Asian longhorned beetle (Anoplophora glabripennis), or ALB, remains a serious threat to maples and other hardwood trees in Massachusetts.
Nearly two decades after the invasive beetle was discovered in a Worcester backyard, parts of Worcester County remain under quarantine as state and federal officials continue working to eradicate it.
Unfortunately, trees confirmed to be infested with ALB cannot recover, making early detection especially important. Massachusetts homeowners should know what the beetle looks like, which trees it attacks, and the signs and symptoms that may indicate an infestation.
Homeowners in and around the quarantine area also need to understand the rules governing firewood, branches, and other regulated wood. Knowing what to look for — and what to do if you spot something suspicious — can help prevent ALB from spreading to additional trees and communities.
What Is the Asian Longhorned Beetle?
The Asian longhorned beetle is a large, invasive wood-boring beetle native to China and the Korean Peninsula. It likely reached the United States in the 1980s by hiding in solid wood packing material.
Adults are about 1 to 1½ inches long, with shiny black bodies, irregular white spots, and long black-and-white-banded antennae, while the larvae are white, legless grubs.
After hatching, the larvae feed beneath the bark before tunneling deeper into the wood. This feeding damages the tree’s vascular tissues and structural wood, eventually causing decline and death.
| Quick Fact | Asian Longhorned Beetle |
| Scientific Name | Anoplophora glabripennis |
| Origin | China and the Korean Peninsula |
| Adult Size | About 1–1½ in. long |
| Hosts | 12 genera of hardwood trees, including maples, elms, willows, and birches |
| Massachusetts Status | Federally quarantined in part of Worcester County |
| Primary Damage | Larval feeding and tunneling beneath the bark and into the wood |
The History of the Asian Longhorned Beetle in Massachusetts
Though it likely arrived in the U.S. in the 1980s, ALB was first detected in the United States in Brooklyn, New York, in 1996. It probably reached our shores by traveling in solid wood packing material used in international trade. Twelve years later, the beetle was discovered in our state.
The Worcester infestation was detected in August 2008. As surveys uncovered its extent, federal and state officials established a regulated area encompassing Worcester and surrounding communities to contain the beetle and prevent infested wood from carrying it elsewhere.
A separate infestation was discovered in Boston in 2010, but it was declared eradicated in 2014. Unfortunately, the infestation has not yet been eradicated from Worcester County.
Nevertheless, the city of Holden was removed from the quarantine area in July 2025. This reduced the regulated area from 110 to 97.7 square miles, leaving Worcester, Boylston, West Boylston, Shrewsbury, and part of Auburn within the current quarantine.
How the Asian Longhorned Beetle Spreads
Adult beetles typically stay close to the trees where they emerge, although they can fly several hundred yards in search of new hosts or mates. But human activity can move ALB much farther through the transportation of infested wood.
Firewood, logs, branches, and other untreated wood from host trees can harbor ALB life stages hidden beneath the bark or inside the wood. Moving these materials can carry the beetle into areas it could not quickly reach on its own.
That risk is why the Massachusetts quarantine restricts the movement of regulated wood from the affected area. The rules apply even when wood shows no obvious signs of infestation because ALB can remain hidden inside.
Massachusetts Trees at Risk from the Asian Longhorned Beetle
Maples (Acer spp.) are the most commonly infested ALB hosts in the United States.
That includes familiar Massachusetts trees such as red (Acer rubrum), sugar (Acer saccharum), Norway (Acer platanoides), and Japanese maple (Acer palmatum), all of which are considered regulated host material within the quarantine.
But ALB isn’t limited to maples, and it has a host list covering 12 genera, including:
- Birches (Betula spp.)
- Elms (Ulmus spp.)
- Willows (Salix spp.)
- Ashes (Fraxinus spp.)
- Buckeyes (Aesculus spp.)
- Golden Raintrees (Koelreuteria spp.)
- Silk Trees (Albizia spp.)
- Sycamores (Platanus spp.)
- Katsura (Cercidiphyllum spp.)
- Mountain-ash (Sorbus spp.)
- Poplar (Populus spp.)
Signs and Symptoms of Asian Longhorned Beetle Infestation
Because much of ALB’s life cycle takes place inside the tree, an infestation can be easy to overlook. So, be sure to watch for both evidence of beetle activity and changes in the tree itself.
This includes watching for things like:
- Egg-Laying Sites: Female beetles chew shallow depressions into the bark before laying their eggs. Sap may ooze from these areas.
- Sawdust-Like Frass: Coarse, sawdust-like material may collect at the base of the tree, on branches, or where branches meet the trunk.
- Round Exit Holes: Adult beetles leave distinct, round holes in the trunk and branches when they emerge from the tree.
- Adult Beetles: Look for a shiny black body with irregular white spots and long antennae banded in black and white.
- Crown Dieback: As an infestation progresses, branches may die back and foliage may thin as internal damage interferes with the tree’s normal function.
What Should Massachusetts Homeowners Do if They Suspect ALB?
Asian longhorned beetle infestations are taken seriously in Massachusetts, particularly within the regulated area around Worcester County. If you notice any signs or symptoms of an ALB infestation, you’ll want to take the right steps to protect nearby trees and prevent the insect from spreading.
1. Report Suspected ALB Activity
Because Asian longhorned beetle is a regulated invasive pest, suspected infestations should be reported to the Asian Longhorned Beetle Eradication Program.
Homeowners can report suspicious beetles or tree damage through the USDA’s online reporting system or by calling the Asian Longhorned Beetle hotline at 1-866-702-9938.
2. Have the Tree Inspected
After reporting the suspected ALB activity, consider having the affected tree evaluated by an ISA-certified arborist. Many insects and tree problems can produce symptoms that resemble ALB damage, so proper identification is important.
