What is a powder beetle? We were told by an exterminator that we have these beetles in our hardwood floors. How can we be sure that’s what is causing the damage and what do we do about them?

I’m pretty sure you mean powderpost beetle, and probably the lyctid powderpost beetle. The larvae of these very tiny beetles (1/6 inch long) tunnel and feed in new or recently seasoned hardwoods, usually woods that are less than 10 years old.

What Does Powderpost Beetle Damage Look Like?

When the powderpost beetle larvae have completed their development, they pupate inside the wood and the resulting adult beetle emerges from the wood through an exit hole. The exit holes are tiny (less than 1/10-inch in diameter) completely round, and may be surrounded by powdery “frass.” The size and shape of the exit holes is a clue to the type of beetle that is infesting.

Frass is digested wood that has passed through the larvae but it’s dry and looks like fine, powdery sawdust. The texture of the frass is another clue as to which wood-boring insect is causing the damage (see What’s Causing Sawdust Piles?). The frass of lyctid powderpost beetles has the consistency of talcum powder, it’s smooth when rubbed between the fingers, and falls easily out of the exit holes. If infested wood is sawed or probed, you may see winding tunnels inside, loosely filled with powdery frass.

Is the Infestation Still Active?

Another question you need to answer is whether or not beetles are still present in the floorboards or in other wood in your home. Powderpost beetles are capable of reinfesting wood in a home after they have emerged, but unless moisture levels and wood conditions are ideal, the infestation often dies out. You probably need a pest control professional to answer this question.  An expert can usually tell whether the infestation is still active by the presence of either live beetles, new exit holes, or new frass. However, since powderpost beetle emergence is seasonal (usually spring), you may not be able to get the answer right away. See Are the Holes Old or New Powderpost Beetle Damage?

What Should You Do About Powderpost Beetles?

Often the infestation is limited to one or a few floorboards that will simply have to be replaced. A professional would have to determine the extent of the infestation and the likelihood of reinfestation. Control options range from simply replacing a couple of infested boards and lowering humidity levels, to treating the wood surface with a borate product, to injecting the wood with a special insecticide. For more information, see our blog, Powderpost Beetles in Hardwood Floors, and give Colonial Pest a call today.