The wings are a pale yellow colour which fades whiter with age, with two darker lines crossing the forewings and one line crossing the hindwings.

The adults are occasionally disturbed during the day but they are strictly nocturnal flying rapidly at night. They are attracted to light. They overwinter as caterpillars in a bark crevice.

Size and Family

  • Family – Thorns, beauties, umbers and allies (Geometridae)
  • Large Sized
  • Wingspan Range – 44-60mm

Conservation status

  • UK BAP: Not listed
  • Common

Caterpillar Food Plants

Woody broadleaves including Blackthorn (Prunus spinosa), Hawthorn (Crataegus monogyna) and Goat Willow (Salix caprea) as well as Elder (Sambucus nigra), Horse Chestnut (Aesculus hippocastanum) and Ivy (Hedera helix).

Habitat

Woodland, hedgerows, parks and gardens.

Distribution

  • Countries – England, Wales, Scotland and Ireland
  • Well distributed and fairly frequent across most of England, Wales, Ireland and the lowlands of Scotland. Also widespread in the Channel Islands and the Isle of Man.
Swallow-tailed Moth - Patrick Clement

Swallow-tailed Moth

Swallow-tailed Moth - Sue Davies

Swallow-tailed Moth

Swallow-tailed Moth - Iain Leach

Swallow-tailed Moth

Swallow-tailed Moth - Iain Leach

Swallow-tailed Moth

Swallow-tailed Moth - Stuart Read

Swallow-tailed Moth

Swallow-tailed Moth

Swallow-tailed Moth

Swallow-tailed Moth - Ben Sale

Swallow-tailed Moth

Swallow-tailed Moth - Koen Thonissen

Swallow-tailed Moth

Swallow-tailed Moth

Swallow-tailed Moth