Waterville City Councilor Thomas Klepach in March 2022 demonstrates 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

As April wanes and May arrives, so too does the dreaded browntail moth.

But this season, at least in Waterville, we may not have it as bad as we did last year.

“We’re lucky to have this cold, wet weather,” said Thomas Klepach, a professor in Colby College’s biology department. Klepach also is a city councilor who for the last three years has worked on the browntail moth problem.

I called him Wednesday to get his take on what the city may be facing this season. He said if the cold, wet weather persists into May, both this year and next, that would keep the moths at bay.

“We would hope to push it out of central Maine,” he said.

Such weather has delayed the emergence of the browntail moth caterpillars a bit, so if people want to manually remove the nests in the next week or so, they may do so, and the Waterville Public Library loans pole pruners to members, Klepach noted.


One should wear protective clothing and drop nests into a bucket of soapy water for about 10 minutes before placing them in the trash, he said. Never burn nests, as the smoke can be toxic. When doing yard work such as raking, people with respiratory issues also should wear protective clothing, including gloves and masks, Klepack advises.

The city last year, and again this year, is treating all public spaces such as parks, school properties and the Quarry Road area, with a nontoxic pesticide, Spinocid. Klepach says people with a lot of browntail moth caterpillars on their property may want to hire a licensed arborist or pesticide applicator to do the work.

I’m particularly conscious of browntail myself, as I have suffered the itchy rash, caused by the microscopic, poisonous hairs shed by the caterpillars. My husband and I both got it in the summer of 2019 at China Lake. The saving grace was that a health care worker advised us to mix equal parts maximum strength Cortizone-1o ointment, extra strength Benadryl cream, witch hazel and Vicks VapoRub, and apply it to the rash morning and night, after showering. The remedy served to cool the burning rash, which lasted about 10 days.

We Watervillians are lucky to live in a city whose officials take the issue seriously. Three years ago, they began working on the problem, with Klepach heading the effort. The city hired tree experts, conducted a survey of residents and offered them help with mitigation and treated the most infested areas, including public spaces. Thus, we are ahead of some other communities affected by browntail caterpillars.

But as Klepach explains, to really alleviate the problem, we must take a regional approach. Klepach is putting his expertise as a trained biochemist to work on the issue.

He is working with Colby students on three projects, one of which involves isolating a protein from soybeans that inactivates a toxin in the browntail caterpillar hairs. Those hairs are hollow and contain the toxin, so when they become embedded in the skin, a chemical reaction occurs causing an allergic response, according to Klepach. The student research includes soaking soybeans in water for a day, isolating the protein in the water and putting the solution in a spray bottle. The idea is that, as soon as someone knows the caterpillar hairs are embedded in the skin, they can remove them with tape and then spray the solution on the skin as an antidote.


The second project involves taking data from an arborist’s survey of public spaces, the city’s residential survey and a Maine Forest Service survey, identify areas with the most tree density and light pollution and possibly limit nighttime lights in those areas between, say, 10 p.m. and midnight during peak browntail season. The third research project seeks to capture drone images of infestations on public lands, analyze them with help from Colby’s Davis Institute for Artificial Intelligence, and develop appropriate mitigation plans. The goal is to to share information with other municipalities so they don’t have to break the bank, Klepach said.

The browntail work is time-consuming but important to Klepach, who says that as a city councilor he tries to identify issues that he has expertise in or is passionate about, and focus his energy there. As we head into the peak season of May through July, area residents should familiarize themselves with browntail moth caterpillars and may do so by perusing material provided by the Maine Forest Service and Maine Center for Disease Control and Prevention, according to Klepach.

“There’s a lot of information easily accessible online and it’s wise for people to educate themselves,” he said.

Amy Calder has been a Morning Sentinel reporter 35 years. Her columns appear here weekly. She is the author of the book “Comfort is an Old Barn”, a collection of her curated columns, published in 2023 by Islandport Press. She may be reached at acalder@centralmaine.com. For previous Reporting Aside columns, go to centralmaine.com.

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