Psocids
Psocids (pronounced so-sids)
From time to time people find that their food cupboards have become infested with tiny grey or brown insects. These are often found on the packaging of dry goods such as flour, powdered milk, sugar or semolina. The aim of this leaflet is to explain what these insects are and how best to prevent them.
What are psocids?
Psocids- or booklice – which are often between 1 and 2mm long might be found in dry foods. They are not caused by poor hygiene, and are just as common in the cleanest of homes be they old or new. They prefer to live in dark, warm, humid places – such as the folds of packaging in food cupboards, and dislike light or disturbance. They feed on a wide variety of food products – such as flour – and also the microscopic moulds that develop in humid conditions. They may live for a bout 6 months during which time the female may lay up to 100 eggs. Several independent studies have shown that the psocid species which causes the majority of problems in homes, is rarely found where food is produced.
Conditions
Psocids prefer areas with high humidity but can tolerate dry conditions for some days. The kitchen environment is likely to provide the conditions they need and fitted cupboards provide the darkness that attracts them. Some food products, including flour, naturally contain moisture. In warm conditions psocids can rapidly increase in number. This is most likely to occur during the summer months when temperatures are higher, leading to their discovery in the autumn.
