In recent years, the effectiveness of conventional contact insecticides as fabric treatments for grain stores has been called into question. Dryacide has replaced these compounds and is now widely used in Australia for structural treatment in wheat and rice stores. It is applied either as a dust at 2 g/m’ or as a 10% aqueous slurry to provide 6 g/m’. Dust application is confined to grain-handling machinery, ducts and vertical silos, and slurries are applied to horizontal grain stores. Slurries are particularly useful where there is a need for personnel to avoid exposure to very dusty atmospheres which would be created if the dry dust was applied. Although Dryacide remains sufficiently active to exert control when applied as an aqueous suspension, other inert dusts lose their efficacy when applied in this way.