The Grey Hadena caesia
([Denis & Schiffermüller], 1775)
Wingspan 36-42 mm.
A very local species, occurring in a small number of western coastal localities, notably in the Western Isles, Isle of Man and south-west Ireland.
It frequents rocky seaside habitats close to the shore, usually within a short distance from the shoreline.
The larvae feed on sea campion (Silene maritima), and the adults fly between May and August.