Adults are black beetles about ½ inch long; they are bronze-colored iridescent on their backs. They love sun, so they are more apt to be found on the sunny side of a tree trunk. They bore under the bark to lay their eggs. The eggs hatch within two weeks. The larvae start tunneling as soon as they hatch, eating a high-cellulose diet. The larvae emerge from inside the plant as adults.

Prevention is the best way to control borers and bark beetles. Protect trees and roses from injury and provide good growing conditions by watering and fertilizing them properly. Healthy plants can actually defend themselves against borers by drowning them with sap as they burrow into the wood.

To rid infested plants of borers, you can try removing them from the bark. Prune and destroy any infested or dead branches. For chemical control, apply Bayer Advanced Garden Insect Control for trees and shrubs or Fertilome Borer, Bagworm, Leafminers and Tent Caterpillar Spray; keep in mind that pesticides are only effective against the adults at egg-laying time. Once the larvae have entered a plant, they will be undeterred by spraying. Consult with our experts about the optimal spraying times in your area.