Emerald Ash Borer Beetle Detected in Somerville

State officials have confirmed the presence of emerald ash borer – an invasive beetle responsible for the destruction of millions of ash trees in the United States – in the City of Somerville. This is the first detection in Somerville, making it the 43rd Massachusetts community to confirm the presence of the pest. On August 10, the beetle was found during a routine inspection of ash borer traps and submitted to the State Department of Conservation and Recreation Forest Health Program, which confirmed the detection on Friday, August 17.

Ash Borer Prevention in Public Trees in Somerville

Ash is a main component of the Northern Hardwood forest in Massachusetts and is a common street tree in eastern Massachusetts. The City of Somerville has approximately 1,000 public ash trees (100 of which are on State property), which represents roughly 8 percent of the more than 12,000 public trees currently in the city. In 2016, the City of Somerville intensified efforts to help slow the spread of emerald ash borer and minimize tree loss. Ongoing preventive measures include:

• Trapping: Ash borer traps have been installed on select ash trees across the city for early detection of this pest, and to monitor population size and distribution.
• Preventive Treatment: As a preventive measure, healthy and fair condition trees are injected on a regular schedule with the organic insecticide TreeAzin, which can ward off ash borers. This treatment must be applied every two years.
• Tree Removal ONLY When Necessary: Unfortunately, sometimes trees are too sick to respond to treatment. In these cases, where absolutely necessary, dying and sick ash trees, which are more susceptible to infestation and can thus endanger nearby healthy ash trees, are removed and replaced with other varieties of tree that thrive well in an urban environment.

Signs of Ash Borers

Residents are urged to take the time to learn the signs of EAB tree damage and be sure to report any sightings.

• Look for tiny, D-shaped exit holes in the bark of ash trees, die-back in the upper third of the tree canopy, and sprouting of branches just below this dead area.
• The Emerald ash borer is a small, emerald-green metallic beetle, so small that seven of them could fit on the head of a penny.

To report suspicious tree damage or insect sightings, or to learn more about this pest, visit www.massnrc.org/pests. You can also call the toll free EAB hotline at 1-866-322-4512.

Ash Trees on Private Property

Ash trees on private property are also susceptible to emerald ash borer. If you have an ash tree on your property, you should look for the signs of EAB listed above and consult with a certified arborist for recommendations and/or treatment. If the certified arborist determines that your ash tree needs to be treated or removed, please let the City know by emailing or calling 311. This allows the City arborist to collect data about where ash borers have been found and which trees have been treated. 

• If you are not sure if your tree is an ash tree, this website can help you identify it.

Information Sessions and Hearings on Ash Borer Prevention Tree Removal/Replacement

Click on the links below to view materials from the City's past EAB hearings and information sessions.

May 2015, 2016

• Presentation (PDF)

October 25, 2018

• Presentation (PDF)
• Video