Asian Longhorned Beetle 
(Anoplophora glabripennis)

Plant Protection and Quarantine 
January 2001

The Asian longhorned beetle's recent introduction to the United States has earned it the title of pest both here and in its home country of China.  The beetle is a serious threat to hardwood trees and has no known natural predator in the United States.  If the Asian longhorned beetle becomes established here, it has the potential to cause more damage than Dutch elm disease, chestnut blight, and gypsy moths combined, destroying millions of acres of America's treasured hardwoods, including national forests and backyard trees.  The beetle has the potential to damage such industries as lumber, maple syrup, nursery, commercial fruit, and tourism accumulating over $41 billion in losses. 

Current quarantines and eradication efforts established by the United States Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) have confined infestations to Chicago and New York. 


Determined by USDA officials to have entered the United States inside solid wood packing material from China, the Asian longhorned beetle was first discovered in 1996 in the Greenpoint neighborhood of Brooklyn, NY.  Within weeks, another infestation was found on Long Island in Amityville, NY, after officials learned that infested wood had been moved from Greenpoint to Amityville.

In 1998, despite USDA's national Asian longhorned beetle pest alert campaign, a separate infestation was discovered in the Ravenswood area of Chicago.  This discovery prompted APHIS to amend its existing quarantine of wood movement in infested areas and place additional restrictions on importing solid wood packing material into the United States from China and Hong Kong. 


Asian longhorned beetles are about 1 to 1 1/2 inches in length, are black and shiny with white spots, and have long distinguishable antennae that are banded with black and white.  They attack many different hardwood trees, including maple (Norway, sugar, silver, and red), birch, horsechestnut, poplar, willow, elm, ash, and black locust. 

Female Asian longhorned beetles chew depressions (oviposition sites) in the bark of trees to lay eggs.  A single female beetle can lay from 35 to 90 eggs.  Hatching within 10 to 15 days, the worm-like immature beetles tunnel under tree bark and bore into healthy hardwood trees.  The beetle larvae feed on living tree tissue during the fall and winter and, after pupating, emerge through exit holes during the spring.  After emerging, adult beetles feed on tree exteriors for 2 to 3 days, then mate.  Adult beetles remain active only during summer and early fall months before perishingócompleting a 1-year life cycle.


Since beetle larvae live deep inside trees the majority of the year, they can easily and unknowingly be moved in firewood, live trees, or fallen timber.  Asian longhorned beetles more commonly spread by natural means; under their own power they can fly distances greater than 400 yards.  Migration may also depend on the abundance of suitable host materials (i.e., hardwood trees).

Damage to Trees

After maturing, Asian longhorned beetles 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.  Egg deposit sites can be found by looking for dime-sized, dimpled impressions in tree bark.

Unseasonable yellowing or drooping of leaves when the weather has not been especially dry are also signs that the Asian longhorned beetle is present. Leaf symptoms show up when the immature insects, growing inside the tree, have bored through tissue that carry water (xylem) from tree roots and nutrients (phloem) from the leafy canopy above. Once the pest has sufficiently disrupted those pathways, the infected tree will die.

Detecting an Infestation

APHIS works closely with many agencies and resources to inspect for and detect the Asian longhorned beetle, including the  U.S. Forest Service, the Agricultural Marketing Service, and the U.S. Department of the Interior's Bureau of Land Management (BLM).  Other cooperators include New York State Department of Agriculture and Markets, New York City Department of Parks and Recreation, Illinois Department of Agriculture, Chicago Department of Streets and Sanitation, Chicago Bureau of Forestry, and privately contracted tree-service professionals.

Asian longhorned beetle inspectors utilize many methods and resources to conduct tree surveys.  Aerial tree inspections are performed by trained professionals using bucket trucks to peer into trees from above.  The U.S. Forest Service and BLMís smokejumpers (forest firefighters) climb trees in otherwise inaccessible areas to scrupulously search for signs of an infestation. 

Many interest groups and organizations voluntarily assist inspectors by searching trees from the ground; however, anyone with a keen eye and set of binoculars can contribute to this effort. 

