Emerald Ash Borer spotted in Denver, millions of trees at risk

CBS News

8 hours ago

The Emerald Ash Borer has been detected in Denver nearly a decade after city officials began preparing for the invasive wood-boring insect. According to the City and County of Denver, the EAB was confirmed by entomology experts from Colorado State University and Denver's Office of the City Forester after being identified on June 17.
The EAB is a non-native pest that has the potential to dramatically change the landscape of the Front Range.
An emerald ash borer
CBS
The city told CBS Colorado that there are 1.45 million ash trees in the Denver metro area, with 330,000 of them in the City and County of Denver. That means about one in every six trees is an ash tree and one in every 10 trees on public land in Denver is an ash tree.
"We're grateful that our Office of the City Forester has been preparing for this inevitable discovery, yet this is not a low-stakes battle. EAB has devastated ash tree populations in 37 U.S. states and parts of Canada, costing those communities billions of dollars. Based on this widespread destruction, we've been proactively battling EAB for nearly a decade," said Denver Parks & Recreation Executive Director Jolon Clark in a statement. "In 2016, the Office of the City Forester launched a public education campaign, Be A Smart Ash, to encourage residents to be smart about their ash trees—take action, identify ash trees and, when necessary, treat or replace them."
When the EAB was found in Denver, city officials said the Office of the City Forester immediately provided a specimen from the tree to the Colorado State University Entomology Department for confirmation, and the suspect tree was also visited.
Arborists recommend using pesticides to treat ash trees before a possible infestation because once beetles attack, it's likely the tree will die and have to be cut down.
According to the city, properly administered treatments are 95% effective. Tree removal and replacement can be dangerous work, so it's highly recommended that residents work with a reputable tree care professional, no matter which course of action they choose to take in battling EAB.
"Denver has replaced small ash trees on city-maintained land, and a rigorous treatment schedule is in place for some of the historic ash trees on city property. Denver residents who have room in the public right of way next to their property may be eligible for a free replacement tree, and we encourage community members to learn more about that to help sustain our urban forest," said Luke Killoran, Denver's City Forester, in a statement.
Additional Information from the City and County of Denver:
EAB Tips for Denver Residents:
1. Don't procrastinate: Early detection is key to managing the threat posed by EAB, so don't wait to identify if you have an ash tree.
2. Develop a plan: So you have an ash tree—now what? The short answer is that you have two options: treatment or replacement. Contact a licensed tree expert to help execute your EAB defense plan.
3. Know what to look for: How can you tell if your ash tree is infested with EAB? Look for D-shaped exit holes, bark falling off the tree, wavy trail lines and Northern Flickers (type of woodpecker), among other things. Residents can view a full photo gallery of what they should be looking for.
4. Share what you know: Talk to your neighbors, friends and co-workers about EAB and what they should look for on their ash trees.
5. Buy local, burn local: If you don't move any firewood, you won't move any borers. People unknowingly contribute to the spread of EAB when they transport firewood or other products from ash trees, as EAB larvae stealthily survive and travel hidden under the bark. If an ash tree absolutely must be moved, work with a licensed tree care professional to remove and take all debris.