Evolutionary units of Coraebus elatus (Coleoptera: Buprestidae) in central and eastern Europe – implications for origin and conservation

Abstract

Abstract The distribution of steppe‐like habitats and, consequently, species dependent on these habitats in Eurasia is currently highly fragmented beyond the zone of continental climate, as a result of unfavourable climatic conditions and anthropogenic transformation of the environment. This patchy distribution may pose a threat for persistence of steppic species, especially in central Europe. To develop conservation strategies, it is essential to collect information on genetic structure of the species occupying this kind of habitats. We investigated the genetic structure and diversity of central and eastern Coraebus elatus (F.) populations using sequences of mtDNA and an anonymous fragment of the nuclear genome. Both markers exhibited similar pattern, indicating the presence of four or five highly differentiated evolutionary units (2.1–3.2% sequence divergence in mtDNA and 0.7–2.1% in the nuclear marker) encompassing populations from the Caucasus, the Azov Sea coasts, central Europe with the Balkans (with further substructuring) and probably western Europe. These clusters should be considered evolutionary significant units for the conservation biology of this species, and may form the basis for a future taxonomic revision. Pattern of C. elatus diversity suggests that this species presently occupies not only continental ‘warm‐stage’ refugia formerly described in Pontic and Pannonian areas but also cryptic steppic ‘warm‐stage’ refugia in north‐central Europe. In line with other studies on steppic beetles, our data strongly suggest that such species are strongly structured genetically, with very limited genetic variation within populations, which may have very serious consequences for their persistence in the future.