APHIS Factsheet

Plant Protection and Quarantine May 2007

Asian Longhorned 

Beetle: Questions 

and Answers 

Q. What is an Asian longhorned beetle?

A. The Asian longhorned beetle (ALB) is a large, 

bullet-shaped beetle about 1 to 1.5 inches long. 

Shiny and black with white spots, it has exceptionally long antennae that are banded with black and 

white. The elongated feet are black with a 

whitish-blue upper surface. Although its size and 

large mandibles cause it to appear threatening, the 

beetle is harmless to humans and pets. In the larval 

stage, the white, worm-like beetles bore into live 

trees causing sap to flow from wounds and frass 

(sawdust and other insect waste) to accumulate at 

tree bases. Left undetected, the ALB will girdle the 

vascular system of trees eventually causing the tree 

to wither and die. 

Q. Why should the United States be concerned 

about ALB?

A. The ALB is a serious threat to U.S. trees. ALB 

larvae bore deep into deciduous hardwood trees 

such as maple, birch, horse chestnut, poplar, willow, 

elm, and ash, eventually killing them. Damage from 

infestations in Illinois, New Jersey, and New York 

has resulted in the removal of more than 30,000 

trees and costs to State and Federal governments 

in excess of $269 million since the discovery of the 

infestations in 1996. If the ALB were to expand 

beyond the current quarantined areas of Illinois, 

New Jersey, and New York, it has the potential to 

wreak havoc nationwide, affecting such industries 

as lumber, maple syrup, nursery, and tourism and 

causing more than $41 billion in losses. 

Q. How did the beetle get here?

A. ALB, which is primarily found in China and areas 

of Korea and Japan, probably hitchhiked here in 

solid wood packing material (SWPM), such as 

crates and pallets, which accompany commodities 

moving into the United States. 

 U.S. trade with China has increased exponentially over the past decade. In 2000, imported commodities from China to the United States exceeded 

$100 billion. As a result, the risk of this plant pest as 

well as the potential of other invasive insects, plant 

diseases, and weeds being introduced into the United 

States has increased as well.

Q. Can the United States stop importing goods 

from China, Japan, and Korea to avoid these 

pests?

A. No. Instead, the U.S. Department of Agriculture’s 

(USDA) Animal and Plant Health Inspection Service 

(APHIS) works with the authorities of these countries 

to take steps to prevent future infestations of ALB and 

similar pests. These steps include placing restrictions 

on SWPM and imposing treatment requirements for 

these materials before they arrive in the United States.

Q. What is being done to prevent further 

infestations from occurring?

A. In 1998, APHIS published an interim rule immediately requiring that all SWPM from China be completely free of bark and live plant pests and be treated 

with either preservatives, heat, or fumigation prior to 

arrival in the United States. Effective September 16, 

2005, all wooden packaging materials (e.g., pallets, 

crates, boxes, and dunnage) imported into the United 

States from all countries must be heat treated or 

fumigated with methyl bromide and marked with the 

International Plant Protection Convention (IPPC) logo 

and appropriate country code designating the location 

of treatment.

 APHIS analyzes threats to U.S. agriculture and 

develops rules for importing commodities based on the 

risks they present. APHIS provides the U.S. Department of Homeland Security inspectors at U.S. ports 

of entry with pest alerts, outreach material targeting 

importers, and the necessary training to increase overall vigilance during import inspections.

 These inspectors form the first line of defense 

against exotic plant and animal pests and diseases. 

All international passenger baggage, cargo, packages, mail, and conveyances are subject to inspection 

upon entry into the United States. APHIS has worked 

with industry, cooperators, and the public to heighten 

awareness of the ALB to help increase detection. 

APHIS is also conducting thorough surveys in highrisk areas where potentially infested cargo has been 

imported.

 The tremendous volume of imported cargo makes 

it impossible to visually inspect every shipped item for 

evidence of an infestation. However, based on port 

of entry inspections—which include confirming that all 

imported SWPM is marked with the IPPC logo—we 

know that more than 98 percent of imported SWPM 
is in compliance with current regulations. When 

noncompliant material is identified, it is immediately quarantined and promptly shipped back to the 

exporting country until compliance has been met. If 

infested packing material is found, in most cases, 

the infested material must be separated from the 

imported products and immediately destroyed. 

 When an ALB is found in cargo at a port of 

entry, APHIS also identifies the cargo shipment’s 

intended destination, and officials inspect the storage facility and previous shipments that may have 

been imported from the same area. Surveys are 

conducted in the vicinity around warehouses with 

infested cargo to determine if beetles have escaped 

into the environment. 

 More information about Federal regulation and 

related SWPM compliance can be reviewed by 

visiting www.aphis.usda.gov and clicking on “Wood 

Packing Materials” under “Hot Issues.” 

Q. Where in the United States has ALB been 

found?

A. Most recently, the ALB was found on Prall’s 

Island and Staten Island, NY, in March 2007. The 

ALB was first discovered in August 1996 in the 

Greenpoint neighborhood of Brooklyn, NY. In July 

1998, the ALB was found in the Ravenswood area 

of Chicago, IL. In October 2002, the ALB was 

detected in Jersey City, NJ. In 2004, the ALB was 

discovered in the Borough of Carteret, the Avenel 

section of Woodbridge Township, and the cities of 

Rahway and Linden, NJ. In 2005, three beetles 

were found on the grounds of a warehouse in Sacramento County, CA; however, surveys indicate that 

this find was an isolated incident and the ALB did 

not infest the surrounding area.

