The first introduction of the Asian longhorned beetle (ALB) to the United States was discovered in 1996 in the Greenpoint neighborhood of Brooklyn, New York. A man discovered sawdust and perfectly round holes in maple trees in front of his home and notified the department of parks and recreation. An inspector determined the holes were drilled by the wood-boring ALB. Within weeks, another infestation was found on Long Island in Amityville, New York. Officials learned that infested wood had been moved from Greenpoint to Amityville. After determining the extent of the infestation, authorities promptly established quarantine areas in both Greenpoint and Amityville and prohibited the movement of infested trees and wood. United States Department of Agriculture (USDA) officials determined the beetle entered the United States inside solid wood packing material from China.

ALB was later discovered in Chicago in 1998 when a city park employee stopped to pick up cut wood from a friend’s house. While unloading the firewood, he found a large black-and-white beetle on the mirror of his truck. Curious, he searched the Internet and located a USDA pest alert picturing the insect. Authorities promptly established a quarantine area after positively identifying the insect. Hundreds of trees in the Ravenswood neighborhood were found to be infested, as well as, two areas in suburban Chicago: one in Addison in DuPage County to the west and the other in Summit, south of the city.

Arriving in the U.S. from China in solid wood packing material, the Asian Longhorned Beetle (ALB) has wreaked havoc in the Chicago and New York areas, resulting in the destruction of nearly 8000 trees.

Shortly after the infestation was identified in Chicago, USDA issued an interim rule banning the importation of untreated solid wood packing material from China. In October 1999, USDA declared the presence of ALB as a federal emergency prompting the funding and implementation of necessary regulations. To date, ALB has been responsible for the required removal of over 7,900 infested trees in New York and Chicago and the inoculation of nearly 60,000 non-infested trees to prevent further propagation. The most alarming infestation was detected August 17, 1999, within 1 mile of Central Park in New York.

If this pest moves into the hardwood forests of the United States, infestations will lead to economic losses to the nursery, maple syrup, and forest product industries. In addition, urban ALB infestations will compromise the aesthetics of city parks and forest preserves and lessen public enjoyment of recreational spaces.

Since female ALBs can lay up to 90 eggs in a year, the rapid spread of these tree-killers resulted in the USDA declaring the presence of ALB as a federal emergency. The beetles begin feeding on living tree tissue while still in their larvae state, emerging from exit holes in the tree after pupation.

Identification

ALB’s are about 1 to 1 1/2 inches long, are black and shiny with white spots, and have long antennae that are banded with black and white. The ALB is destructive to many hardwood trees, including maple, elm, horsechestnut, birch, ash, box elder, willow, and poplar. Female ALB’s chew depressions (oviposition sites) in the bark of trees and deposit a single egg in each depression. A female beetle can lay from 35 to 90 eggs in her 1-year lifetime. Hatching within 10 to 15 days, the worm-like immature beetles tunnel under tree bark and bore into the healthy heartwood. The beetle larvae feed on the living tree tissue during the fall and winter and, after pupating, emerge through exit holes. After emerging, adult beetles feed on tree exteriors for 2 to 3 days, and then mate. Adult beetles remain active only during summer and early fall months before they die.

Indications that a tree may be infested with ALB are exit holes that are somewhat larger than the diameter of a pencil, oviposition sites, piles of frass (sawdust and waste) at the base of infested trees and in branch crotches, and sap leaking from wounds in the trees. Unseasonable yellowing or drooping of leaves when the weather has not been especially dry are also signs that the ALB may be present. Leaf symptoms show up when the immature insects, growing inside the tree, have bored through tissues that carry water (xylem) from tree roots and nutrients (phloem) from the leafy canopy above. Once the pest has sufficiently disrupted those pathways, the infested branch or the entire tree will die.

Regulatory

Under the provisions of the Code of Federal Regulations, the following are articles regulated due to ALB: Firewood (all hardwood species); and green lumber and other material living, dead, cut, or fallen, including nursery stock, logs, roots, branches, and debris of half an inch or more in diameter from certain specific genera. These families of tress and shrubs include Acer (maple), Aesculus (horsechestnut), Betula (birch), Hibiscus syriacus L. (Rose of Sharon), Malus (apple), Melia (chinaberry), Morus (mulberry), Populus (poplar), Prunus (cherry), Pyrus (pear), Robinia (locust), Salix (willow), Ulmus (elm), and Citrus. The regulations also cover any article, product, or means of transport that is determined to enhance the risk of spreading ALB.

To move regulated articles such as firewood or green lumber from the quarantined areas in New York and Chicago, a USDA certificate or permit is required. The USDA can move articles without such documentation only for experimental or scientific reasons.

Conditions of Quarantine

Articles may be moved interstate from quarantine areas only if an accompanying certificate or permit has been issued by the USDA and is attached. Articles may be moved without a certificate or limited permit if the regulated article is moved by the USDA for experimental or scientific purposes.

Articles may also be moved under this provision provided the points of origin and destination are indicated on a waybill accompanying the regulated article and it is moved through the quarantined area without stopping; has been stored, packed, or handled at locations approved by an inspector; and has not been combined or commingled with other articles. Articles not in compliance with these regulations may be seized, quarantined, treated, destroyed, or disposed of as the inspector deems necessary.

Female ALBs chew holes in trees and deposite their eggs within; they hatch within 10 to 15 days and begin boring into the healthy wood.

Eradication

Currently, the most effective method of eradicating the ALB is to cut, chip, and burn infested trees and replace them with nonhost species such as conifers. Cooperative research continues in the United States and Asia in an effort to find acceptable alternatives to tree removal.

Last year the insecticide imidacloprid displayed favorable results in field applications and is increasingly being used in conjunction with other methods to protect trees and eradicate the pest.

Imidacloprid is a systemic insecticide that, when applied directly into the trunk of a tree or the soil near a tree, moves quickly upward into stems, twigs, and foliage where the beetles would be expected to feed and lay eggs. The potential for traps and pheromones as methods of eradication has not shown considerable promise; however, more time is required to determine the impact of all eradication options. Collectively, USDA and New York and Illinois State and local governments have invested over $77 million to eradicate ALB and prevent the loss of millions of trees in New York City and Chicago.

USDA’s Animal and Plant Health Inspection Service (APHIS) primarily aids eradication efforts by imposing quarantines and conducting intensified visual inspections around confirmed sites to delimit infestations. Visual inspections are time intensive and involve inspections from the ground or from bucket trucks. APHIS employees and tree climbers from the U.S. Bureau of Land Management and USDA Forest Service do most of these inspections.

Landscape professionals have an important role to play in preventing ALB damage. By respecting quarantine lines and regulations, you can help prevent the further spread of this devastating pest. Movement of trees and wood products from quarantined areas is prohibited, and you need to exercise extreme caution to assure that unintentional transport of the beetle does not occur.

Additional Information

Although the potential for invasive species to be unknowingly introduced into the United States has increased with the increase in world trade, no forest pest has proven to be more of a threat to America’s hardwood forests than ALB. The recent introduction of the citrus longhorned beetle (CLB) through bonsai shipments to Washington State is a reminder that continued diligence is needed by industry professionals. Without the additional assistance and cooperation of professionals in the nursery and landscape industry, ALB and the recent introduction of CLB could have gone undetected.

For more information concerning quarantine areas, regulations, reporting an infestation and other program information, visit the USDA APHIS Web site at http://www.aphis.usda.gov/oa/alb/alb.html. For more information concerning the CLB, please visit the Washington State Department of Agriculture at http://www.wa.gov/agr/CitrusLHBeetle.htm.