Description: Wingspan 46-58mm. Adults at rest appear whitish-brown. The forewings are ochreous-white with a dark brown, elongated apical patch along the costa. There is also a fine white line and a wedge-shaped, white mark along the marginal edge, and a sub-dorsal streak from the basal area to the outer margin of the wing. The hindwing is similar in colour with a small dark discal spot. The thorax and abdomen are dark brown. Late April until the end of August; sometimes a little later in upland localities.

World Distribution: Throughout Europe as far east as Siberia.

Irish Distribution: Common and widespread in the southern counties; apparently more local in northern counties.

Ecology: Found in a variety of habitats particularly bogs, fens, damp woodland and, occasionally, urban areas. Adults come frequently to light in small numbers. The larvae are more elusive than the adults and have only been seen on a few occasions. Late July until the end of August is perhaps the best time to find them. In N. Ireland it has been recorded feeding on birch Betula spp. It overwinters as a pupa.

Key Identification Features:

• Resting posture
• Wedge shaped mark on forewing
• Dark apical patch
• Lacks white wavy line on the anal patch of the hindwing

Distribution Map from NBN: Pheosia gnoma at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Pheosia gnoma at iNaturalist World Species Observations database.