Description: Wingspan 34-40 mm. Forewings are dark blackish brown with paler stigmata which are outlined with ochreous white. Subterminal line is pale and irregular. Hindwings are white with darker veining. Beginning of August to the end of September.

World Distribution: Throughout western Europe as far north as central Scandinavia.

Irish Distribution: Scarce; restricted in recent times to sites in Down and in Fermanagh. These include, Murlough National Nature Reserve, Seaforde Estate and a suburban garden in the Greater Belfast area, Down and Garvary Wood and Coolcran, Fermanagh.

Ecology: This species prefers grassy habitats, according to Baynes, especially in coastal areas. Adults appear sparingly at light, but also visit flowers, especially ragwort Senecio jacobaea. The larvae are nocturnal, feeding from March to July, on Mat-grass Nardus stricta and probably other species of grasses. It overwinters as an egg.

Key Identification Features:

• Dark coloured forewings with finely outlined stigmata
• Lighter subterminal line
• White-coloured hindwings

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

iNaturalist: Tholera cespitis at iNaturalist World Species Observations database.