FAIRBANKS — If you’ve purchased or plan to get firewood from a retailer in Fairbanks, be wary of bringing home unwelcome guests, as spruce beetles have been found in firewood brought in from Southcentral Alaska.

The spruce beetle outbreak of the 1990s did not reach the Interior, and forest entomologist Stephen Burr of the U.S. Forest Service does not expect beetle-infested firewood to lead to an epidemic here.

“Spruce beetle is native to spruce forests in Alaska,” he told me. “If an epidemic occurs in the Interior, it will be due to spruce beetles already present in our stands, not to beetles transported in firewood.” 

He concluded by saying he wants people to buy firewood harvested in Alaska but to take precautions to protect high-value trees on their property.

If you find spruce beetles in your firewood, measures should be taken to prevent them from attacking new trees. The easiest step is to burn the wood by late April/early May before beetles begin to emerge. According to Burr, adult beetles can emerge when temperatures reach roughly 60 degrees.

Infested firewood can also be debarked. Debarking exposes the insects, drying them out, but can be difficult without the proper tools. A drawknife or debarking spade makes the job easier, but you’ll need to secure the pieces prior to debarking. Videos showing you how it’s done can be found on the internet.

If you have to store firewood beyond May, and debarking is not an option, proper storage is important. Do not store firewood outside next to the house and don’t stack wood that might contain spruce beetles beneath your favorite large spruce tree. While it’s unlikely that one or two bundles will contain enough spruce beetles to kill a tree, large amounts of infested firewood may. Pesticides should not be applied to firewood.

UAF Cooperative Extension Service’s wood energy website, www.alaskawoodheating.com, recommends not storing firewood in the house. I especially like this idea after two spruce beetle escapees plopped down on my desk. I had placed infested firewood inside a plastic container not realizing the lid was unsecured. If you do have spruce beetles emerge inside your home, don’t panic. These beetles will not infest furniture or structural timbers. Dispose of the adults and burn the wood quickly.

Adult spruce beetles are reddish-brown to black and a little over a quarter of an inch long. You might find them squashed beneath the plastic shrink-wrap used to hold bundles of wood together. Spruce beetle entrance and exit holes are round, not oval, and about an eighth of inch in diameter. You might also see reddish boring dust. Be aware that many different beetles and other insects can inhabit firewood, including engraver beetles, which are more common in Interior Alaska. Dry, well-seasoned firewood processed from trees that have been dead for more than two years is less likely to contain live spruce beetles.

If you have questions about spruce beetles or need help with identification, specimens can be brought to the Cooperative Extension office. An Extension YouTube video on how to identify spruce beetles and their damage can be found at https://youtu.be/xM-HUuA8Ko0.

Additional information on spruce bark beetles can be found in an Extension publication at http://bit.ly/2ysiBi0, and on the Forest Service website at http://bit.ly/2Gf4h0l.

The Alaska Division of Forestry website also has information on assessing the condition of spruce firewood and ways to reduce beetle populations. It can be found at http://bit.ly/2J2G4IH.

Burr will teach a free spruce beetle class from 5 p.m. to 6:30 p.m. April 12 at the Cooperative Extension Service in Room 158 of the University Park Building, 1000 University Ave. To add your name to the list, contact the Tanana District office at 474-1530 or email jariley@alaska.edu.

Inspect firewood you’ve purchased for signs of spruce beetle and burn or debark beetle-infested wood before it warms up. In the future, remember to check for spruce beetle when purchasing firewood.

Julie Riley is horticulture agent with the University of Alaska Fairbanks Cooperative Extension Service Tanana District. Her office has moved back to the University Park Building at 1000 University Ave., but is now located in Room 109. Julie can be reached at 907-474-2423 or jariley@alaska.edu. She thanks the Forest Service’s Stephen Burr and Jessie Moan of the UAF Cooperative Extension Service for their contributions to this article.