Yarns On Lockdown! How to Avoid Clothes Moth Larvae

I recently came back from a trip with a suitcase of souvenir yarns and woven shawls. Even though it’s getting cold, however, I haven’t even brought them inside. Instead, they’re plastic wrapped in quarantine. Before letting these new goodies touch my clothing and yarn stash, I store them separately, just in case I brought home clothes moth larvae or eggs.

Now, the high, dry Andes may not have too many clothes moths to worry about, especially because most of the yarns have been dyed in near-boiling dyepots. However, I learned a sad lesson once. A friend once brought me handspun yarn in natural wool colors, and when I looked at those yarns a while later, I saw a fluttering of wings and a sad number of holes in the balls of yarn.

More than once, I’ve caught a small flying insect out of the corner of my eye and wondered whether it was a clothes moth. Even though the flying Tineola bisselliella scare me, they can’t do any harm to my treasures. The adults are simply the telltale signs of a moth infestation; the clothes moth larvae are the ones who do the damage. And the eggs from which they hatch are very hard to kill.

There are ways to fight a moth infestation, but I’d rather keep the buggers at bay if I can. So I follow one of Judith MacKenzie’s smart pieces of advice in her book The Intentional Spinner: I keep my new purchases in quarantine.

Judith advises, “As an extra precaution, isolate any incoming fleeces, yarns, and other textiles for several weeks if possible. Store them in separate trash barrels or heavy-duty plastic bags. Keep them warm to see if any insects appear; moths hatch above 70° Fahrenheit (21° Celsius).”

Pretty soon, I’ll shake up the plastic bags and see if there are any signs of moths in my new pieces. If not, I can soon wear, knit, and weave my new purchases!

clothes moth larvae

Casemaking clothes moths in three life stages. Photo by Clemson University – USDA Cooperative Extension Slide Series, Bugwood.org

Featured Image: Original photo by solitude72/iStock/Getty

Keep your yarn and fiber safe from clothes moth larvae!


  1. Betty R at 11:17 am December 29, 2017

    I wonder if you could microwave the natural fiber items to kill larvae and/or eggs

  2. Anne M at 11:33 am December 29, 2017

    That’s an interesting idea, but I don’t know anyone who’s tried it. I’d be afraid of burning it–I’ve known of cellulose fibers that burst into flames in the microwave! Protein doesn’t behave the same way, and people dye fiber and yarn in the microwave. I’m not keen to try it out with my regular microwave oven or special fiber, but next time I’m working with an old microwave I might test some yarn (running it on an extension cord out in the driveway!).

    • M W at 9:33 am January 3, 2018

      Several years ago I found moth larvae or beetle larvae in fleece and the yarn that I spun from it. I put a small ball of the infested yarn in the microwave with a micro safe glass of water in the back of oven, set at low power for a short time – less than minute. Bug survived. Increased power and time until bugs died, checked after each test. Used the time and power of last try for next ball. It worked. Most important to have glass measure cup with water in the oven with yarn to prevent oven from burning out. You wouldn’t run oven with nothing in it. The yarn/fleece has very little to absorb the microwaves. My oven was fine after bug processing. Didn’t seem to harm the yarn/fleece. No need to put microwave in garage if you have glass of water – like making hot water for tea.

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