Photo Credit (header): Kenneth R. Law USDA APHIS PPQ, Bugwood.org
The Asian longhorned beetle (Anoplophora glabripennis) was first found in the United States in New York City in 1996. This very serious and destructuve tree pest has since been found in Chicago, two locations in New Jersey, Toronto and most recently, in Worcester, Massachusetts. The insect most likely entered this country, as many others do, in packing crates or wood products. The insect has killed thousands urban trees and has the potential to destroy millions of acres of hardwood forest. Although it has not yet been found in Virginia, we should be knowlegable about signs and symptoms.
According to the Virginia Department of Forestry Forest Health Review, May 2009, ” The Asian longhorned beetle, if it were to become established in Virginia, could pose an even greater threat to our forest resources than the emerald ash borer. Because its primary host is maple, we stand to lose a great deal more forest and urban trees from this pest if it were to spread and go uncontrolled within the Commonwealth. While our two major ash species, green and white, make up approximately 1.5 percent of all forested volume in Virginia based on FIA inventory data, red maple and a much smaller amount of sugar maple make up approximately eight percent of forested volume. Furthermore, while ash may on average make up perhaps five percent of all urban street trees, the combined plantings of red, sugar, Norway and silver maples could exceed 20 percent of all urban street trees.”
- Host trees include boxelder, Norway maple, silver maple, red maple, sugar maple, horsechestnut, willow, American elm, birch and poplar. Maples seem to be a favorite.
- The female Asian longhorned beetle damages its host tree by chewing oval grooves in the bark to deposit its eggs.
- Further damage occurs when eggs hatch and largae by feeding on the sapwood beneath the bark layer. The tree suffers since it cannot proprerly transport nutrients and water.
- The adult beetle also harms trees when it bores out of the wood by creating exit holes of ⅜” or larger in diameter.
- Once a tree has an Asian longhorned beetle infestation, it will generally die within 1-2 years.
- The insect can be spread by moving firewood, wood (living or dead), wood products, nursery stock. Quarentine zones are in effect in some areas.
- Control is primarily accomplished by prompt removal or the tree followed by chipping and burning.
Signs and Symptoms – report immediately if seen:
- Sawdust around tree or found in the crotch of branches
- Dime-sized holes in the bark which may ooze sap
- Dieback of the upper crown
- Unseasonable yellowing of leaves