Older larvae tunnel deep into the tree at an upwards angle with larval tunnels being four to six inches long. Larvae push frass consisting of wood fibers and feces out of the tunnels. This results in piles of sawdust below active tunnels. The larvae spend the winter deep in the tree, tunneling and feeding again in the spring before pupating in late spring or summer in the larval tunnel. Most life cycles last one year, although some last for two years.
Damage consists mainly of weakened branches that break off during heavy winds.
Attack for several years could cause the death of branches, limbs, or entire trees. Cottonwood borer makes this size of hole in cottonwood and other poplars, but it is uncommon in Illinois. The shallow egg-laying holes made by the females are similar to those made by woodpeckers searching for insect larvae in or under the bark. However, these beetles make round holes that are similar in diameter whereas woodpeckers tend to make jagged holes of various sizes. Control is difficult due to the extended adult emergence period.