What is Emerald Ash Borer?About
About Emerald Ash Borer
Emerald Ash Borer is a beetle that kills ash trees when its larvae burrow under the bark and feed on the nutrients that circulate inside the tree. The beetle was first detected in the United States in 2002. Experts think it probably came from Asia in wood-packing material. The Emerald Ash Borer has been spreading in Boston since it was first found in the Arnold Arboretum in 2014.
Emerald Ash Borer and Boston's Trees
Some ash trees in Boston’s neighborhoods have started displaying signs of infestation. It may take three to five years for trees to begin showing outward signs of Emerald Ash Borer activity.
Signs of activity include:
- D-shaped exit holes in the bark of ash trees
- "Blonding” from woodpecker feeding
- Dieback in the upper third of the tree canopy
- Sprouting at the base of the trunk
What does Emerald Ash Borer eat?
The pest feeds only on ash trees. But, the Emerald Ash Borer kills 99% of the ash trees it infests. If more than one-third of an infested ash tree is dead due to damage from Emerald Ash Borer, the tree cannot be saved and must be removed.
The invasive beetle has been identified in the neighborhoods of Allston-Brighton, Dorchester, Fenway-Kenmore, Hyde Park, Jamaica Plain, Roslindale, Roxbury, Mattapan, and West Roxbury, as well as the Arnold Arboretum, Franklin Park and the Muddy River area.
Protecting Boston's tree canopy
The Boston Parks and Recreation Department is working to ensure the health of our public street trees as well as trees in the parks, squares, and plazas that the Parks Department maintains. We’ll protect healthy trees and remove dead and heavily infested trees to stop the spread of the Emerald Ash Borer.
We’re also working on a comprehensive Urban Forest Plan to preserve and expand our tree canopy — and the overall quality of life for Bostonians. Increased funding and staffing for tree care will help us respond to pests like Emerald Ash Borer.
Look out for public street trees marked for removal or treatment over the coming months. Never move tree material from one location to another.
The Boston Parks and Recreation Department cares for street trees and trees in parks. If you see a street tree or a tree in a public park that you think may be infested with Emerald Ash Borer, contact 3-1-1. If you have questions about identifying ash trees on private property, like the grounds of homes or businesses, contact a certified tree care professional.