Pearl-bordered Fritillary
Boloria (Clossiana) euphrosyne

HOME
Boloria euphrosyne

Male, Switzerland, May 2018

Boloria euphrosyne

Male, Switzerland, May 2014

Boloria euphrosyne

Female, Switzerland, May 2014

Boloria euphrosyne

Female, Switzerland, April 2017

Boloria euphrosyne

Male, Switzerland, April 2017

Boloria euphrosyne

Female, Switzerland, July 2016

Boloria euphrosyne

Male, Switzerland, June 2014

Boloria euphrosyne

Switzerland, August 2014

Boloria euphrosyne

Female, Switzerland, July 2013

Boloria euphrosyne

Male, Switzerland, June 2013

Boloria euphrosyne

Female, Switzerland, June 2012

Switzerland, May 2005

Switzerland, May 2005

Switzerland, June 2009


Taking minerals, Switzerland, May 2009



At bugle, its favourite plant. Switzerland, May 2009.

Boloria euphrosyne distribution

Distribution

This is the most widespread and familiar of the Boloria species. It flies from late April or early May in most of Europe (from late May in the north and at altitude), typically in a single brood but with a weaker second brood in hotter areas. Although a woodland species, most often seen flying along spring rides and nectaring on bugle and other flowers, it reaches up into the mountains and can be found on flowery alpine slopes well away from the nearest trees.

Males are a rather bright orange above, with characteristic 'floating triangles' around the borders, rather than closed arches. Altogether, this gives them an open, spotty appearance, unlike the linear appearance of small pearl-bordered fritillaries. In females - which are generally larger and less bright - the triangles (or chevrons) often touch the border, enclosing discrete spots, more like small pearl-bordered. Another useful feature from above is the distribution of spots in s.2 of the forewing. In pearl-bordered, the inner mark, near the cell, is relatively large, and the post-discal spot never seems terribly far away from it, dividing the space to the submarginal triangle in a ratio between 1 : 1 and 2 : 1. In small pearl-bordered, the post-discal spot looks further away, dividing this space in a ratio of (typically) more than 2 : 1. Beneath, the two species are readily separated. The pearl borders of the pearl-bordered fritillary are edged internally by red chevrons, with reddish post-discal spots inside that. In small pearl-bordered fritillary the pearly are edged in black, with black post-discal spots.

The caterpillars feed on violets of various species, including the familiar dog violets and early dog violets, as well as sweet violets. Although in hot parts of Europe some may complete their development the same year, flying in August and September, most go into hibernation relatively soon and feed up the following spring.