Increasing Public Awareness

Although conventional methods of newspaper and television are effective in informing the public, APHIS also works cooperatively with many other groups to battle the beetle.  Groups such as New York ReLeaf, University of Vermont, and Trees New York assist APHIS with public outreach efforts.  By distributing printed material and arranging public, community, or organizational forums, these groups and other special interest contributors broaden efforts to inform the public of this devastating pest. 

APHIS continuously requests the assistance and cooperation of residents, business owners, and professionals in identifying, reporting, and providing assistance to the Asian longhorned beetle eradication program.  Citizens of New York and Chicago are encouraged to remain aware of signs of an infestation and current quarantine areas and regulations governing the sale and transport of tree-based products in and around restricted areas. 


Currently, the most effective method of eradicating the Asian longhorned beetle is to cut, chip, and burn infested trees, replacing them with nonhost species.  Cooperative research continues in the United States and Asia in an effort to find acceptable alternatives to tree removal.

Recently the insecticide Imidacloprid has presented good results in field applications and is increasingly being used in conjunction with other methods to protect trees and eradicate the pest.  The potential for traps and pheromones as methods of eradication has not displayed considerable promise, and more time is required to determine the impact of all eradication options. 

Collectively, APHIS and New York and Illinois State and local governments have invested over $30 million to eradicate the Asian longhorned beetle and prevent the discerning loss of the combined 6.7 million trees in New York City and Chicago.

APHIS primarily aids eradication efforts by imposing quarantines and conducting intensified visual inspections around confirmed sites to delimit infestations. 

Protecting Ports of Entry 

APHIS' Plant Protection and Quarantine (PPQ) officers diligently conduct visual inspections of high-risk cargoes and in high-risk areas, such as cargo distribution warehouses. 

To further address the Asian longhorned beetle problem at U.S. ports of entry, APHIS has issued pest alerts to ports of entry personnel, conducted outreach to local importers, and targeted high-risk importers and Chinese exporters for outreach and increased inspections.  As part of a national survey, APHIS is focusing on cargo labeled for high-risk destinations (warehouses that have previously received cargoes found to be infested with beetles). The Agency conducts secondary inspections and surveys of the environs at these destinations. 

Additionally, Federal regulations prohibiting the importation of solid wood packing materials from China and Hong Kong to the United States are in place, thwarting further Asian longhorned beetle infestations via such hosts.  By conducting extensive periodic inspections at ports of entry, targeting Chinese shipments with solid wood packing materials APHIS inspectors work to detect wood-boring pests and locate problem importers.

The Asian longhorned beetle is just one of a numberof exotic pests that present a serious threat to U.S. trees. Spruce bark beetle (Ips typographus) and Mediterranean pine engraver beetle (Orthotomicuserosus) are two other nonnative wood-boring pests of concern.  APHIS inspectors search for all such pests on imports of solid wood products and also on solid wood packing materials like pallets and crates.

Guarding our Borders

APHIS stations PPQ officers at all U.S. ports of entry and in some foreign countries.  These inspectors form the first line of defense against exotic plant and animal pests and diseases. All international passenger baggage, cargo, package mail, and conveyances are subject to inspection at these ports of entry.

By monitoring pests and diseases in other countries, APHIS analyzes threats to U.S. agriculture and develops import  restrictions on commodities based on their risk of introducing harmful organisms.  APHIS inspectors ìpreclearî some commodities before they leave their country of origin.  Domestic package mail and passengers bound from Hawaii or Puerto Rico to the U.S. mainland are inspected too.

APHIS also develops treatments and rapid response techniques to fight outbreaks of unwanted pests as well as detection and monitoring programs to ensure that foreign pests do not become established here.  Regular surveys and trapping are done to detect the arrival of new pests or chart the movement of existing pest populations.

For more information regarding the Asian longhorned beetle, reporting an infestation, solid wood packing material, Imidacloprid, or quarantine and regulations, please visit on the Internet. 


The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, or marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326-W, Whitten Building, 14th and Independence Avenue, SW, Washington, DC 20250-9410 or call (202) 720-5964 (voice and TDD). USDA is an equal opportunity provider and employer.

[ Back to LICWeb Home Page ]