The emerald ash borer, Agrilus planipennis Fairmaire, an insect native to
Asia, has recently been introduced to North America, probably in the wood of
Asian ash species used for stabilizing cargo in ships or for crating heavy
consumer products. Scientists first detected this insect in May 2002 in
southeastern Michigan, and by July 2002, they detected it across the St.
Clair River in Windsor, Ontario in Canada.
Its rate of spread has been alarmingly quick and has already killed or damaged millions of ash trees. It apparently infests all species of ash. In an effort to control its spread, government authorities in the United States and Canada have issued a quarantine on all ash trees and products, including firewood, in all affected areas.
Adult emerald ash borers lay eggs on the bark of ash trees during late spring and early summer. Soon thereafter, the eggs hatch, releasing larvae that bore through the outer bark to feed on the inner bark and sapwood. The larvae overwinter one or two seasons in the tree, pupate, and emerge as adult beetles the following spring. Adult females live for approximately 20 days; adult males live only about 13 days.
The adult borer measures approximately 2 inch long. Its iridescent, metallic green backside compliments its right, emerald green bottom side. The larva, at maturity, has a wormlike body measuring approximately one inch long and divided into triangular-shaped segments.
A tree's inner bark and sapwood provide the transport system for nutrients and water. As the number of emerald ash borer larvae increase, this transport system becomes seriously debilitated until, after two or three years of continuous infestation, the tree dies. Trees rarely survive an infestation. Healthy trees with low levels of infestation may potentially be saved using insecticides. But even then, the effectiveness of insecticides has not yet been conclusively determined.
The potential for the emerald ash borer to decimate ash tree species in North America has experts gravely worried. Hence, a program has been initiated to educate the public on the need to abide by the established quarantine areas and to report suspected infestations. Furthermore, the public has been instructed to dispose of infested ash trees by either burning or taking them to designated disposal sites.
Resources
Emerald Ash Borer Hotline 1-866-325-0023 (toll free)
