (P.) serbica indicates survival of Pleistocene glaciations in microrefugia throughout southeastern Europe. These results serve as a useful framework for future studies ranging from the systematics of the group to historical biogeography, ecology and biodiversity conservation.