Holes appear in the lower part of the trunk or in the upper trunk and lower crotches. A thick, gummy substance oozes from the holes. Sawdust may surround the holes or collect under the holes at the base of the tree. During spring and summer some leaves and branches may wilt and some trees may die.
In fall or early spring, kill borers by hand, by removing 4 inches of soil from around the trunk. Locate the hole; kill the larva inside the hole by inserting a wire or by making vertical cuts with a knife. Avoid damaging the bark, especially when planting, as the most severe damage is to young trees.