The spring-generation galls, described here for the first time, appear in early to mid May in young S. gigantea sprouts, and are therefore found very close to the ground... The galls are composed of many short and narrow leaves among which 1–8 white, conical chambers are situated ... each containing a single orange larva. The white chambers appear in the gall only when larvae are second instars. ..The central complex of short leaves is about 3 cm in diameter and surrounded by 5–10 much longer and wider leaves, giving the gall a star-like shape and an overall diameter of up to 10 cm ... At young stages of development, the longer, surrounding leaves may sheath tightly the center of the gall and these loosen at a later stage.