The Asian LonGhorned 

Beetle: An invasive 

pest of Trees

United States

Department of

Agriculture

Animal and Plant Health Inspection Service

Program Aid No. 2144
2 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 (SWPM), 

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 beetle 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 first discovery in Brooklyn, NY, in 1996, the beetle has been 

detected in a total of five U.S. States—New York (1996), Illinois (1998), 

New Jersey (2002), Massachusetts (2008), and Ohio (2011)—and in Toronto 

and Vaughan, Ontario, Canada. Alert workers have reported the beetle 

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) cooperates 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 infested and 

noninfested areas must remain vigilant for this invasive and destructive pest.

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.

This publication supersedes Program Aid No. 1655, “WANTED: The Asian Longhorned Beetle,” 

which was originally issued in 1998 and last revised in April 2008.

Issued October 2013

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 

7, 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.

Figure 1—An adult male ALB on a striped maple.
4 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 beetle has been collected, enabling the eradication 

program’s government partners to refine the eradication protocols, or methods, 

used against the beetle to achieve this goal.

Through years of study and 

field examination of the ALB 

in all its life stages, USDA 

knows that the protocols 

currently in use represent the 

best, science-based approach 

to ALB eradication available 

to date. And, with all 

cooperators working together, 

these protocols are effective 

against infestations.

The protocols used by the 

eradication program include 

regulatory requirements 

that limit 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.

Meet the ALB

The adult beetle 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, tree limbs, and branches.

Many different hardwood tree species can host the beetle 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, katsura, and golden raintree. 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 lays a single egg beneath the bark at each site. After 

the egg hatches in 10 to 15 days, the white 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 start to 

develop (pupate) into adults, only to emerge in summer, 

when the fully developed adult beetles chew their way out, 

leaving perfectly round exit holes one-fourth to one-half 

inch in diameter. As each beetle emerges, it often pushes

 sawdust-like 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 as the weather turns colder.

Figure 2—ALB up close.

Figure 3—ALB larva.

Figure 4—ALB pupa surrounded 

by frass.

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

exit hole.

Figure 6—An adult ALB rests beside its exit hole.
6 7

Survey and Detection:

Constantly on the 

Lookout for the Beetle

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 eradication program requires 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 was. 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.

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 eradication 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 eradication 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 

eradication 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 eradication program in your 

State. See the “Contacts” section at the end of this brochure for details.

As of June 2013, ALB quarantines exist in New York, including in Brooklyn 

and Queens and a portion of Nassau and Suffolk Counties. In Massachusetts, 

quarantines exist in Worcester County and portions of Norfolk and Suffolk 

Counties. In Ohio, quarantines exist in Clermont County. For the latest 

ALB quarantine information, go to www.aphis.usda.gov/ALB, visit 

www.AsianLonghornedBeetle.com, or contact the nearest ALB 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 Illinois (2008); Islip, NY (2011); New Jersey (2013); and Manhattan 

and Staten Island, NY (2013). 

Homeowner outreach and education are also provided to inform people living 

in quarantine zones that Federal and State ALB eradication program employees 

must have access to private property to survey, treat, and remove infested 

host trees. Residents who live in an ALB quarantine zone and have questions 

should contact their local ALB eradication program office.
8 9

Replanting

Because trees are so vital to the urban and suburban 

landscape—preserving air quality and providing shade 

and cooling in the summer—APHIS works with 

State partners to replant nonhost trees on properties 

that have had trees removed because of the beetle 

eradication efforts. 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. 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 eradication 

program and its partners.

Control: Tree Removal and Treatment

Research and experience have shown 

that host-tree removal is critical to 

ALB eradication. The ALB eradication 

program removes and chips infested 

host trees. In addition, host trees 

near infested trees may be cut and 

chipped because they, too, likely harbor 

undetected ALB eggs, larvae, or pupae. 

The chips are landfilled or incinerated; 

insects do not survive this treatment.

Control efforts can 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. 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 can decrease beetle populations and help protect 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.

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 was chipped prior to 

incineration at a local cogeneration plant.
10 11

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 

SWPM 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.

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, Massachusetts, and Ohio.

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 remove 

infested trees, if needed, 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 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 leave 

firewood behind or purchase only USDA- or State-certified, treated, and 

labeled firewood. 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.

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, and other useful resources—please 

visit www.aphis.usda.gov and click on the button for Asian longhorned 

beetle under “Hot Issues.” Or visit the ALB information site at 

www.AsianLonghornedBeetle.com.

•	 To report a sighting of the beetle or signs of damage in a State other

than New York, Massachusetts, or Ohio, please call 1-866-702-9938,

contact your nearest APHIS State Plant Health Director, or call the

State department of agriculture or agricultural extension service. 

Contact information for the State Plant Health Directors can be 

found at this Web site: www.aphis.usda.gov/StateOffices. On the 

U.S. map, just click on the State of interest.

•	Those living in New York may call: 1-866-265-0301 or 

1-877-STOP ALB.

•	 Those living in Massachusetts may call: 508-852-8090 or

1-866-702-9938.

•	 Those living in Ohio may call: 513-381-7180 or 1-866-702-9938.

ALB Eradication Programs Are a Partnership

ALB eradication programs are cooperative programs. APHIS works with 

USDA’s Forest Service, Agricultural Research Service, and partnering 

organizations in each affected State. In Ohio, the cooperative eradication 

program is composed of the Ohio Department of Agriculture, Ohio 

Department of Natural Resources, Ohio State University Extension, 

and Clermont County. In Massachusetts, the cooperative eradication 

program is composed of the Massachusetts Department of Conservation 

and Recreation; Massachusetts Department of Agricultural Resources; 

the cities of Boston and Worcester; and the towns of Auburn, Boylston, 

Brookline, Holden, Shrewsbury, and West Boylston. In New York, the 

cooperative eradication program is composed of the New York State 

Department of Agriculture and Markets, the New York State Department 

of Environmental Conservation, and the New York City Department of 

Parks and Recreation.