Endemic-population
Guides
Plebejus optilete
Cranberry Blue
Plebejus optilete, commonly known as the Cranberry Blue, is a montane lycaenid butterfly species found in European mountain systems. The species has a restricted distribution in Slovenia, limited to six separate sites on the crests of the western Pohorje Mountains. It is associated with silicate grasslands containing abundant Vaccinium species, which likely serve as larval host plants. Population monitoring indicates declining abundance across most sites, with habitat degradation from overgrazing, inappropriate land use, and tourism development posing significant threats.