The four psocid species tested were from the genus Liposcelis: L. bostrychophila, L. entomophila, L. decolor and L. paeta. Strains of all species were collected from farms in the Darling Downs region of Queensland, Australia, and tested for resistance to registered grain protectants by following the methods of Nayak et al.1 (Table 1). These strains were not selected in the laboratory prior to the current study and were maintained on a culture medium consisting of whole wheat, kibbled wheat, whole wheat flour and brewer's yeast (10 + 10 + 10 + 0.1 by weight) at 30 ± 1 °C, 70 ± 2% RH and 12:12 h light:dark photoperiod.