Lakewood has confirmed its first case of emerald ash borer, an invasive insect that’s killed millions of North American ash trees,
The insect was found “in a small area in central Lakewood” last week and in Jefferson County this week, said city spokesperson Amber Thill.
Emerald ash borer beetles infest and kill green and white varieties of ash trees, including the popular autumn purple ash. Approximately 15% of urban trees are ash trees, according to the city.
One tree on private property was confirmed as a host to the beetle, Thill said.
Ash trees infested by the beetles can be identified through “D-shaped” exit holes, splitting bark and “S-shaped” tunnels under the bark, city Forestry Supervisor Luke Killoran said in a statement.
Other signs include thinning tree canopy, abnormal shoots of growth, smaller leaves and lots of woodpecker activity.
In Colorado, the bugs were first found in Boulder County in 2013 and have since been confirmed in Adams, Arapahoe, Broomfield and Larimer counties. Arvada’s first beetle was discovered in 2020.
Lakewood city leaders have been monitoring and treating large, healthy ash trees on public property for several years knowing the ash borer would eventually make its way to the city, Thill said.
Residents may be able to protect healthy trees through preventative insecticide treatments but should make sure to use a certified arborist licensed by the Colorado Department of Agriculture as a commercial pesticide applicator, according to city officials.
