Regional Species


Pearl-bordered Fritillary
Boloria euphrosyne

Photograph by Dave Thorpe

Regional Species

This is one of our scarcest species and one that has declined alarmingly throughout Britain. The butterfly survives at a few sites in Montgomeryshire and also at Butterfly Conservation's Eyarth Rocks reserve in Denbighshire which now holds the last remaining colony in the north. Considerable effort has been devoted to improving the habitat quality at all remaining sites in the hope of benefitting this species. Due to confusion with the Small Pearl-bordered Fritillary it will never be known how widespread the butterfly used to be in North Wales but some of the older records were from knowledgeable people who were unlikely to have been mistaken. The conclusion is that the butterfly used to be widely distributed but that most sites have been destroyed by overgrazing, afforestation or the complete exclusion of livestock from woodland resulting eventually in a closed canopy. Note that the High Brown Fritillary has also been lost from North Wales for similar reasons.

Adults fly in the spring and early summer. Common Dog-violet (Viola riviniana) is the usual larval foodplant.

 A very careful examination of the underwing pattern is essential to be sure of identifying this butterfly correctly. The larger size and earlier flight period, relative to the Small Pearl-bordered Fritillary, provide a clue but not the means for a definite identification.

Further information available from the NW Lepidoptera Database, including access to detailed records, maps, flight-time charts and photographs.