Mountain Pine Beetle
The Colorado State Forest Service is monitoring outbreaks of mountain pine beetles on the Front Range and other parts of Colorado. Access resources and guidance for managing this native insect in your trees.
Mountain pine beetles (Dendroctonus ponderosae) are native to the forests of western North America. They are beneficial ecologically when they attack and kill diseased and dying pine trees, clearing the way for healthy, young trees to thrive. When forests are dense, unhealthy and stressed by drought and warm temperatures, however, populations of these deadly insects can explode to epidemic levels and be detrimental to forest health.
From the late 1990s through 2013, mountain pine beetles affected 3.4 million acres of forests in Colorado, predominantly attacking lodgepole pines. They killed up to 80-90% of trees in some lodgepole pine forests in Summit, Grand, Eagle and Routt counties during the epidemic. Along the Front Range in the early 2010s, mountain pine beetles began transitioning into ponderosa pine forests. Heavy rains and flooding ended the epidemic there, leaving many ponderosa pine forests susceptible to future bark beetle infestations.
In recent years, oscillating precipitation and warm temperatures have left pine forests that largely escaped the prior epidemic susceptible to outbreaks of mountain pine beetles.