Bug Blog

Bug off: Beware of stowaways

Recently, the mountain pine beetle, spruce beetle and the emerald ash borer have been involved in a number of devastating outbreaks of wood-boring insects in our native and urban forests. In addition, removing a tree from your property or using wood for fuel or woodworking could inadvertently cause and infestation near your home.

The lara of these insects often continue to reside under the bark of newly cut wood. If that wood is transported from an infested to an uninfested area, it becomes the source for adult insects in search of new homes. They could move into the trees in your landscape or forest and facilitate an eventual outbreak of wood-boring insects .

A new campaign from the Colorado Department of Agriculture was enacted when an emerald ash borer was found in Boulder last fall. This ash borer attacks ash trees, which are common in urban landscapes in Colorado. Speculation is that the insect was transported to Colorado in firewood from one of the eastern states where emerald ash borer is common.

According to Linda McMulkin is the horticulture coordinator at the Colorado State University, “Pine, spruce, ash, locust, black walnut, oak, elm and other Colorado trees are infested with insects that could be moved in cut wood. Each species of plant has specific insects that target that plant. Unfortunately, the appearance, life cycle and time of emergence from inside the tree varies from species to species and location to location, so I can’t give you a generic guideline for what to look for in the forest or landscape.”

The Colorado Department of Agriculture recommends that firewood be purchased locally. Firewood brought from out of state should be properly seasoned at the source. According to Mulkin, “Seasoning includes drying the cut wood for at least a year and debarking the wood to help kill eggs, pupae and fungal spores that may be lurking under the bark. When traveling to campsites, buy local wood rather than transporting from home. Yes, it is more expensive, but you will be protecting the local trees.”