Endelomyia aethiops
Pest description and crop damage Larvae are slug-like and light green. They skeletonize leaves or make holes in leaves.
Management-chemical control
See:
Chemical Control of Nursery Pests
For more information
Johnson, W.T. and H.H. Lyon (1991), Insects That Feed on Trees and Shrubs, 2nd ed., Cornell University Press (p. 132).
PNW Nursery IPM: Rose slug (http://oregonstate.edu/dept/nurspest/roseslug.htm)