Lasiocampa trifolii, the grass eggar, is a moth of the family Lasiocampidae first described by Michael Denis and Ignaz Schiffermüller in 1775 and found in Europe.
The Grass Eggar (Lasiocampa trifolii) is a medium-to-large, hairy, reddish-brown moth found across Europe and in coastal areas of the UK. Active in late summer (August-September), adults are nocturnal, attracted to light, and do not feed. They are classified as Nationally Scarce in the UK.
Key Facts about the Grass Eggar Moth:
Appearance: Adults have a 40–60mm wingspan, with females generally larger than males. They are reddish-brown with a distinct white spot in the center of the forewing and a curved outer line. A pale, straw-colored form (f. flava) also exists.
Habitat: Primarily found in coastal sand dunes, shingle beaches, and maritime cliffs, though some populations exist on inland heathland.
Life Cycle & Behavior:
Larvae: The caterpillars are hairy, typically yellow, and feed at night on various plants, including grasses, Calluna, and shrubs like bramble.
Pupation: They pupate in a tough, brown cocoon on the ground.
Overwintering: They overwinter as eggs, which are laid loosely among vegetation.
Flight Time: Adults fly at night from June to September, depending on the location.
Conservation Status: The species is considered "Nationally Scarce" in the UK. In some parts of Europe, it is threatened by habitat loss, agricultural intensification, and changing grazing practices.
Differences from Similar Species: It is often compared to the Oak Eggar (Lasiocampa quercus) but is generally smaller and paler.
