Stop spraying: Pine beetles no longer a threat
May 23, 2017
Residents of Grand County for over the last decade have had to explain to visitors and transplants why the local mountainsides are covered in dead trees.
You don't have to live in Middle Park very long before someone will inform you of the pine beetle epidemic Grand County endured over the past 10 years.
During the latter portion of the last decade, a massive infestation of pine beetles wrecked havoc on the lodgepole pine population that fills much of the high country, killing countless numbers of the iconic arbor. Thankfully officials from the Colorado State Forest Service say the epidemic is over.
"Basically, the pine beetle epidemic ended several years ago," said Assistant District Forester Ran McNertney. McNertney would know. He has worked out of the Granby District office for the State Forest Service for several years and has seen firsthand the impacts of pine beetles. McNertney was emphatic in his assessment.
"Over the past two years we haven't seen or heard of any pine beetle activity," he said. "Period."
According to McNertney, the pine beetle population has decreased below what was probably normally here before the epidemic. Though there is always a natural pine beetle population.
Officials from the Granby District noted the absence of widespread pine beetles means spraying trees for the pests is not just ineffective, it can be counterproductive.
Officials believe the pine beetle population began declining steadily from 2012 to about 2015 and that pine beetles have since been almost nonexistent in Grand County. The pesticides and insecticides used to kill pine beetles are not target specific, meaning they kill other bugs along with pine beetles, including things like bees and other predatory insects that are beneficial and help control pest populations like pine beetles.
"We have all heard the saying the pine beetles ate themselves out of house and home," McNertney said, noting the broad truth of the statement. "There are not enough host trees to sustain the type of population that we saw during the epidemic. They were spreading, but there was nowhere else to go. They hit natural barriers."
Officials consider the peak of the outbreak to have been between 2007 and 2009 with the epicenter of the infestation occurring in the Williams Fork area, where state foresters estimate 75 to 85 percent of the trees were killed by the bugs.
The pine beetle epidemic in Grand County can be attributed to several factors but as McNertney explained the main driver was related to overall forest management and the development of large monocultures of trees in the same age groups.
"Our even aged forest was over mature," McNertney said. "That was the reason the pine beetle did what it did and went running through so many acres. Our forests were prime for that infestation to take hold."
McNertney explained high country forests like those in Grand County do not typically have a wide variety of species and tend to rely on age variances to blunt the impacts of invasive pests. "Because we don't have a lot of species in the high country, diversity in our forests is based on age classes, not species."
The pine beetles devoured the older trees in Grand County but were less successful in younger stands. Because Middle Park was filled with vast amounts of nearly 100-year-old lodgepole pines, though a high percentage of local trees were unable to survive the outbreak.
Officials are now working to spread the word that local citizens aren't helping matters by spraying for pine beetles; heavy spraying could be a contributing factor of the growth of pine needle scale in Middle Park. The areas with the highest infestations of pine needle scale were the areas sprayed most heavily for pine beetle.
"We are saying wait it out," McNertney said. "We feel like spraying is making the problem worse than if people weren't spraying."