Scientific name: Tetheella fluctuosa
June to early August. Local to south-east England and scattered locations further north and in Wales.
Generally larger than the Common Lutestring. Look for a small dark dash at the leading edge of the forewing near the wing tip. The outer half of the forewing is usually a paler colour but a darker form f. albilinea is darker.
The adults fly at night and are attracted to light.
The caterpillars can be found from late July to mid-September feeding at night and resting between two leaves spun flat together during the day. They overwinter as pupae in a delicate cocoon between leaves of the foodplant which fall to the ground with the leaves in autumn.
Size and Family
- Family – Thyatridae
- Medium Sized
- Wingspan Range – 34-42mm
- UK BAP: Not listed
- Local (only found in some areas)
Caterpillar Food Plants
Birches and sometimes Alder (Alnus glutinosa)
Mature broadleaved woodland and wooded heath in south-east England
- Countries – England, Wales and Scotland
- Found locally in south-east England mainly in Kent, Sussex and Surrey. Northern records in west Wales, the Lake District, Cumbria and Inverness-shire. Rare in the Channel Islands.