Skip to content
News

The five most common insect pests at National Trust places in 2021

Written by
Image of Hilary Jarvis
Hilary JarvisAssistant National Conservator, National Trust
Silverfish damage to the wallpaper in the Chinese bedroom at Saltram, Devon.
Silverfish damage to the wallpaper in the Chinese bedroom at Saltram | © National Trust/Hilary Jarvis

Hilary Jarvis, one of the National Trust’s Assistant National Conservators has identified the most common pests found in 2021 at National Trust places during a year that saw us emerge from lockdown and welcome visitors once again.

A destructive minority

Only a tiny proportion of the UK’s insect species cause damage to the collections and interiors at the places we care for. However, the few species that do cause harm can become serious pests and cause irreversible damage to objects including books, textiles and taxidermy in a short period of time.

Pest numbers in 2021

Last year, National Trust staff identified and logged 56,742 insects at the places we care for.

The five most common insect pests found in 2021 remain the same as those recorded in 2020. Interestingly, though, there has been movement at the top, with the webbing clothes moth knocking silverfish off the number one spot.

Here are the troublesome pests that topped the damage-causing leaderboard in 2021:

Webbing clothes moth (Tineola bisselliella)
This pest rose 18 per cent in 2021, leaping to the number one spot and outnumbering silverfish.
Silverfish (Lepisma saccharina)
SIlverfish slumped 31 per cent to take the number two slot in 2021, continuing their decline from a 2019 peak. The fall in numbers is possibly due to drier conditions across the year overall.
Australian spider beetle (Ptinus tectus)
Numbers of this pest are showing signs of retreat but remain high at Tredegar in Wales and are growing at three sites in Northern Ireland. The Australian spider beetle remains a 'north of the Midlands' phenomenon, with regional weather trends likely to be the determining factor as we see warmer, wetter winters. Unfortunately, once embedded, they’re very difficult to evict.
Common booklouse (Liposcelis bostrychophila)
The common booklouse was fourth on the list in 2021, after a sharp increase in 2019 and a steady climb in 2020.
Woolly bear
The woolly bear (a generic term for various carpet beetle larvae) occupies fifth place in the chart of least welcome visitors for 2021.

How your visits help to protect precious collections

Insect pests such as moths and silverfish thrived during Covid-19 lockdowns. Less disturbance and relative darkness provided the perfect conditions for pest larvae and adults and their numbers increased by 11 per cent during this time. However, their efforts were slowed in 2021.

With the reopening of houses in May 2021, visitors unknowingly played an important role in keeping pests at bay, helping drive a 6 per cent downturn in moths, silverfish and other insects that can cause damage to historic collections.

A rugged coastline in summer with a calm sea

Our news

Take a look at the latest news from across the National Trust.

You might also be interested in

Close view of part of carved armchair with beetle damage, from the Drawing Room at Ickworth, Suffolk
Article
Article

Expert tips for tackling insect pests that damage clothes, paper and furniture 

A National Trust conservator explains how to identify insect pests like clothes moths, carpet beetles and silverfish and prevent the damage they can do in your home.

Conservator vacuuming a tapestry chair seat using monofilament screening to protect loose threads from the suction of the special museum upholstery tool in the Long Gallery at Osterley Park, Middlesex
Article
Article

How to care for your precious objects 

National Trust conservationists know a thing or two about protecting valuable items. Get some top tips to protect your precious objects.

A close-up of a hand gently brushing a dusty surface with a specialist brush, at Tyntesfield in Bristol
Article
Article

Tackling dust in historic houses 

Discover why the issue of protecting historic surfaces from dust is important to conservation work.

Tapestries returned to The Vyne, Hampshire, post-conservation. Set of six tapestries, wool and silk, 6-7 warps per cm. 'after the Indian Manner', London, c. 1700-1720.
News
News

Rare surviving tapestries return to The Vyne 

Exquisite tapestries that were once cut up as part of a nineteenth-century ‘extreme makeover’ have returned home to The Vyne in Hampshire, following conservation.

Puffin on the Farne Islands, Northumberland
News
News

Farne Islands puffin count 2022 is under way 

The annual count of puffins across the Farne Islands has begun. Find out how the ranger team carries out the census and why it’s so important to the survival of the species.

The winners of The Forthlin Sessions outside 20 Forthlin Road
News
News

Bringing live music back to the birthplace of the Beatles 

20 Forthlin Road is where the Beatles were born. Discover the winners of The Forthlin Sessions and find out how we're bringing live music back to this remarkable house.