Pheromone Clothes Moth Traps

You usually spot the damage before you spot the moth. A few small holes in a wool jumper, a bald patch on the carpet under the sofa, maybe a scruffy little moth fluttering out when you open the wardrobe. By then the larvae have been feeding for weeks.

We've been selling pest control for forty years, and clothes moths are one of the problems people get most wrong. They buy a trap, hang it in the wrong place, catch nothing, and decide the moths have gone. They haven't.

What you're actually dealing with

Two species do the damage. The webbing clothes moth is the common one, and the casemaking clothes moth turns up less often. Both are small, roughly 6mm long with a wingspan around 12mm, gold or buff coloured, and neither behaves like the moths you're used to.

They are weak fliers and they are not attracted to light. That's the bit that catches people out. A clothes moth doesn't cross the landing to bang against your lamp. It stays in the dark, close to whatever it hatched from. If you've seen one, it almost certainly came from somewhere in that room.

The adults you see don't eat fabric at all. The larvae do, and they're shiny white, a few millimetres long, with a dark head. They feed where you won't look: under collars and cuffs, down the crevices of an armchair, in the bit of rug that's been under the sofa for a year. Their droppings take the colour of whatever they've been eating, so on a navy jumper you're looking for navy grit.

The numbers are why this gets away from people. One female lays 40 to 50 eggs over two or three weeks, then dies. The males outlive her and carry on mating. Eggs hatch in four to ten days in warm weather, and the larvae then feed for anything from five weeks to two and a half years depending on temperature and how good the food is. Egg to egg is four to six months, so that's two generations a year, and in a heated house they carry on right through winter rather than stopping for it.

They also prefer dirty clothes. Anything marked with food, sweat or pet mess gets eaten before the same garment clean. Wool, cashmere, silk, felt, fur and sheepskin are the targets, plus cotton and synthetic blends where there's enough wool in the mix to be worth chewing.

So here's how we'd tell you to do it.

Put them high, near the clothes, and out of draughts

Head height or above, in the room you actually suspect. Top shelf of a wardrobe, hung from the rail, a high shelf in the bedroom, up in the loft.

Because they're such poor fliers, a trap two rooms from the problem tells you very little. Put it where the wool is. And the trap works on scent, not light, so it isn't going to pull moths in from across the house the way a UV unit pulls flies.

Draughts are the thing nobody mentions. The trap gives off a scent plume that moths follow in, and a draught from a window, a vent or a radiator scatters it before anything picks it up. Put a trap next to a vent, catch nothing, and you'll draw exactly the wrong conclusion. If a trap comes up empty in a draughty spot, move it and start the six weeks again.

Six weeks, not three months

That's how long the lure lasts. We'd rather tell you that than sell you a handful of traps and let you think you're covered until Christmas.

Write the date on the edge with a biro when you put one up. Six weeks later it comes down, whether it's full or not.

Working out which size you need

Three or four traps to a room is what actually tells you something. One trap in a house is a coin toss.

4 traps is one room for six weeks. That's the size for confirming or ruling out a single wardrobe, and be realistic about what it can tell you. One room, six weeks, and that's it.

10 traps is three rooms for six weeks, and it's the size for finding the problem. Put three or four in each of the rooms you suspect, wait six weeks, and the counts will point you at the right one. Ships free.

40 traps is four rooms for twelve weeks, so two full rounds with spares in hand. That's the size for a house you already know has a problem, or a bigger property where you want the loft, the spare room and the wardrobes all monitored at once without reordering halfway through summer. It also works out at £2.70 a trap against £4.50, so it's the better value by a distance. Ships free.

Setting one up takes ten seconds

Peel the backing off, push the tab through the slot, put it in place. No sachets, no fiddling, the pheromone is already in the adhesive.

What the count is telling you

One or two moths in six weeks is background noise. Most UK homes have that and always will. Ten or more, or one trap filling while the rest stay empty, and you've found a breeding population.

This is where we'll be blunter than most people selling you traps. A pheromone trap catches adult males. Adults don't eat your clothes, and a female that has already mated will lay her 40 to 50 eggs whether or not you catch the male afterwards. The trap doesn't touch the larvae or the eggs. If your count is high the trap has done its job by finding the problem, and now you have to deal with it:

1. Empty the wardrobe, drawers or room the trap flagged
2. Vacuum it out properly, cracks and crevices included. A soft long haired brush gets where the nozzle won't. Vacuum bag straight out to the bin, not left in the cupboard
3. Hot wash everything that'll take it. Anything held above 49 degrees for twenty to thirty minutes kills every stage including the eggs, so a 60 degree cycle where the label allows is comfortably over the line. Whatever won't wash goes in the freezer for a few days instead, which does the same job. Dry cleaning does too
4. For the things you can't wash, hang them outside in bright light and brush them along the seams, folds and pockets. Brushing knocks the eggs off, and the larvae hate light enough that they drop off once they've nowhere to hide
5. Do the suitcases, bags and baskets stored alongside. That's where people miss them
6. Put anything you're storing away clean, and store it sealed. Larvae go for soiled fabric first, and a properly closed box or bag keeps new eggs off it
7. Put a fresh trap back up so you can prove to yourself it worked

If the count is high enough that you need a treatment as well as a clear out, we sell those too, and we'll tell you straight if you don't need one.

What you get

• Traps supplied in sealed packs of 2, so the ones you're not using stay fresh
• Pheromone lure built into the adhesive, nothing to assemble beyond folding it
• Six weeks per trap
• Insecticide free, no vapour, no odour
• Clothes moths only. If you're finding moths in the pantry or in cereal packets you want a food moth trap, different pheromone, different pest

Life cycle and identification detail from Michigan State University Extension, Plant and Pest Diagnostics.