Pest description and damage Carpenterworms are the larvae of a large mottled gray and black moth (goat moth). 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 carpenterworm infestation. Symptoms of tree 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 as safety precautions. Infestations may kill trees eventually.
For biology, life history, monitoring and management
See Table 4 in: