The presence of booklice usually means that mould is present or that the RH is too high.
Not to be confused with bookworm which are the larvae of the common furniture beetle.
species Liposcelis bostrychophilus
Colorless to gray or light brown, ranging from 1 to 2 mm in length. Soft bodied without scales. The common house-dwelling booklouse is wingless or its wings are reduced to small scale-like, non-functional wings. Characteristic long, thread-like antennae.
Most numerous in houses during spring and summer. Probably the most common insect found in libraries. Prefer to live in damp, warm areas and can be found outdoors in grass or leaves, and in areas where moulds grow. Fast-moving and shun light.
Microscopic moulds and starchy materials such as paste and glues of book bindings and wallpaper.
Damage is usually in the form of grazing.
Adults lay 20 to 50 eggs depending on seasonal conditions. They are usually laid separately at a rate of 13 per day and, being sticky, become covered with fragments of food or rubbish or adhere to the substrate. The eggs of some outdoor species are however laid in batches and covered with a silken web. The smooth, pearl- coloured eggs hatch in 21 days. The life cycle from egg to adult is around 110 days.
The emerging nymph closely resembles the adult and will pass through 4 moults (to reach maturity in about 15 days. With each successive moult the nymph becomes progressively more like the adult as eyes, antennae and wings (if present) begin to develop.
Adults live 24 to 110 days. A single female produces between 120 to 456 offspring. Because there are no males and females do not require fertilisation to lay eggs, populations of Liposcelis can increase very rapidly at temperatures over 25 °C and give rise to apparent population explosions. Incomplete metamorphosis with nymphs appearing like small adults.
Booklice possess a relatively thin cuticle which, coupled with a large surface/volume ratio, means that they are not well adapted to survive adverse conditions, and, in particular, low relative humidities. Control requires correcting the environment by reducing the RH to below 60%.