Approx size: 1-2mm

Colour – yellowish brown

How do they affect you?

Booklice are harmless in small numbers, but in large numbers they can cause significant damage to delicate materials, such as books and fur.

The signs of an infestation are holes and tunnels, in which the insect hides, plus a covering of white powdery material and salt crystals.

Booklice will contaminate raw, processed foods and infest items such as bagged nuts, chocolate, milk powder, cereals, sugar, flour, etc.

How do booklice live?

The greatest activity of booklice is between April and November. Booklice can develop more successfully in warm, damp conditions or places of high humidity, i.e. kitchens.

The female may produce up to 200 eggs in her life time and between 1 and 3 a day. The eggs are sticky and pearl in colour, which hatch between 1 and 2 weeks.

Depending on the species, the nymph passes through 3-8 molts before it reaches maturity in approximately 15 days. The lifecycle is usually complete in approximately 1 month and the adult may survive up to six months.

How to control them

The most effective form of control is to thoroughly air and dry the premises to reduce the risk of mould developing. Packet foods should be stored in well ventilated cupboards, away from cookers and steam. Cupboards and storage areas should be cleaned and food debris not allowed to accumulate. Ensure good stock rotation and regularly check cupboards and packets for signs of infestation.

Booklice are susceptible to a wide variety of insecticides. However, they are difficult to control with insecticides because you may contaminate your food.

How can I prevent reinfestation?

As long as the kitchen and food cupboards are well ventilated and dry and you have not kept the food in these cupboards after its best before date, it should be possible to prevent a reinfestation of psocids.

Check packaging before buying to make sure that it is not damaged, and foods that are vulnerable – flour, semolina, etc. – can be stored in washable covered containers.