Evergreen Shedding Can Appear Similar to Bark Beetle Infestation

October 13, 2014

Evergreen shedding is a natural occurrence in the fall in Colorado. As KRCC’s Tucker Hampson reports, foresters say it’s simply a part of an annual growth cycle and not a sign of illness or bark beetles. 

Typically the needles of Ponderosa Pines, Lodge Pole Pines and Douglas Firs will turn yellow and red before dropping off. The trees may also shed small branches. 

Kathryn Hardgrave is the Assistant Forester with the Salida district of the State Forest Service. She says while bark beetles can cause evergreen color changes as well, it’s a different process:

“If it has bark beetles, then all the needles are going to be turning at once, or depending on what kind of bark beetle it is it may be that an entire branch is going to change, so its not just the back needles, all of the needles are going to be changing.”

Bark beetle infestation can also create sawdust at the base of the tree and popcorn-shaped masses of resin on the trunk, and may kill the tree. Bark beetles can be found in the fall but are most common in early spring.