Protecting your home, family from insects residing in firewood

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RBC I Each fall, as we cut firewood and bring it into our homes, we may also be bringing in some unexpected hitchhikers. Fortunately, these shelter seekers pose no danger to humans, our homes, or our furniture.
They are either feeding directly on the wood, nesting in the wood or are overwintering under the bark. Unfortunately, they do create a very visual nuisance crawling around your home.
Because insects generally require several days to warm up in your home before they become active, the best way to prevent the insects from emerging from firewood in your house is to leave the firewood outside until it is to be burned, bringing, at most, a few days’ supply into the house at one time.
Spraying firewood with insecticide is of very little benefit and potentially dangerous. Therefore, experts strongly advise against treating firewood. Insecticides will not penetrate deeply enough into firewood to control the insects. In addition, storing and burning insecticide-treated firewood indoors could be a health hazard if the insecticide is vaporized into the living area of the house.
Insect invasion of homes from firewood can be reduced by following these rules:
• Avoid stacking the wood directly on the ground. This will keep the wood from getting too wet and 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 as it is most likely to be infested. Avoid the tendency to stack new wood on top of old wood.
• Cover the wood during the summer and fall. This will keep it drier and exclude some creatures seeking overwintering sites.
• Shake, jar or knock logs together sharply to dislodge insects and brush off any obvious structures such as webbing or cocoons before bringing it inside.
• Bring in small amounts of firewood that can be used up in a day or so and keep it stacked in a cool area (e.g., garage or porch) until it is burned. When wood warms up, the creatures in or on it 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.
Insects you might see include:
• Carpenter ants: Wood that remains moist for an extended period is a likely candidate for infestation by carpenter ants. Carpenter ants hollow out galleries in the wood for nesting. Chances of these ants establishing a nest in your house are very slim.
• Termites: Wood that is stacked directly on the ground may be fed upon by termites. Termites brought into your home in firewood will not damage your home or furniture. If you feel you might have termites in your walls or floors (common in Meeker and Rangely), call the Extension office for a positive identification. These termites enter through cracks in your foundation. They have a queen, moisture and a place to hide, which is necessary for invasion.
There are several groups of beetles found in the upper White River Valley that feed on wood and can accidentally be brought into your home in firewood. These beetles can be a nuisance if they emerge from firewood; however, none of these beetles will harm your home or furniture.
• Longhorned beetles: Attracted to dying, freshly cut or recently killed trees. The larvae emerge from the eggs and burrow into the tree and spend one to three years tunneling through the wood.
• Metallic wood-boring beetles: Called flatheaded borers because they have a large, flattened head, they are similar to the longhorned beetles in that the larvae bore into wood, pupate and adults can emerge from firewood.
• Bark beetles: One of the more common firewood insect found in dead trees. These beetles are small (less that 1/8 inch in length), brown or black and cylindrical. The adult beetles tend to attack wood in groups, so a log cut from a tree they are feeding on can contain hundreds of individuals.
• There is also a variety of other insects that spend their winters in your wood pile. When you bring firewood into your house and it warms, these insects crawl out of the wood.
• Pillbugs, spiders, centipedes, millipedes and ground beetles are commonly found in firewood. They will not harm you or your house and need only be picked up and removed.
Bottom line: Most insects do not cause a problem, but if you see something on the floor simply put it in a glass jar and drop it by the Extension office for identification and help with options for control.

By Bill Ekstrom
CSU Extension Agent, Rio Blanco County