The town will spend $50,000 to help or remove trees damaged by the pest. 

With winter moth taking a toll on trees all across Cape Elizabeth, the Town Council has created a $50,000 fund to treat, remove or replace trees impacted by the insect.

“This could be something that could cost us hundreds of thousands of dollars in the next few years,” Town Manager Mike Mcgovern told the council on July 11 in supporting the special winter moth fund. Having funds on hand “would enable the tree warden to address the immediate hazards,” he said.

Earlier this summer, the town’s tree warden, Mike Duddy, was able to successfully treat an approximately 80-year-old red oak on Scott Dyer Road, adjacent to the playground at the middle school.

Duddy, who also works full time as an attorney at Kelly, Remmel & Zimmerman in Portland, is a licensed arborist and professional forester. He is contracted by the town to take care of the trees on public property, including any planting, maintenance or removal.

He described winter moth as an invasive species that is dangerous to trees because the severe defoliation caused by winter moth caterpillars across several seasons can kill a tree, especially older or already vulnerable trees. The winter moth is particularly harmful to oaks, maples, ashes, cherries and apples, Duddy said.

The winter moth joins a growing list of invasive insects that are damaging trees in Maine, including the emerald ash borer, the Asian longhorned beetle and the Hemlock woolly adelgid.

So far, according to Duddy, four trees on public land in town have been treated by a licensed commercial pesticide applicator with a pesticide known as Conserve SC. The four trees chosen, he said, “had significant landscape value,” including the red oak in the town center.

He said an uncontrolled winter moth infestation could end up having an impact on thousands of trees in Cape Elizabeth, including those located in open spaces such as parks and along public walking trails.

In addition, Duddy said, winter moth could have a financial impact on local homeowners, who may find themselves having to go through the expensive process of removing trees weakened by winter moth.

Duddy also suggested that homeowners in Cape, particularly those east of the town center, avoid planting red maple cultivars or ornamental crabapple trees, which seem to be a favorite of the winter moth.

Charlene Donohue, an entomologist with the Maine Forest Service, will give a talk on winter moth at the Thomas Memorial Library on Tuesday, Aug. 2, which is designed to share information with homeowners and others interested in combating the insect.

Duddy will also be on hand to discuss the issue as it applies specifically to Cape Elizabeth.

Donohue told the Current this week that defoliation due to winter moth has been a significant problem, particularly in coastal towns in southern Maine, since about 2012.

She said winter moth is not native to North America and was introduced from Europe sometime in the 1930s.

Winter moth first began showing up in eastern Massachusetts in the early 2000s and has since spread into coastal Maine, from Kittery to Bar Harbor, according to the Maine Forest Service website.

The winter moth has no negative impact on human health, unlike the browntail moth, which can cause a painful and itchy rash on skin that’s been exposed to the caterpillar’s hairs. But the winter moth is a tree killer.

In addition to the integral role that trees play in the ecosystem, Donahue said, the trees the winter moth is most attracted to also have commercial value, from hardwoods to fruit trees.

The winter moth mates and lays its eggs in December and then the larvae hatch in April, just in time to feast on the newly sprouting leaves. If a tree suffers defoliation from a winter-moth infestation, it will then expend precious energy putting out a second canopy, Donahue said, which ends up weakening the tree.

When winter moth caterpillers are done feeding, they then drop to the soil to pupate and the pupae remain in the ground through late spring, summer and early fall, according to the Maine Forest Service website.

Unfortunately, Donahue said, there is not a lot an individual homeowner can do to combat the winter moth, other than hiring a licensed pesticide applicator.

She said there are only two ways to control winter moth – applying a horitculture oil to smother the winter moth eggs or applying a pesticide to kill the caterpillars as they emerge.

Donahue also cautioned homeowners impacted by winter moth from removing infested trees themselves, because they might unintentially spread winter moth, particularly through disturbing the soil around a tree’s roots.

A closer look

The Cape Elizabeth Garden Club will host a public discussion on winter moth with Charlene Donohue, an entomologist with the Maine Forest Service, and Mike Duddy, the town’s tree warden, Tuesday, Aug. 2, at 7 p.m., at Thomas Memorial Library.

The life cycle of a winter moth, an invasive insect now impacting trees in Cape Elizabeth and other coastal Maine towns.

A male, adult winter moth.

A winter moth caterpillar.

Mike Duddy, Cape Elizabeth’s tree warden, stands under the historic red oak he saved earlier this year from winter moth.