Walls scarred with transverse lines. Cutting into the infested wood often reveals many tunnels filled with frass. Characteristics of the frass and the tunnel system vary between different wood-boring beetle species. Subflooring, hardwood flooring, interior trim, joists, sills and especially beams are subject to attack. Other wood products, such as hardwood furniture, implement handles and ladders, may also be attacked.
Log houses are especially vulnerable.
Vacation or recreation structures are also more prone to beetle attack because they often have higher moisture content in the wood due to intermittent heating or poor ventilation. Damage weakens structural timbers and results primarily from the feeding activities of the beetle larvae. The stages in the life cycle of wood-boring beetles are illustrated in Figure 2. Young beetle larvae hatch from eggs, burrow into wood, and begin feeding. The strong jaws enable the larvae to construct tunnels as they feed on starch and other compounds within the wood.