What’s Black and White, and Dread All Over?

Contact: Carol Holko, MDA | 410-841-5920 or holkoca@mda.state.md.us

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ALB adult male. Photo: Michael Bohne, Bugwood.org
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ALB damage Photo: E. Richard Hoebeke, Cornell University, Bugwood.org

ANNAPOLIS, MD (July 8, 2009) – The Asian longhorned beetle (ALB, Anoplophora glabripennis) is a damaging exotic insect pest that poses a serious threat to many species of deciduous hardwood trees such as maple, elm, willow, birch, horsechestnut, and poplar. The beetle larvae harm trees by feeding under the bark in the living tissue of the tree for a period of time and then boring deep into the wood where they pupate. This tunneling damages, and eventually kills, the tree. Like most non-native pests, ALB has no known predators in the U.S. ALB could be one of the most destructive and costly invasive species ever to enter the United States. It threatens urban and suburban shade trees and recreational and forest resources valued at hundreds of billions of dollars. It might also impact such industries as maple syrup production, hardwood lumber processing, nurseries, and tourism. If it became widely established, its impact would be felt in urban, suburban, and forested areas. The ALB has the potential to wipe out entire populations of trees in a short period of time. Although the ALB hasn’t been detected in Maryland, it has been found in four other states. We are ever watchful for this emerging plant pest and have selected it as the MISC Invader of the Month for July 2009.

The adult ALB is a large, stunning insect measuring 1 to 1.5 inches long, not including its antennae, which are as long as the body itself in females and almost twice the body length in males. The beetle’s body is shiny black with white spots; the antennae are banded in black and white. During summer months, adult beetles can be spotted on walls, outdoor furniture, cars, sidewalks, and tree limbs and branches. The ALB has one generation per year. Adult beetles are usually present from July to October, but can be found later in the fall if temperatures are warm. Adults usually stay on the trees from which they emerged or they may disperse short distances to a new host to feed and reproduce. Each female usually lays 35-90 eggs during her lifetime. The eggs hatch in 10-15 days. After maturing, ALB leave behind deep, perfectly round exit holes somewhat larger than the diameter of a pencil. Tree exit holes may ooze sap, and deposits of frass (insect waste and sawdust) may collect at tree trunk and tree limb bases. Additional symptoms include dead and dying branches, as well as yellowing leaves when there has been no drought.

After ALB was discovered on several hardwood trees in Brooklyn, New York in 1996, the U.S. Secretary of Agriculture declared an extraordinary emergency in order to combat the infestation with regulatory and control actions. ALB is believed to have been introduced into the United States with wood pallets and other wood packing material accompanying cargo shipments from Asia. The beetle infestation in New York spread to Long Island, Queens, and Manhattan. In 1998, a separate introduction of the beetle was discovered on trees in the suburbs of Chicago, Illinois. Beetles were also detected in two separate New Jersey locations – in Jersey City in 2002 and in Middlesex/Union counties in 2004. In 2007, ALB was found on Staten and Prall’s Island in New York. Most recently, beetles were detected in Worcester, Massachusetts in August of 2008. ALB also has been detected in warehouses in other parts of the United States, where the insects were destroyed before they could escape to start new infestations.

The current strategy to combat the ALB is to eradicate it, and to prevent its spread. The only effective way to eliminate ALB is to remove infested trees and destroy them by chipping or burning. To date, more than 60,000 known infested and at-risk host trees have been removed in the four infested states. Control efforts also include treating noninfested host trees in quarantine areas with insecticide, protecting these trees and reducing the chance that an undetected ALB population survives. State and federal quarantines are in place to prevent the spread of ALB to new uninfested areas. Many individual state agencies across the country participate in surveys for ALB and other wood boring insects through the USDA supported Cooperative Agricultural Pest Survey (CAPS) program. Massive outreach efforts are ongoing to educate tree professionals and the public about how to recognize this pest and avoid human assisted movement on firewood, and other host wood. Due to successful ALB eradication efforts, established quarantines have been lifted in Hudson County, NJ, and in several areas of Illinois, including Chicago.

WHAT CAN YOU DO TO HELP? Quick identification and containment is vital to controlling this pest. It is important that Maryland homeowners, arborists and anyone else finding a beetle that looks like it may be an Asian longhorned beetle contact the Maryland Department of Agriculture (MDA) immediately. Save the beetle, even if it is already dead. Place the beetle in a secure container and store in a freezer. Immediately call the MDA at 410-841-5920. Learn to identify the signs and symptoms of ALB. Some excellent resources can be found on line:

USDA Forest Service 


Massachsetts Introduced Pests Outreach Project 

For more information about this and other Invasive Species of Concern, visit www.mdinvasives.org