Picture taken by Judy Wilson, Support Staff
These galls found on wild roses are "temporary homes" for the Cynipid wasps, Diploplepis bicolor.
These wasps are usually found in galls on oak trees. For control of these wasps there are no effective sprays at this time. The galls do not cause any serious harm to the roses. Prune them out to remove them, if they are not totally covering the rose. The wasps can use daisies and other woody perennials besides roses and oak trees.