Their tunneling weakens the wood and allows the invasion of canker and decay fungi. Aspen is an attractive host for the insect, especially when the aspen tree is already under some kind of stress or decline. Aspen is not well adapted to living in the valley areas. They do much better in the mountains. Grow aspen in a grove with continual renewal of trunks rather than as single specimen trees in your landscape.
Aspens have a strong ability to sucker and send up new shoots.
A healthy, vigorous tree will resist borer attack. You cannot remove the damage that the borers have already done. You must treat before the adult beetles lay their eggs in the late spring through summer. Once eggs hatch and larvae bore into the trunk, the damage is done. It's time for the event of the season, Ballyhoo, which takes place at the Jewish country club.