Toward a rapid antibody test (RAT) for phosphine resistant insect pests of stored grain (2024-2025)

Phosphine fumigation is the mainstay of insect pest control in stored grain, making it essential to international trade and global food biosecurity, a role threatened by phosphine resistant pests. Our goal is to put cost effective, real-time diagnostic technology in the hands of grain growers and grain handlers to transform the way they manage resistance to phosphine. This test will reinforce Australia's reputation as the world leader in the postharvest grain handling, thereby improving our competitive position in international markets. The current project will allow us to extend our proof of concept to a proof of commercial utility. We previously identified the single most economically important gene for phosphine resistance in insect pests of stored grain and developed a DNA test to detect all resistance variants. While this test has been incorporated into the national phosphine resistance monitoring program due to its scalability to very high capacity, it must be carried out in a lab and does not provide a point-of-need test that is useful for decision-making by grain growers and handlers in the field. We have now identified a biochemical assay that distinguishes between phosphine resistant and susceptible individuals with the potential to provide a simple, universal field test for phosphine resistance. Providing growers and grain handlers with immediate feedback on the resistance status of infesting insects will allow them to control pests more effectively.