The blue or blue-grey border on the outer edge of the forewing is what gives this species its name.  The darker northern form of this moth usually has a complete band of brown across the grey forewings whereas the southern form has lighter forewings with distinct brown blotches. Flies in late afternoon, early evening and after dark.

The larvae can be seen from April to early June. They overwinter as eggs in a fork of a twig on the foodplant.

Size and Family

  • Family – Carpets and Allies (Larentiines)
  • Small Sized 
  • Wingspan Range - 24-30mm

Conservation Status

  • UK BAP: Not listed
  • Common

Caterpillar Food Plants

Alder (Alnus glutinosa) and Blackthorn (Prunus spinosa) but also found on birches, Hawthorn (Crataegus monogyna), Plum (Prunus domestica) and Apple (Malus domestica).


Frequents habitats where foodplants occur, including areas surrounding streams, ponds and wet meadows, damp woodland, hedgerows, scrub, orchards and sometimes gardens.


  • Countries – England, Wales, Scotland, Ireland
  • The lighter form occurs throughout the lowlands of England, Wales, Ireland and in the Channel Islands.  The dark form is common in restricted areas of northern England, lowland areas of Scotland and the Inner Hebrides.
Blue-bordered Carpet (upperwing) - Ilia Ustyantsev

Blue-bordered Carpet (upperwing)

Blue-bordered Carpet (upperwing) - Ilia Ustyantsev

Blue-bordered Carpet (upperwing)

Blue-bordered Carpet (underwing) - Andrew Hardacre

Blue-bordered Carpet (underwing)

Blue-bordered Carpet (upperwing) - Vlad Proklov

Blue-bordered Carpet (upperwing)

Blue-bordered Carpet (upperwing) by Ian Kimber

Blue-bordered Carpet (upperwing)