The possible region of the Late Miocene split of the sandfly subgenus Transphlebotomus Artemiev and the early late Neogene to late Quaternary dispersal of the ancestor of Phlebotomus mascittii Grassi

Abstract

The distribution of the Mediterranean Transphlebotomus species shows a marked zoogeographical dichotomy in the sense that Phlebotomus mascittii has a wide range in Europe, and the other species are restricted to the East Mediterranean region. The study aimed to investigate how the Neogene to late Quaternary climatic-geographical alterations could influence the split of the sandfly subgenus Transphlebotomus and the speciation of Phlebotomus mascitti. For this purpose, the climatic suitability patterns of the species were modelled for seven Neogene and Quaternary periods and the divergence times of Transphlebotomus clades were estimated. The model results suggest that the common ancestor of the extant Mediterranean-European Transphlebotomus species could be adapted to the Late Miocene climate of Western and Central Europe. Phylogenetic results suggest that the speciation of Ph. mascittii started in the Tortonian period, plausibly related to the rise of the Dinaric land bridge. The Central and Eastern Paratethys Seas could have played an important role in the split of the ancestral Phlebotomus mascittii populations and other Transphlebotomus populations. These other species can be the descendants of ancient Transphlebotomus populations adapted to the hotter and drier climate of the areas south of the Central and Eastern Paratethys. Their divergence could be strongly linked to the formation of the Aegean trench and, later, the Messinian salinity crisis. The Pliocene climatic fluctuations could result in habitat loss of Transphlebotomus populations in Europe which was particularly significant during glacial maxima such as the Last Glacial Maximum.