If You have Moths

I have noticed that a lot of surfers coast through here from Google looking for information on clothes moths, so while I slog away at PS 136, I thought that I'd take a moment to fill you in on what I know about webbing clothes moths, living as I do with a community of them in this here 200 year old house.  I didn't call this blog Moth Heaven just because I think it's a cute name for someone who works with wool; it's a fact of my life.  I have only my experience and not an entomology degree, so take this only as opinion, and not as the last word on the subject.

We have moths.  I think they arrived on a rug we bought at auction our first year here.  So here's lesson number one:

Prevention: when you buy a rug at auction, or acquire anything for that matter that might harbour moths (tapestries, old upholstery, a trunk of clothes for dress-up, some departed knitter's stash) you might feel safer if you first gave it some air and bright sunshine and then heat or cold treat the items.  Evaluate the potential for infestation of anything that enters your house.  Obviously the wool skirt from Target is a safe bet, but the bag of old sweaters from the Salvation Army you bought for felting projects could have some hitchhikers.  Keep such things quarantined in plastic (more on this later) for the time being until you feel safe about them. 

Detection:  Moths have a long life cycle from what I understand: there are two crops a year, and they live for almost 90 days once they're hatched.  The little ones you see flitting about are the males.  When you see these guys it means trouble, but killing them will do you little good.  It's the lone female you have to worry abou because she is laying the eggs that hatch into the larvae that do the damage.  She doesn't flit.  She hangs out in the back of your closet on the Alice Starmore sweater you finally finished.  Moths have notoriously uncanny senses of what would upset you the most.  They certainly like wool, but they love expensive wool or hard-won knitting accomplishments the best.There are expensive  Pheromone traps available which are less effective as a way of snaring the little beasts than for determining that you do in fact have a colony working its way through your winter storage closet.  You could put one of these traps in a confined space with the item in question to see if it would be worth the cleaning bill for that ballroom sized rug.  Male moths are attracted to the scent and become lodged in the sticky space trying to get to the female.

Treatment:  I wash things I worry about.  Or they get sent to the dry cleaner.  It seems common knowledge that moths like soiled things, but in my house, they eat everything, soiled or not.  I have things cleaned to get rid of hidden pests, and I favour Eucalan for hand washing both because you don't have to rinse it out, and because it is reputed to have moth deterring qualities. You can iron items to kill eggs and larvae or where that isn't practical, you can leave things in your car trunk in the summer for a few days to cook the little pests, or leave things in the unheated garage in the winter for a few weeks.  When you discover something has moth damage, you should assume that it is infested, since the eggs are really hard to detect, and the larvae are very small before they've glutted themselves on your lovely alpaca handspun you bought at the Alpaca Farmers' open house last winter. Vacuum thoroughly anywhere eggs might have fallen when you moved things about, and wash surfaces with soap and water.  I know of a knitter who re-painted her closet when she found that she had moved into a house with resident moths, and found that an end to her problem.

Storage: Plastic works for short term storage only.  Moths will eat through a plastic grocery in short order, and the heavy plastic zippered bags many of us favour don't breathe and traps moisture with the wool, and moths like moisture and the dark.  Zippered cotton pillowcases are the best thing to store yarn in for long term, or plain white paper (hopefully acid-free, but how realistic is that while Martha is in jail?) wrapped fully and taped or tied with a string will keep your wool safe.  I keep most of my stash in Rubbermaid bins, which I know, is not a good thing.  I think of it more as a way of keeping any potential damage localized to the DK bin or the Magpie bin rather than spreading throughout the whole stash (I have begun a slow acquisition of pillowcases, but my local Kmart only ever has three of them at a time).  Because of the semi-annual life cycle, I try to inventory the stash twice a year (it's a lot of fun but a sobering remnder of how little I need to buy any more yarn), and when I do find damage, I take as quick an action as I have time for, if nothing else, throwing the mess into the deep-freeze until I can spend time with it.  As for your closets, I don't have a lot of confidence in cedar oil or cedar balls or even cedar-lined closets or any other aromatics for deterring moths, since they don't seem to care in my house if there's vats of cedar or lavender oil in the place.  Even moth balls, as loathsome as I find the smell, are probably only effective within a radius of a few feet; good for trunks and small closets, not so good for your walk-in.  They're the citronella candles of the closet.  I live in a salt marsh; our mosquitoes laugh at citronella. However, I have heard of plenty of people who claim that they store their woolens with aromatics and never have had a problem.  My attitude on that is like the old chestnut:
"Why are you wearing that garlic necklace? "
"Because it wards off vampires"
"There's no vampires around here"
"Works well, don't it?"

I read recently in the Fall Spin-Off that there is a spray from Off called Moth-proofer that claims to last for a season, which would be good for applying to baskets and on the outside of storage bags, but I'm not in a hurry to have that in my house because some moth-deterrent products contain carcinogens.

