The term “bookworm” commonly refers to an individual who enjoys reading extensively. However, this popular phrase also has a literal, biological interpretation, pointing to various insects that consume and damage books. These creatures are a genuine concern for preserving valuable collections, as they actively feed on the organic materials found in books. This article identifies the actual pests, details the specific ways they inflict damage, and offers practical strategies to protect book collections from infestation.
Identifying the Pests
The creatures often called “bookworms” are not a single species of worm, but rather a collective term for the larvae of various insects that bore through books, along with other destructive adult insects.
Beetles: Their larvae, such as drugstore, anobiid, and powderpost beetles, are significant culprits, often laying eggs on book edges and spines.
Silverfish (Lepisma saccharina): These are small, wingless insects, typically 12-19 mm long, recognized by their silvery, fish-like appearance and three tail-like appendages.
Booklice (Psocoptera): Not true lice, these are tiny, soft-bodied insects, usually 1-2 mm in length, appearing white or light brown.
Termites (Isoptera): Including drywood and subterranean types, these are highly destructive pests that can infest books.
Cockroaches and certain types of moths: These can also contribute to book damage.
How They Damage Books
These diverse insects inflict damage primarily by consuming the organic components of books. Many pests, especially beetle larvae, create tunnels and holes directly through the paper, often seeking the starch or glues used in bindings.
Silverfish and booklice primarily graze on the surface of paper and bindings, feeding on cellulose, starch-based adhesives, and microscopic molds that grow in damp conditions. This surface feeding can lead to irregular holes, shallow losses, and abrasions, sometimes accompanied by yellow stains from their excrement or body oils. Termites, in contrast, consume almost every part of a book, including paper, cloth, and cardboard, causing extensive tunneling and structural weakening. Visible signs of infestation can include small, cylindrical holes, surface scraping, and frass, which is the powdery excrement left behind by the insects.
Protecting Your Collection
Protecting books from insect damage involves environmental control and proper storage techniques.
Maintain stable temperature and humidity: Maintaining stable temperature and humidity levels is important, as many book pests thrive in warm, damp conditions. Ideally, books should be stored in environments with temperatures around 68-72 degrees Fahrenheit and relative humidity between 40-50%. Higher humidity encourages mold growth, a food source for some pests.
Ensure proper storage: This includes keeping books on shelves rather than directly on the floor, ensuring good air circulation, and avoiding overcrowded conditions.
Conduct regular inspections: Regular inspection of books and bookshelves can help detect early signs of infestation, such as small holes, frass, or the presence of the insects themselves.
Address existing infestations: For existing infestations, isolating affected books in sealed plastic bags and freezing them for several days can eliminate pests.
Consult professionals: For severe or widespread infestations, consulting a professional pest control service is recommended to ensure effective and safe eradication.