What is happening to spruce and Douglas fir trees in Colorado?
The Roaring Fork Valley has seen a noticeable increase in the number of beetle-infected spruce and Douglas fir trees over the past three years, and we now call upon you to help save your trees.
Fir Beetle Damage
What to look for
Ips and spruce/Douglas fir beetles have infected millions of acres in Colorado since 1996, with 176,000 acres impacted statewide in 2018, alone. The insect targets Douglas fir and spruce in both native and landscape settings. Once your trees have been attacked, there are no known remedies. Trees that have been attacked by beetles show many different signs and symptoms. Needles on infested trees may turn a pale yellowish-green color, then a deep rust red color, and tend to drop to the ground after high winds.
Woodpecker damage, where the birds have stripped portions of the bark from infested trees in search of larvae (leaving accumulations of bark at the base of trees), is often an indicator of bark beetle presence. Exit holes on the bark surface may be seen after the adult beetles emerge from infested trees.
How to Prevent Infestation
To protect spruce and Douglas fir trees, preventative measures are paramount and time sensitive. Each year from May to July and sometimes later, adult beetles emerge from infested trees and seek out new host trees to attack. Treatments should be employed prior to the beetle’s flight.
Steps to take:
1. Consult a certified arborist to correctly identify the species of trees on your property.
2. Maintain the overall health of spruce and Douglas fir trees with proper fertilization and pest management.
3. Be sure to maintain proper soil moisture levels.
4. If beetles have already attacked your spruce trees, in some cases it is best to have the trees removed before they spread to adjacent host trees.
5. Depending upon tree size and location, install pheromone (MCH) packets to help deter beetles.
6. A trunk spray or a trunk injection should be employed to high value spruce as a preventative measure.
7. Trunk sprays provide 1 year of protection, while trunk injections provide 2 years of protection.
8. Call Aspen Tree Service at 963-3070 to answer any questions—we are happy to help!