Browntail moth caterpillars are once again infesting a popular Bangor neighborhood park, even after the city has repeatedly used chemicals meant to control the itchy pests.
This year, city parks and recreation staff injected nine oak trees in Fairmount Park with a pesticide that is intended to kill browntail moth caterpillars when they emerge from their nests, said Aaron Huotari, Bangor’s public works director.
Two oak trees that shade the playground in Fairmount Park are especially infested with nests that sit in the trees’ top branches. Each nest holds as many as 400 caterpillars, Huotari said.
Despite the city’s efforts, browntail moth caterpillars covered the park’s playground equipment when Cassie Belka, who lives in Bangor’s Fairmount neighborhood, took her daughter there on Tuesday.
Belka said she has seen browntail moth webs in trees in the neighborhood for years, but the problem seems to have gotten worse. While she recognizes the city is doing what it can to remove the pests, she said it’s frustrating to see the efforts haven’t worked
“Clearly there are still caterpillars reaching the ground — and they’re alive,” Belka said. “I would consider chopping the oak trees around the playground down at this point since they’re hard to trim.”
Over the past few years, Mainers have come to fear the arrival of the browntail moth caterpillars, an invasive species that sheds tiny poisonous hairs that cause a rash lasting days or weeks. Cities are trying to kill the pests, which are active April through June, but have yet to find a way to eradicate them for good.
This is the second year Bangor has injected trees with the pesticide Acephate to kill browntail moths. The city tried two different chemicals last year to test which one worked best and injected trees with a lower dose, Huotari said.
After injection, the pesticide travels through the inner layer of the tree’s bark and up to the leaves. When the caterpillars emerge from their nests, they eat the leaves — and the pesticide.
Trees in Coe Park, Broadway Park, Davenport Park, Old Cemetery Park and Talbot Park were also injected with the browntail moth pesticide, according to the city’s website. In total, 31 trees were treated.
The city chose to inject the trees with pesticides rather than spray them because the wind can carry the chemicals away and they can fall on the grass, Huotari said.
Last year, crews attempted to cut the browntail moth nests out of the oak trees in Fairmount Park, but the city’s bucket trucks couldn’t reach them. The city then rented 45-foot and 65-foot lifts, but still couldn’t reach the nests.
Though the area is still full of caterpillars, Huotari said they’re young enough that they likely aren’t yet shedding the hair that causes rashes and respiratory problems.
“Hopefully they’re eating the leaves from the injected trees and dying before that happens,” said Huotari, who is also hopeful that a fungus that kills browntail moths will thrive thanks to the spring’s rainy weather.