Palaeoclimatic models\xa0- predicted changes in the potential Neogene distribution patterns of Phlebotomus similis and Phlebotomus sergenti (Insecta: Diptera: Psychodidae)

Attila J Trájer

doi:10.1007/s12549-021-00483-2

Abstract

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.

Highlights

As members of the Mediterranean fauna, the Mediterranean sandfly species are the vectors of several Phleboviruses and Leishmania parasites which are the causative agents of serious veterinary and human diseases
Climate determines the range of sandfly taxa, and it is possible that climatic variables strongly influenced the past occurrences of the species. As it was described in the ‘Introduction’, sandfly species appear to be quite conservative in their environmental demands, and it is possible that the environmental requirements of the Mediterranean sandfly were determined by the climatic effects and geographic conditions of the Neogene period (Esseghir et al 2000; Trájer et al 2018a)
It is known that the distribution limiting climatic values of Ph. sergenti, which is one of the closest living relatives of Ph. similis, is very similar to the previous species (Table 1; Trájer et al 2013) even though the divergence of the two species should occur in the mid-Miocene epoch, before the disappearance of the Paratethys Sea (Depaquit et al 2002)

Summary

Introduction

As members of the Mediterranean fauna, the Mediterranean sandfly species are the vectors of several Phleboviruses and Leishmania parasites which are the causative agents of serious veterinary and human diseases. Leishmaniasis is an emerging epidemiological hazard in Europe (Ready 2010). Sandfly-borne diseases mean significant health risks, but they impose a notable economic burden on society. Only in Italy, the direct costs for hospital admissions related to human leishmaniasis were between 1,637 and 1,370 thousand euro per year in the period 1999–2003 (Mannocci et al 2007). Sandflyborne diseases cause great veterinary expenditures in Europe. In Spain, a study revealed that up to 13–20% of dogs

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