Scientific name: Euthrix potatoria
July to August. Common and well distributed to England, becoming more coastal to the north and in Scotland. Their name is derived from the habit of the caterpillars which are said to like drops of dew.
Distinguished from other large eggar moths by the diagonal cross line on the forewing and two small white spots. Males are usually a warm reddish-brown with yellowish patches. The females are larger and can vary in colour from deep yellow to a very pale buff, whitish or a darker reddish-brown similar to the male. In the fens of East Anglia the males are often yellowish.
The adults fly at night and are attracted to light, the males especially.
Size and Family
- Family – Eggar moths (Lasiocampidae)
- Large Sized
- Wingspan Range – 42-70mm
- UK BAP: Not listed
Caterpillar Food Plants
A wide range of coarse grasses and reeds including Cock’s-foot (Dactylis glomeratus), couches, Common Reed (Phragmites australis), Reed Canary-grass (Phalaris arundinacea) and Wood Small-reed (Calamagrostis epigejos).
Most frequent in tall, damp grassland, fens, marshes, damp open woodland, scrub and ditches.
- Countries – England, Scotland and Ireland
- Well distributed throughout England and Ireland, becoming more coastal north to Northumberland and on the western side of mainland Scotland. Rare on the Isle of Man and Guernsey. Widespread and abundant on Jersey.