 In the past decade longhorned beetles have 

been found inside warehouses in: Mobile, AL; 

Hawthorne, Los Angeles, and South Gate, CA; Fort 

Lauderdale, FL; Martin Grove, IL; Indianapolis and 

Porter County, IN; Lansing and Warren, MI; Charlotte, NC; Camden, Cream Ridge, Linden, Mahwah, 

New Brunswick, and Secaucus, NJ; Jamestown and 

Rochester, NY; Cincinnati, OH; Lycoming County 

and Sinking Springs, PA; Charleston, SC; Houston, 

TX; Bellingham and Seattle, WA; and Sauk County, 

WI.

Q. How does APHIS survey for these pests?

A. In the absence of a trap, APHIS and cooperating State inspectors must tackle the difficult task of 

surveying beetle-infested areas by examining individual trees for signs of beetle damage. State and 

local government cooperators include the New York 

State Department of Agriculture and Markets, New 

York State Department of Environmental Conservation, City of New York Parks and Recreation, Illinois 

Department of Agriculture, City of Chicago Department 

of Streets and Sanitation’s Bureau of Forestry, New 

Jersey Department of Agriculture, and the New Jersey 

Department of Environmental Protection. APHIS 

also contracts with local tree service professionals 

for bucket truck and tree climbing services. In addition, USDA’s Forest Service contributes resources to 

APHIS’ tree inspection effort. 

 Inspectors search for exit holes, egg deposit 

sites, piles of frass at the base of infested trees and in 

branch crotches, and sap leaking from wounds in the 

trees. Unseasonable yellowing and 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 

from tree roots and nutrients from the leafy canopy 

above. Once the pest has sufficiently disrupted those 

pathways, the infested branch or the entire tree will 

die.

 Inspectors use innovative methods to conduct ALB 

surveys. Trained professionals perform aerial tree 

inspections using bucket trucks, and USDA and State 

tree climbers inspect trees in difficult areas. Many 

interest groups and organizations participate in ground 

observations. Anyone with a keen eye and set of 

binoculars can contribute to this effort.

Q. Is there an effective treatment to control or 

destroy these pests?

A. Although treatments exist to control ALB-infested 

cargo, the ALB is not easily controlled once it is introduced into the environment. Because the majority of 

the beetle’s life is spent deep within the heartwood 

of host trees, it is difficult to control using contact 

insecticides. Although costly and undesirable, the 

only assured method of eliminating the beetle is to cut 

and chip or burn infested trees and replace them with 

nonhost species.

 The use of the insecticide imidacloprid has shown 

to decrease beetle populations and help in preventing the spread of ALB and has become an additional 

effective control tool in the eradication of this pest. 

Imidacloprid is a systemic insecticide that, when 

applied directly into the trunk of a tree or injected 

into the soil near a tree, moves quickly upward into 

stems, twigs, and foliage where the beetles would be 

expected to feed and lay eggs. 

 Research to attain additional survey and control options remains ongoing. Scientists continue to 

experiment with new chemicals, application methods, 

biocontrol methods, and devices to detect ALBinfested trees. 

Q. What can homeowners do to prevent ALB from 

attacking their trees? 

A. Homeowners can assist officials in preventing an 
infestation in several ways. By cooperating with 

officials, allowing them to survey trees, remove ALBinfested trees along with high-risk exposed trees, 

and treat noninfested susceptible host trees, homeowners can help prevent further devastation. When 

planting yard or ornamental trees, homeowners 

within regulated areas should select varieties that 

ALB does not prefer. Host trees—meaning trees 

that the ALB likes to attack—include maple (Norway, 

sugar, silver, and red), birch, horse chestnut, poplar, 

willow, elm, ash, mimosa (silk tree), hackberry, 

sycamore, mountain ash, and London plane. Homeowners should adhere to current quarantines and 

regulations in their area concerning the movement 

of host material, firewood, and other wood products. 

 Homeowners may also visually inspect tree 

health by keeping a close watch for signs of distress 

that may occur as the result of an infestation. Indicators of distress may include dead leaves during 

normal seasonal conditions, excessive sawdust 

buildup near tree bases and tree crotches, excessive sap oozing from trees, and random holes in 

trees measuring approximately three-eighths of an 

inch or about the diameter of a dime.

 If any signs or symptoms of an ALB infestation 

are observed, immediately contact the State Department of Agriculture, County Extension office, or 

USDA–APHIS office. 

Additional Information

Additional information about this and other APHIS programs is on our Web page http://www.aphis.usda.gov. 

For details specific to the Asian longhorned beetle, 

click on “Newsroom,” “Hot Issues,” “Asian Longhorned 

Beetle.” 

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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 to USDA, 

Director, Office of Civil Rights, 1400 Independence Avenue, S.W. , 

Washington , D.C. 20250–9410 , or call (800) 795–3272 (voice) or 

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United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture