A new conservation unit in the butterfly Erebia triaria (Nymphalidae) as revealed by nuclear and mitochondrial markers

Priorities for conservation of biological units should ideally combine ecology and genetics. The European butterfly Erebia triaria (Nymphalidae: Satyrinae) has disappeared from several sites in Europe during the 20th century. In order to assess the conservation values of this species in NW Iberia, we screened the genetic variability and differentiation of four nuclear microsatellite markers in five populations from this area. We used a Pyrenean population as an outgroup. One particular population (Xistral, NW Iberia) was significantly different from the others. Thus, the nuclear results fully agreed with the pattern found using mitochondrial DNA sequences, and the hypothesis of incipient speciation of this population, due to an ancient isolation event, gained additional support. By combining our genetic findings with morpho- and ecological data, we argue that this population be considered a distinct unit for conservation.