The Asian 

Longhorned 

Beetle

United States

Department of

Agriculture

Animal and Plant 

Health Inspection 

Service

Program Aid

No. 1655 WANTED
2

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and 

activities on the basis of race, color, national origin, age, disability, and where applicable, sex, 

marital status, familial status, parental status, religion, sexual orientation, genetic information, 

political beliefs, reprisal, or because all or part of an individual’s income is derived from any public 

assistance program. (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 to USDA, Director, Office of Civil Rights, 1400 

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

(202) 720–6382 (TDD). USDA is an equal opportunity provider and employer.

This publication reports research involving pesticides. All uses of pesticides must be registered by 

appropriate State and/or Federal agencies before they can be recommended.

CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and 

fish or other wildlife—if they are not handled or applied properly. Use all pesticides selectively 

and carefully. Follow recommended practices for the disposal of surplus pesticides and pesticide 

containers.

Revised April 2008

Slightly revised June 2010

Photo credits: All the pictures in this brochure were taken by employees of APHIS. The photos in 

figures 1–4 were shot by David Lance, those in figures 5 and 6 by Alan Sawyer, those in figures 8, 

11, 12, 13, 16, 17, and 18 by APHIS photographer R. Anson Eaglin, those in figures 9 and 10 by 

Marlene Bombara, and those in figures 14 and 15 by Robert Benjamin. The last picture is from the 

APHIS photo library. 

Cover photos were taken by Alan Sawyer (ALB insect), Marlene Bombara (photos of technicians 

performing a ground survey and the tree canopy survey by USDA climber), and Robert Benjamin 

(imidacloprid injection) of USDA.
3

The Asian Longhorned Beetle

The Asian longhorned 

beetle (Anoplophora 

glabripennis) (ALB) is an 

invasive pest from Asia 

that came to the United 

States concealed in solid 

wood packing material, 

the pallets and crates used 

to transport goods from 

overseas. Nobody is sure 

exactly when the first ALB 

arrived here.

This insect is a serious threat 

to many species of deciduous hardwood trees in the United States (e.g., maple, 

elm, willow, birch, horsechestnut, and poplar). During its larval stage, the ALB 

bores deep into a tree’s heartwood, where it feeds on nutrients. This tunneling 

damages, and eventually kills, the tree.

If the ALB were to become established here, it 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 parts of the country.

Since its discovery in the Greenpoint section of Brooklyn, NY, in 1996, 

the ALB has been found in other parts of the greater New York City area 

and nearby suburbs in New Jersey; in and around Chicago, IL; in the 

Worcester, MA area; and in Toronto, ON. Alert workers have reported ALBs 

in warehouses in other parts of the United States, where the insects were 

destroyed before they could escape to start new infestations.

The U.S. Department of Agriculture’s (USDA) Animal and Plant Health 

Inspection Service (APHIS) has been cooperating with State and local 

governments and residents of affected areas to find and destroy ALB 

infestations. For USDA’s eradication efforts to be completely successful, 

Americans in both infested and noninfested areas must keep a sharp eye out for 

this showy but destructive pest.

Figure 1—An adult male ALB on a maple branch stripped of bark.
4

Meet the ALB

The adult ALB is a large, 

distinctive-looking insect 

measuring 1 to 1.5 inches 

long, not including its 

antennae. These antennae, 

which give the insect its 

common name, are as long 

as the body itself in females 

and almost twice the body length 

in males. The insect’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.

Many different hardwood tree species can host the ALB 

and are therefore at risk of infestation. Host trees include 

all species of maple (Norway, sugar, silver, red, and 

boxelder), elm, willow, birch, horsechestnut, London 

planetree, poplar, ash, mimosa (silk tree), mountain ash, 

hackberry, and katsura. While these beetles can fly for 

distances of 400 yards or more in search of a host tree, they 

tend to lay eggs in the same tree from which they emerged 

as adults until the insect population becomes too dense on 

that tree.

Adult beetle activity is most obvious during the summer 

and early fall. A mated female chews 35 to 90 individual 

depressions, called oviposition sites, into the bark of a 

host tree. She then lays a single egg beneath the bark 

at each site. After the egg hatches in 10 to 15 days, the 

white, caterpillarlike larva tunnels in the phloem and 

cambium layers beneath the bark. After several weeks, the 

larva tunnels into the woody tree tissue (xylem), where it 

continues to feed and develop over the winter.

