Larva (center) and galls (left and right) of Urophora quadrifasciata (similar to Urophora affinis) within spotted knapweed seed head.  The larva looks like a light colored maggot with a black head.
Photo: from slide show: Biological Control of Noxious Weeds, by Reeves Petrof, by R. Richard.

---

mtwow.org HOME    Urophora quadrifasciata     Urophora affinis