The flightless ground beetle Carabus variolosus Fabricius, 1787 (Coleoptera: Carabidae) is a rare and threatened habitat specialist of headwater areas and swamps in deciduous woodlands. Both larvae and adults live close to the water edge where
Institute of Ecology and Environmental Chemistry, Leuphana University Lüneburg, Scharnhorststraße 1, D-21335 Lüneburg, Germany e-mail: [email protected]
Department of Entomology, The Natural History Museum, Cromwell Road,
London, SW7 5BD, UK and Division of Biology, Imperial College London, Silwood Park
Campus, Ascot, Berkshire, SL5 7PY, UK
J.C. Habel and T. Assmann (eds.), Relict Species: Phylogeography and Conservation Biology, 253 DOI 10.1007/978-3-540-92160-8_14, © Springer-Verlag Berlin Heidelberg 2010
they forage (Sturani 1963). Populations persist in localised areas under pristine habitat conditions of which C. variolosas is considered to be an indicator (Turin et al. 2003). Remaining populations are spread in a disjunct range throughout Central and South Eastern Europe. While already confined to a restricted range, the distribution of C. variolosas is further contracting presumably due to habitat destruction and pollution (Pavicevic and Mesaros 1997; Turin et al. 2003; Matern and Assmann 2004), resulting in its status as a "relict species" (sensu Fryxell 1962).
Taxonomically, C. variolosas has been subdivided into two allopatric subspecies, which can be distinguished reliably only by the different tip shape of the male genitalia (Breuning 1926). The Western C. v. nodalosas Creutzer, 1799 extends to Germany and France and along the Dinaric mountains Southwards to Macedonia (Breuning 1926; Turin et al. 2003). The Eastern C. variolosas s. str. ranges from the Czech Republic and South Poland along the Carpathian mountains to the Western edge of the Balkan mountains in Bulgaria (Breuning 1926; Turin et al. 2003). Over the past 20 years some authors considered both taxa as sister species (e.g. Casale et al. 1982; Deuve 1994), triggering a debate about their taxonomic rank. In 2004, C. variolosas was listed as a "species of Community interest" under the EU Habitat and Species Directive, which requires the European member states, to secure its long-term survival. This may be achieved by strict measures for protection, including the designation of reserves, the application of suitable management plans, and the establishment and maintenance of a "favorable conservation status" for the species (The Council of the European Communities 2004). However, expanding basic knowledge about this rarely studied beetle is necessary to assess and monitor its conservation status and devise effective management measures.
Population ecology and population genetics are complementary approaches to address questions about species conservation management. Combined, they offer valuable insights into viable population size and structure, population dynamics and isolation, dispersal and colonization ability, while addressing different spatial and temporal scales (e.g. Ranius 2006; Schmeller and Merilä 2007; Schwartz et al. 2007). This is of great importance for the protection of biodiversity and the improvement of conservation measures, providing information on, for example, the habitat requirements of species (e.g. Gröning et al. 2007), the levels of genetic variability in populations (e.g. Böhme et al. 2007), and the recognition of distinct gene pools and evolutionary lineages (e.g. Palsb0ll et al. 2007).
Here, we review our ongoing investigations on the population ecology and population genetics of C. variolosas, including recent results from mtDNA data. We discuss the findings with a specific focus on the (1) postglacial history of the Western subspecies C. v. nodalosas and (2) the implications of the results for conservation issues showing the benefit of combining field-based and genetic approaches.
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