Spruce Beetle replaces Mountain Pine Beetle as biggest insect threat to Colorado forests | AspenTimes.com

Spruce Beetle replaces Mountain Pine Beetle as biggest insect threat to Colorado forests

Deepan Dutta
Summit Daily
An adult spruce beetle (Dendroctonus rufipennis). The spruce beetle is quickly gaining on the Mountain Pine Beetle for devestation it is causing in Colorado forests.
File photo

The Colorado State Forest Service released its annual report on the health of the state’s forests last week, and it showed the growing shadow of a lingering threat. The spruce beetle has now replaced the mountain pine beetle as the biggest insect disease threat to Colorado’s forests, as wildfire continues to threaten communities and drain resources.

The cover of the report, which covers the state’s forest management efforts, features a photo of the Buffalo Mountain Fire last year. Record-high temperatures and record-low precipitation is blamed for the ferocity of that fire and the many others that sprung up across the state.

The Buffalo Mountain Fire itself came close to destroying billions in real estate and the Colorado State Forest Service emphasized the economic impact of forests. When the forests are healthy, tourism and recreation are very good for the state economy; when it’s sick, fire and blight puts a major dent in both industries. Last year, the state saw more forest acreage burned than any year aside from 2002. The costs of doing nothing far exceeded the money spent on proactive forest management.

“The state of Colorado spent an estimated $40 million for fire suppression efforts in 2018 — and this figure does not include what federal and other agencies spent, nor add in vastly greater financial impacts due to property losses, reduced tourism and potential future damage to water supplies and infrastructure,” wrote Michael B. Lester, Colorado state forester and director, in a letter introducing the report.

Since dead and sick trees are one of the main underlying causes of wildfires, concern naturally goes toward what is causing the blight. The mountain pine beetle affected 3.4 million acres during its locust-like infestation from 1996 to 2014. But compared to the rampage of its cousin, the spruce beetle, the mountain pine epidemic might turn out to be a mere blanching.

“This insect has now affected more than 1.8 million cumulative acres since 2000, with a total of 178,000 acres of active infestations occurring in high-elevation Engelmann spruce forests in 2018,” the Colorado State Forest Service report noted. The beetle is now infesting tens of thousands of new acres each year.

The damage estimate comes from an aerial forest survey the Colorado State Forest Service and the U.S. Forest Service conducted last year. This is the seventh consecutive year that the spruce beetle was the biggest forest insect threat to Colorado’s trees.

Other domestic insects causing damage are the roundhead pine beetle, the Douglas-fir beetle, the Western spruce budworm and the Western balsam bark beetle. As far as invasive, non-native species causing damage, the emerald ash borer continues to devastate forests in Boulder County and across North America, along with the Japanese beetle.

To combat the combined effects of these insect infestations, Lester urged the public to support forest management efforts, which he said prevented a much worse wildfire season than what we experienced last year. To that end, the report highlighted how forest mitigation efforts prevented the Buffalo Mountain Fire as well as the Golf Course fire in neighboring Grand County from destroying homes.

“Just as building a levee far in advance of a storm can help protect a neighborhood from flooding years later, proactive forest management work has very real implications when a catastrophic event occurs,” Lester wrote.