Maple tree with possible blite

Asked March 29, 2017, 8:35 PM EDT

I have a 20 year old maple tree (15 " diameter) at the base that appears to have some sort of blite or bore. There are holes bored into the bark approximately 3/16 of an inch in diameter. These holes are in a straight horizontal line with five to six holes per line. Is this a bore or something that might cause serious damage to the tree?

Jefferson County Kentucky

1 Response

This could be one (or more) of several problems that have occurred in the affected area. Woodpeckers, borers or wounds that attract insects are the most likely possibilities.

The damage you have described sounds like it is woodpecker damage. The birds make holes in a relatively straight line searching for insects or sap for food. Information for control of woodpeckers is here:

Maples in stress can attract flathead apple tree borers. They enter the tree as tiny larvae and make D shaped exit holes as they leave the tree as adults. These holes are not lined up in any way and are randomly placed. Control of borers starts with spraying the trunk and larger branch bark with an appropriate insecticide. UK entomologists tell us "Bark sprays with pyrethroids will provide good preventive control of clearwing borers on woody ornamentals. Onyx®(bifenthrin) and Astro® (permethrin) work well; Talstar® (bifenthrin) also can be used."

Please read and follow all label directions before applying pesticides.

More information on borers and preventing damage is here:

Trees are either successful sealing off wounds or they are not. There is little we can do to assist them as it is an internal process. Wounds make the interior of the tree accessible to both insects and disease. Fence off young trees to avoid mower and weed whacker damage and keep mulch away from the trunk at least several inches to discourage wildlife from chewing on bark. Do not spray sealant or other compounds on wounds, research has found that trees actually recover faster on their own!

Feel free to contact our office if you have other questions.

Let me know if I can help you further!

Carol Wilder
Horticulture Technician
Jefferson County Cooperative Extension Service
200 Juneau Drive
Louisville KY 40243