Don’t give bugs a free ride: Use local firewood

by | Jan 30, 2013

With the cold winter months comes the comforting crackle and warmth of a fire in the fireplace.  We’re also just around the corner from camping season, with campfires and s’mores to complete the experience. It’s tempting to try to save some money by hauling your own wood. But before you transport firewood, it’s important to know the risks that you may be taking –­ risks that could lead to irreparable damage to our forests.

Firewood with bark removed, showing galleries formed by the emerald ash borer. The emerald ash borer, which is not yet found in North Carolina, is easily spread in firewood. This destructive boring insect causes mortality to all species of ash native to North Carolina. To date, it occurs in eastern Tennessee and southern Virginia, very close to the state line. Image: Troy Kimoto, Canadian Food Inspection Agency, Bugwood.org.

When transporting firewood long distances, we may be unknowingly giving a free ride to destructive forest insects and diseases. Some of the invasive insects that are wreaking havoc on our native trees are wood borers, which bore into trees to complete their life cycle. By cutting and moving wood from infested trees, we may also be moving these borers into new, never-before-infested areas where they emerge, eager to attack (and kill) more trees.

The redbay ambrosia beetle, which spreads a tree disease known as laurel wilt, was first found in an area in North Carolina more than 50 miles north of the nearest affected areas in South Carolina. It is presumed that this beetle entered North Carolina accidentally through the transportation of wood materials, possibly firewood, from an infested area. The beetle and associated disease is now killing countless redbays in five known counties in the southeastern part of state.

However, this is not the only region of the state that may be affected. In addition to several other plants in the laurel family, laurel wilt also affects sassafras, a plant native across North Carolina. Movement of firewood from a site with laurel wilt near the coast could therefore jeopardize the health of sassafras in the piedmont and mountain regions.

Other invasive insects, such as the gypsy moth, are not hidden within wood, but lay their eggs on the outside of wood products. This may include trees, cut logs, firewood, wooden crates and boxes, and even some non-woody materials (the gypsy moth has been found on tires, trucks, etc.). When these items are innocently moved from place to place, so is the insect and the damage it causes.

Gypsy moth egg masses on the trunk of a tree. If this tree were cut for wood and transported, these eggs would emerge as larvae wherever they ended up. The gypsy moth is responsible for extensive defoliation to hardwoods each year in the northeastern U.S. Image: Haruta Ovidiu, University of Oradea, Bugwood.org.

The best way for us to slow the human-assisted movement of destructive pests is to limit the movement of firewood from place to place. As a general rule of thumb, firewood should be burned no more than 50 miles from its source. Firewood is readily available near most destinations and should be used at the site it is obtained. (Plus, that frees up more cargo space for s’mores supplies!)

If firewood should be moved, it is wise to inspect and/or treat it before movement.  In some areas, it’s the law. In Haywood County, where thousand cankers disease was recently found, a quarantine prohibits the movement of black walnut wood products, including firewood, from within the county to outside the county without precautionary measures. North Carolina also has an external quarantine, preventing the movement of untreated walnut materials into the state.

Each person must do his or her part to reduce the risk of accidentally spreading insects and diseases. More information can be obtained from the N.C. Forest Service website or from “Don’t Move Firewood,” a campaign aimed to increase awareness of and slow the spread of forest pests. By reducing the risk of transporting invasive pests, we can all protect the beautiful forests we share, enjoy, and love!