Description: Wingspan 39-44mm. Similar in appearance to other thorns but unlike the Early Thorn S. dentaria it normally rests with its wings slightly apart. Colouration is subject to much individual variation. The wings have scalloped edges and there are dark patches on the apex of the forewings. From early May to late July.

World Distribution: Throughout Central Europe and parts of Asia.

Irish Distribution: Regarded by Baynes as being scarce in Ireland, although recent records show it to be widespread in southern counties, particularly in Down and south Fermanagh. Recorded frequently from well-trapped sites such as the Argory, Peatlands, Brackagh in Armagh, Crom, Florencecourt, Garvary and Monmurray in Fermanagh and Lackan, Seaforde and Castle Espie, Down.

Ecology: Found in a wide range of habitats including woodland, heaths, bogs and suburban gardens. Adults are attracted to light in small numbers. They can occasionally be found during the day by beating the branches of trees. The larvae can be found from July to September on oak Quercus spp., ash, birch Betula spp and possibly other trees. It overwinters in the pupal stage.

Key Identification Features:

• Rests with wings slightly apart
• Dark patches to the apex of the forewings.
• Scalloped edges to all wings
• Small discal spot on all wings

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

iNaturalist: Selenia lunularia at iNaturalist World Species Observations database.