The larvae of the midge Rabdophaga marginemtorquens cause galling in the leaves of Osier (Salix viminalis). The edges of the leaves roll inwards creating a tube, which may be short or long, this contains one or several orange larvae.

Similar galls are caused by Dasineura auritae on sallow, or Rabdophaga clausilia on white willow.  Mites also cause leaf-rolls on various Salix species. 

Gall Adult

Check inside gall for presence of midge larvae.  Ensure you have identified the host Salix correctly; see our Trees, Shrubs and Climbers galleries form guidance on identifying willows and sallows.  https://www.naturespot.org/family/salicaceae

Where the host species occur.

When the host species is in leaf.

Widespread in England and Wales.

Status in Leicestershire and Rutland not known.