Saturday, August 4, 2012

The Dreaded Wool Moth

When I was feeling so discouraged about felting, I had the additional fright of seeing what I thought was a wool/clothes moth in my upstairs studio. Then, when I was cleaning in the basement I thought I saw two...or three? This is such a big fear for those of us who have huge stashes of wool and other natural fibers. The very thought of it was so overwhelming to me that I wanted to throw everything away and be done with fiber. Having to look in all my bins of wool; hoping, yet fearing to find where the greatest infestation was; possibly having to throw out so much money in wool was all way more than I could handle at that time. I put it off for a week or two but finally decided to peek in one bin. No moths or anything that looked like the eggs or casings I was seeing in images on the internet. But there was some dirt and dusty stuff in the bottom of the bin. Could that be the eggs? I decided to go to the best resource of all things having to do with felt Pat Spark's Feltmaker's List and ask questions about how to go about my hunt. The information was not quite as definite as would have liked so when I found my 'problem' I thought I would take photos to show just what an infestation can look like.
Before I show the nastiness I want to share some information about the little buggers. First off, clothes moths (Tineola bisselliella and Tinea pellionella) aka webbing clothes moths and casemaking clothes moths...
  should not be confused with Indian meal moths (Plodia interpunctella) .
The clothes moth wants your natural fibers especially that yummy wool. Indian meal moths (Mom always called them 'millers') want your cereal and crackers and flour and chocolate and dried fruit and dried flowers and spices and...well, you get the idea.
I was quite familiar with the meal moths, as Mom often had a nice crop of them. After I moved in here I went on the attack to get rid of them and discovered that although the pantry and kitchen cupboards had been cleaned of the pests, they had set up camp in other places such as in the dried flowers that Mom used for crafts and in old, unused spices. The meal moths are bigger and darker in color than the clothes moths are. They are pretty easy to catch as they fly (I remember the cats loved getting them). The clothes moths flit too fast to get them and seem much more desperate to hide from the light than the meal moths.
 I tried to catch any little moths I saw without squashing them too much so I could try to make the positive identification that what I was seeing was in fact a clothes moth. It can be hard in the heat of the moment not to smash them into dust! Those that were still whole-ish I looked at with a magnifier to see the head. That is what I found  to be the best way to differentiate between the two, since the body size and color can vary so much. In the photos above you can see that the clothes moth has a fuzzy head. The moth that I had found in my upstairs studio had a smooth dark head and was actually just a very pale and small meal moth. When I looked at him with a loupe I could faintly see the stripe on his wings too.
I went through all my bins of wool upstairs just to be sure that there was nothing lurking anyway. I refreshed the sachets of lavender while I was at it. One thing I discovered in my research is that all those scents and oils such as cedar might make your wool less attractive to the bugs but to really be noxious to them it would have to be in such concentrations as to be noxious to us too. And the traps for both the meal moths and the clothes moths only catch the males so they do diminish the population but mainly serve as a way to monitor the situation, because by the time you see one or two of them you really have a nasty invasion somewhere.
My somewhere was down in the basement. The little buggers were in some scrap wool that I had in a felt bowl, and in a bag of locks from a fleece that I had cleaned. The felt bowl was in a dark corner of the studio and not put away in the cupboard where I keep my wool bins. The bin with the locks had also been out of the cupboard. The moths prefer dirty wool and the locks had not been washed too much as I wanted them for my natural rug felting. The scrap wool was mainly wool that had been dyed with natural dyes. There is much more helpful information on the internet than I can include here so it is a good idea to look at sites such as this one from Cornell and this one from Colorado State University.
Here are my photos of the moths, casings, frass (aka bug poop which can be any color depending on what color wool they are eating), and eggs. Here is what I found in the felt bowl.

 And here is what the bag of fleece looked like.

I hope this gives you a good idea of what to look for if you ever have to go on the dreaded wool moth hunt. (Sorry about the type in the photos but I am too antsy to go back and fix it now.)
By the way, I left the scrap wool outside for the birds as nest material. I am using the freeze thaw cycle for the fleece. And I plan on washing the the felt to try to save it though thankfully it was not a treasure.
Next up a post on a fantastic marbling workshop I took with the wonderful Laura Sims.


  1. Thanks so much for all of this information. I will be sure to keep an eye out for those pesky and destructive little buggers. The bane of all wool-lovers, they are!

    Let us know how the freezer method works, too. Would be good to have that in case those things ever appear on our doorsteps (or in our bags of wool).

    Thanks again,

  2. Thank you for such an informative post!

    We've never been too sure what to look for etc but now we feel fully armed with info.

  3. Thanks for the comments, Dawn, Annie, and Lyn.

    My freeze, thaw, freeze, thaw cycle seems to have worked. In between I let the wool bake out in the summer heat. I figured it could not hurt too much and it kept them out of the house.
    I am not so afraid of having an infestation now. But I can see where having a routine of just getting out the bins and moving the wool around every so often would be the best thing. As with most insects it is about controlling the population and damage. Going through the old textiles in this house I can see damage and evidence of old infestations but they must be self-limiting as I have not found any other active infestations....and I am good with that!

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  5. Hi Diane,
    I'm currently airing out some handspun yarn that has soaked in mothballs. I'm hoping airing them in sub-zero temperatures will do the trick. One of the Wensleydale skeins was "sticking" after an overnight exposure. Do you think if felted, or simply frozen stuck and stiff due to moisture content in the air and/or the yarn?

    Thank you!

  6. Hi Anonymous, Wool will start to felt with just a bit of moisture and a bit of movement. Just the moisture that is in the air is enough. You should be able to tell if it is felted or frozen when you warm it up. I don't think that the cold temps will do anything to get rid of the mothball smell. Mothballs do not kill the moths, the smell just discourages them. They don't like it either.