Galls are found in clusters of 3–15 on rhizomes, at the base of spring shoots. The gall is single-chambered, resembles a bud, with acute apex and base, 4.5–6.0 mm long and 1.5–2.5 wide. The surface of the gall is smooth and white, with green stripes where it is exposed to light.
”- Netta Dorchin, Miles V. McEvoy, Todd A. Dowling, Warren G. Abrahamson, Joseph G. Moore: (2009) Revision of the goldenrod-galling Rhopalomyia species (Diptera: Cecidomyiidae) in North America©