Presence of mountain pine beetles more evident on northern Front Range

If you saw red when visiting the northern Front Range foothills over the past few weekends, you’re not alone.

Compared to past years, many more ponderosa and lodgepole pines along Colorado’s northern Front Range have faded to red and yellow in recent months, said Sky Stephens, forest entomologist for the Colorado State Forest Service. She said the visible patches of dying trees in the Poudre and Big Thompson canyons, along the Peak to Peak Highway and near U.S. Highway 287 north of Fort Collins are a reflection of the increase in local mountain pine beetle activity over the past few years.

“People living along the Front Range don’t have to drive as far as they used to before they run into beetle infestation,” Stephens said. She said that infested lodgepole pines tend to be redder in color, while ponderosa pines appear more yellow.

Based on 2010 aerial detection surveys by the CSFS and U.S. Forest Service, mountain pine beetle activity in lower-elevation stands of ponderosa pine on the Front Range increased more than tenfold from the previous year. Most of this activity was observed in Larimer and Boulder counties, where infestations were mapped on 181,000 and 36,000 acres of ponderosa pine forest, respectively. Nearly 3.2 million acres in Colorado have been impacted by mountain pine beetles since the first signs of outbreak in 1996.
Landowners who want to prevent the beetles from spreading to healthy trees must act soon, as emerging adults typically depart dying trees to infest new hosts starting in early July. While there is no effective treatment available to save trees already infested by mountain pine beetles, Stephens said landowners can apply preventive treatments to non-infested trees and kill late-stage larvae and pre-emergent adults in dead or dying trees through management measures.

“Landowners who are considering mountain pine beetle treatments should contact their nearest Colorado State Forest Service district office to discuss the most effective options,” Stephens said.