The larva is cream colored with a brownish orange head. It is grublike and legless. Larvae will not be seen on exterior surfaces of the plant. Scouting This sawfly feeds inside the rose cane rather than on foliage. The larva first feeds just beneath the bark and can girdle the cane from the inside, causing the cane to wilt and die.
Older larvae feed in the center of the cane and work downward.
One generation is thought to occur per year. Control Control recommendations are the same as for the rose stem girdler. As the larvae move downward in the stem, prune in small increments until you come upon the larva or the pith is solid. Identification Carpenter bees are small, thin, and metallic blue-black. Scouting Rose is one of the favored plants of small carpenter bees for nesting.