This page is about stem borers that attack and bore into the canes of roses, shrubs and even trees.
If several of your rose plant's large canes wilt and die, your rose bush most likely have been invaded by stem cane borers.
The symptoms for borers are wilting and dying canes and swelling on the lower part of the stems.
If you slice the dying canes open, you'll find white yellowish worms or grubs up to 3/4 inch long.
Borers are tiny worm-like insect larvae.
The affected stems may be swollen at the base.
Many kinds of insects bore into rose stems.
Some prefer weakened plants, but some other attack healthy plants as well.
You can usually see entry holes lower down on the canes.
These insects like and prefer young canes or recently pruned ones.
The recommended treatment is to treat the borer problem immediately by cutting out and destroying infested rose stems.Make the cut several inches below the point where the stem is wilted or swollen.
There are no recommended chemical controls or treatments.
To avoid having cane borers enter newly pruned rose stems, seal the cut with clear nail polish or Elmers Glue.