In the spring, beetle larvae inside the host tree build a 

hard case for themselves and develop (pupate) within it. In summer, the fully 

developed adult ALBs chew their way out, leaving perfectly round exit holes 

one-fourth to one-half inch in diameter. As each beetle emerges, it often pushes 

sawdustlike material, called frass, out onto the ground or onto tree branches.

ALB adults feed on small twigs and leaves and then mate, beginning the cycle 

again. Adult beetles remain active only during the summer and early fall, 

when—depending on the climate—they begin to die. 

Figure 2—ALB up close.

Figure 3—ALB larva.

Figure 4—ALB pupa surrounded 

by frass.
5

Battling the Beetle

Due to the danger the ALB poses to trees in the United States, the 

environment, and various industries, USDA’s goal is to eradicate it by 

eliminating reproducing populations in the United States. Over the years, 

extensive data on the ALB has been collected, enabling the ALB Cooperative 

Eradication Program’s government partners to refine the eradication protocols, 

or methods, used against the ALB to achieve this goal.

Through years of study and 

field examination of the 

ALB in all its life stages, 

USDA–APHIS knows that 

the protocols currently in use 

represent the best, sciencebased approach to ALB 

eradication available to date. 

And, with all cooperators 

working in concert, these 

protocols are effective against 

infestations.

The protocols used by the 

ALB Program to accomplish 

eradication include 

regulatory requirements 

that curtail the movement 

of host material, survey and 

detection activities to find 

infestations, control efforts 

that remove infested trees 

and treat trees against the 

ALB, restoration to replace 

lost trees, continued research 

into what constitutes best 

practices against the ALB, 

and public outreach and 

education.

Figure 5—An adult ALB emerges, leaving a perfectly round 

exit hole.

Figure 6—An adult ALB rests beside its exit hole.
6

6

Regulatory Response Starts 

With ALB Quarantine Areas

To limit human-assisted spread of the ALB, officials from the Federal and State 

Governments establish quarantines around detected ALB infestations. When 

they detect and verify an infestation, ALB Program employees examine, or 

survey, host trees located in proximity to infested trees to identify the extent of 

the infestation and set the quarantine boundaries.

Quarantines reduce the chance that human actions will transport ALB-infested 

host materials to new areas. Federal and State regulations require that no 

individual or business remove firewood, trimmed or downed branches, logs, 

stumps, roots, or other wood debris from an ALB quarantine area.

The ALB Program enters into compliance agreements with businesses, local 

government agencies, and industries operating within quarantine zones to 

regulate host material moved for commerce. Compliance agreements also 

establish the mitigation methods for the safe disposal of removed ALB host 

trees, tree trimmings, and woody debris. The ALB Program provides training 

for businesses and municipalities that work with or handle firewood, nursery 

stock, tree limbs, branches, and any other woody debris. People who live or do 

business within ALB quarantines should be in compliance with all regulatory 

requirements put in place to protect trees from ALB infestation.

If you have any questions about working or living within an area under active 

ALB quarantine, please get in touch with the ALB Cooperative Eradication 

Program in New York, New Jersey, or Massachusetts. See the “Contacts” 

section at the end of this brochure for details.

As of February 2008, ALB quarantines exist in parts of New York State 

including portions of Manhattan, Brooklyn, Queens, Staten Island, and 

Nassau and Suffolk Counties. In central New Jersey, a quarantine exists in 

portions of Middlesex and Union Counties. For the latest ALB quarantine 

information, please log on to www.aphis.usda.gov/ALB or contact the nearest 

ALB Cooperative Eradication Program Office. These offices are listed in the 

“Contacts” section at the end of this brochure.

Due to successful ALB eradication efforts, established quarantines have 

been lifted in Hudson County, NJ, and in several areas of Illinois, including 

Chicago. An ALB has not been seen in Hudson County since 2002 or in 

Chicago since 2003. Both of these areas became eligible for a declaration of 

eradication in 2008.

Homeowner outreach and education are also provided to inform people living 

in quarantine zones that Federal and State ALB Program employees must have 

access to private property to survey, treat, and remove infested host trees and to 

perform restoration activities. Residents who live in an ALB quarantine zone 

and have questions should contact their local ALB Eradication Office.
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Survey and Detection: 

Constantly on the 

Lookout for ALBs

APHIS and cooperating State inspectors 

survey for ALBs within and outside of the 

quarantine zone by examining individual 

host trees from the ground for signs of beetle 

damage. Tree climbers also perform yearround searches in host-tree canopies, carefully 

examining every tree limb and branch for signs 

of ALB infestation.

Inspectors are looking for 

exit holes, oviposition sites, 

and frass, all of which signal 

a possible ALB infestation. 

