A previously rare immigrant from mainland Europe to the coast of south-east England, first discovered in Britain in 1987, although investigation has revealed earlier records that had been misidentified, dating back to 1948. Since 1992 the species is now established in south-east Kent, where it is recorded regularly at light around the New Romney and Dungeness areas. In Hampshire recorded for the first and only time at Southsea on 28 June 2001. Not recorded from the Isle of Wight to date. Wingspan 20-24 mm. The main confusion species is
S. hostilis from which distinguished by the shape of the antemedian bar on the forewing, which angles strongly outward at the dorsum in
S. adelphella but in
S. hostilis meets the trailing edge of the forewing more or less at a right angle. Larva feeds on White Willow, over-wintering in a cocoon.