Typical forms have two pairs of membranous wings, but there is an evolutionary tendency to loss of wings in many species. Liposcelis entomopbilus Colour, yellowish brown, with conspicuous dark reddish bands across abdomen. However, those species that have achieved pest status are widely distributed and often found in warehouses, food manufacturing premises, granaries and museums as well as domestic and retail premises. Here they will infest materials of plant and animal origin including stored food, plaster, leather, woodwork and even books. Many species are cosmopolitan and their countries of origin are unknown.
Different species exhibit different temperature requirements.
Thus Lepinotus patruelis is frequently encountered in cool situations, e.g. warehouses, whilst Liposcelis bostrychopilus, which is thought to have originated from Africa, prefers warmer situations. Significance Psocids rarely cause damage directly by feeding and are virtually harmless in small numbers. Large infestations, however, may cause significant damage to delicate materials such as books and furs. Signs of spoilage of dried meat have included holes and tunnels in which the insects hide plus a covering of white powdery material and salt crystals. The major problem posed by psocids is the nuisance which they cause.