The larvae of the gall wasp Xestophanes potentillae causes galls on the stem or petioles of Creeping Cinquefoil (Potentillia reptans). The galls can be found very low down close to, or below soil level. Several galls can often been seen on the same shoot, and sometimes fuse together. The galls are a reddish-brown colour when mature.

X brevitarsus on Tormentil

Gall Adult

Adult: Detailed examination of the specimen is needed to identify the species (a photograph alone is not normally sufficient because key features are too small or hidden) and/or there are one or more similar species and confusion is common.

Gall: Please provide photographs of the gall to support your record, and state the host plant (different Xestophanes species gall other Potentilla species). A photograph of the host plant would also be useful.  Rather than grubbing up plants from established grassland, look where the plant grows against walls, kerbs, paths etc. where there is often a mat of trailing stems.

Particularly associated with Creeping Cinquefoil (Potentillia reptans) and found in gardens, churchyards, on roadsides and waste places 

There are one or two generations of larval galls, the first appearing in July and the second generation of larvae overwintering inside the gall, and pupating within the gall.

It seems to be widespread in England but true status is difficult to determine due to the paucity of records.

Infrequently recorded in Leicestershire and Rutland.