‘Extreme Outbreak': Caterpillars Causing Rashes, Respiratory Problems Spreading in Maine

In parts of Maine, caterpillars that can cause rashes and respiratory problems are spreading, and scientists are calling it an "extreme outbreak" along the mid-coast.

Browntail moths are invasive pests that have poisonous hairs. They can be found on Cape Cod and Maine’s mid-coast, but signs are that they are spreading further to Downeast Maine.

"The population really picked up in 2016, and it’s gotten even larger," said Maine Department of Forestry Entomologist Charlene Donahue. "We’re really seeing an extreme outbreak now."

In the spring, the caterpillars emerge from nests in trees, feed on foliage, and shed their skin several times before entering the cocoon.

They pose the greatest threat around June, when their hairs become airborne.

"Just being outside in a Browntail moth infested area can cause a problem," said Donahue, "even if you don’t touch them, or even see them."

The rash can be treated with a spray or ointment available at pharmacies.

Scientists recommend pruning trees in the early spring to remove nests, and killing them by putting them in a bucket of soapy water. In the summer, people should limit their exposure by wearing long sleeves and long pants, and limiting activities like mowing when the weather is dry.

"There’s no silver bullet for Browntail moths, you just have to mitigate the effects where you live," said Jeremy Cluchey, a Bowdoinham resident who has been trying to remove the nests on his property for years.

He and his 2-year-old daughter have both gotten rashes.

"We’ve seen it get progressively worse, each year," he said.

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