Description: Wingspan 24-28 mm. Forewings normally a darker brown than the Fan-foot H. tarsipennalis. Antemedian and post median lines darker than base colour and strongly marked; subterminal line distinctly curved towards the apex. Hindwings fuscous with a pale postmedian fascia that is clearly visible, but occasionally absent in some individuals. End of May to early August.

World Distribution: Eurasiatic; common across western Europe from Portugal to Fennoscandia.

Irish Distribution: Widespread and commonly encountered in the east especially in Down and north Armagh; scarcer further north and west.

Ecology: A small species found mainly in woodland margins, clearings, bogs and some suburban gardens. Adults become active from dusk onwards and come to light in small numbers. They are occasionally disturbed from ground vegetation during the day. The larvae feed from August until October on a variety of trees including oak Quercus spp., Hazel Corylus avellana, birch Betula spp., Hawthorn Crataegus monogyna, and Alder Alnus glutinosa. It overwinters as an a pupa.

Key Identification Features:

• Size
• Darker overall appearance
• Curved subterminal line towards the apex of forewing

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

iNaturalist: Herminia grisealis at iNaturalist World Species Observations database.