The forestry community notes that the emerald ash borer (EAB) is the most destructive forest pest in recorded history, responsible for the death or decline of millions of ash trees in 25 states and Canada. An EAB infestation is almost always fatal to infested ash trees (unless treated) and infested trees usually succumb within four years.
EAB adults typically fly less than ½ mile from their emergence trees and most long-distance movement has been directly traced to human movement of ash firewood or ash nursery stock. Risk of spreading is also presented by movement of untreated ash wood such as yard trimmings, ash wood chips greater than one inch, and ash products such as lumber and pallets. When EAB was discovered in the city of Boulder fall of 2013, the Colorado Department of Agriculture (CDA) imposed and has enforced quarantine on the movement of all ash tree products and hardwood firewood out of Boulder County to prevent the spread within Colorado. Subsequently infestations have been found in Gunbarrel, Longmont and Lafayette. The quarantine took effect Nov. 12, 2013 and remains in effect. It is important to note that the method used by Western Disposal to process yard waste collected at the curb and at our drop-off center is CDA approved for managing EAB.
EAB is difficult to detect until more than a year or two after initial infestation. Many symptoms of an EAB infestation are typical of other common ash problems. Symptoms of EAB include:
- Thinning of upper branches and twigs
- Loss of leaves
- S-shaped tunnels produced by larvae under the bark
- D-shaped exit holes about 1/8-inch wide
- New sprouts on the lower trunk or lower branches
- Vertical splits in the bark that exposes the wood
- Woodpecker activity
Pesticide application treatments can sometimes be effective in protecting ash trees. Contact a certified arborist to understand your options.