Scientific name: Liposcelis bostrychophila Family: Liposcelididae Order: Psocoptera Risk level: Moderate Category: Insect
? What is a booklouse
The booklouse (Liposcelis bostrychophila) is tiny (0.5–1 mm) and cannot be seen clearly with the naked eye. It feeds on microscopic algae, fungi and starch in books and dry foods. Its presence in a store is a reliable indicator of high relative humidity (over 65%).
Booklouse life cycle
It undergoes complete metamorphosis. Eggs are laid directly on food. The larvae are the damaging stage. A full generation takes 4–8 weeks, and multiple generations can develop in an infested store.
Where booklice occur
They are found in food warehouses worldwide and are common in the Gulf, Saudi Arabia and Egypt, especially in warm stores.
Damage and risks associated with booklice
They damage books, documents and dry crops. Their presence indicates storage conditions that encourage fungal and mold growth.
Signs of booklice
Adult insects may be seen around light sources; larvae and silk threads may be found in food (moths), along with droppings and hollow grains (weevils and beetles), or small white eggs on food surfaces.
Where booklice are found
They occur in old books, damp stores of flour and starch, archives and pharmaceutical laboratories.
Booklouse control methods
Monitor with pheromone traps. Treat the warehouse with pyrethroids. Fumigate stored products with phosphine or methyl bromide. Physical control can use temperatures below 10°C or above 55°C. Rotate stock using FIFO.
Booklouse control products
Use pyrethroids in warehouses, phosphine (PH3) for fumigation, deltamethrin for residual spraying, and diatomaceous earth for grains.
Food-facility control requirements
FSSC 22000 V7: stored-product pests are high-priority; pheromone traps and weekly records are mandatory. BRCGS: finding stored-product pests in a product is a major non-conformance (NC).
A fact about booklice
Booklice can reproduce parthenogenetically, without males, enabling a single female to establish large colonies in suitable conditions.
Frequently asked questions
Q: How do stored-product pests enter a facility?
A: Usually through incoming shipments. Carefully inspecting samples from each shipment and quarantining new purchases are essential steps.
Q: Is low temperature enough to eliminate stored-product pests?
A: Yes. Temperatures below 10°C for two weeks stop reproduction and kill the weaker life stages. Below −18°C for three days kills all stages
