The pearl-bordered fritillary (Boloria euphrosyne) is a butterfly of the family Nymphalidae found in Europe and through Russia across the Palearctic to the north of Kazakhstan.
Named in the Classical tradition.In ancient Greek religion and mythology, Euphrosyne is a deity, one of the Charites.
The adult butterfly is orange with black spots on the upperside of its wing and has a wingspan of 38–46 mm. The underside of the wings have a row of silver-pearly markings along the edge, which give the species its name. The pearl-bordered fritillary is often confused with the small pearl-bordered fritillary, but can be distinguished by the triangle along its pearl border (the small pearl-bordered has black chevrons) as well as the presence of a single silver spot in the middle of a row of yellow spots. The female has darker markings and rounder wings than the male. The caterpillars are black with white or yellow spines along their backs.
Like other species of fritillary, the males have special scent glands on their wings so that they can be recognised by females of their own species and therefore find a suitable partner.
The pearl-bordered fritillary is widespread throughout Europe, ranging from Scandinavia to northern Spain and from Ireland eastwards across the Palearctic to Russia and to the north of Kazakhstan. In England and Wales (plus another 10 countries) it has declined rapidly in number and is a highly threatened species.