Answer: Cane borers are the larvae of Sawflies and Carpenter Bees and some Wasps. Ceratina spp. Cane Borers can enter the rose through the tops of pruned canes. These pests lay their eggs on the freshly pruned stems of roses in the late spring or early summer. The eggs hatch and the larvae bore and eat their way into the center of the plant down the length of the cane. This can kill the cane down as far as the borer goes. If the borer reaches the bud union, it can sometimes lead to the death of the rose. If you notice a small hole in the center of a pruned cane end, you probably have cane borers. Wilting, and dying foliage at the top of the bush with yellowing leaves which drop off can also indicate the presence of cane borers. Sometimes you will notice a small swelling where the cane borer is present inside of the cane. As the borer hollows out the inside of the rose cane (the pith), the cane will turn brown lose all its foliage and die. To treat, prune the bush below any areas of pith damage. Put a little dab of household glue. Rose afficionado's use Elmer's Glue on the canes right after cutting. The glue is water based so it won't burn the plant tissue, and it hardens as it dries. Good old Elmer's Glue is quick, convenient and inexpensive.
Good luck with your roses!
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