Emerald ash borer confirmed in Aurora, city urges homeowners to take action
The emerald ash borer, a tiny yet destructive invasive beetle, has been confirmed in Aurora. That's prompting officials in the Colorado city to remove or treat infected trees and encourage residents to monitor their own.
The pest has already damaged trees near Quincy Reservoir, where city crews have removed several dead ash trees. Officials say while not all of Aurora's estimated 110,000 ash trees are infected, many are vulnerable -- and about 90% are located on private property.
"This is the best time to start monitoring this pest and start treatments if you really want to save the ash trees in your yard," said Gopal Ghimire, Aurora's Forestry Superintendent.
Ghimire said residents should look for D-shaped holes in the bark -- a sign of emerald ash borer activity. In front of a home on South Fundy Way, he showed CBS Colorado a tree damaged by EAB.
"You can see these tiny holes here, you can see one beetle here also," he said of the tree that's marked with a yellow tag for removal.
The city is replacing removed trees with new species and working to protect historic trees in parks and public spaces.
"We have identified our historic trees in different park areas," Ghimire said. "We want to save those trees. We don't want those trees to get infected."
The emerald ash borer was first detected in Boulder in 2013 and has since spread to multiple cities on the Front Range and at least one mountain town, Carbondale.
"This year alone, we've confirmed emerald ash borer in Wheat Ridge, Edgewater, Golden, Denver and Aurora," said Mary Danser, a community program specialist with the Colorado State Forest Service.
Danser said the beetle is one of the most costly and destructive forest pests the state has ever seen.
"Colorado is about 15% ash trees in our urban forest," she said. "So, when you're talking about one in 10 trees being an ash tree that has potential to be susceptible to an insect, it carries a pretty hefty weight."
She added that the pest often goes unnoticed until it's too late.
"By the time that we're able to see the devastation on the outside of the tree ... the devastation is already completed," Danser said.
Aurora's forestry team is offering resources to help residents identify ash trees, monitor for signs of infestation, and connect with licensed arborists for treatment or removal. The city also encourages replanting with diverse tree species to strengthen the urban canopy.
More information, including treatment options and a tree identification guide, is available at AuroraGov.org/EAB.
Ten years ago, the Colorado State Forest Service wrote the following about the emerald ash borer: "The potential economic impacts of EAB in the Metro Denver area alone could be as high as $82 million, based on a loss of annual services provided by the canopy cover, and not including potential costs for ash tree removal, treatment and replacement. This pest has the potential to be the most devastating insect Colorado's urban forests have ever seen."