Emerald Ash Borer
Confirmation of Emerald Ash Borer (EAB) in Colorado warns of unavoidable introduction of a new tree pest to Greeley’s urban forests. This infestation could adversely affect thousands of ash trees in the Greeley community.
Emerald Ash Borer in Colorado
Confirmation of Emerald Ash Borer (EAB) in Colorado warns of upcoming and unavoidable introduction of a new tree pest to Greeley’s urban forest. This infestation could adversely affect thousands of ash trees in our community and hundreds of thousands across the Front Range.
In 2013, it was identified in Boulder, and has recently been found in Berthoud, Loveland and Fort Collins. The insect has not yet been identified in Greeley. With EAB, it is not a matter of if the beetle will appear in Greeley; it is a matter of when.
As a part of Greeley’s EAB management plan, staff have worked to educate the public to identify and avoid bringing the beetle to the area (and to manage the beetle when it is found inside city limits).
Ash Tree Identification
Only ash trees are at risk from the EAB. In Greeley, ash trees make up around 15% of the urban forest. Homeowners may not even realize they have an ash on their property.
Here are some characteristics:
- Multiple leaves come from a single stalk and typically have five to eleven leaflets
- Leaflet margins are smooth or finely toothed along the edge
- When present, seeds are paddle-shaped
- Branches and buds grow directly opposite each other
- Mature bark displays diamond-shaped ridges
Please note: European Mountain ash trees, Sorbus aucuparia, are not true ash and are not susceptible to EAB.
Signs of Infestation
By the time leaves show evidence of EAB, significant damage has already been done to the tree’s interior. Early detection of the beetle’s presence is important to keeping Greeley's urban forest healthy.
Signs of an EAB infestation include:
- Sparse leaves or branches toward the top of the tree
- Increased woodpecker activity
- D-shaped exit holes approximately 1/8 inch wide
- Vertical splits in the bark
If an ash tree appears unhealthy, consider having it examined by a professional. If you suspect your tree has been infested by the EAB, call the City’s Forestry Program at 970-351-5150.
What Can You Do?
- Do not move firewood! If you go camping, burn or dispose of the wood where you buy it
- Determine if you have an Ash Tree
- If planting new trees, plant other tree varieties not impacted by EAB
More EAB Resources
The Colorado State Forest Services offers resources on how to manage EAB threats.