Emerald Ash Borer

The Emerald Ash Borer (EAB) is an invasive beetle first identified in the United States in 2002. In 2013, it was identified in Boulder, Colorado. In the U.S., EAB is a federally quarantined, invasive tree pest responsible for the death or decline of more than 50 million ash trees to date.

At this time, the Emerald Ash Borer has not been identified in the City of Greeley. Samples from local ash trees will continue to be collected on a regular basis to look for the beetle’s presence.

The City of Greeley first developed its management plan in 2014, and as of early 2016, the beetle had not been found in city limits. By educating the public on how to identify and avoid bringing the beetle to the area (and managing the beetle should it be found in city limits), we can help protect the city’s urban forest from the potential dangers caused by the pest.

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 unsure visit EABColorado.com.com
  • If planting new trees, consider planting other tree varieties not impacted by the EAB
  • Learn more about the EAB at EmeraldAshBorer.info

Ash Tree Identification

AshTreeExampleOnly 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:

  1. Multiple leaves come from a single stalk and typically have five to eleven leaflets
  2. Leaflet margins are smooth or finely toothed along the edge
  3. When present, seeds are paddle-shaped
  4. Branches and buds grow directly opposite from each other
  5. Mature bark displays diamond-shaped ridges

Signs of Infestation

EAB-with-D-Shaped-HolesEmerald ash borer (EAB), Agrilus planipennis fairmaire, is an exotic beetle that was discovered in southeastern Michigan near Detroit in the summer of 2002. The adult beetles nibble on ash foliage but cause little damage, they are metallic green and up to one half inch long. The larvae (the immature stage) feed on the inner bark of ash trees, disrupting the tree's ability to transport water and nutrients. Please note: European Mountainash trees, Sorbus aucuparia, are not true ash and are not susceptible to EAB.

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 970-339-2405.

Managing the Emerald Ash Borer

If the EAB is detected in the City of Greeley, to prevent the spread in Colorado, the Colorado Department of Agriculture will impose and enforce a quarantine on the movement of ash tree products (i.e. chipped wood, branches, logs, stumps and firewood). If that happens, a landfill will be identified for public disposal of EAB-infested material. The City of Greeley Forestry Program maintains an inventory of publicly owned trees and that includes all varieties of ash trees. City staff will immediately begin determining the health of each infected tree located on city property and treat or replace it depending on its health.

Private properties with an infected ash tree larger than 15 inches in diameter and in good health can hire a professional to treat it with insecticide or they can choose to remove the tree and dispose of it in the pre-determined ash tree drop-off site. If the tree is smaller than 15 inches in diameter, residents can choose to treat otherwise healthy trees themselves. If the tree is in poor health, it may need to be cut down and taken to the disposal site. Keep in mind that it could take up to three years for a tree infected with the insect to show signs of decline, so regular checks are recommended.

Emerald Ash Borer US Dept of Ag

Contact Us


2631 52nd Avenue Ct
Greeley, Colorado 80634

Monday - Friday
7:00 a.m. to 3:30 p.m. 

970-339-2405 tel
970-339-2452 fax

Helpful Links

General EAB information: EmeraldAshBorer.info
and StopTheBeetle.info

EAB in Colorado: (survey progress, identification, reporting, quarantine boundaries and treatment options): EabColorado.com

Facts about insects and diseases that threaten Colorado’s trees: CSFS.Colostate.edu