Silverfish: The Insect That Loves to Eat the Books

Silverfish, having the scientific name Lepisma saccharina, is a tiny insect that does not have wings. It is an ancient being that existed on Earth 400 million years ago, prior to the invention of printed books. Nevertheless, having silverfish around can be a dreadful situation for libraries and archives.

Let's find out why

The diet of silverfish includes paper products such as books, newspapers, cardboard, and wallpaper

Unwanted guest of libraries

Silverfish vary in size from approximately 12 to 19 mm and have small scales covering their bodies, as well as long antennae and a bristle-like tail. It is commonly found in basements, bathrooms, kitchens, and other locations with elevated levels of humidity.

Silverfish get their name from their silvery, metallic appearance

Even though the silverfish is small, it presents a significant danger to valuable historical documents, because it chews irregular holes and leaves behind yellow stains that degrade the appearance and integrity of paper. 

After the sun has set, books, periodicals, wallpaper, and even personal documents can become its next meal. 

Why Silverfish found the paper tasty?

Silverfish are not drawn to books simply because they love books themselves, but rather because they find certain parts of each book attractive.

Silverfish feed on the glue found in book bindings

Many older books used starch-based adhesives to bind the pages. Silverfish are particularly attracted to these adhesives as food source.  Additionally, the major component of paper, cellulose, is something that silverfish like very much. 

Silverfish also consume the proteins found in book bindings that are made of fabric or leather. They even enjoy the gelatin and casein used in the finishing operations of paper and covers. 

Signs of Silverfish Presence in Your Library

Signs of silverfish on paper include irregular holes, tiny yellow stains and chewed edges

When silverfish invades the library, it leaves behind several telltale signs. The most noticeable are irregular holes in the pages or coverings. Another is yellow streaks, which is simply silverfish excrement. Silverfish also shed their tiny scales as they travel, and these can be too found on the surface of the paper.

Silverfish's Wedding Dance

Silverfish can live up to 8 years, which is quite long for an insect. They are the Methuselahs of the insect world

Silverfish engage in a unique three-step dance before reproducing, which can last over thirty minutes. Initially, the male and female stand facing each other, their antennae vibrating as they move back and forth before returning to their starting positions. In the next stage, the male flees while the female chases him. Eventually, the pair lines up side by side, with the male gently vibrating his tail against the female's.

Silverfish often deposit their eggs in dark, hidden, and wet spots such as cracks, crevices, and behind baseboards, rather than directly on books. When the eggs hatch, the nymphs emerge as miniature white versions of the adults, lacking the characteristic silver shimmer. As they grow, nymphs undergo a series of molts, typically between 5 and 7, gradually increasing in size and developing their distinctive silver hue.

Silverfish typically measure between 13 to 25 millimeters in length

The nymph stage lasts from a few months to several years, depending on availability of food. Increased humidity and temperatures accelerate the maturation process.

How to Protect Your Books Against Destruction

It is vital to maintain a humidity level below 50% as silverfish are known to thrive in humid environments. To achieve this, consider using dehumidifiers and ensuring proper ventilation in the affected areas.

Consistent and thorough cleaning is crucial to eliminate potential food sources, such as crumbs, dust, and debris, which attract silverfish. Pay special attention to areas where food particles and organic matter may accumulate, such as kitchens, basements, and attics.

When it comes to storing books, it is recommended to place them in airtight containers or sealed plastic bins to prevent silverfish infestation. Additionally, consider using insecticides or natural repellents like diatomaceous earth to deter silverfish. However, exercise caution and consider consulting a professional when using chemicals near books to prevent any potential damage.