Maine is experiencing its worst browntail moth season in a century, with the pests identified in all 16 counties, and forest experts say that unseasonably warm temperatures and dry conditions are contributing to the outbreak.
As caterpillars, browntail moths shed poisonous hairs that cause irritating rashes when they come in contact with skin or respiratory discomfort if inhaled. The hairs float through the air and stick to outdoor surfaces.
Jim Dill, pest specialist for the University of Maine Cooperative Extension, says the hairs can stick around for two to three years.
"If you had browntails last year and you sit here and say, 'Wow, it's great, I don't have any browntail moths this year': those hairs can last two or three years in the environment. If you're out there mowing and, you know, you've had an infestation in the last year or two, take the same precautions," he says.
Browntail moth nests begin to open in the spring, and by late June, the caterpillars are active. Dill recommends hosing down outdoor furniture before sitting on it, taking a shower after doing yard work and, weather permitting, wearing long clothes.
The rash is not dangerous, but experts recommend consulting your doctor for treatment.
The current outbreak began in 2015 and experts say it's the worst in a century. Moth infestations are declared an outbreak when the moth activity has a significant impact on tree defoliation.
Allison Kanoti, Director of Forest Health and Monitoring with the Maine Forest Service, says that once an outbreak occurs, there is no way to stop it.
"One of the realities is that browntail moth is in an outbreak condition right now. And preventing an outbreak, certainly with the knowledge we have at this point, is really not possible," she says.
Kanoti says communities can take steps to temporarily reduce populations of the moths by cutting nests out of trees or spraying the trees, but that will not end the active outbreak.
