Stored grains sampling strategies

22 - 24 September 2009

Stored product pests are a significant problem for the domestic and export grain industry. Substantial costs are associated with treatment of infested grain lots, commodity loss due to insect damage and rejection of shipments by importing countries. Quarantine regulations of importing countries often dictate that grain commodities entering a country must be free from live insects, as stored product insects are seen as a significant biosecurity risk. In order to minimise the risk of commodities being exported with live insects, sampling strategies are employed along the production and supply chain, to detect pests prior to shipment. The aim of our project is to identify currents sampling strategies used for detection of insect pests and proof of area freedom in export grains commodities.

To date, the project has focused on acceptance sampling methods for bulk grain storage. Similar to acceptance sampling programs in other industries, sampling strategies in grains have typically assumed a homogeneous distribution of insect pests throughout grain bulk. Stored product insects however, are known to respond to microclimatic conditions in grain storage facilities, with insects clustering in different areas of bulk grain commodities. Here we consider an alternative approach to acceptance sampling of bulk grains that unlike other acceptance sampling methodologies takes into consideration insect behaviour and biology and the potential for a heterogeneous distribution of insect pests.