The Browntail Moth (Euproctis chrysorrhoea) was accidentally brought to Massachusetts from its native Europe in 1897, and soon after spread to the rest of New England and also moved into New Brunswick and Nova Scotia. The caterpillars have a huge host range of plants that they feed upon.
The ‘problem’ with this insect derives mostly from the fact that throughout much of its life cycle (and especially in the very hairy caterpillar stage), it is armed with defensive, barbed hairs which break off and–for many people exposed to the hairs—cause skin rashes, headaches, and even difficulty breathing.
The moths are attracted to light, fly at night, and are active in July and August. They have a wingspread of about 1.5 inches (36-42 mm). The wings and midsection are solid white on both the male and the female. The abdomen has brown on it, and the brown coloration extends along most of the upper surface of the abdomen in the male [photo], whereas in the female, the top (upper/dorsal surface) of the abdomen is white, but the tuft of brown hairs is much larger [photo]. Fortunately, the hairs on the adult moths are not toxic so those hairs do not cause a skin rash.
Additional Information (with photos):
- Browntail Moth (Maine Forest Service) (includes a video on removing browntail caterpillar nests)
- Maine Forest Service Map of Exposure Risk (Year 2020) (pdf)
- February is an ideal time to remove their nests
- Browntail Moth (BugGuide.net) (numerous photos of the moth stage)
- 2019 Report: Suspected Browntail moth caterpillar webs spotted in Bangor, Orono and Old Town
- A report on some UMaine research on Browntail Moth