New app helps determine if trees are susceptible to emerald ash borer

color photo of the Emerald Ash Borer app
The new app offers a step-by-step process to determine if a tree appears to be a true ash or not.

To help Colorado homeowners determine whether trees on their property are susceptible to being killed by emerald ash borer, the Colorado State Forest Service and Colorado State University Extension have released a free app that allows people to use a mobile device to ascertain which trees are at risk and what steps to take before they are infested.

Emerald ash borer is a highly destructive, non-native insect from Asia, first detected in Colorado in 2013. The pest is fatal for all infested ash trees unless the trees have been chemically treated.

“The most important thing Colorado communities can do now is prepare for emerald ash borer’s arrival by increasing their awareness, sharing information about how to identify ash trees, and learning the symptoms of this pest,” said Keith Wood, Colorado State Forest Service community forestry program manager.

The EAB/Ash Tree ID app can be downloaded on almost any Apple or Android-based device, and is easily located in app stores by simply searching for “ash tree.”

The app offers a step-by-step process to determine if a tree appears to be a true ash or not, and offers links and other information about EAB. The app is intended not just for homeowners, but also for business owners, school groups or anyone concerned about the potential impacts of this pest.

The app is also intended to prompt homeowners and other landowners to consider early management options for EAB, including replacing unhealthy trees before they die, treating high-value trees with the proper insecticides, and planting new trees near ash that might ultimately succumb to the pest.

Pest responsible for death of millions of ash trees

adult emerald ash borerEmerald ash borer, which is responsible for the death of tens of millions of ash trees in 30 states and two Canadian provinces, has only been detected in Boulder County within Colorado. Yet the pest has become a concern for communities all over the state because each year it can fly up to a half mile to infest new trees, and it spreads much faster through the human transport of firewood and other raw wood.

An estimated 15 percent or more of all urban and community trees in the state are ash trees.

Boulder and Longmont have been dealing with the pest’s impacts since confirming detections in September 2013 and June 2016, respectively. Many other Colorado communities are preparing for EAB’s arrival.

The City of Denver began its “Be a Smart Ash” campaign last year to raise awareness of the threat in the metro area, where one in six trees are ash, and since then has been implementing a 15-year plan to identify, treat and replace ash trees on city property.

The Colorado State Forest Service has more information online about ash tree identification, the symptoms of EAB and treatment options. The state Department of Agriculture has information about EAB in Colorado, including quarantine information.

Emerald Ash Borer: What Coloradans Need to Know

  • Learn how to identify true ash trees:
    • compound leaves with 5 to 9 leaflets
    • leaflets, buds and branches growing directly opposite from one another

      color photo of a person holding ash tree leaves
      Ash trees have compound leaves with five to nine leaflets. The leaflets, buds and branches grow directly opposite from one another.
    • diamond-shaped bark ridges on mature trees
  • Know the signs of infestation in ash trees:
    • thinning of leaves and upper branches and twigs
    • serpentine tunnels produced by larvae under the bark
    • D-shaped exit holes 1/8-inch wide
    • new sprouts on the lower trunk or lower branches
    • vertical splits in the bark
    • increased woodpecker activity
  • Be aware that multiple management strategies exist for homeowners and communities, including monitoring trees for the early presence of the pest, removing and/or replacing ash trees, protecting trees with insecticides, and planting different species of trees nearby in an effort to get them established before the arrival of EAB.
  • If hiring someone to apply pesticide treatments to protect ash trees, the applicator must be licensed by the Colorado Department of Agriculture as a Commercial Pesticide Applicator.
  • Never transport firewood or other products from ash trees, as this is the most likely method of accidental spread. A quarantine is now in place in Boulder County and surrounding areas to prevent the human-assisted spread of EAB.

If you think you have detected emerald ash borer in your ash trees, please contact the Colorado Department of Agriculture at (888) 248-5535 or send the department an email.

The Colorado Emerald Ash Borer Response Team includes members from the following agencies and organizations: Boulder County, City of Boulder, Colorado Department of Agriculture, Colorado State Forest Service, Colorado State University Extension, Colorado Tree Coalition, Green Industries of Colorado, University of Colorado, USDA Animal and Plant Health Inspection Service and various Front Range municipalities.