Sawflies called rose slug sawflies can feed on rose plants.  They have a shiny appearance, they only eat the surface off the leaves. This can slow the growth of the plant because of the loss of photosynthetic area. If the larvae are still present they can be controlled with most rose treatments (permethrin, sevin, etc.) or insecticidal soap.

Extension Bulletin

This article was posted in Outdoor Worms, Shrubs.