What is the name of the book louse that damages old books? - briefly
The species responsible is «Liposcelis bostrychophila», commonly called the booklouse. It feeds on paper, glue and mold, causing deterioration of old volumes.
What is the name of the book louse that damages old books? - in detail
The pest responsible for destroying historic paper collections belongs to the order Psocoptera, family Liposcelididae. The most frequently encountered species in libraries and archives is Liposcelis bostrychophila, commonly called the common booklouse.
Adult individuals are minute, measuring 1–2 mm, flattened, and wingless. Their bodies are pale‑brown to yellowish, with long, slender antennae and three visible tail‑like cerci. Nymphs resemble adults but lack fully developed genitalia and are slightly smaller.
Reproduction occurs rapidly: females lay 30–50 eggs over several weeks; embryonic development lasts 5–7 days at 25 °C, and the nymphal period comprises three molts within 2–3 weeks. Under favorable humidity (≥ 75 % RH) and temperature (20–30 °C) a generation can be completed in less than a month, allowing populations to increase exponentially.
Damage results from feeding on the cellulose, starch, and protein components of paper, bindings, and glue. Feeding creates irregular, ragged holes and a powdery residue of frass. Severe infestations weaken pages, cause discoloration, and may lead to total loss of manuscripts.
Control measures include:
- Environmental regulation: maintain relative humidity below 60 % and temperature under 22 °C; reduce moisture sources.
- Physical removal: vacuum or freeze infested materials at ‑20 °C for 72 hours.
- Chemical treatment: apply low‑toxicity insecticides (e.g., pyrethrins) in accordance with preservation guidelines.
- Monitoring: place sticky traps or pheromone‑based lures to detect early activity.
Identification relies on microscopic examination of morphological features or DNA barcoding for species confirmation. Prompt detection and integrated pest‑management practices are essential to protect valuable collections from this minute but destructive insect.