Searching for the glacial refugia ofErebia euryale(Lepidoptera, Nymphalidae) - insights from mtDNA- and nDNA-based phylogeography in the Western Carpathians

Abstract

The refugial history and postglacial re-colonization routes of Western Carpathian insects are insufficiently understood. Therefore, we investigated the spatio-genetic structure (phylogeography) of Western Carpathian populations of Erebia euryale (Esper, 1805) (Lepidoptera, Nymphalidae) and inferred their colonization routes over the postglacial period. Our results provide new insights into the phylogeography and origin of Erebia euryale in the rarely studied region of the Western Carpathian Mountains. Their phylogeography, including glacial refugia and Pleistocene expansion routes, was reconstructed based on two mitochondrial (COI and CR) and three nuclear markers (CAD, MDH and IDH). Statistical parsimony networks showed the following geographic coherences: (1) populations from Romania and the Bukovske Mountains (Kremenec) grouped together; (2) a Cergov group containing populations only from the Cergov Mountains; (3) a Volovske Mountains group with populations from Kojsovska hoľa and Slovak Paradise grouped together, most likely due to the lack of geographic isolation between the areas; (4) haplotypes characterized from the Volovske Mountains populations were widespread. Comparisons of Western Carpathian E. euryale COI-haplotypes with haplotypes from the Southern Carpathians and Balkans suggest that the refugial areas were located in south-eastern Europe in the Balkan region and Southern Carpathians. We also hypothesize possible central European contact zones in Slovakia for E. euryale in the Western Carpathians. Our results indicate that the Western Carpathians could have served as one of the contact zones between Eastern and Western populations, and additionally as an extra refugium in the southern part of the Volovske Mountains for populations also occurring in Czech mountain regions.