Caterpillar Causing Itchy Skin Likely a Rusty Tussock Caterpillar (Orgyia antiqua)

Observation by Augusta Edmund:

There's been a different kind of caterpillar/Moth in that area or not really sure but a lot of people broke out in rash that was very itchy during berry picking. The rash/bumps were so itchy.

Comments from LEO Editors:

This observation has been shared with the Forest Health Protection program at the US Forest Service.

During the summer of 2019, LEO members in Nome reported an outbreak of rusty tussock caterpillars that also caused skin rashes. Based on the symptoms Augusta described, we forwarded a photo of rusty tussock caterpillars and Augusta was able to confirm that that those resembled what she saw. The hairs on the rusty tussock caterpillars are shaped like very small harpoons that irritate the skin. They can also cause damage to a variety of trees and shrubs when populations are high.

According to the US Forest Service rusty tussock moth species profile, tussock moth eggs overwinter and hatch in to caterpillars in the spring. In August, the caterpillars spin cocoons on the underside of branches and emerge a few weeks later as adult months. The timing of this cycle increases the likelihood of interactions as people are out berry picking. Erica Lujan