I've become adept at darning and repair, I never get rid of the last bit of yarn after a project is finished because I assume that the moths will love my sweater in direct proportion to how unprepared I am to mend their damage.  They seem to adore Rowan Magpie and clean fleece, which I take as a sign of the purity of their tastes.  I remain ever vigilant, and I never ever utter out loud anything like "I think we may have finally licked that moth problem" because those words have in the past served as a swift invocation of moth resurgency.
I wish you luck in fighting back, and if anyone has a major disagreement or addenda to what I've offered here, please make use of the comment section.

Comments

[Norma]

Holy Crap. I hesitate to announce "I don't have moths," because that would be the exact moment it'd come back to bite me.

[Susan]

Well, now I'm terrified of moths! And I'm freaked out about my stash and my finished items that are living in Rubbermaid containers. I haven't had any moth problems in 15 years of knitting in one apartment and three houses. I think the key has to be that I never had a moth infestation, so as long as I keep the containers closed and open them only when I need to add or remove something, I should be okay. If I'm wrong about that or if there's some other reason why Rubbermaid is very bad for knitted items, please let me know! Thanks for a very informative post. . . it brought me out of lurkdom.

[Katy]

Your timing is impeccable. I just found a moth-damaged sweater last week. I was devastated. I have yet to truly tackle the issue, but I'm gearing up. Sigh. I also live in an old house, so this may be a long-term issue. Guess I'd better learn how to darn, eh?

[LeAnne]

Very informational, thanks so much. I have had lots of moth damage (house is only 55 years old) and it pisses me off!

[michellenyc]

ARGHHHH!!!

I also live in a MOTH HELL - so i feel your pain - i was hoping that there was some magic solution i hadn't heard yet and that YOU had the secret to making them ALL GO AWAY

As for the storage thing - i found the zipper bags seems to work well IF you squeeze all of the air out of them - they might like dark and moist - but NOTHING can survive without AIR. I am actually thinking of investing in those larger bags you seal with a vacum! That "should" work - the little bags seem to work so far as long as they are "vacum sealed".

I'm scared to try the pillowcase thing - does it really work?? I'm afraid they will still find a way in somehow.

[Emma.]

That was depressing !

[Christie]

ew...I'm thoroughly grossed out...I'm keeping all my stuff in the freezer from now on!

[Laura]

That's very informative and depressing. I live in a tropical country, guess it is less of a problem for me. I found some of my yarn chewed before, but no insects. Luckily that was cheap wool and damage was minimal. No sign of the culprites though. Lucky me. Now after reading ur post, I'm doubly grateful the problem took care of itself.

[Chris]

Thanks for the comprehensive review/opinions on moths. It's a recurring subject on a few lists, so it's obviously necessary info. Spin-Off has an in-depth article in a winter issue from a couple years ago, I believe. As I remember, it suggests that pretty much the only real way to kill off all stages of the pests is with heat or drowning (have to have the entire fiber object submerged for at least 24 hours). Freezing apparently only buys you time, because it does not kill the eggs. Again, going from memory on that info so could have things not quite like Spin-Off intended - best to find the article and read it.

[kimberly]

i so sad <-- toddler voice

that is horrible, i never knewn it could be so bad. i honestly dont think that i have ever seen an item that a moth got ahold of. then agian i did grow up in texas!!! wow... i'm still shocked. now i'm a bit freaked about my stash. GREAT POST...

[Julia]

What if you put wool in a plastic zipper bag with some of those little ascorbic acid packets they put in vitamin bottles and then seal it up as air tight as possible. Would that work? I had heard that plastic bags were bad, but we live where there doesn't seem to be a condensation problem. Thanks for the great tips and info.

[Molly]

I recently discovered some unspun alpaca that had been eaten by moths. I didn't want to throw away the entire thing, so I carefully simmered it (not boiled) at 200 degrees for a couple of hours in a covered stock pot. A couple of people who have experience with museum restoration said that a half an hour would be plenty, but I didn't want to take any chances!

Have you ever tried sewing your pillowcases shut? I know a couple of people who do that. They just take a seam ripper and cut it open when they want to view the contents, and then sew it back up again when they put it away. It could be cheaper, and you could make custom sized packages and label them! And without Martha, we'll just have to make do.... :)

[laurie]

Thanks for the benefit of your experience. It was a wonderfully informative post. I have read repeatedly about the carcinogenicity of mothballs, and have purged them from my life.
There is little data about the problem, and solutions, which seem to be: keep wool and moth separate. Ha!

[Ailsa Craig]

You are absolutely right to say you won't get rid of a moth problem, but let me add that pheromone traps are effective in controlling moths, not just in identifying your plague.

Part of my non-knitting working life involves technical publishing and I recently published a paper on pheromones for control of pests, including an outbreak of webbing clothes moths at the Museum of the Welsh Woollen Industry. (Can you imagine the panic involved?)

They set thirty pheromone traps at two-week intervals for two months, after which time no further moths were seen. Some limited spraying was done on wool bales as well, and over the next two years, a few traps in the formerly infested areas caught only a small number of moths.

If your stash of wool is a significant investment, the expense of pheromone trap treatment might be worthwhile -- it does work.

Anyway, good luck in Moth Heaven with your freezer technique -- there's some research on that too, and it's a good way to go.