Xestophanes brevitarsis is a gall wasp that causes galls to form on Tormentil (Potentilla erecta) and Trailing Tormentil (Potentilla anglica). The galls are seen more often than the adult. Galls are usually found on the aerial stem or sometimes at the root and take the form of rounded swellings, 2 to 3 mm across, often several in a group and sometimes coalesced. They are green or pink at first, becoming brown and hard.

Xestophanes potentillae forms similar galls on Creeping Cinquefoil

Gall  Adult

Provide a photo showing the host species - leaves and/or flowers - as well as the gall.  There is no need to grub up the plant - follow the aerial stem down through thatch/moss etc.; the galls are close to the ground

Where Tormentil (Potentilla erecta) and Trailing Tormentil (Potentilla anglica) are present.

Galls appear in summer and autumn.

Infrequently recorded in Britain.

Rare or under recorded in Leicestershire and Rutland. The Charnwood Lodge record of 17th September is believed to be the first record of this species in VC55.