Prionoxystus robiniae
Pest description and damage Carpenterworms are the larvae of large, mottled gray and black moths (commonly called goat moths) whose size ranges from 1.75 to 3.0 inches in length. The caterpillars are white to pinkish red with a dark head and are 1 to 3 inches long when mature. The caterpillars bore in the trunk and main branches. Discolored or bleeding limbs, branch dieback, and lumpy or gnarled trunks may be indications of infestation. Typical symptoms of carpenter infestation include sawdust-like material (frass) and wood chips mixed with loose webbing. Trees with severe carpenterworm infestations are susceptible to wind breakage and are removed to reduce safety risks.
For biology, life history, monitoring and management
See:
Cottonwood (Populus)-Carpenterworm
Management-chemical control
See Table 4 in: