Rare immigrant from mainland Europe to the coast of south-east England, arriving in some years in sufficient numbers to breed and established since 1992 in south-east Kent. In Hampshire recorded for the first 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.