Skip to Main Content

How Invasive Insects Can Cause a Power Outage

Trees increase property values, reduce energy costs, and improve air quality. Invasive insects pose a threat, not only to trees, but to our infrastructure as well.
emerald ash borer

Invasive insects have wreaked havoc in the United States by destroying trees, endangering our environment. Trees that are damaged or killed by invasive diseases and insects also contribute to power outages, as the weakened trees can fall onto overhead utility lines. Here are some ways you can help preserve our trees and forests by taking measures to inhibit the spread of invasive tree-killing insects and diseases.

Wood Debris and Firewood

If tree work leaves you with wood debris, remember to never move it across state lines or to another property. Purchase firewood for your summer cottage or campsite locally and look for commercially kiln-dried firewood or bulk regular firewood.

Kiln-dried wood will have a stamp on the package identifying it as “heat treated” or “kiln dried.” Untreated firewood is straight from the forest or woodpile and carries the lowest risk if it comes from a nearby source (ideally, under 10 miles).

“Invasive pests are often spread through the transportation of firewood, which can be infested with insects, even if there is no visible evidence.”
– Piera Siegert, New Hampshire State Entomologist

Invasive Insects Identification

There are two species of insects that are of particular concern to our New Hampshire and Massachusetts service areas: the Asian Longhorned Beetle and the Emerald Ash Borer. By learning to identify both the insect and the damage it inflicts, you may very well save a tree in your own backyard.

Asian Longhorned Beetle

The adult beetle is 1” to 1½” in length. It has long antennae banded with black and white and a shiny, jet-black body with distinctive white spots. The Asian Longhorned Beetle’s preferred trees are maple trees (sugar, Norway, red, and silver), box elder, horse chestnut, elm, poplar, birch, and all willow species.

What to Look For

In the summer, the adult beetles chew their way out, leaving dime-sized, perfectly round exit holes in the bark.


Emerald Ash Borer

The adult beetle has a shiny emerald-green body with a coppery red or purple abdomen. The beetle measures ½” long and ⅛” wide. Adult Emerald Ash Borers are most common in June and July, but are active from May to early September.

What to Look For

In the United States, Emerald Ash Borers attack ash trees exclusively. Affected trees may exhibit dead branches at the top of the tree, or leafy offshoots from the lower trunk. Signs of infestation also include thinning and yellowing leaves, D-shaped holes in the bark, and canopy and bark loss.

Customers are urged to watch for symptoms in their trees and report any possible infestations. Any specimens you capture should be placed in a jar and kept in the freezer.

New Hampshire residents, please call to report a pest at 1-800-444-8978 or report online at

Massachusetts residents, please call the Pest Hotline at 1-617-626-1779 or report online at