Name: Bronze Birch Borer
Symptoms: Check branches for this miniscule pest’s mark: raised ridges or small bumps on the bark.
Controls: First, simply reinforce good health by mulching and watering properly. Birch trees thrive in cool, moist soil; help suffice this need with regular deep, heavy watering sessions. Then, apply insecticides to the bark on the branches and main stem to prevent new attacks. This will not kill insects already under the bark, but will stop new waves. Consult your local County Extension office for specific insecticides and recommended times of the year for applications. Three applications may be needed through the spring and summer months to fight off this pest.
This last tip to fighting the pest is very important, for it is a common mistake, whether it is infected already or not. Do not prune, even the dead branches, until the fall or winter. May 1–Aug. 1 is the flight period of the Bronze Birch Borer and the females are especially attracted to the wounds left by freshly pruned wood.