Maine CDC Provides Tips to Reduce Exposure to Browntail Moth Hairs

May 13, 2025

AUGUSTA-- The Maine Center for Disease Control and Prevention (Maine CDC) and the Maine Department of Agriculture, Conservation and Forestry's Maine Forest Service (MFS), remind Maine residents and visitors to take precautions to protect against browntail moth caterpillar hairs this spring.

Browntail moth caterpillars are hairy, dark brown caterpillars with two red-orange dots on the back. Older caterpillars have two broken white stripes running from head to tail. The caterpillars are active as the weather warms and shed tiny, toxic hairs that can get stirred up during outdoor activities such as raking, mowing, and typical yard work. Hairs can land anywhere, including on trees, gardens, lawns, outdoor furniture, and decks. The hairs can stay toxic in the environment for up to three years. Over the last several years, the MFS has found evidence of browntail moths in all 16 Maine counties.

Most people affected by the hairs develop a localized rash that lasts for a few hours up to several days. In more sensitive people, the rash can be severe and last for weeks. Hairs may also cause respiratory distress. Treatment for the rash or breathing problems caused by browntail moth hairs focuses on relieving symptoms and eliminating further exposure.

Photos from left to right: Browntail moth winter web, Many young browntail moth caterpillars basking on a winter web in late April, Browntail moth cocoon in late June

To reduce exposure to browntail moth hairs:

Stay informed about browntail moth hotspots by visiting the Interactive Browntail Moth Dashboard to see where the MFS notes high activity. Then, be proactive, know the risks, take steps to protect yourself, and monitor your surroundings.

When performing outdoor activities that may stir up caterpillar hairs:

• Cover your face and any exposed skin by wearing a long sleeve shirt, long pants, a dust mask, a hat, and a disposable coverall.
• Avoid places infested by caterpillars. Check for winter webs in spring when they are easiest to see.
• Aim for damp days or spray vegetation down with water. Moisture helps keep hairs from becoming airborne.
• Take cool showers and change clothes after outdoor activities in infested areas.
• Dry laundry inside to avoid getting hairs on clothing.

For more information:

• Contact 211 Maine for answers to frequently asked questions on browntail moths:
  • Dial 211 (or 207-874-2211)
  • Text your zip code to 898-211
• Maine CDC Browntail Moth Webpage
• Maine Department of Agriculture, Conservation and Forestry Browntail Moth Webpage