Wyoming News Exchange
State foresters race to save trees from budworm infestation
By Stephen Dow
Buffalo Bulletin
Via Wyoming News Exchange
BUFFALO — It is a race against time where the ending is already predetermined. The trees will turn from green to red to gray. The gray is more or less inevitable.
But that isn't stopping Wyoming State Forestry from fighting to protect 12,000 acres of Douglas fir trees in Johnson County from the western spruce budworm, said Kelly Norris, district forester.
If just one tree can be saved, the effort will be worth it.
“We have never seen an epidemic like this before," Norris told the Johnson County Commission on Nov. 5. "We know we can’t save everything, but we are prioritizing the areas we can save. These trees are beneficial to the entire system down there. If we lose thermal cover from the trees, the elk move away. And then we start to talk about soil degradation. If we can't save the trees, it will have a chain reaction that will affect the
entire forest."
“We cannot slap a dollar amount on the intrinsic costs of this," said Jacob McCarthy, assistant district forester. “And we cannot begin to imagine the damage that this insect could do."
The western spruce budworm is a moth-like insect that is also “the most damaging defoliator in western North America," according to Kurt Allen, an entomologist with the U.S. Forest Service.
Their principal host tree is the Douglas fir and the insect travels easily in dense tree stands like those that have proliferated throughout Johnson County in recent years, Norris said.
Budworms are native to Johnson County and have a one-year life cycle, according to Allen. Adult moths emerge, mate and lay egg masses in July or August. Eggs hatch within several days and larval feeding starts in the spring – first inside old pine needles and then in new buds. When buds begin to expand, the larvae bore into them and feed on the new foliage. Larvae complete development in 30 to 40 days and then pupate. New larvae are dispersed by dropping on silk threads to other trees in May and June. Adult moths fly away and lay eggs in late July to early August, starting the cycle anew.
It is possible for trees to recover from defoliation caused by budworms, Allen said. But repeated defoliation over a number of years can lead to trees with no remaining foliage, decreased growth, deformities and eventual death.
Norris told the Buffalo Bulletin in December 2018 that the spread of the insect was already at epidemic proportions.
Since then, the acreage of trees affected by the insect has grown exponentially. In 2018, 2,000 acres of Johnson County trees were affected by the insect, Norris said. In 2019, that number jumped six times to 12,000.
And Johnson County isn’t the only county that has seen an exponential growth in affected acres. Bighorn County has 19 times as many affected acres as in 2018. Washakie County has 13 times as many affected acres. Total acreage affected in Albany, Big Horn, Carbon, Fremont, Johnson, Park, Sheridan and Washakie counties jumped from 29,870 in 2018 to 35,300 in 2019. Of the eight counties, Johnson has the highest number of affected acres, Allen said.
“At this time, it appears that the epidemic is going to continue increasing based on our sampling, and this is even though it was probably not a great year to grow budworms (which struggle in wet and cold environments),” Allen wrote in an email to Norris. “(I'd) hate to see what happens if we get some hot/dry conditions. I would think we'd start killing a whole bunch of trees.”
Realistically, there is no way to stop the budworm's advances, Norris said, but it can be slowed through strategic forestry management activities. Norris and McCarthy spent the summer thinning out 579 acres of trees in the Bighorns in order to prevent the spread of budworm. Nearly 200 acres of timber sales are scheduled for 2020 with others planned for 2021 and beyond.
"What we're trying to do is draw a line in the sand and stop their advance,” McCarthy said.
Still, drawing that line isn’t easy with limited staffing and funding, Norris said.
“We are short on capacity,” Norris said. “It is just Jacob and myself. We work with the NRCS (Natural Resources Conservation Service) and the conservation districts, but they do not have a forest management background. Realistically, we either need more funding so we can contract out the work that needs to be done or we need to create a position that focuses entirely on the western spruce budworm. This is a very time-sensitive issue, and we're
trying to do a lot of work pretty quickly to save a lot of trees. Right now, we just don't have
the capacity to do everything that needs to be done.”
But that won't stop Norris and McCarthy from doing what they can to stop the forest from going gray. It's a big task and perhaps a futile one. But they have to try, Norris said.
“Everything will be eaten alive and killed – from the tiniest tree to the tallest mature tree if we don't do something,” Norris said. “The Shoshone National Forest has already had this happen, and it could happen here in a matter of years. We are on a tight time frame to save whatever trees we can.”