Answer: The ash borers tend to attack the trunk and, sometimes, the larger branches. After the larvae have finished feeding, they pupate and emerge from the tree, leaving holes in the trunk. They tend to leave their pupal cases extending outward from the tree at the point from which the adult moths emerged. These pupal cases are tan or brownish and papery. This occurs in late summer and is characteristic of the borers. Have you observed these pupal cases remaining on the tree trunk?
If in fact you have, there are insecticide labeled for use on ornamental or shade trees, and can be effective in limiting the damage caused by these insects. It is important to apply chemicals at the time when they will be effective. Check with your County Extension Agent for the proper time of year to apply these products once you have determined whether it is borers or bark beetles doing the damage. Whether or not the pesticides will be effective also depends on the extent of the damage which has already occurred.
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