This is challenging work 

because signs of ALB 

infestation can be few and 

obscure—one or two egg sites or healed-over exit holes, for 

example. Other signs of infestation include sap flows from 

wounds caused by the ALB, unseasonable yellowing or 

dropping of leaves when the weather has not been especially 

dry, and broken, dead, or dying branches.

The ALB Program requires 4 years of negative survey results 

to declare an area free of 

ALB infestation.

Figure 7—Surveys are performed by ALB 

Program professionals, who look for 

any signs of ALB infestations high 

in host-tree canopies.

Figure 8—Trained ALB 

Program technicians are 

searching trees for signs of 

infestation, such as these 

multiple egg sites found 

on a New York tree.

Figure 9—Not all ALB-infested trees are as 

easy to spot as this one. Nearly 200 

exit holes and more than 1,550 egg 

sites dot the trunk and branches 

of this red maple in Massapequa, 

NY. It was infested in 2000 and 

discovered in 2005.
8

Control: Tree Removal and Treatment

Research and experience have shown 

that host-tree removal is critical to 

ALB eradication. The ALB program 

removes and chips infested host trees. 

In addition, host trees near infested 

trees are cut and chipped because 

they, too, may harbor undetected ALB 

eggs, larvae, or pupae. The chips are 

landfilled or incinerated; insects do not 

survive this treatment.

Control efforts also include treating 

noninfested host trees in the 

quarantine area with the insecticide 

imidacloprid. Whether a host tree is treated or not is determined by its distance 

from the original infestation. Program protocol calls for trees to be treated for a 

minimum of 3 consecutive years. The treatment reduces beetle populations and 

can prevent trees from becoming infested, protecting these trees and ensuring 

that an undetected ALB population cannot persist in the area.

In spring, imidacloprid is injected directly into the tree or into the soil at the 

tree’s base. The insecticide disperses through the tree’s vascular system to the 

smallest branches and twigs by the time adult beetles emerge in summer. ALB 

adults feed on the small twigs and leaves, ingest the chemical, and die. Young 

larvae tunneling under the bark may also ingest the insecticide and die.

Consumers use imidacloprid in some over-the-counter lawn and garden products, 

and some lawn-service companies use it to kill grubs in turf. Imidacloprid is also 

an ingredient in some domestic pet treatments used to kill fleas.

While imidacloprid decreases beetle populations and protects against future tree 

loss, APHIS removes every tree found to be infested—even if it has been treated.

Figure 10—Ground inspections are carried out by 

trained program professionals.

Figures 11 and 12—ALB host trees are cut and chipped, a process that destroys all ALB eggs, larvae, and pupae.
9

Restoration

Because trees are so vital to the urban and suburban 

landscape—preserving air quality and providing shade 

and cooling in the summer—the program offers to 

replace removed trees with new, nonhost trees. The goal 

is to ensure diversity of tree species while reinvigorating 

neighborhoods and streetscapes.

Research

Research is continuing in laboratories across USDA 

to refine and improve the Department’s knowledge 

about invasive pests and diseases. U.S. scientists have 

even traveled to China to learn more about the insect 

known as the “starry night beetle” in its homeland. But, 

even in Asia, little scientific information was available 

back in 1996, when the beetle was first detected in the 

United States. Field studies and trials and laboratory 

research over the years have proven to be invaluable in 

developing the protocols used today to fight the ALB.

This research has 

disclosed a great deal 

of useful information 

about the ALB. First, it is now understood 

that the ALB has no known predators in 

the United States. There are no pheromones 

(sex-attractant scents) that lure ALBs for 

trapping purposes. Research has taught 

USDA scientists how far the beetle typically 

flies in search of new host trees. Scientists can 

now date infestations by evaluating the annual 

growth rings of infested trees and can even 

link infestations via insect DNA. Research 

has demonstrated that generations of ALBs 

will live in one or a few trees in a localized 

area before spreading out in search of new 

hosts in response to overcrowding or declining 

food resources. Scientific research guides 

all decisions on eradication strategies and 

protocols formulated by the ALB Program 

and its partners.

Figures 13 and 14—Imidacloprid 

is injected directly into the host 

tree or into the soil around the 

base of the tree, where it is taken 

up by the roots.

Figure 15—In New Jersey, woody debris from 

ALB Program activities is chipped prior to 

incineration at a local cogeneration plant.
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Public Outreach and Education

Sharing information about the ALB 

with homeowners and residents of 

affected areas is a critical component 

of the ALB program. An alert 

Brooklyn homeowner was the first to 

notice beetle damage on his trees and 

report it to authorities, leading to the 

discovery of this invasive pest in the 

United States. Since then, residents 

have been instrumental in helping to 

uncover infestations in New Jersey, 

Illinois, and Massachusetts.

