THE PEST STATUS OF PSOCIDS IN THE UK

Abstract:
Psocids, and particularly the species Liposcelis bostrychophila , have become an increasingly recognised pest of stored food products and grain. In the UK, L. bostrychophila is the most important cause of consumer complaints in some areas of the food industry. A similar picture emerges from other European countries. Extrapolation from warehouse psocid population dynamics to psocid prevalence in products in the home is erroneous since different, although similar looking, species are found in the two habitats. Patterns of psocid prevalence in households and storage facilities are presented and discussed. Liposcelis bostrychophila, is parthenogenic yet shows considerable variability in morphology, physiology and behaviour between populations. In addition there are differences at the molecular level among four polymorphic enzymes. Several of these patterns of variability are vectored along a north south axis in the UK. The possible causes and implications of this suite of variations are discussed.