Description: Wingspan 32-40mm. This species shows considerable variation throughout its range. The forewings are generally reddish grey with a darker central band. This band is not always well-defined, but is always indented on the inner edge. The basal area is usually the same colour as the band. From early September to the beginning of November.

Irish Distribution: Widely distributed but local. Known from Castlewellan Forest Park, Murlough NNR and Seaforde in southeast Down. In north Armagh it is reliably recorded from the Argory and Peatlands Park. The only recent record for Fermanagh is from Monmurray.

Ecology: A species associated principally with pine woodland. Adults show some attraction to light but are never seen frequently or abundantly. The larvae feed on Scot's Pine Pinus sylvestris. It overwinters as a larva.

Key Identification Features:

• Indent on inner edge of central band
• Whitish brown hindwings
• Flight period

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

iNaturalist: Thera firmata at iNaturalist World Species Observations database.