In addition to detection, informed citizens and 

residents also understand the importance of granting 

program officials access to their property so the 

experts can search for signs of the ALB, apply 

treatments, and address infestations before they 

impact entire neighborhoods.

Residents all across the United States should 

familiarize themselves with the ALB adult and with 

the signs of ALB infestation so they can report any 

possible ALB sightings to the proper authorities.

Firewood Movement Can Spread the ALB

Human transport is a prime way that invasive diseases, pathogens, and insects, 

including the ALB, move. So residents must refrain from moving wood out of 

ALB quarantine areas. Cutting a tree into firewood does not kill any of the life 

stages of ALB living within it. When firewood is moved from a quarantine area 

to an area free of pests and sits without being burned, any larvae and pupae 

inside can continue to develop until they emerge from the firewood as adults 

and spread the infestation to nearby trees.

To protect against spreading invasive insects and diseases, it is best to buy 

firewood where it will be burned. Many State parks and campgrounds will 

not let people bring in their own firewood. It will be confiscated and burned 

immediately.

Figure 16—Planting nonhost trees to replace trees lost 

to eradication activities is an integral part 

of restoring ALB-ravaged communities.

Figure 17—ALB Program professionals 

share beetle information with 

a New Jersey homeowner.
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APHIS’ Role in Excluding Foreign Pests

In order to keep the ALB 

and other invasive pests 

from entering the United 

States, APHIS analyzes 

threats to U.S. agriculture 

and develops rules for 

importing commodities 

based on the risks they 

present.

The best way to fight 

the ALB and similar 

nonnative wood borers 

is to exclude such pests 

from the country. To stop 

ALBs from entering the 

United States, international 

regulations now require 

all solid wood packing material imports to be heat-treated, fumigated, or 

treated with preservatives before being sent to this country. Special stamps 

and paperwork must accompany shipments to verify which of the prescribed 

treatments took place. Items that do not meet regulations are returned to their 

country of origin.

Inspection specialists at U.S. ports are the first line of defense against exotic 

plant and animal pests and diseases. In addition, all international passenger 

baggage, cargo, packages, mail, and conveyances are subject to inspection upon 

entry into the United States to exclude exotic pests.

Figure 18—Specialists at U.S. ports inspect high-risk cargoes for the 

ALB and other pests.
Contacts

For more information regarding the ALB—including quarantine maps, 

photographs, publications, pest alerts, the ALB Strategic Plan for 

Eradication, a detailed timeline, and other information—please visit 

http://www.aphis.usda.gov on the World Wide Web and click on the button 

for Asian longhorned beetle under “Hot Issues.”

• To report a sighting of the ALB in a State other than New York or New 

Jersey, please contact your APHIS State Plant Health Director or call 

the State department of agriculture or agricultural extension service. 

The State Plant Health Directors can be found at this Web site: http://

www.aphis.usda.gov/contact_us/ppq.shtml. On the U.S. map, just 

click on the State of interest.

• Those living in New Jersey or Staten Island, NY, may call the New 

Jersey ALB Cooperative Eradication Program at 732–815–4700 or the 

New Jersey Department of Agriculture hotline at 866–233–8531.

• Those living in New York, including Staten Island, may call 

1–866–265–0301 or 1–877–STOP ALB.

• Those living in Massachusetts may call the ALB Program at 

508-852-8090 or 1-866-702-9938.

• Those living in Illinois may call the ALB Program at 847–699–2424.

The ALB Cooperative Eradication 

Program Is a Partnership

State and local government agencies working together comprise 

the ALB Cooperative Eradication Program. In New York, the partnership 

includes USDA–APHIS along with the New York 

State Department of Agriculture and Markets, New York State Department 

of Environmental Conservation, and The City of New York Department of 

Parks & Recreation. ALB Program partners in New Jersey include the New 

Jersey Departments of Agriculture and Environmental Protection. 

In Illinois, ALB Program partners are the Illinois Department 

of Agriculture and the City of Chicago Department of Streets and 

Sanitation’s Bureau of Forestry. In Massachusetts, partners include the 

Massachusetts Department of Conservation and Recreation, the 

Massachusetts Department of Agricultural Resources, and the 

City of Worcester. Within USDA, partners include the Forest 

Service and Agricultural Research Service.