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 Bukovské Mountains (Kremenec) grouped together; (2) a Čergov group containing populations only from the Čergov Mountains; (3) a Volovské Mountains group with populations from Kojšovská hoľa and Slovak Paradise grouped together, most likely due to the lack of geographic isolation between the areas; (4) haplotypes characterized from the Volovské 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 Volovské Mountains for populations also occurring in Czech mountain regions.

Linking large‐scale genetic structure of three Argynnini butterfly species to geography and environment

“…Varga, 2012) for S. aglaja, as observed for some other Lepidoptera species, such as Polyommatus coridon(Kühne et al, 2017), Erebia euryale(Paučulová et al, 2017) and Coenonympha arcania(Cassel- Lundhagen et al, 2020).distances in females and a lifespan twice as long as in males, which would support the hypothesis of sex-biased dispersal as the reason for the observed mitonuclear discordance. Most other explanations…”

“…Because mtDNA is more vulnerable to selective sweeps, such phenomena can be observed more strongly when sequencing the mtDNA. In contrast to nuclear data attained via ddRADseq, the most distinct lineage formed by Eastern European samples (Ag1, 6 bp from the rest) suggests that some areas in the Carpathians might have constituted an extra‐Mediterranean microrefugium (Schmitt & Varga, 2012) for S. aglaja , as observed for some other Lepidoptera species, such as Polyommatus coridon (Kühne et al, 2017), Erebia euryale (Paučulová et al, 2017) and Coenonympha arcania (Cassel‐Lundhagen et al, 2020). An early split might have happened between this region and the rest of Europe (Schmitt & Varga, 2012), with the Carpathians staying separated for a relatively long time and thus being less affected by gene flow or selective sweeps.…”

Mitochondrial DNA-based phylogeography of the large ringlet Erebia euryale (Esper, 1805) suggests recurrent Alpine-Carpathian disjunctions during Pleistocene (Nymphalidae, Satyrinae)

“…A mtDNA based study (Vila et al 2011) revealed that (i) the populations from the Pyrenees and Cantabria represent a single lineage, and (ii) the ocellaris and isarica samples are phylogenetically closer to syrmia than to each other. Paučulová et al (2017) found two genetic lineages in the Carpathians and the Sudeten Mts, coinciding with the morphologic ssp. euryale and syrmia, and established the border between them.…”

“…Additional COI sequences were retrieved from BOLD and GenBank, from localities not represented in our samples. These covered bp 1-658 (Dincă et al 2010), bp 668-1483 (Vila et al 2011) or bp 305-1475 (Paučulová et al 2017) (Table 1, Suppl. material 1: Table S1).…”

“…The number of genetic lineages of E. euryale in the Alps thus may vary between two and five, depending on the underlying data. In order to obtain one dataset covering all recognized and potential lineages, we extended previously published mtDNA data (Dincă et al 2010;Vila et al 2011;Paučulová et al 2017) with 15 Alpine populations and a Jurassian one. We sequenced both the 5'P section of the Cytochrome C Oxidase I gene (the "barcode section"), and the 3'P part, which has proven to be more informative in some Erebia species (Vila et al 2005;Vila et al 2011), although not all of them (Cupedo and Doorenweerd 2020).…”