Asian Longhorned Beetle
Martha Maletta, Home Horticultural Consultant
Dated - August 06, 2004

Asian longhorned beetle (ALB) was first found in New Jersey in 2002 and no additional infestations have been reported until now. This destructive, potentially devastating, tree pest has been found in Carteret, Middlesex County. The United States Department of Agriculture (USDA) in cooperation with state and local agencies has moved aggressively against all identified infestations in New York, Illinois and New Jersey. The goal: to eradicate ALB by destroying infested trees (the only option at this time) and replacing them with non-host trees, restricting movement of firewood and wood debris from the quarantine area, continued surveillance and, possibly, treatment of susceptible but un-infested trees in and near the area.

This wood-boring beetle attacks healthy hardwood trees and could destroy forests and landscapes and threaten tree-related industries if left unchecked. The USDA publication “Wanted: The Asian Longhorned Beetle” states that “…it has the potential to cause more damage than Dutch elm disease, chestnut blight and the gypsy month combined….”. Public vigilance has been the key to uncovering most infestations to date, those in the Greenpoint section of Brooklyn, Chicago, Jersey City and Carteret. The public’s continued cooperation is vital to the eradication effort.

Because ABL is unique in appearance, it can be rather easily distinguished from the one native New Jersey insect with which it might be confused: the spotted pine sawyer, another wood boring beetle. Adult ABL is 0.8 to 1.4 inches long and cylindrical, shiny jet-black, smooth, with up to 20 irregular but distinct bright white spots and blotches. The 1 to 3 inch long antennae (length varies with sex) are distinctly black and white banded. The spotted pine sawyer, by comparison, is 0.6 to just over 1inch long, dark in color, not shiny smooth, and all black to mottled with whitish patches (depending on sex). The sawyer’s long antennae are not distinctly banded but faintly gray and black. For photo comparison check

The ALB is known to attack many species of healthy hardwood trees. Most favored hosts are maple (Norway, sugar, silver, red and others), horsechestnut and buckeye, poplar, birch, willow, and elm. Occasional or rare hosts in the US are mimosa, hackberry, ash, sycamore and planetree, and mountain ash. The pine sawyer attacks only coniferous trees. The ALB adult female chews dime-size pits in the bark of trunks and branches, and lays eggs during summer and early fall. The eggs hatch in 1 to 2 weeks and the larvae bore into and feed on sapwood and heartwood during fall and winter. After pupation, the adults emerge in spring through large holes chewed out through the wood and bark of the trees. Currently, there is no treatment for infested trees so they are destroyed. Protection of susceptible trees near infested trees by injecting insecticide looks promising.

Some indications of ALB infestation are: large-3/8 inch or more in diameter-very round emergence holes on the branches, trunk or roots of a host tree; ragged oval, dark areas in bark where females chew egg laying pits; sap running from holes/pits and abundant sawdust accumulating at the based of trees and/or in branch crotches; the presence of the beetles from May until cold weather.

If an insect or tree damage matching the above descriptions is noticed residents should contact the Rutgers Master Gardener Helpline of Hunterdon County at 908-788-1735 or the New Jersey Department of Agriculture at 1-866-BEETLE-1 or 609-292-5440. For more information on this potentially very serious pest, visit the USDA-APHIS web site at: