Asian Longhorned Beetle (ALB) can severely damage or kill many different species of deciduous trees. The first U.S. discovery of the pest occurred in Brooklyn in 1996; they were found in wooden packing material from China. Since then, they have arrived in other U.S. and Canadian locations in shipping materials.
ALB are large beetles with conspicuous coloring. The shiny black insects with white spots can grow to be 1 ½” long; their black and white striped antennae are longer than their bodies.
The insects have a broad range of host trees including maple, horse chestnut, willow, birch, and elm. Because of the danger they pose to deciduous trees, the U.S. Department of Agriculture is seeking to eliminate ALB. Infested trees must be destroyed and a quarantine area is established where potential host trees are either removed or treated preventatively.
In addition to Brooklyn, ALB has been found in Long Island, New York, New Jersey, Ohio, Chicago, Illinois, Worcester, Massachusetts, and Ontario, Canada. The insect has been eliminated from several locations but eradication efforts continue in areas of New York City and Long Island, as well as Massachusetts and Ontario. Although eradication has been successful in some areas, locations with recent infestations continue to be monitored carefully.
After mating, females chew dime-sized depressions in the tree bark where they deposit up to 120 eggs, typically in the upper branches of the tree. The eggs soon hatch and the larvae bore into the wood. As the larvae grow, they tunnel deep into the tree, creating galleries that interrupt water and nutrient transport. Lacking essential nutrition, the tree goes into decline and dieback occurs. The following year, from spring to early fall, the adult ALB emerge.
A tree infested with ALB will begin to decline, usually beginning with the upper branches. Round emergence holes, which can be more than 3/8” in diameter, can be seen and may ooze sap. Sawdust may be visible near the emergence wounds. Adult beetles may also cause damage to foliage.
ALB is a regulated pest that requires establishment of a quarantine by the U.S Department of Agriculture when infested trees are detected. Surveys are conducted to define the extent of the infestation, and infested trees must be removed and destroyed.
Buffer zones are usually created whereby non-infested host trees in the vicinity of infested ones are removed or treated in an attempt to eradicate the pest and reduce the risk of spread.
In order to prevent the spread of ALB, plant material may not be moved from a quarantined area. This includes firewood from all deciduous (hardwood) tree species as well as any living or dead plant material, including nursery stock.