Trichogramma are tiny wasps that kill the eggs of Lepidoptera by laying one or more of their own eggs inside the much larger eggs of Lepidoptera. Hotter winters are almost certainly to blame, plus the fact we keep our homes so warm. “I constantly put things in to freeze the eggs and stop them in their tracks,” she said. “I would suggest avoiding the chemical blitzkrieg that we tend towards whenever we notice something alive around us, which we never tend to win,” says Rob Dunn, a professor of biology at North Carolina State University and the author of Never Home Alone, a book about all the tiny beings with which we share our homes. Trichogramma wasps specialize in parasitizing lepidopteran (moth and butterfly) eggs. The larva of this species can only complete its life cycle by feeding on animal fibers such as wool, hair and feathers. I’m encouraging spiders in my house now; they’ve got lots of cobwebs and I’m trying to get them to catch the moths.” It has been frustrating – and expensive. The main approach for controlling numbers is regular cleaning. “And it’s all been a waste of time.”. The idea that in the absence of a moth infestation your clothes are “clean” is wrong. Trichogramma are little parasites that inject their own eggs into the eggs of the moths.
We use that to treat nooks and crannies where moths might like to hide away.” The National Trust has done a trial using tiny parasitic wasps, which seek out moths’ eggs and lay their own inside, hatching new wasps.
Our housekeeping is probably not what it once was, either.
Parasitic Wasps For Control of Moth Populations! I’m always jumping up to try to catch them; I see them flying around.
She had the stairs and two floors of her cottage carpeted, at a cost of thousands of pounds. Among other things, it features chemical weapons, smoke bombs and armies of tiny, parasitic wasps. It’s not a case of running a vacuum over the carpet and thinking that’s done – at least once a month, and particularly during the spring and summer months, you need to thoroughly go round the edge of the carpet with a nozzle on the vacuum. “We don’t know whether the Romans brought them over when they invaded, although we know they have been around a long time in the UK and northern Europe,” says Pinniger. You don’t want them devouring all your clothes, but once they’re there, it’s worth a moment to reflect on their loveliness.” Can that really make up for a treasured cashmere sweater that has been lost, gobbled by the beasts? In houses up and down the country, there is a war being waged against clothes moths.
It didn’t work. Take out items in your wardrobes and give them a shake out because moths don’t like disturbance.” If you have carpet underneath your cupboards, you might want to think about getting rid of it, she says. Our approach has always been trying to do it in the most natural ways possible.” It is constant, she adds. “The theory at the moment is that it probably came over from South Africa in Victorian times when they imported a lot of skin and feathers.” They like the warmth – they thrive in heated buildings and aren’t normally able to complete their life cycle outdoors in the UK. They will munch through antique rugs and treasured cashmere.
“Whereas we know the case-bearing clothes moth can live in birds’ nests,” adds Pinniger. When Janine Christley moved into her new house, she thought buying woollen carpets would be the sustainable option. The TV presenter Kirstie Allsopp recommends freezing clothes to kill moths’ eggs. This is less of a problem if you wear something regularly, but lots of us have so many clothes that outfits go unworn for months or even years. This was carried out in one property, but Blades says it isn’t yet clear how effective it has been. “And then suddenly the conditions are right and you get a population explosion,” says Pinniger. “We have collection-care assistants who are trained to go into the houses and carry this out all the time for us. “In some cases where we need to go beyond that, we use a commercial product called Constrain, which has a residual effect for a number of months. These are increasingly the things you need to concentrate on in the average home as well. “If you’ve got heavy items of furniture, and sofas, you need to be pulling them out at least once a month and thoroughly vacuuming underneath. ‘Every time you’ve got rid of them, they appear again’ ... a case-bearing clothes moth. “Of course, they’re into clothes as well,” she says. Trichogramma are useful against food as well as clothes moths. Moths will happily breed in warm, centrally heated homes throughout the year, says Pinniger, “but there is a peak of adult emergence usually in April and May, and often another one in late August/early September when you get another generation through. Unlike the many moths that are in decline, these moths – the webbing (or common) clothes moth and the case-bearing clothes moth – are believed to be increasing in numbers. Every morning when I wake up there are about 10 or 12 on the wall.
The National Trust uses pheromone traps as part of its monitoring programme – this doesn’t control the population, but gives an indication of the scale of the problem. “They’re busy living on your clothes, slowly breaking it down. They can’t get it out and they’ve got moths – they’re going to have to live with moths the whole time they live in that house.”, The previous owners of Emma Harrison’s house warned her there could be a moth problem when she moved in five years ago. There has also been a shift back to natural fibres in carpeting and clothing, which has created food for the pests. You’ve also got your skin bacteria that wait for you to put clothing on and then they metabolise your sweat.