Arapahoe County hosting emerald ash borer info session after Littleton sighting

AURORA | Forestry experts will equip Arapahoe County residents with facts about the iridescent green beetle besieging Colorado ash trees May 2, close to a year after the county’s first emerald ash borer sighting in Littleton.

Emerald ash borers lay their eggs on the outside of ash trees, causing trees to die over time as the immature insects eat their way through the wood beneath the bark.

Once the larvae mature and exit the trees, they leave behind tiny, “D”-shaped holes that are one sign of infestation, along with thinning tree canopies and patchy bark, beneath which the serpentine tunnels left by the insects may be visible.

The emerald ash borer has killed tens of millions of ash trees in the United States since it was accidentally imported from Asia in the 1990s, according to the U.S. Department of Agriculture.

In 2013, Colorado arborists spotted the beetle for the first time in Boulder. More than a decade later, the bugs continue to pose a threat to urban forests across the state, including Aurora’s, where the city estimates there are about 110,000 vulnerable trees.

City spokesman Michael Brannen wrote in an email that the city is continuing to follow its plan for inspecting and treating the 5,776 ash trees growing on public land. The bug has yet to be sighted in Aurora — communities as close as Westminster and Littleton haven’t been as fortunate.

“As far as the public trees, EAB will be impactful but manageable,” Brannen said. “As for the wider urban forest, the (City of Aurora) forestry department has been proactive in communicating to council about this issue for the last five years and will keep the city informed as events unfold.”

Aurora residents are prohibited from planting new ash trees because of the threat, and the city has published a list of alternatives that also fare well in Aurora’s semi-arid prairie climate.

The May 2 virtual meeting hosted by Arapahoe County will bring together experts from CSU Extension and the City of Littleton, who will talk about recognizing ash trees and signs of beetle infestation.

Interested members of the public can register for the meeting, which is scheduled to last from 6 to 7 p.m., at col.st/Z2gUn. More information about how local governments are responding to the emerald ash borer threat is available at arapahoeco.gov/eab.