Galls of this species ... are similar in appearance to galls of R. clarkei on S. rugosa ... and of its close relative on S. gigantea. ... They are 2.8–5.0 mm long and 0.6–1.3 mm wide at widest part (n=22), smooth and green, often with purplish longitudinal lines and tip, and are most often found on the upper side of leaves. The position of the gall is usually apparent on the other side of the leaf only as a small scar, but some galls had a long, curly appendage extending from that side. ... Galls were found in mid May to mid June and adult emergence began in early June ... Further examination of the plants in early August failed to reveal any galls, but Gagné (1989 and pers. com.) found similar galls in late September on leaves subtending and composing the rosette galls of Asphondylia monacha on S. juncea in Silver Spring, MD. It therefore appears that this species completes at least two generations per year.