Boring Insects

Oak with severe tip die back from Two-lined chestnut borer.

Description: Insects that feed under the bark of braches and trunk causing major dieback, crown thinning and tree death. Borers on birch and oak trees generally will attack trees that are stressed or weak. Emerald ash borer will attack any ash regardless of health. Healthier trees have a better chance of survival.

Trees Affected: Ash (Emerald ash borer), birch (bronze birch borer), oak (Two-lined chestnut borer)

What to look for: Sunken or “lumpy” areas along branches, exit holes, dieback, and thinning, insect larval gallaries under bark.

Treatment Options: May need several systemic insecticide soil applications. Prune out infected limbs. Keep trees as health as possible with proper watering, mulch and fertilization.