RELATIONSHIPS BETWEEN INSECTICIDE USE, GRAIN HYGIENE AND INSECTICIDE RESISTANCE IN ORYZAEPHILUS-SURINAMENSIS (L) (COLEOPTERA, SILVANIDAE) ON GRAIN-PRODUCING FARMS

Levels of resistance in Oryzaephilus surinamensis were related to grai n treatments and hygiene practices on 63 grain-producing farms in New South Wales, Australia. Grain-protectant treatment was generally effec tive in reducing infestation levels. Hygiene measures by themselves ha d little effect on infestation levels, but good hygiene improved the e fficacy of protectant treatment. In some instances, protectant use was associated with high resistance levels; high insect densities and the highest levels of resistance were recorded from storages in which tre ated grain was added to old grain residues. We consider good farm hygi ene should be practised to slow the development of resistance. Copyrig ht (C) 1996 Elsevier Science Ltd