Well, they didn’t fly in. You probably brought them home yourself! Their eggs or larvae hitchhike on thrifted clothing or vintage rugs. Once inside, that’s where they grow and reproduce, later spreading to the dark forgotten corners of your home.
This larva chomps on strand after strand of wool like al dente spaghetti. As it eats, it poops sand-colored frass. The pellets add some bling to the cocoon, and make it a nice, dark home to grow up inside.
Hey! Turn the light off!
Adult clothes moths are about the size of a pinkie nail, and they’ve had a glow up. They’re no longer hungry for what’s left of your sweaters. They couldn’t eat them anyways; they have no working mouthparts.
They turn around and plop their eggs in the same nutritious sweaters and rugs they grew up in. And in others nearby. And they mate with their own siblings. That means they multiply – fast.
So if you’ve got them in your closet, you might want to call in some backup. To fight clothes moths, researchers are enlisting another tiny insect: parasitoid wasps.
They’re no bigger than a grain of salt. Trichogramma wasps have long been used to control pests in agriculture and gardening. They come on what looks like a business card, covered in thousands of eggs – moth eggs that have already been parasitized. Slip it into your closet, and about a week later, wasps emerge. They’re all female, ready to lay their own eggs.
This lady patrols your sweaters, searching for moth eggs. When she finds one, she inspects it with her antennae to sense its freshness, size, and if it’s already been parasitized. Then she pierces the egg with her needlelike ovipositor and pushes her own egg inside.
She didn’t even have to mate before laying her eggs – she reproduces asexually. A few days later, instead of a moth larva, a wasp emerges; she’s ready to parasitize more moth eggs.
The new wasps keep the cycle going until the entire moth population is gone. That could take as little as a few weeks, depending on the size of the infestation. The best way to stop a clothes moth invasion is to prevent it in the first place!
Inspect and vacuum secondhand rugs and furniture. Toss thrifted clothes in the freezer for at least seven days to kill any hidden eggs or larvae. And remember those smelly mothballs? They’re effective, but some contain chemicals that can be harmful to humans and pets.
So next time you find holes in your clothes, you might want to consider starting up a little biology experiment in your closet.
