Pests in collections – silverfish

Silverfish (Lepisma saccharina) are commonly found in homes worldwide, especially in more humid or damp areas, where they can be seen at night, scuttling across surfaces. These long-living insects derive their name from shiny metallic scales on their bodies and the way they move side to side, like a fish. They’re notoriously very difficult to get rid of and are able to live for a year without food as long as they have access to water.

The good news is that they don’t bite, predate on other insects or spread disease. But if left unchecked, they can damage your treasured pictures, furnishings and wallpapers, grazing through objects that contain starch or other sugars. They’re also partial to dandruff, glue, toothpaste, detritus and microscopic mould.

Speedy little critters, they can run faster horizontally as opposed to vertically, being equipped with six legs to get away from predators such as spiders. If you do see one and think they resemble something prehistoric, then you’d be right as there were silverfish around some 100 million years before dinosaurs.

In historic houses they enjoy eating the organic ink on historic labels, scraping letters away as they graze, making the text illegible and causing loss of vital information. As with most unwanted pests in historic properties, they thrive in isolated, dark, infrequently used areas and are not always obvious until the damage has occurred.

Pest problems are not new and treatments have been undertaken since the 1700s, which have saved many historical objects. However, as some of the treatments included pesticides or the use of poisonous substances, which we now understand have risks to human health, modern approaches are geared towards preventative measures known as integrated pest management programmes (IPM).

IPM was first used in the food industry in the 1950s to prevent the overuse of pesticides. These principles were adopted and introduced into museums in the 1980s and we use them today throughout all Trust properties.

The use of chemical treatments to eradicate pests is limited to when it’s absolutely necessary. The advantages of an IPM systematic approach to monitoring and targeting treatment is that it’s minimally invasive for our collections, as well as being better for the health and safety of people and the environment. Once established, it’s also cost-effective and sustainable.

Silverfish will always be present in our properties, but we have learned to live with them in a controlled and monitored way by having housekeeping regimes including dusting, checking and maintaining environments that suit the collection’s care rather than the insects. So if you visit our properties and see someone with a torch, dusting, or strange little triangular traps under furniture, you know that the battle to preserve Scotland’s heritage is ongoing.