Asian Longhorned Beetle
The Asian longhorned beetle (Anoplophora glabripennis or ALB) is an invasive wood-boring insect. The adult beetle has a distinctive appearance and grows to 1.5 inches in length. The body is shiny jet black with irregular white spots. Antennae are typically longer than the body—up to 2 ½ times the body length—and banded black and white. The beetles have six legs, sometimes with bright blue on the legs and feet.
ALB cause the most damage during the larval phase of their life cycle, which is spent entirely within the wood of trees. The larvae are light cream-colored and do not have legs or a distinct head.
The Asian longhorned beetle (ALB) is a destructive wood-boring pest of maple and other hardwood species. ALB larvae tunnel deep into the wood of host trees to feed, disrupting water and nutrient transport and compromising the structural integrity of trees as they do so. Trees weaken and die with repeated attacks.
ALB's first detection in the U.S. occurred in 1996 on several trees in Brooklyn, NY. The insect demonstrated the potential to cause environmental and economic losses exceeding those caused by Dutch elm disease, chestnut blight and gypsy moth combined; this prompted an emergency order to mobilize regulatory and control actions at the federal level.
The only effective means to eliminate ALB is to remove and destroy infested trees. Early detection of ALB and rapid response can protect our forests and urban landscapes, but we need your help!
The Asian longhorned beetle first came to the US from Asia in wood packing material cut from infested wood. Now that it is present in select parts of the country, its range can increase naturally and due to human activity. Adult ALBs can fly distances greater than a mile to find new host trees, naturally increasing their range. People can assist and expedite range increase by unintentionally moving wood that contains the insect. Since ALB larvae live deep inside trees most of the year, they can easily be transported to new areas in firewood, live trees, or fallen timber.
The Asian longhorned beetle is just one of many significant “pests” that people can spread to new areas. Unwanted pests and plant diseases can be spread into new areas unintentionally on firewood or live plant material. One way to help limit human-assisted spread of these plant pests and pathogens is by burning firewood where you cut it. Learn more about human-assisted spread of plant pests and pathogens from our friends at Don't Move Firewood.
ALB has an extensive host list, making it extremely dangerous. Preferred hosts include maples (Acer spp.) like red maple, sugar maple, silver maple and Norway maple; horsechestnut (Aesculus spp.); willows (Salix spp.); American elm (Ulmus americana); birch (Betula spp.); sycamore (Platanus spp.) and other hardwood species. A complete list of host trees in the US has not been determined. ALB only attacks hardwoods, so conifers such as pines, spruces, firs and hemlocks are safe from this insect.
August is tree check month! USDA has made August tree check month for ALB. Wherever you live, take time every August to check your trees for signs of the beetle. If you live in or nearby an ALB quarantine area, view the ALB forecast map to see when adults will be active.
When monitoring for ALB look for the following signs and symptoms:
- Dead or fallen branches
- Dime-sized, 3/8 inch or greater, perfectly round exit holes
- Egg-laying sites in the bark
- Sawdust-like excrement (frass) in branch crotches or at the base of trees
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