Extinction of Lasiommata petropolitana (Fabricius, 1787) (Lepidoptera: Nymphalidae) in the Czech Republic: a case of habitat loss at a range margin

Lasiommata petropolitana is a boreomontane butterfly, declining in Central Europe and not recorded in the Czech Republic since 1975. Based on revision of all existing archival records and results of recent targeted surveys in mountainous regions of East Moravia, area of its past occurrence, we document its gradual retreat and ultimate regional extinction. The historical range, marginal with respect to contiguous distribution along the Carpathian mountain chain, included both foothills and higher elevations of Bílé Karpaty, Hostýnské Vrchy, Javorníky, Moravskoslezské Beskydy and Vsetínské Vrchy Mts; pre-1950 records document also a past occurrence at calcareous bedrock localities in Brno environs. Other past lowland records (Oslava valley, Olomouc, Znojmo) were due to misidentifications. Within the historical Czech range, the butterfly inhabited pastures with exposed calcareous, flysh or sandstone bedrock, maintained by traditional grazing. The decline of the species proceeded from lower elevations and foothills towards mountain ridges. The higher elevation sites were encroached by successional changes, or intentionally afforested, with post-war decline of mountain grazing. This development went largely unnoticed by conservation authorities, and represents a loss of mountain butterfly from marginal parts of its range.