The Grass Eggar is reddish-brown in colour with a curved outer cross-line on the forewing and a central white spot. The colour varies with location. The pale form f. flava is a straw or brownish yellow with similar markings.

The adults are incapable of feeding. They fly at night and are attracted to light. The caterpillars can be found from March to July feeding at night. They pupate in a tough brown cocoon on the ground. They overwinter as eggs laid loosely among vegetation.

Size and Family

  • Family – Eggar moths (Lasiocampidae)
  • Medium / Large Sized
  • Wingspan Range – 42-60mm

Conservation Status

  • UK BAP: Not Listed
  • Grass Eggar - Nationally Scarce A
  • Pale Grass Eggar – Red Data Book species

Caterpillar Food Plants

Foodplants vary between areas including False Oat-grass (Arrhenatherum elatus), Tree Lupin (Laburnum arboreus), Marram (Ammophila arenaria), Bramble (Rubus fruiticosus) and Creeping Willow (Salix repens).

Habitat

Sand dunes with light vegetation, sea cliffs, coastal shingle and acid heathland

Distribution

  • Countries – England and Wales
  • Grass Eggar – Nationally Scarce A. Found very locally on sand dunes on Scilly, in Dorset, Hampshire, Somerset, Glamorgan, Cheshire and Lancashire, and on sea cliffs in south Devon and Cornwall. Also heathland in Dorset. Widespread and frequent in the Channel Islands.
  • Pale Grass Eggar – Red Data Book Species. Found in Kent.
Grass Eggar (male) - Adam Gor

Grass Eggar (male)

Grass Eggar (female) - Marcell Kárpáti

Grass Eggar (female)

Grass Eggar (male) - Marcell Kárpáti

Grass Eggar (male)

Grass Eggar (male) - Marcell Kárpáti

Grass Eggar (male)

Grass Eggar (male) - Adam Gor

Grass Eggar (male)

Grass Eggar (male)

Grass Eggar (male)

Grass Eggar (caterpillar)

Grass Eggar (caterpillar)

Grass Eggar (caterpillar) - Garry Barlow

Grass Eggar (caterpillar)