Larvae mine the cambium, resulting in girdled trees. Mortality can be extensive in weakened stands. Identifying the Insect. Larvae in galleries. Identifying the Injury.
Attacks usually begin in the upper tree canopy and extend downward as the tree continues to weaken.
D-shaped adult emergence holes are evidence of infestation. Eggs hatch in 10 to 14 days. The larvae burrow through the bark and cambium. They overwinter in cells in the bark and pupate the follwing spring. There is one generation per year.