The term “bookworm” refers to insects and their larvae that consume books, posing a threat to physical collections. These pests bore holes and create tunnels, damaging books. This damage is caused by various insects with an appetite for book materials.
Understanding Book-Damaging Insects
Booklice (Psocids) are tiny (1-2mm), soft-bodied, often wingless insects. They feed on mold and fungi on damp books, and also consume starch-based glues and paper. While they don’t bore into books, their presence indicates moisture issues and they can contaminate materials with their feces.
Silverfish are wingless, silver-gray insects (12-19 mm long) with three tail-like appendages. They feed on starchy materials like paper, book bindings, and wallpaper, leaving irregular holes and yellowish stains.
Carpet beetles are small, oval-shaped beetles whose larvae graze on page surfaces and fabric bindings. They feed on animal products like leather, vellum, and glues.
Drugstore and cigarette beetles are small, reddish-brown beetles whose larvae tunnel through books, creating holes in pages and bindings. Termites are destructive, consuming cellulose in paper, cardboard, and wooden shelves. They can quickly make book collections unusable, often undetected until significant damage occurs.
Why Books Become Targets
Books attract insects due to their composition and storage conditions. Book components serve as food sources. Cellulose, the primary material in paper, is a common attractant. Starches in glues and adhesives, and fabric covers, also provide sustenance. Older books often contain appealing organic, animal-based glues.
Environmental factors play a significant role in attracting and sustaining insect populations. High humidity encourages mold growth, attracting booklice. Dark, undisturbed spaces with stable temperatures and poor air circulation create favorable habitats for pests like silverfish and booklice. Books in damp basements or attics are vulnerable.
Preventing Infestations
Preventing infestations involves controlling the environment and good storage practices. Maintaining optimal temperature and humidity levels is a primary defense. Books thrive in cool, stable temperatures (60-70°F/15-21°C) and 30-50% relative humidity. Dehumidifiers and good air circulation help maintain these conditions.
Regularly clean and dust bookshelves and books to remove potential food sources like dust and debris. Store books properly, on shelves rather than the floor, to deter insects. Airtight plastic containers create a physical barrier for stored books. Before introducing new or used books, inspect them for pest activity.
Addressing Existing Damage
If an infestation is discovered, immediate action can mitigate further damage. Quarantining affected books in sealed plastic bags prevents pests from spreading to other items. For small infestations, freezing is effective: place sealed books in a freezer at 0°F (-18°C) or lower for at least four days to kill insects and eggs.
After treatment, gently clean books by brushing away dead insects and debris, or carefully vacuuming. Address environmental conditions that led to the infestation, such as humidity or poor ventilation. For widespread infestations, professional pest control can help. For severe damage or valuable books, consult a professional conservator for restoration options.