The Emerald Ash Borer (EAB) is slowly moving across Colorado. It is important to properly diagnose issues with the ash. I have been looking at several across across the region that have succumbed to many winter conditions the last few years. In addition, they can have other issues other than borers In most cases that I have seen the last few years, it has been lilac borer.

However, be aware:

City announces first official report of emerald ash borer in Arvada

State officials have confirmed the presence of emerald ash borer (EAB) in the City of Arvada. First detected in Colorado in 2013 and more recently found in neighboring municipalities, this invasive and highly destructive insect attacks and kills ash trees. Approximately 97,000 ash trees on both private and public land in Arvada could eventually be affected by the EAB.

The City has been preparing for the eventual infestation of EAB well ahead of its official arrival. During the last several years, forestry staff have completed an inventory of the size, location and health of all 1,500 ash trees on City of Arvada public property, and the City has identified resources to proactively respond to the potential EAB infestation of ash trees in City parks and on other public land. The City of Arvada maintains an EAB webpage ( that includes the City’s EAB management plan and community resources for preparing for EAB.

About EAB

Emerald ash borer (EAB) is a non-native, wood-boring beetle that is responsible for the death or decline of tens of millions of ash trees in the United States and Canada. This insect was first discovered in Michigan in 2002, and since then it has spread to at least 35 states, including Colorado. As a non-native insect, EAB lacks predators to keep it in check. EAB only attacks ash trees in the genus Fraxinus, but has also been documented infesting white fringe trees. Mountain ash and other tree species are not susceptible.

It is unknown whether EAB arrived in Arvada by natural spread or via accidental human transport, such as in firewood or other raw ash material. Populations of the insect are capable of spreading a half-mile each year on their own. EAB was first confirmed in Colorado in 2013 in the City of Boulder. Since then, EAB has spread to other nearby cities including Westminster, Longmont, Broomfield and now Arvada. 

For additional information about how to identify ash trees, the symptoms of EAB, treatment options and wood utilization workshops, visit