You Are Here: Home » RMNP News » Has It Been Cold Enough To Kill The Pine Beetles?

Has It Been Cold Enough To Kill The Pine Beetles?


The low at Bear Lake (elevation 9,475′) on the east side of the park Wednesday morning was -29 degrees. The low at Kawuneeche Visitor Center on the west side of the park (elevation 8,720′) was -36. Bright blue skiies, no clouds and COLD!

That leads to the question we all are anxious to know the answer to…will this cold kill the Pine Beetles?

Kyle Patterson Public Information Officer at Rocky Mountain National Park gives us this information from “Frequently Asked Questions Regarding Mountain Pine Beetles in Colorado” from the USFS:

How cold do temperatures need to be to trigger insect mortality?

There is no simple answer to this question. Mountain pine beetles overwinter primarily in their “worm” or “grub” stage (the larvae). During this time, they accumulate alcohols that act as an anti-freeze and provide protection from freezing. The beetles are more susceptible to cold temperatures early in the fall and late spring, when alcohol levels are low, and less susceptible to cold in mid-winter when alcohol levels are highest. Studies show that temperatures from -13 F to -31 F in mid-winter can cause mortality. However, factors such as the stage of development, duration of exposure to cold temperatures, responses to seasonal changes in temperatures, and geographical location will influence potential mortality.

So what temperatures, at what time of the year, or for how long will cause extensive insect mortality is not yet well-understood.

However, we can all hope the beetles alcohol levels are low right now!

© 2014 Estes Park News, Inc

Scroll to top