TOPSHAM — Following a presentation on browntail moth infestation in Maine communities, town staff plan to present a report to the Board of Selectmen in the coming weeks.

“We are learning like everybody else is learning,” Town Manager Rich Roedner said in an interview earlier in the day on Jan. 26. “What we … learn tonight, we’ll come in to report back to the board. And we’ll take our direction from the board.”

Potential browntail moth mitigation measures the panel could adopt include aerial spraying of trees throughout town, or focusing on town-owned parcels while offering residents access to information for battling the insects on private property.

The browntail moth first appeared in Somerville, Massachusetts, in 1897, after being accidentally brought over from Europe, according to the website of the Maine Department of Agriculture, Conservation and Forestry. The insect by 1913 had migrated throughout New England, as well as New Brunswick and Nova Scotia, Canada.

Although the browntail moth population declined throughout the rest of the 20th century, the insect remains in two places in North America – the coast of Maine and the tip of Cape Cod, according to Charlene Donahue, a forest entomologist with the Maine Forest Service.

It’s moving inland, she said in an interview Jan. 26, with an epicenter in Bowdoinham, and is showing up in Topsham, Brunswick, Bath, West Bath, Freeport and Cumberland. Donahue spoke on the matter in Topsham that night.


Browntail moths are hairy caterpillars, but it’s not the hairs you can see that are the problem.

“They have microscopic hairs … that break off” during the six times the insect molts during its lifetime, Donahue explained.

The wind carries those hairs, which can cause a human skin rash similar to poison ivy, she said. People can experience respiratory distress in more extreme cases.

“It’s a health nuisance,” Donahue said.

For mitigation, Donahue said, “the tools in the tool box are not very many,” since the caterpillars sit in the tops of oak and apple trees, and in webs for the winter.

If reachable in apple trees, which have branches that are lower to the ground, the webs can be clipped and burned, or dropped in soapy water overnight. But if they’re at the tops of oak trees, mitigation becomes more difficult.


“They can be pruned out if you have the equipment to get up there,” Donahue said, “but there can be thousands in a tree, and it’s costly and time consuming to do it.”

The Maine Forest Service offers a list of arborists willing to prune browntail webs during the winter, as well as a list of licensed pesticide applicators willing to tackle the insects and other pests with chemicals in the spring.

A bacterial insecticide called bacillus thuringiensis, or BT, has the advantage of only infecting the caterpillars that eat it, and not other insects. But “the issue in the past is that it didn’t seem to do a good enough job,” Donahue said.

The Jan. 26 meeting was an opportunity for her to provide residents information about browntail moths and what to do about them, as well as ways people can protect themselves against them, she explained.

Cumberland last year tried to tackle the caterpillars through ground spraying along Route 88, and is considering an aerial attack this year, the effectiveness of which depends on how many residents opt into the program.

For people who work outdoors in browntail moth areas in May and June, the Forest Service recommends doing so only in wet conditions.


“If you’re going to mow, if you’re going to weed-whack, if you’re going to handle brush, they’re all going to have hairs on them,” Donahue said. “And if you wet things down, those hairs don’t blow around, and you don’t come in contact with them.”

Wearing long sleeves, long pants, gloves and goggles are other means of prevention, as well as changing clothes and taking a cool shower after the work is complete, she said.

The hairs can stay active as long as three years, Donahue added: “It’s a long-lived toxin that you have to pay attention to.”

Alex Lear can be reached at 781-3661 ext. 113 or [email protected]. Follow him on Twitter: @learics.

Topsham area residents heard a presentation on browntail moth infestations Jan. 26.

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