Tree Tech’s pest and disease control services can help identify what may be affecting the tree and determine the appropriate next steps.
3. Avoid Moving Potentially Infested Wood
Do not move branches, logs, firewood, or other woody material from a tree suspected of harboring ALB until the situation has been evaluated.
Within the quarantine area, the movement of hardwood firewood and host-tree material is regulated. This includes logs, branches, stumps, roots, green lumber, nursery stock, and woody debris.
4. Follow Quarantine and Disposal Requirements
The Massachusetts ALB quarantine currently includes portions of Worcester County and is part of a cooperative state and federal eradication program.
Homeowners within the regulated area should make sure that tree care companies handling regulated material have the appropriate ALB compliance agreement and follow current transport and disposal requirements.
5. Understand What Happens if ALB Is Confirmed
Unfortunately, trees confirmed to be infested with Asian longhorned beetle cannot be saved. Once an infestation is confirmed, removal and destruction of the tree are generally required as part of the state and federal eradication response.
For homeowners, this means removal of a confirmed ALB-infested tree is not simply a treatment choice. It becomes part of a larger eradication effort designed to eliminate the beetle before it can spread farther.
Asian Longhorned Beetle: FAQ
Here are answers to common questions Massachusetts homeowners may have about ALB and the Worcester County quarantine.
Is the Asian longhorned beetle still active in Massachusetts?
Yes. The Worcester County infestation remains a threat, meaning that homeowners and property managers must remain vigilant and monitor their trees carefully.
Can I spray or inject my tree to prevent Asian longhorned beetle?
Homeowner products containing imidacloprid can help protect individual, uninfested trees, but they won’t cure a tree that’s already infested, and treating on your own isn’t a substitute for professional diagnosis.
If you suspect ALB, report it rather than treating first — a misdiagnosed tree can mean a missed infestation.
Do I have to pay if the eradication program removes an infested tree from my property?
No. Trees confirmed to be infested with ALB are removed and destroyed by the eradication program at no cost to the property owner.
Can I move firewood off my property if I live in the quarantine zone?
It depends on where the firewood is going. All hardwood firewood is regulated within the quarantine, and it cannot be moved out of the regulated area unless applicable program requirements are met.
Check current rules before transporting firewood or other regulated wood.
Is Boston still under an ALB quarantine?
No. A separate ALB infestation was discovered in Boston in 2010 and declared eradicated in 2014. Boston is no longer part of an ALB regulated area.
What should I do if I spot possible ALB damage on my tree?
You should report suspected ALB activity to the Asian Longhorned Beetle Eradication Program. Take clear photos of the beetle or suspicious damage if possible and avoid moving potentially infested wood until the situation has been evaluated.
Can Tree Tech remove or treat a tree that’s confirmed infested with ALB?
Removal of confirmed ALB-infested trees is directed by the state and federal eradication program. Tree Tech can evaluate tree health concerns, but suspected ALB will have to be reported to the program so officials can determine the appropriate response.
Tree Tech, Inc.: Protecting Massachusetts Trees from the Asian Longhorned Beetle
Tree Tech has cared for trees across eastern Massachusetts and Rhode Island since 1986. Today, our ISA-certified arborists help homeowners identify tree health problems and make informed decisions about their care.
If something looks off with a maple or another hardwood on your property, you don’t have to figure it out on your own. Schedule a consultation with Tree Tech to get expert eyes on your trees.
Sources and References
- USDA Animal and Plant Health Inspection Service (APHIS) – “Asian Longhorned Beetle”
Primary federal source for current ALB biology, identification, signs of infestation, reporting guidance, quarantine rules, regulated materials, and eradication procedures. It confirms that infested trees cannot be treated or saved and provides current federal requirements for handling regulated material.
https://www.aphis.usda.gov/plant-pests-diseases/alb - Massachusetts Department of Conservation and Recreation – “Asian Longhorned Beetle in Massachusetts”
Primary state resource for the Massachusetts-specific history and current Worcester County eradication effort. It supports the timeline from the 2008 Worcester discovery through the separate Boston infestation and current quarantine, including the communities within the 97.7-square-mile regulated area.
https://www.mass.gov/guides/asian-longhorned-beetle-in-massachusetts - UMass Extension – “Asian Longhorned Beetle”
University extension resource supporting ALB biology, appearance, life cycle, host range, and damage. It is particularly useful for the host section, including the 12 susceptible hardwood genera and the importance of maples (Acer spp.) as hosts.
https://www.umass.edu/agriculture-food-environment/landscape/fact-sheets/asian-longhorned-beetle - Massachusetts Introduced Pests Outreach Project – “Massachusetts ALB Eradication Program”
Massachusetts-focused resource covering reporting, compliance requirements and training, identification resources, and the history of the Greater Worcester regulated area. It provides useful local context for homeowner and tree-care-company responsibilities within the quarantine.
https://massnrc.org/pests/alb/ - USDA APHIS – “APHIS Eradicates the Asian Longhorned Beetle from Holden, Massachusetts”
Federal announcement documenting Holden’s July 2025 removal from the ALB quarantine. It supports the recent historical milestone and confirms the reduction of the Worcester County regulated area to 97.7 square miles.
https://www.aphis.usda.gov/news/program-update/aphis-eradicates-asian-longhorned-beetle-holden-massachusetts - Massachusetts Department of Conservation and Recreation – “Asian Longhorned Beetle Eradicated in Holden”
State announcement documenting Holden becoming the first Worcester County community removed from the quarantine. It also provides Massachusetts-specific context for the cooperative state and federal eradication effort.
https://www.mass.gov/news/asian-longhorned-beetle-eradicated-in-holden