Allozyme polymorphism and variability in permethrin tolerance in British populations of the parthenogenetic stored product pest Liposcelis bostrychophila (Liposcelididae, Psocoptera)

Variability in allozyme patterns is demonstrated among 111 British populations of Liposcelis bostrychophila (Badonnel), an obligatory parthenogenetic liposcelid species that is a common domestic pest in the United Kingdom. In addition four tropical strains and a laboratory culture were included in the analysis. Permethrin toxicity was measured in a subset of the populations. Using cellulose acetate paper electrophoresis, 16 of 34 enzymes tested were found in the liposcelid material and, of these, four were polymorphic. A total of 47 distinct morphs were recognised. This enzyme variation appears to be random with respect to geography throughout the country. Permethrin tolerance was highly variable among populations. A significant relationship was demonstrated between the mean LC50 for permethrin and latitude such that there appears to be higher levels of tolerance in southern, than in northern, Britain. No link could be established between the allozyme polymorphisms, particularly in the esterases, and permethrin tolerance. (C) 2000 Elsevier Science Ltd. All rights reserved.