Blue-bordered Carpet Plemyria rubiginata
([Denis & Schiffermüller], 1775)
Wingspan 22-28 mm.
A distinctive species in its typical form, this moth is fairly widespread and moderately common throughout much of Britain. In northern parts, especially Scotland, the subspecies plumbata occurs, which is rather more dusky, with little obvious white on the forewing.
It inhabits woodland, damp areas and gardens, and feeds on a range of trees and bushes, including alder (Alnus glutinosa) and blackthorn (Prunus spinosa).
It has one generation, and can be found on the wing from June to August.