Call me reckless, call me naive but, having never had so much as a nibble from a clothes moth before, I have not to date been as exacting in my precautions as other, wiser knitters. Now my lax attitude has come back to bite me or at least my woollens – with a mild, damp summer resulting in an increase in moth numbers, I have been hit by the holes of doom in nightmare inducing quantities.
Given the amount of knitwear/ yarn in my house there is actually only a tiny percentage that has been nobbled. Statistics is poor comfort though in the face of each new discovery. For a full day the frantic opening of cupboards and shaking out of every skein and garment owned was accompanied by an increasingly shrill note of panic. So far, the damage count is: 4 hand knit socks, a vintage dress WIP, my Lady Heather sample shawl, a pair of Cranford Mitts, one slouchy hat, multiple crocheted snowflakes and a kilo of yarn!
The internet has, as always, proved to be a valuable resource for tackling the infestation. For starters I now know what they look like!
Tineola bisselliella are less than a 1/4” in length and hide in dim, damp areas to breed. Particularly attracted to laying their eggs in dirty clothes (human sweat being a great source of water for their larvae), they do not themselves eat and die after laying several hundred eggs. The larvae hatch out onto an immediate food source (your yarn!) and spend around two months chowing down until they have enough energy to spin a cocoon in which to pupate into an adult moth. Favourite food stuffs are feathers, hair, bran, semolina, flour, furs, cotton, linen, silk and most of all wool, whether it be stored yarn, upholstery, carpets, rugs or clothing.
Top Tips for tackling Clothes Moths
Periodic cleaning – our household has always been of the opinion that basic hygiene matters but everything else is time we could be doing something more interesting. Well now I am motivated to hoover regularly as well, including inside the closets where my wool is stored. This both reduces food sources targeted by the laying female moths and can pick up all stages of the insect too. Bags should be disposed of promptly as the turbulence is not necessarily fatal. Moth larvae are sensitive to disruption and dislike strong sunlight, so bringing out stored items and shaking out or brushing down regularly will interrupt life cycles. Don’t put garments that have been worn back into the wardrobe as the tiniest wafts of sweat will act as a scent trail leading directly to ALL of your clothes.
Heat – washing above 48oC (for those fabrics that can withstand high heat – not wool!) will kill all stages of the insect. Dry cleaning is also effective.
Freezing – fumigation with dry ice is immediately effective (in an enclosed space this is as much to do with asphyxiation as it is to do with temperature) but, as this is not easily sourced in the UK, several days in the freezer (below -7oC). My most expensive fibres and most precious garments now take up more space than food in my freezer and I am seriously considering investing in a separate freezer just for yarn.
Poison – naphthalene or paradichlorobenzene moth balls are effective only for as long as the area being fumigated remains airtight as the sublimated vapour is only toxic in high concentration. They also transfer a vile odour to your clothes and if ingested are toxic to children and household pets. Pyrethrin insecticide sprays immediately kill moths and larvae and do not leave a persistent toxic residue so are more effective and safer if you have a particularly severe infestation. Oil-based sprays will stain silk, rayon, linen and even linoleum and parquet flooring however. In high concentration cedar and lavender are a traditional, less toxic and more fragrant repellent but need to be refreshed frequently.
Trapping – after I revealed that I had woken up in a cold sweat on more than one occasion post-invasion day, Amy from handmadenest.co.uk suggested I place a clothes moth-specific pheromone trap in each cupboard to act as a warning system and hopefully reassurance that my other measures have been effective. A quick web search revealed that the cost of a good night’s sleep is only around £5.
Barriers – stop them getting near your yarn in the first place! Sadly cloth and paper bags are just so much food to the clothes moth larvae. The only real barrier is plastic and in this instance I find I value its efficacy more than I dislike its production. Zip-lock bags are ideal for individually storing each skein of sock yarn. For bigger stashes (and mine is mahoosive) vacuum storage bags save space whilst preventing new moth attacks and suffocating any larvae already in residence.
Introduce a predator – I was overjoyed to discover that the Ratettes have already been acting as exterminators by catching and eating the moths. I try to give them a stimulating and ‘natural’ environment, including giving them live crickets to catch and eat occasionally. It looks like their training paid off!
Let my tale of woe be a parable to other knitters: prevention is always better than cure, so take up these measures before you too become the victim of the holes of doom!
This post was written with much reference to the University of California’s Integrated Pest Management Program, found at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7435.html