The flood bug, Australiodillo bifrons (Isopoda: Armadillidae): A potential pest of cereals in Australia?

Agricultural invertebrate pests cause substantial losses through reduced productivity and increases in pesticide application. Understanding the basic biology of pest species and how they interact with other invertebrates within specific industries is important for developing targeted control strategies. In 2006, feeding damage to emerging cereal crops in parts of New South Wales, Australia, was caused by Australiodillo bifrons (Budde-Lund, 1885), an endemic slater species. This appears to be a new phenomenon as slaters are not widely known to be a pest of cultivated plants, but rather feed on decaying organic matter. Samples were collected from these areas and affected farmers interviewed. We observed and report on the swarming of A. bifrons populations in the field, a characteristic behaviour that may contribute to the pest status of this species. We also examined the feeding characteristics of A. bifrons and another slater species, Porcellio scaber (Latreille), to wheat seedlings under laboratory conditions. Our results suggest A. bifrons can cause significant feeding damage to wheat seedlings and reaches very high densities in the field. The presence of shelterbelts along crop margins could be harbouring large populations of A. bifrons, although they also provide a refuge for many beneficial invertebrates that could control pest populations. We propose that the pest status of A. bifrons in parts of New South Wales may be increasing due to changes in farming practices and/or in response to climate change.