Hardwood Floor Damage - Wood Borers

Which wood borers damage hardwood floors?

Both solid and laminate hardwood flooring can be infested with the larvae of wood boring beetles called powderpost beetles in the family Lyctidae (right). There are other insects that damage wood but only powderpost beetles are capable of re-infesting the wood from which they emerge. This is important because it is this "cycle of infestation" that leads, over time, to significant subsurface damage.

Beetle larvae (young, immature beetles; right) bore through wood fibers in order to gain access to starch stored in dead wood cells. As wood ages its starch content declines but even well seasoned wood often has enough starch to support powderpost beetle larvae.

Larvae develop over months, or even years, depending on starch and moisture content of the wood, eventually emerging as adult beetles. Emergence holes and powdery boring dust are usually the first signs of a beetle infestation. Adult beetles mate and the females lay eggs on the surface of wood. Larvae hatch and bore into the wood to start the cycle again.

Wood flooring can be safely and inexpensively treated during installation to prevent new infestation. Treatment after installation is more complicated and expensive but is still possible.

How much actual damage is done by powderpost beetles?

Two kinds of damage are done by powderpost beetles infesting hardwood flooring. First, emergence holes detract aesthetically from the floor's appearance. While a few holes may add to the floor's "patina", a lot of holes can be quite disturbing for some owners.

More serious damage occurs below the surface. As larvae bore in search of starch they weaken the wood's structure. Eventually the wood may be so weakened that it crumbles. Wood flooring that has a manufactured surface (laminate flooring) is especially susceptible to subsurface damage because thin laminates can easily crack if not supported from below.