The emerald ash borer is a tremendously damaging invasive pest. In its native range of eastern Asia, it seems to be a minor pest -- here in North America, it has proven to be a relentless killer of ash trees.
This beetle is harmful for three reasons:
- it has no effective native enemies in North America,
- it attacks and kills healthy trees and
- our native ash have very little resistance to it
While woodpeckers will eat the larvae, they are not fast or efficient enough to curtail the spread of established beetle populations. Infested trees usually show dieback or yellowing of their canopies and sucker growth, followed by peeling bark and finally death in as little as 1-3 years.
Approximately 99% of ash trees in an infested region die within 6 years of initial beetle arrival. Emerald ash borer was first found in Canada in 2002 in Windsor, Ontario. Since then, it has spread to most of the St. Lawrence region despite best efforts to destroy or contain its spread. Recently, a population has been found in Winnipeg, Manitoba. Similar infestations have taken hold in much of the U.S.A. as well and the beetle is expected to continue to expand its range. The transportation of wood products, especially firewood, is a major factor in this spread.
While there is no native ash forest in Alberta, approximately 60% of the boulevard trees in Edmonton are green ash. Because of this, much of our urban forest is at serious risk. If left unchecked, emerald ash borer could cause untold costs to our quality of life and local infrastructure as beetle-damaged trees fall apart with little provocation, damaging houses, vehicles and citizens alike.