How to Tackle Booklice

Booklice belong to a group of insects known as “psocids” and despite their common name – which they get from their habit of lurking amongst old books and feeding on the paste used to bind the pages – this is not the only place they can be found. Although they may also frequent wall paper and recently laid plaster attracted by the bacteria and moulds which grow in damp conditions, booklice are probably best known as pests of domestic cupboards and food manufacturing or retailing premises.

Although these small, greyish brown insects, some 1 – 4 mm long, do not bite people or pets, cause any structural damage or spread disease – though some sensitive individuals may develop skin rashes – they inevitably contaminate food when present in large numbers. Their close association with foodstuffs makes it difficult to use pesticides against booklice without the risk of tainting the food itself, but fortunately there are some simple practical steps to help control them.

Tackling the Problem

When an infestation is first spotted, especially a big one, with large numbers of psocids swarming all over food packaging at the back of a dark cupboard, it may seem as if this has erupted from the product itself. However, poor hygiene at the food manufacturer or retailer is not to blame, since the type of booklice found in our homes are seldom seen at these places; problems at food premises are caused by a different kind of psocid.

To begin to tackle booklice, it is important to understand why they bother us in the first place. Booklice are attracted to humid conditions, the slightly damp warmth of kitchen cupboards being ideal and here they can increase in numbers very quickly, especially if there is a ready supply of food – either yours, or the microscopic mildews that form in moist places. Bathrooms too can provide them with a good place to live.

Although insecticides are not really suitable for use where there is a danger of contaminating food, products which are effective against crawling insects, can be applied in bathrooms and other parts of the house. In the kitchen, management is the key to eradicating this pest.

All infested food or spillages need to be removed and thrown away into an outdoor bin, before cleaning the cupboard itself thoroughly, either by hand or with a vacuum, again making sure that everything removed ends up outside. Once cleaned, the cupboard should be allowed to dry out completely before being used again.

Insufficient ventilation is often to blame for producing the sort of damp conditions favoured by booklice, so it is important to address this to prevent their return. Depending on the cause, unblocking air bricks or vents, using or fitting extractor fans or simply opening the window when cooking can all help to avoid the build up of moisture which they find so attractive.

Although finding any kind of unwanted guest in your food cupboards is never a pleasant experience, the good news is that with booklice, once you have sent them on their way, provided conditions remain well ventilated and dry, you should not be seeing them again.