City Issues Statement on Ips Engraver Beetle
Denver Parks & Recreation Office of the City Forestry has identified conifer trees in the Denver area infected with the Ips engraver beetle. The bark beetle is always present in Denver’s urban forest and flares up every 9 to 10 years. The beetle rarely attacks healthy trees and mostly occurs in newly transplanted or stressed trees. In 2002, we lost over 300 spruce throughout the city; in 2012, we lost over 200. Currently, we have documented about 74 this year throughout the city and the park system.
Denver Forestry’s strategy for the park and parkway system is to remove infested trees quickly, inspect existing trees, and apply a preventative treatment to trees that are in proximity but not infested. All removed trees will be replaced.
The Ips engraver beetle is 1/8 to 3/8-inch-long, reddish-brown to black in color and lives under the bark of conifer trees, producing girdling tunnels that cause foliage discoloration, crown dieback, eventually killing the tree.
To aid in the prevention of beetle infestation, practice proper tree maintenance including adequate watering, pruning out deadwood, protecting the tree from injury from construction activities, mechanical damage and soil compaction.
Preventative treatments may be helpful for other trees but once infected, no chemical treatment exists, and swift removal is the only option to keep the beetle from spreading.
To identify if your tree may be infected, look for fading needle color at the very top of your conifer or signs that the top of the tree is dead. If you suspect your tree is infected, contact a licensed and insured tree company for inspection. Colorado State University Extension also provides information on this pest and others. https://extension.colostate.edu/