Emerald Ash Borer

green sign for an emerald ash borer

white sign for emerald ash borer

Managing Emerald Ash Borer: Decision Guide

 

Emerald Ash Borer (EAB) was found in Boulder, CO, in September 2013. As a non-native insect, EAB lacks predators to keep it in check. EAB only attacks ash trees in the genus Fraxinus (so mountain ash are not susceptible). 

Approximately 15% of the trees that make up Colorado's urban forest are ash. There are an estimated 98,000 in the city of Boulder alone.  The Denver Metro area has an estimated 1.45 million ash trees. EAB is responsible for the death of millions of ash trees in the United States.

Help protect Colorado's ash trees! Don't move firewood, and consider chemical treatments to protect high-value ash trees within or near the EAB Quarantine area. 

Emerald Ash Borer

MAKE A PLAN: PRIVATE PROPERTY OWNERS
MAKE A PLAN: CITIES, COMMUNITIES AND HOA's
DOES MY TREE HAVE EAB?

It is possible that EAB could infest an ash tree for 3 or 4 years before visible signs of decline appear. If you think you have EAB in your ash trees, have any questions or concerns, or would like additional information, please contact the Colorado Department of Agriculture at 888-248-5535, email CAPS.program@state.co.us or visit the EAB Identification and Reporting page.

Use the links below to find a certified arborist to inspect your ash tree: 

EAB only infests true ash trees (genus Fraxinus). Is your tree an ash tree?

There are many other insects and environmental factors that can damage ash trees in Colorado including cold injury, soil conditions, improper planting (such as planting too deeply or leaving the cage and/or burlap intact), and insects such as lilac/ash borer and ash bark beetle.

Infestation Symptoms:

  • Sparse leaves or branches in upper part of the tree. (Click a thumbnail to see a larger image - Photos by Kathleen Alexander)
Ash Borer Images
  • Vertical splits in the bark. (Click a thumbnail to see a larger image - Photos by Kathleen Alexander)
Ash Borer Examples
  • Winding S-shaped tunnels under the bark, often visible within vertical bark splits. (Click a thumbnail to see a larger image - Photos by Kathleen Alexander)
Ash Borer Examples
  • D-shaped exit holes about 1/8 inch wide. (Click a thumbnail to see a larger image - Photo on left by Laura Pottorff and the Photo in the middle and on the right are by John Kaltenbach)
Ash Borer Examples
  • New sprouts on the lower trunk or lower branches. (Click a thumbnail to see a larger image - Photos by Kathleen Alexander)
Ash Borer Examples
  • Increased woodpecker activity. (Click a thumbnail to see a larger image - Photos by Kathleen Alexander)
Ash Borer Examples
  • Leaf feeding damage (Click a thumbnail to see a larger image - Photo by Laura Pottorff)
adult feeding damage
  • Adult EAB on leaf (Click a thumbnail to see a larger image - Photo by Laura Pottorff)
Ash borer


Don't be fooled by look-alikes!

PESTICIDES FOR EAB CONTROL
REPLACING ASH TREES
  • The Front Range Tree Recommendation List© was developed through the collaborative efforts of 12 individuals, three from each of the four participating professional groups: the American Society of Landscape Architects (ASLA), the Colorado Nursery & Greenhouse Association (CNGA), municipal arborists representing the Colorado Tree Coalition (CTC), and the Colorado State University (CSU) Extension. Based on the committee's collective education, knowledge, and experience, more than 250 trees or varieties were evaluated and rated, resulting in a single reference list for professionals to use and share with their customers or residents.
  • The Colorado Ash Tree Replacement Selection Tool
BIOLOGICAL CONTROL OF EAB
WOOD UTILIZATION
ADDITIONAL INFORMATION ABOUT EAB
INFORMATION ABOUT EAB IN SPANISH
OTHER WEBSITES

Contact the EAB Program

The Colorado Emerald Ash Borer Response Team

eab response team logo

EAB Quarantine Information

EAB Industry Contact List for Boulder County Quarantine Area - List of companies that do work in Boulder County and have formally agreed to abide by all of the applicable regulations imposed by the Emerald Ash Borer Quarantine. The following businesses can provide various services ranging from tree evaluations, pesticide treatment options, structural management/care, wood/mulch/chip resources, waste disposal as well as Emerald Ash Borer tree care management information.

EAB Quarantine Rules

EAB Quarantine Map

EAB Incident Command Team Updates

Please click on the below links to download a copy of each update provided by the EAB Incident Command Team.

10/30/2013: Update

11/20/2013: Update

12/16/2013: Update

01/10/2014: Update

01/27/2014: Update

02/18/2014: Update