There are many different kinds of wood destroying beetles, but probably the most common and most destructive is the Powderpost Beetle. The adults mate, and the female lays eggs in cracks and crevices on the wood. Shortly, the larvae hatch out and burrow into the wood, feeding on it as they tunnel through. When finished growing the larvae tunnel close to the surface and pupate. When the adult hatches out, they chew to the surface, mate, and the cycle repeats itself. Powderpost beetles are second only to termites in destuction of wood and wood products. They can actually be built right into a structure by using infected wood during construction, and are sometimes brought into structures with firewood.
Typical powderpost beetle damage. Damage may be old and inactive unless accompanied by Frass(sawdust) that has the consistency of talcum powder.
Wood Destroying Beetles