Waterville City Councilor Thomas Klepach demonstrates in March 2022 how to remove a browntail moth nest from a tree outside the First Baptist Church at 1 Park St. in Waterville. Michael G. Seamans/Morning Sentinel file

WATERVILLE — Those visiting four city parks in the next few days might see some unusual-looking light structures made of canvas stretched across wooden frames.

No one should touch or handle the structures, which are part of a test project to determine how limiting certain kinds of light might reduce browntail moths in the city, according to City Councilor Thomas Klepach, D-Ward 3.

The goal is to help the city and surrounding communities find low- or no-cost ways to limit exposure to browntail moths, said Klepach, a biochemist and professor in the biology department at Colby College in Waterville.

Klepach launched an effort three years ago to help mitigate the impact of browntail moths. He said the insects began emerging from their cocoons a few days ago and will fly from one tree to the next and defoliate them.

“We can expect in the next week to see the moths that will be here for the next three weeks or so,” he said.

Microscopic, poisonous hairs on browntail moth caterpillars can cause severe rashes on sensitive human skin and prompt respiratory trouble. Exposure to the hairs is not as great with the moths that emerge from the caterpillar cocoons, but people should stay away from them, according to Klepach.


He said the moths can have a striking appearance, explaining that they are a “lovely white, and in between the wings, along the end of their body, it’s sort of like a rust color, and they have a rust-colored tail, a fluffy tail.”

They tend to be drawn to fruit and oak trees — anything that drops a leaf, including hardwoods, Klepach said.

“The job of the moth is to travel to a tree that has a new food source, and they mate and the females lay eggs and the eggs will incubate,” he said. “And sometime in late August, the eggs hatch and the baby caterpillars emerge and start eating in the fall, and they form silk webs over the winter.”

Three 4-foot test structures will be at each of four parks — Head of Falls, off Front Street; North Street Park; Quarry Road Recreation Area; and Veterans Memorial Park, at the corner of Elm and Park streets.

“These frames are meant to attract browntail moth and, because of that, people should just stay away from them, should not touch them,” Klepach said. “They will be posted. I’ll put signs on them.”

Matt Skehan, director of the Waterville Parks & Recreation and Public Works departments, said Monday the city is working with Klepach on the project.


“It’s an interesting program that could provide us with useful data,” Skehan said. “We identified nine lights at Head of Falls, four at Veterans (Memorial) Park and one on North Street that were temporarily disabled for the research program. They were disabled on Friday, July 7, and will go back online in three weeks — July 28.”

Klepach said a goal is to develop ways for Waterville and other municipalities to deal with browntail moths, and the results can be shared with surrounding communities. To do that, he and others are trying to collect data to share.

He also suggests ways for people to limit exposure to browntail moths inside and outside of homes.

“A low-cost, no-cost strategy they can do to try to limit exposure is to limit exterior lighting on their property between 10 p.m. and 2 a.m.,” he said. “If they can just keep it off all night, that would be even better.”

If people do not want to turn lights off, they can use red-shifted lights, which are old-school sodium vapor lamps, according to Klepach. Moths are more attracted to blue-shifted lights, or those that are harsh, bright lights or LED lights that are very white, he said. Red-shifted lights are on the more-orange, more-red end of the color spectrum.

Klepach also recommends that to limit exposure, people draw window shades or drapes if they have lights on inside homes.


“Nothing is better than turning lights off, particularly within a 60-foot radius, or 20 yards, of any tree that is a potential food source,” Klepach said.

Waterville conducted a comprehensive survey this year showing the browntail moth infestation is significantly less than last year, according to Klepach.

The city has been working to mitigate browntail moths with nontoxic pesticides, but environmental factors were also at play. The chilly, wet spring also helped slow browntail moths because they did not feed as much, and fungus grew on the caterpillars against which they have not developed a defense, according to Klepach.

“If it’s cold and wet early in the fall and spring next year,” he said, “we’ll be on the way to pushing browntail out of the region for a while.”

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