Nationally scarce (Nb) in damp woodland and heathland in central southern and south-eastern England; adults appear only in even years. In Hampshire where the species was discovered new to Britain in 1926 near Southampton, the galls made by the larva of this species on Grey Sallow Salix cinerea are sometimes locally common in the winters of "even" years, mainly in the south-east of the county, but the insect is often heavily parasitised. There are a few scattered records from the Isle of Wight. Wingspan 17-20 mm. Day-flying. The early stages may be sought during the winter months, but synthetic pheromone lures are used to attract males nowadays, and this has led to a marked increase in records of the species in recent years. Larva feeds within stems of Sallow, over-wintering twice.