A mountain pine beetle epidemic that has destroyed more than 5,000 square miles of Colorado forest since 1996 may be ending. The good news was revealed recently after a 2015 aerial survey that was conducted by the U.S. Forest Service and the Colorado State Forest Service.
According to The Durango Herald, the epidemic is believed to be slowing because there are not many vulnerable trees left for the beetles to attack. The beetles are responsible for damaging more than 3 million acres of Colorado forest during the past 20 years. By comparison, only about 5,000 new acres of forest were affected over the past year. The pine beetle epidemic also affected forests in Wyoming and South Dakota.
Meanwhile, spruce beetles are reported to be causing more damage for the fourth consecutive year. The spruce beetles have infected more than 180,000 new acres of trees in the past year, bringing the total affected area in Colorado to now more than 400,000 acres, reports The Denver Post.
Spruce beetles are native to Colorado, but have been expanding to epidemic levels during the past few years. Spruce beetles will infect any type of spruce tree, but prefer Engelmann spruce. The beetles normally infect trees that have fallen or been downed by high winds, but may also begin to infect living trees as the beetle population grows when there are many downed trees in one area.
Infected trees may not show immediate evidence of a problem, notes a quick guide on the beetle from the Colorado State Forest Service. Needles tend to change color slowly, first to a pale yellow-green and later to a dull gray. Earlier signs of a spruce beetle infection include reddish dust from bore holes, streams of pitch or resin at heights of eight feet or higher in the tree, small pitch tubes, and an increase in woodpecker activity in the tree.
Preventive spraying of insecticides can be effective in avoiding a spruce beetle infestation. Spraying needs to be done annually and cover the entire tree, and should be performed in late spring or early summer to be effective. The Colorado State Forest Service recommends only spraying high-value spruce trees for environmental and cost reasons.
Mountain pine beetles and spruce beetles are not the only damaging insects at work in Colorado’s forests and landscapes. The Douglas fir tussock moth and the western spruce budworm are also responsible for a lot of damage, notes The Denver Post. These pests increased their range last year as well, and have now damaged more than 300,000 acres of forest.
Fortunately, Spruce Point Tree Farm’s Colorado blue spruce trees have remained protected from most of these pest attacks. Our farm in Western Colorado has offered beautiful, high-altitude trees since 1979. To learn more about our trees, give us a call at 970-379-2241.