Think like a bug and win the battle against household insect pests
Insects are a critical part of our ecosystem, making up more than 80 per cent of the animal kingdom. They are also a fact of life in our historic houses. Many species, including spiders and ladybirds, are perfectly harmless. Others, like clothes moths and carpet beetles, are less welcome because of the damage they can wreak to our collections.
So, what can you do if you discover that something has been feasting on your favourite woolly jumper or carpet? Hilary Jarvis, one of the National Trust’s Assistant Preventive Conservators, shares tips and thoughts.
Small but destructive
Only a tiny proportion of the UK’s insect species damage our collections and interiors. However, the few that do can become serious pests and cause irreversible damage to our objects in a short period of time.
Among the worst offenders are silverfish (Lepisma saccarina), webbing clothes moth (Tinneola bisselliella) and varied carpet beetle (Anthrenus verbasci). These pests, or more usually their larvae, will happily graze on a host of objects including books, wallpaper, textiles and taxidermy.
Prevention is better than cure
In order to deter unwanted insect guests in our historic houses, we adopt a preventive approach, combining the best traditional housekeeping knowledge with modern conservation science. If you find yourself sharing your home with uninvited creepy crawlies, here's a list of things you can do:
- Seal gaps in windows and doors. Insects are getting in from somewhere, so stop up the obvious places
- Call in the sweep! When birds create nests in your chimney they are also creating homes for insects too
- Be mindful of shrubs and plants growing right by your windows. Adult beetles eat plant material but will come indoors to lay their eggs on your wool, silk, fur or feathered objects
- Consider turning down your thermostat a notch: bugs and beasties generally prefer warm, cosy environments, so if you are struggling with a stubborn resident, try keeping your home (or maybe a certain room) a few degrees cooler
- Most insects struggle if the air is too dry, so if you do have damp rooms or problems with leaks, you may find yourself quite popular
- Leave your wardrobe doors open from time to time to allow the air to circulate and to let in sunlight
- And make sure your favourite garments have been washed or dry cleaned before you pack them away, as moths rarely eat clean silk or wool.
Above all, our number one recommendation is good housekeeping, which really is the answer in most cases.
Spring clean, anyone?
Historically, most of our houses would have been closed at some point in the year, usually in the winter. House staff would have used this as an opportunity to strip rooms down and give them a thorough clean. They’d also be on the lookout for insect pests or damage.
This is still the case in some of our houses today, so on top of your general housekeeping, consider giving each space a really good spring clean every year.
Use a soft rubber pet brush and your vacuum crevice tool for reaching tight, carpeted corners and skirting boards. Try to vacuum busy hallways and stairways regularly to remove the dirt, dust and debris that can also act as insect food. Plump up cushions and try to vacuum underneath furniture from time to time.
Insects like to be safe and undisturbed, so think like an insect and try and see your living space with their buggy eyes!
Remedies and eradication
If you do find a jumper with a hole in, pop it in a plastic bag and leave it in the freezer for about 14 days. This will kill any remaining eggs that you might not be able to see and which can survive the lower-temperature washing machine cycles we favour today.
Nibbled carpets are not easy to repair. Have a good go with the vacuum cleaner and consider tracing over the chewed area with a soft pencil on a piece of paper. This will give you a record of how big it is, and you will know for sure if another insect friend has found the same spot.
If circumstances like this we might considering using an insecticide, incidentally, to try and limit the risk of further damage. We a use colourless, biodegradable chemical that is harmless to pets or humans. The residue can kill returning insect pests before they start nibbling. You can find a range of products in most hardware stores these days.
" Our number one recommendation is good housekeeping"
We’ll never be rid of insects and generally find we can co-exist perfectly happily. Our primary role is to ensure our special places are there to be enjoyed for everyone, forever, so we need to be ready if we find too many critters getting overly comfortable. Hopefully you can now be a bit more insect-pest ready too!
Five most common insect pests in 2019
Last year National Trust staff identified and logged more than 45,000 insects!
The five most common insect pests reported were :
- Silverfish (Lepisma saccharina)
- Webbing clothes moth (Tinneola bisselliella)
- Woolly bear (a generic term for various carpet beetle larvae)
- Australian spider beetle (Ptinus tectus)
- Common booklouse (Liposcelis bostrychophila)
2019 was a year of very changeable weather and some notable extremes. Warmer winters and hotter summers are probably supporting pest cycles, making diligent housekeeping more crucial then ever.