Battling the Bark Beetle in Rocky Mountain National Park
In all, the bark beetle has impacted more than three million acres of Colorado forests since the first signs of an outbreak in 1996. Park officials are spraying insecticides on thousands of trees to help mitigate the effects of a bark beetle outbreak.
KUNC’s Emily Boyer spoke with Park Forester Brian Verhulst about the park’s plan, which trees they are targeting and how long the spraying will take.
Boyer: The park usually sprays insecticides to fight the spread of bark beetles annually. But why do it in the Spring?
Verhulst: The primary objective is to spray when the visitation numbers are low, so we have fewer impacts to visitor recreation activity. And also to spray at the start of the summer season prior to the emergence of the bark beetle.
Boyer: Now, you’re only actually able to protect about 5 percent of the park?
Verhulst: We spray high value trees which serve one or more of the following purposes such as providing shade, visual screening or are part of the cultural or historical landscape.
Boyer: How do the insecticides you use work?
Verhulst: Well we have continued to use one consistent product and that’s a compound called Carbaryl. And Carbaryl is a highly effective compound at defended trees against Bark Beetle infestation. We also use a compound known as Verbenone which is a pheromone that deters infestations. They are very different products. The Carbaryl is an insecticide that is actually a neurotoxin where as the Verbenone is pheromone that deters beetles from infesting but doesn’t actually kill them.
Boyer: So it’s not as much about eliminating the bark beetle as it is controlling the damage?
Verhulst: Our objective is to allow bark beetles to remain a natural part of the ecosystem. The spraying we do in the park not change the fate of the forest. But it can protect specific trees in visitor use areas.
Boyer: So, how long will it take to spray the 67-hundred trees you want to protect?
Verhulst: We try to get it done by Memorial Day weekend. However we don’t spray near any residual snow or anything that is going to become runoff, so we might have to wait for the snow to melt oout in some of the areas we spray.
Boyer: Well considering how warm of a winter we’ve had, I don’t know if that’s going to be too much of a problem.
Verhulst: It doesn’t seem like it’s going to be a problem this year. We may be ahead of schedule.
Boyer: Brian Verhulst is a forester at the Rocky Mountain Nation Park. For KUNC I’m Emily Boyer.