What are powder-post beetles and what do you do about bugs in wood?

This 1/4 inch brown insect spends most of its life cycle as a whitish larva feeding on the interior of wooden beams that often have a high moisture content (11 percent is normal) and that are often in poorly ventilated basements and attics. A dehumidifier may rectify the problem, unless the moisture problem is due to seepage or leakage.

As the larvae turn into beetles. they bore their way out, leaving small round or oval holes the diameter of a pencil lead and small piles of powdery sawdust on the ground.

If you see sawdust deposits, tap the wood above with an awl handle. Where timbers sound hollow, puncture the area with the point of the awl; if it plunges through, the wood is damaged. If the damage is extensive, you may want to consult a structural engineer about repairs. If the area is small, coat it with deodorized kerosene, then repaint or refinish it.