Many people use a wood-burning stove for heat or occasionally light some logs in the fireplace for enjoyment on cold winter nights. However, a quiet rick of firewood can harbor its own life.
Many different insects can develop in stressed, dying, or recently downed trees. Their activities ensure that the resources in the wood are broken down and recycled. These insects are naturally attracted to trees that are cut for firewood. In many cases, borers can complete their life cycle in cut, cured firewood. In addition, several insect species hide in crevices or under loose bark.
These insects remain inactive as long as the wood is outdoors and cold. That changes if the wood is brought inside for several days. Cold-blooded “dwellers of the wood” are roused by warm temperatures. Sawdust can begin to appear from logs containing borers. In a few cases, adults will emerge prematurely. In general, there is no cause for concern. These species are unlikely to attack structural wood; they are only a temporary nuisance.
Potential Firewood Insect Species
Round-headed wood borers are brightly marked, fast beetles with long antennae. The elongate flat-headed woodborers often have a metallic sheen.
Carpenter ants and termites may be found in firewood that has been wet or stacked in one place for a long time. Termites form mud tunnels and this mud can be found in wood that they are attacking.
Carpenter ant galleries are very clean, with no mud or sawdust. These individuals brought into the house in logs will not start an infestation, but a colony may exist in the soil beneath outdoor wood piles.
To reduce experiences with firewood insects:
- Avoid stacking firewood directly on the ground. This will keep the wood from getting too wet and will reduce the chances for infestation by termites and ants.
- Don’t stack firewood in or against the house or other buildings for long periods of time. Termite or carpenter ant problems can develop and cause more serious problems.
- Use the oldest wood first; it is most likely to be infested. Avoid the tendency to stack new wood on top of old wood.
- Cover firewood during summer and fall. This will keep it drier and exclude some creatures seeking overwintering sites.
- Before taking wood inside, shake, jar, or knock logs together sharply to dislodge insects; brush off any obvious structures such as webbing or cocoons.
- Only bring in small amounts of firewood that can be used up in a day or so, and keep wood stacked in a cool area (e.g., garage or porch) until it is burned. When firewood warms up, the creatures in or on the wood will become active.
- Do not treat firewood with insecticides. It is unnecessary and potentially dangerous due to fumes that may be produced when the insecticides burn.
by Lee Townsend, Extension Entomologist