Abundance of Tussock Moth Caterpillars Observed in Nome Area

Close-up of a caterpillar on a green leaf

Large populations of caterpillars have been observed in the Nome area this month, and experts have identified them as rusty tussock moths. A high concentration of this type of caterpillars is uncommon for this part of the state.

According to Jessie Moan with the University of Alaska–Fairbanks’ Cooperative Extension Service, these caterpillars are known to “feed on a variety of trees and shrubs and can defoliate large areas when populations are high. Their populations can vary from year to year, depending on the weather.”

Rick Thoman, a climate specialist with UAF’s Alaska Center for Climate Assessment and Policy, says temperatures in Nome and Western Alaska have been warmer than usual so far.

“Especially mid-June to mid-July; (that) was far above normal. And even since then, although we’ve had more wind off the ocean — so somewhat cooler temperatures — for the most part, it’s been pretty mild, as well. Most days (are) still near or above normal, but overall, Nome, like the rest of Alaska, is having a warm summer coming on the heels of a warm spring.”

Tammy Davis, the invasive species program coordinator for Fish & Game, confirms that the department received a couple reports of tussock moth caterpillars earlier in July during a time when Nome was experiencing a heatwave. However, she could not give more details about the invasive insect, as she mostly deals with fish species. 

Davis referred KNOM to Dr. Stephen Burr with the U.S. Forest Service, an expert on rusty tussock moth caterpillars. But Burr was unavailable for comment before the airing of this story.

According to previous reports, one characteristic of the moth caterpillar is they can cause dermatitis, a type of skin irritation, if people touch the hairs of the caterpillars.

If you observe populations of these caterpillars in your community, please call the Invasive Species Hotline at 1-877-INVASIV (1-877-468-2748).

Image at top: A tussock moth caterpillar. Photo: Anahma Shannon, via the LEO Network (2019).


  1. Crystal joe on July 30, 2019 at 11:58 pm

    We’ve been having a lot of this on the Yukon River, south western area. I live in Mountain Village. And have gotten that very bad rash, not knowing I probably touch one while berry picking. Along with many many other community members got that rash as well.

    • Cynthia on July 31, 2019 at 3:45 pm

      We had seen a lot of these where we went berry picking, three our ride from where we live, the old village where my parents grew up. We all came home with rash and very itchy. Again upriver from our village half hour ride again few of us came home very itchy and in one part of the tundra where my husband was picking he saw bunch of ants on the tundra. It’s awkward to see these things we never saw before.

  2. Berts on July 31, 2019 at 3:38 am

    There are a lot of those to here in Mt Village to. Everywhere like they got dumped here n there on the tundra

  3. Hillary Gregory on August 2, 2019 at 12:22 am

    I been seeing these all over in Bethel. While I was waiting have my baby. During the day I went for a good fresh air in the smoke and the hot days I seen kids playing with all these bugs that look like this. Even killing them I tried been wanting to hold one but I’m glad I didnt touch them.