This project aims to develop mathematical models to investigate the emergence of resistance to fumigants, particularly phosphine based fumigants. A particularly important aspect is the possibility that resistance is directly influenced due to the migration of resistant stored grain insects from silos to and from surrounding farmland, where they breed with non-resistant insects. Computer software will be developed to assess different fumigation strategies with the aim to reduce (or eliminate) resistance, taking into account ecological data on movement of insects to surrounding farmland.

What is the biosecurity problem?

Phosphine is the most common fumigant used today to treat stored grain infestations. Resistance to phosphine is a major threat to the grain industry and inadequate fumigation strategies may result in infestations of resistant insects that are difficult to control. Grain borers tend to reach unnaturally high population numbers due to mass storage of grain food. There is a need to understand the impact of refuges on the emergence of resistance.

The main outputs of this project are to:

• understand the impact of refuges on the emergence of resistance
• develop a management tool for farmers to allow more effective management strategies to be applied
• develop much needed skills in mathematical model development in the grains industries, and
• limit the risk of resistant strains of stored grain insects becoming endemic to the Australian grain industry.

Who will be the end-users of your research?

Grain handling companies and farmers will have a fumigation management tool (as computer software) that will help them decide the most effective fumigation management strategies.