Browntail Moth Hairs Pose Risk for Spring Outdoor Activities

Maine CDC and Forest Service Urge Precautions When Outside

AUGUSTA – The Maine Center for Disease Control and Prevention (Maine CDC), the Maine Forest Service (MFS), and 211 Maine remind Maine residents and visitors to watch out for browntail moth caterpillars and take steps to limit health risks caused by the caterpillars.

Browntail moth caterpillars shed tiny toxic hairs that can cause a skin rash like poison ivy. The hairs remain toxic in the environment for up to three years. When hairs become airborne, they may cause trouble breathing and other respiratory problems, if inhaled. The Maine Forest Service has found evidence of browntail moth in all 16 Maine counties.

As people head outside in the warmer weather, they should take precautions against increased risk from these toxic browntail moth hairs. The greatest risk for exposure is between April and July when caterpillars are most active. Hairs can land anywhere, including on trees, gardens, lawns, outdoor furniture, and decks. They may also be in the air. Activities like mowing, raking, and sweeping can stir up the hairs.

Most individuals affected by the hairs develop a rash that lasts for a few hours up to several days. In more sensitive individuals, the rash can be severe and last for weeks. This can be severe and require emergency medical attention. Treatment focuses on relieving symptoms and eliminating ongoing exposure.

Browntail moth caterpillars are easy to identify. They are dark brown with white stripes along the sides and two red-orange dots on the back. Younger caterpillars lack these white stripes. Images of the caterpillars, their winter nests, and their cocoons are included with this release.

Precautions to take to reduce exposure to browntail moth hairs:

  • Avoid places infested by caterpillars. Check for winter webs in spring when they are easiest to see. Visit the Interactive Browntail Moth Dashboard to see where MFS notes high activity.
  • When performing outdoor activities that may stir up caterpillar hairs:
    • Aim for damp days or spray vegetation down with a hose. The moisture helps keep the hairs from becoming airborne while working.
    • Cover face with respirator and goggles.
    • Tightly secure clothing around the neck, wrists, and ankles.
  • Take cool showers and change clothes after outdoor activities in infested areas.
  • Dry laundry inside to avoid hairs embedding into clothing.

For more information:

Browntail moth winter web, brown tail moth, and a brown tail moth cocoon

Browntail moth winter web, Browntail moth, and a Browntail moth cocoon (Photos courtesy DACF)