Palaeoclimatic models - predicted changes in the potential Neogene distribution patterns of Phlebotomus similis and Phlebotomus sergenti (Insecta: Diptera: Psychodidae)

Former studies proposed that the speciation of the subgenus Paraphlebotomus happened in the Neogene Epoch in the circum-Mediterranean region due to the geographical segregation effect of the former Paratethys Sea. It was aimed to study whether the modelled Neogene ranges of Phlebotomus sergenti and Phlebotomus similis support or contradict this barrier role of the Paratethys in the speciation of Paraphlebotomus sandfly. For this purpose, the potential Neogene geographical ranges of Phlebotomus sergenti and Phlebotomus similis were modelled based on the present climatic requirements of the taxa. The Miocene models do not support the circum-Paratethyan migration of the ancestor of Phlebotomus similis. In general, Phlebotomus similis shows a low affinity to the North Paratethyan shorelines during the entire Miocene epoch. The only exceptions are the Tortonian and early Messinian periods when the climatic conditions could be suitable for Phlebotomus similis in the North Paratethyan shorelines. It was found that neither the modelled late Miocene, Pliocene nor the mid-Pleistocene period distributions of Phlebotomus sergenti and Phlebotomus similis shows notable differences in the suitability values in the Balkans and the Middle East. It is most plausible that the divergence of the Phlebotomus similis and its relatives was related to the tectonic subsidence of the Hellene Orogenic Belt and Phlebotomus similis specialised in the Balkan Peninsula and the present-day North Pontic area during the middle-late Miocene epoch. The Messinian desiccations of the Mediterranean Basin and the Zanclean re-flood caused the migration, but not the speciation of Phlebotomus similis and its sister taxa.

Automated summary

Previous studies suggested that speciation of the subgenus Paraphlebotomus occurred in the Neogene Epoch in the circum-Mediterranean region due to the geographical segregation effect of the former Paratethys Sea. The models of Neogene ranges of Phlebotomus sergenti and Phlebotomus similis did not seem to support the idea of circum-Paratethyan migration of Phlebotomus similis, indicating a low affinity to the North Paratethyan shorelines during the Miocene epoch. The study found that tectonic subsidence and climatic conditions in different periods likely played a role in the divergence and distribution of Phlebotomus similis and its relatives.