Why are there tiny powdery holes in my stacked lumber?
Some insect has infested my stack of drying cherry and red oak lumber. The oak, especially, has thousands of tiny holes with powder under each hole. It doesn't look like termites. Can you tell me what it is and how to get rid of it?
—Charles Edgington, Orlando, Fla.
Sounds like powderpost beetles, Charles. Once your hardwood is infested, these little guys hatch, munch their way through the wood, and pop out, leaving tiny exit holes and signature piles of floury sawdust.
There are two common types of powderpost beetle: anobiid and lyctid. If the holes are about 1⁄8 " in diameter, it's probably the anobiid.
The anobiid really only likes wet wood. Once it dries below about 20 percent moisture content, the beetles lose interest and the problem takes care of itself. A borate-based treatment, such as Bora-Care (Nisus Corporation, 800-264-0870), will slow the pests down, but you'll have to give the wood a thorough wetting with the treatment.
If the holes are about 1⁄32 " to 1⁄16 ", you likely have the lyctid variety. These will continue to eat dried hardwoods.
Heat kills both types of beetles and their eggs. 130° for about 24 hours does the trick, making kiln drying an effective way to eliminate infestations. But be sure the kiln owner knows that you're handing over infested wood. He may not want to risk contaminating his operation.
In the meantime, quarantine the infected lumber from other wood (including your home and buildings). Powderpost beetles won't go after softwoods, such as the framing in most homes, but could spread to trim, cabinets, furniture, etc.