JOINT BASE ELMENDORF-RICHARDSON, Alaska -- Small reddish-brown and black beetles a quarter of an inch long are sinking their teeth into Alaska’s tree population from the Kenai Peninsula to the Matanuska Valley and Joint Base Elmendorf-Richardson.
The State Division of Forestry is very concerned about a resurgence of spruce bark beetles, according to Jason Moan, Department of Natural Resources Division of Forestry forest health program coordinator.
Moan said an infestation that began in 2015 is building steam each year. While the insects are doing the bulk of their damage on the Kenai Peninsula and Matanuska Valley, other areas of the state, like Anchorage and JBER are also affected.
Those harvesting spruce firewood on JBER can play an important role in limiting the spread of the beetles by stripping bark before transporting it.
“Spruce bark beetles only attack spruce trees,” said Charlene Johnson, 673d Civil Engineer Squadron biological scientist. “White spruce are preferred, but they will also attack black spruce and other native and introduced spruce. Only black and white spruce found on JBER are native to Alaska, but JBER does have blue spruce planted as landscape trees in the cantonment area.”
Some resources mention Lutz and Sitka spruce native to Southcentral Alaska, but these species are not common on JBER; they are much more abundant on the Kenai Peninsula.
Spruce bark beetles typically attack trees greater than six inches in diameter. Adults burrow into the bark, leaving behind a small hole, and then mate under the bark where the female lays eggs. Based on the typical climate in Alaska, the lifecycle of the larva take about two years to mature and then emerge from the tree (usually dead at this point) and fly to the next host tree to start the cycle over again.
In the past 35, years spruce beetle outbreaks have resulted in the loss of an estimated three billion board feet of timber in Alaska.
During the 1990s, the spruce beetles caused an epidemic in Alaska, when their activity in the state was mapped on over 1.3 million acres based on statewide aerial surveys conducted in 1996. Cumulative spruce bark beetle activity as of 2010 now totals over six million acres statewide, according to Alaska Department of Natural Resources division of forestry.
JBER last encountered an extensive outbreak in the late 1990s. The hardest-hit areas included Richardson Training Areas along Poleline Road and north of Clunie Lake. A large portion of Elmendorf hit in the late 1990s was handled through a commercial contract to remove the affected trees. Other areas were open for woodcutting for several years before the bulk of dead trees were removed from the Richardson Training Areas.
Since the outbreak in the 1990s, the Division of Forestry, has actively worked with JBER Forestry and Natural Resources to monitor beetle activity on JBER. JBER is host to an annual monitoring effort staged near the Port of Anchorage to detect introduction of other invasive beetles as they may emerge from shipments received at the port.
In 2018, in response to beetle activity near JBER’s Green Lake, two “trap trees” were cut down to lure a large abundance of beetles. The tree will be stripped of its bark this month, killing the eggs and larvae produced in the tree and preventing those from infesting new trees.
According to Johnson, this is sometimes an effective means to curb a small outbreak or to protect a smaller, more isolated stand of trees; but is less effective in large outbreaks. Additionally outbreaks have been observed in small patches throughout the forested training areas. Trees that have been affected recently can be seen as the evergreen changes rather rapidly to bright red, and then yellow, when the needles begin to fall.
Some EPA-approved insecticides have provided 100-percent protection from beetle attacks for at least two years, based on research results, according to Alaska DNR Division of Forestry.
The trouble is that it’s not financially practical to spray entire forests in a state as large as Alaska or even an area as large as JBER’s 37,054 acres of forest coverage.
For more info on spruce bark beetles and how to deal with them, visit http://www.alaskasprucebeetle.org/ or https://jber.isportsman.net/forestry, or call Johnson at 384-3913.