Pearl-bordered Fritillary (Boloria euphrosyne)
Species

Male. Taken at Bentley Wood, Wilts, on May 19th 2012.
(1/250th sec at f13. Approx 2.75x lifesize. © David Hastings)

Female. Taken at Bentley Wood, Wilts, on May 19th 2012.
(1/250th sec at f13. Approx 2.75x lifesize. © David Hastings)

Male underside. Taken at Bentley Wood, Wilts, on June 6th 2018.
(1/500 sec at f13. © David Hastings)

Female underside. Taken at Bentley Wood, Wilts, on May 19th 2012.
(1/200th sec at f10. Approx 2.75x lifesize. © David Hastings)

Description

Wing span: M 38 - 46 mm; F 43 - 47mm

This butterfly takes its name from the string of "pearls" that run along the outside edge of the underside of the hindwing.

It forms discrete colonies, usually containing a few dozen adults, which can be found in isolated pockets in southern and western England, Wales, Scotland and the Burren in western Ireland. Colonies can contain a couple of dozen to over a thousand adults, this being largely determined by the availability of suitable habitat.

This butterfly is typically found in deciduous woodland containing open areas, such as woodland clearings, that provide the right conditions, foodplants and nectar sources. It can also be found in conifer plantations and limestone pavements in some areas.

This is the earliest British fritillary to emerge. In good years, this begins at the end of April in the south. Most adults emerge at the start of May, but may not appear until the end of May in more northern sites. In exceptional years, there may be a partial second brood at some southern sites, with adults emerging in August. The larva is the over-wintering stage.

The primary larval foodplant is Common Dog-violet. Heath Dog-violet and Marsh Violet are also used.

Adults feed primarily on Bugle.

Males start their day by nectaring on various flowers, before patrolling low over the breeding sites in search of a mate, investigating any reddish brown object encountered.

This species has Endangered status on the UK list.

Sightings

27-Jun-2018 : Gait Barrows NNR, Lancashire (1)
27-Jun-2018 : Arnside Knott, Cumbria (4)
03-Jun-2018 : Bentley Wood, Wilts (1m)

11-Jun-2017 : Velebits National Park, Croatia
20-May-2017 : Bentley Wood, Wilts (5)

02-Jun-2016 : New Copse Inclosure, Hants (8)

26-Jul-2015 : Baderitza, Bulgaria
17-May-2015 : Bentley Wood, Wilts (9+)

17-May-2014 : Bentley Wood, Wilts (12+)