Emerald Ash Borer


Emerald Ash Borer (EAB), Agrilus planipennis, is a small, green metallic beetle indigenous to Asia. It was discovered in North America in 2002 in southeastern Michigan and since has spread throughout 22 states, with Colorado as the western-most state where EAB has been positively confirmed. The EAB only attacks ash trees and all Fraxinus species are at risk from this pest. This destructive pest is responsible for the death of over 50 million ash trees since its initial discovery and has already cost impacted communities billions of dollars for the treatment, removal, and replacement of ash trees. Ash trees comprise an estimated 15% of the Town’s urban forest, or 11,000 ash trees. The loss of this species would have tremendous economic, social, and ecological impacts in the state and within Erie.

EAB - 1
EAB - 2


 Symptoms of EAB infestation include:

  • Sparse foliage or thinning of the canopy
  • Excessive sprouting of epicormic shoots from the trunk or roots
  • Vertical bark splitting
  • D-shaped emergence holes on trunk about 1/8 inch wide
  • Increased woodpecker activity
  • Serpentine (“S”-shaped) galleries from larvae feeding under the bark.
EAB is a federally quarantined tree pest. In September 2013, the presence of EAB was confirmed within the City of Boulder which prompted the Colorado Department of Agriculture (CDA) to established a quarantine zone in November 2013 around Boulder County, the majority of the Town of Erie, the two landfills located in Erie with the goal to reduce or eliminate the spread of EAB to new locations through the inadvertent spread of infested wood products. The quarantine prohibits the movement of all untreated plants and plant parts of ash trees out of the quarantined area and includes, but is not limited to logs and green lumber, ash nursery stock, chips and mulch, stumps, roots, branches, and firewood of any non-coniferous (hardwood) species.

Management of Public Ash Trees
The Town has participated in federally sponsored detection trapping for the last five years and will continue to utilize EAB traps to assist in the detection, delimitation, and survey of EAB populations in Erie.

The Towns goal is to prolong the life of the healthiest, largest, most significant ash trees in the community, and greatest producers of economic, social, and ecological benefits located on Town-maintained properties. The Town will employ a proactive, integrated strategy that utilizes the following management tools on Town-maintained properties: Active Monitoring, Selective Pesticide Treatment, Selective Ash Tree Removal, Ash Tree Replacement with Non-ash Species, and Communications and Public Awareness. The Town of Erie EAB Response Plan details the management strategies to be utilized by the town to maintain ash trees located on public property.

Key Emerald Ash Borer Identification and Management Resources
  • Please visit www.eabcolorado.com for information on identification, management, and reporting
  • EAB Management Resources from Colorado State University Extension
  • A collaborative inter-agency website from the USDA Forest Service, Michigan State, Purdue, and Ohio State provides comprehensive information on the EAB
If you think you have EAB in your ash trees, or if you have any questions or concerns, or would like additional information, please contact:

  • Colorado Department of Agriculture at 888-248-5535 or email
  • Town of Erie Natural Resources Supervisor, Mike McGill at 303-926-2892 or email