Log Home Maintenance - Wood Borers

How do log homes become infested?

There are a number of insects that use dead trees in which to raise their young (larvae). Larvae feed on starch reserves in the wood that were formed when the tree was alive. Recently dead trees, therefore, are more susceptable to infestation because they contain better starch reserves. Most of these insects cannot infest live trees because of the tree's natural defenses.

In some cases the trees that are destined to be logs of a log home become infested while they are still in the forest. In other cases logs become infested after they are debarked and used in construction. In either case it is important to prevent infestation before extensive cosmetic and/or structural damage is done. Fortunately there are relatively inexpensive ways to prevent this damage.

Longhorned beetles

Larvae of longhorned beetles are called round-headed wood borers. Adult beetles [example of longhorned beetle] have very long, prominent antennae; larvae are legless, white grubs with reddish/brown head capsules (see above). Longhorned beetles generally only infest fresh wood so will not re-infest the wood from which they emerge which limits their potential for damage. Log damage is limited to large bore tunnels and circular to slightly oval emergence holes which can be filled with caulk to repair. See Wood-Damaging Insects for more information.

Flat-headed wood borers

Flat-headed borers belong to the beetle family Buprestidae. Adult beetles are sometimes called metallic wood borers [example of metallic wood borer] because of their showy coloration. The larvae are similar to cerambycid larvae (above) except that the area behind the head is somewhat flattened. Like longhorned beetles these wood borers do not re-infest and thus their potential for damage is limited. Emergence holes are flattened oval in shape. See Wood-Damaging Insects for more information.

Powderpost beetles

Powderpost beetles are the only wood borers that commonly re-infest seasoned wood and therefore have potential to do long term damage. The powderpost beetles that infest softwood timbers are usually in the family Anobiidae (anobiid powderpost beetles). See the exterior log home care page for treatments that will limit powderpost beetle damage.

Other wood destroying insects

Carpenter bees --These large dark colored bees bore into wood to construct a nest chamber. These chambers may be enlarged year after year. The holes made by carpenter bees may allow water and rot fungi to attack the wood.

Like any wooden structure log homes are subject to termite and carpenter ant damage as well as the wood boring insects described here. Keep in mind that water and excess moisture, not insects, is always the most serious threat to your home. Annual inspections will reveal many potential problems before they get out of hand.

Exterior log home care -- Log homes need special exterior treatments compared to conventionally-built homes. Log homes are subject to attack by both insects and rot fungi that can be stopped by treatment with relatively inexpensive borates followed by water resistant finishes.

We now offer inexpensive pest control advice by e-mail for structural pest problems. We can tailor a solution to your particular situation.