How to protect your trees from bark beetles

As Colorado experiences its signature whiplash weather, arborists are warning that stressed trees are more vulnerable to pests and diseases.

Peel back the bark, and you may find a predator in your trees.

"See all that tunneling?" asked arborist Mike Dwyer, while pulling back the bark of a pine tree.

Bark beetles attack trees by tunneling in, laying eggs and bringing in a fungus that clogs the tree's vascular system.

"It's heartbreaking, it's heartbreaking because we've got at least three that are completely dead now," said Parker landowner Jim Lusko.

Lusko first noticed something was wrong in September.

"The tips of the trees turning brown, the needles thinning, a lot of heavy needle fall," said Lusko.

Now, his yard looks brown.

"It happens so fast, I mean, I'm still in shock that it's happened so fast," said Lusko.

He called in arborists Mike and Collin Dwyer, who confirmed an Ips bark beetle was likely to blame.

"Up here we see the tops that are going brown," said Mike.

Mike, who founded and owns the family business COVA Tree, often sees other bark beetles, such as the mountain pine beetle, Douglas-fir beetle, and red turpentine beetle. He says the emerald ash borer has not been seen in Douglas County yet but has been devastating to trees in other parts of the state.

The prognosis for beetle-infested trees isn't great.

"Often when the trees are heavily infested, it's definitely too late to save the tree," said Mike.

But the Dwyers believe they can save some of the healthier trees by injecting the trunks with a chemical that kills beetles.

"A small plugged hole, the product is just going to become part of the vascular system of the tree," said Mike.

Deep watering, fertilization, and cutting off dead branches can also help trees fight the beetles.

"I never want to count a tree out too early, we want to give 'em hope," said Mike.

"This branch surely looks dead, but if you pull back the needles, there's still a viable head on here, a viable bud," said Collin, Mike's son, who is also an arborist for COVA Tree.

Mike says any pine tree is vulnerable to bark beetles, and summer is the highest-risk time.

"We see it on a weekly basis," said Mike.

It's why Lusko is warning other homeowners to act now to protect their trees.

"If you start seeing 'em turn brown, don't wait, don't wait, call somebody and get it assessed as soon as you possibly can," said Lusko.

The healthier a tree is, the lower risk it has for bark beetle infestation. 

Make sure to water and keep an eye on your trees. You can also have your trees sprayed or trunks injected to protect them from the beetles.