The City of Lakewood has confirmed its first case of emerald ash borer, an invasive beetle that kills North American ash trees. The infestation was found in central Lakewood and verified by the Colorado State University Extension Office in Jefferson County.

“Commonly referred to as the ‘green menace,’ Emerald Ash Borers (EABs) specifically target and ultimately destroy ash tree species, including both green and white varieties. Among these is the ‘autumn purple ash,’ a popular white ash variety in Colorado.”

The Colorado State Forest Service notes on its website that approximately 15 percent of the trees in Colorado’s urban forests are ash, making this annoying insect a major threat to urban forests statewide.

Experts say early identification is the key to controlling further EAB spread.

“Look for the distinctive D-shaped exit holes, bark splits and S-shaped tunnels — called galleries — underneath the bark, gradual canopy thinning and dieback, abnormal shoots of growth, smaller than normal leaves, and heavy woodpecker activity,” said Lakewood Forestry Supervisor Luke Killoran in a news release from the City of Lakewood.

Residents can take measures to protect healthy trees, although insecticide treatments can be viable options, success will often depend on the tree’s age, size and condition.

Older, healthy trees may benefit from early pre-emptive treatments while younger trees in distress or poor health may not.

Trees deemed unsuitable for such treatments should be removed and disposed of properly to prevent further infestation. 

The Colorado State Forest Service cautions that untreated ash firewood or other products should not be transported beyond the Front Range and recommends disposing of ash wood safely by “chipping, composting, milling into lumber or taking to a landfill.”

Lakewood officials remind residents “when hiring a professional for tree evaluation or pesticide application, ensure they are a certified arborist and licensed by the Colorado Department of Agriculture as a commercial pesticide applicator.”

For more information about ash tree identification, the symptoms of EAB, treatment options and how to use ash wood, contact the Jefferson County CSU Extension office at 303-271-6620 or the Jefferson County Invasive Species Management Office at 303-271-5989.