Western tent caterpillars devour aspen trees in SW Colorado

Created: 07/15/2014 5:07 PM
By: Devin Neeley, KOB Eyewitness News 4

There has been a lot of concern about the aspen trees in southwest Colorado recently. Something is eating the leaves, stripping whole stands of leaves.

“It will gobble up all those aspen leaves,’ Said Steve Hartvigsen, forester of for the US Forest Service.

Sad to see that something this small, less than 2 inches long can do so much damage.

“It can remove virtually all the leaves off an aspen clone on hundreds if not several thousand acres,” Hartvigsen said.

Western tent caterpillars are the problem. They’re small and hairy and live in silken bags at tree tops.

And their favorite food? Aspen trees.

For the last few years, the aspens have been devoured by the little bug, but the last major outbreak was in the 1980s.

“What we try to do is try and monitor these populations, get a sense of the severity but for the most part we let them go and in a few years they will be gone and we will wait another 15-20 years before they cycle back.”

The good news is most of the aspens seem to bounce back after being tent-worm-dinner.

“The aspen clones will gather up their energy and re leaf again. They will put out a whole canopy of leaves and that will carry into the fall, so we will see that color.”

All that is left behind after the caterpillars eat their fill is the adults.

“So folks who have perhaps been putting up with the nuisance of caterpillars well we are going to have a bunch of moths come around at night.”

And after the majority of aspens re-leaf, the prospect of fall color is still to come.

“People love aspen, aspen is one of the favorite forest species throughout the west and one can understand why.”

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