Emerald Ash Borer arrives to Concord

Typical "blonding" of an ash tree loosing it's bark because of Emerald Ash Borer damage.

Our Executive Director, Laney Wilder, just found the first observation of the Emerald Ash Borer in Concord this month, February 2021. The Emerald Ash Borer is an insect that feeds on ash trees, and is native to Asia. It arrived to North America in the 1990’s, and is spreading. It was first found in Massachusetts in 2012, and is slowly being discovered in new towns every year. This insect can kill all varieties of our native ash trees found in our forests and suburban landscapes, and now that it has been found in Concord we are likely to see it spread through our forests at a devastating rate. What can be done about such invasive pests? One thing we can do that can slow down the spread of the Emerald Ash Borer, is avoid moving firewood and ash wood products long distances. It is believed that firewood is often the culprit when new infestations are discovered.

Let’s dig deeper into the topic of invasive insects, because the Emerald Ash Borer is not the only insect of concern in New England. The Asian Longhorn Beetle has been a persistent problem, along with the devastating effects of Hemlock wooly adelgid, gypsy moths and winter moths. There is also a new insect problem on the horizon: the spotted lanternfly. All of these insects have a similar story, the came from another part of the world (often Europe or Asia) and have flourished in North America to the point of devastating certain tree or shrub species they feed on. They are a sign of nature out of balance: here they are not controlled by their natural checks and balances, such as the predators, disease, and competition they would normally encounter in their area of nativity to keep their numbers in a healthy balance within their ecosystem.

Some ways scientists have tried to emulate that natural balance to these insects in North America is by testing and using biocontrols, such as bringing a parasitic wasp or bacteria from their native ecosystem to help keep their numbers in check. However, a biocontrol needs to be tested and vetted first before releasing, to ensure they will only target the insect that is causing the problem, and not impact other native insects or beneficial insects. Other tactics include treating trees with pesticides, though this is ineffective on a large scale, as we cannot practically treat all the trees in New England.

A recent article from the New York Times sparks an interesting parallel to the current Covid-19 pandemic and the pandemics of insects and disease North American trees have faced over the years. You can read this article called “Invasive Insects and Diseases Are Killing Our Forests” via this link. The Land Trust is part of a local CISMA (Cooperative Invasive Species Management Area) that focuses on invasive plant control; however, understanding invasive insects and what can be done to protect forests is a separate and critical challenge we and our sister land conservation organizations increasingly face.

Below are some links to the UMass Extension to help you learn about the invasive insects listed above, because education is the best way for all of us to begin to tackle this in a productive way.

Emerald Ash Borer

Asian Longhorn Beetle

Hemlock Wooly Adelgid

Gypsy Moth

Winter Moth

Spotted Lanternfly

Hemlock Wooly Adelgid infected branch.
Typical D-shaped exit hole of Emerald Ash Borer.
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