This is Britain's most recently-discovered butterfly, being almost identical to the Wood White and originally described as Real's Wood White
Leptidea reali in 2001. However, in 2011 Real's Wood White was itself split through DNA analysis (Vlad, Lukhtanov et al in Nature Communications. 2: 324), resulting in another new species with
L. reali being found in Spain, Italy and southern France, and the so-called Cryptic Wood White
L. juvernica ranging from Ireland and France across to Kazakhstan in the east; in Ireland it is found across the country with the exception of the Burren. Unlike the Wood White, this butterfly is found in more-open habitats, such as scrubby grassland, abandoned quarries, hedgerows and roadside verges. Foodplants include various vetches and trefoils. Not found on the British mainland. Wingspan 36-48 mm. Indistinguishable in the field from
Wood White, from which separable by dissection of the genitalia. Larva feeds on Meadow Vetchling, Bitter Vetchling, Tufted Vetch, Bird's-foot Trefoil and Greater Bird's-foot Trefoil.