Most agricultural research focuses on crops prior to harvest, despite the enormous economic value associated with the postharvest agricultural supply chain. One of the key sources of postharvest losses are caused by stored product insects, which globally result in $100 billion in losses each year. The main way to combat these insect pests in bulk storage of grain and related facilities is through calendar-based fumigations (typically) or fumigations timed with grain movement (e.g., deliveries, shipments, movement between silos). As such, one of the major challenges to fumigation is the increasing worldwide surge in resistance to phosphine in a range of important pest species. However, determining the best management approach is complicated by the fact that testing for phosphine tolerance or resistance is not commonly practiced at food facilities, thus stakeholders typically do not know the level of resistance in the populations with which they are dealing. Further, there are no set recommendations for resistance management tactics for a specific level of phosphine resistance at food facilities.Our overall goal of this project is to increase resilience in the postharvest supply chain at food facilities by training personnel of food facilities to implement new screening procedures for phosphine resistance, and where necessary, validating and recommending a suite of commercially available integrated pest management (IPM) tactics to manage phosphine resistance. Our specific objectives of this project are to: 1) optimize a rapid test for detecting and monitoring phosphine resistance on the Great Plains and compare the test to a commercial standard test, 2) apply the most effective rapid phosphine tolerance/resistance test to food facilities on Great Plains and screen for resistance among multiple stored product insects, 3) deploy a suite of tactics for phosphine resistance management to reduce effects of resistance in food facilities, and 4) transfer knowledge to and engage stakeholders in implementing effective solutions to overcome phosphine resistance.