Hierarchical governance in invasive species survey campaigns

Large-scale delimiting surveys are critical for detecting pest invasions and often undertaken at different governance levels. In this study, we consider two-level hierarchical planning of surveys of harmful invasive pests including a government agency with a mandate to report the spatial extent of an invasion, and regional governments (counties) concerned about the possible threat of an outbreak. The central agency plans delimiting pest surveys across multiple administrative subdivisions. Counties could participate in these surveys if funds become available. Our goal is to find the optimal levels of cooperation between the central agency and regional governments in the form of the central agency sharing funds with regional governments in a way that benefits both it and the other entities. We propose a Stackelberg game model that finds optimal levels of collaboration between two levels of government in large-scale pest survey campaigns. We apply the model to surveillance of hemlock woolly adelgid, a harmful pest of hemlock trees in Ontario, Canada. Our solutions help anticipate the underperformance of surveys conducted by regional governments because their goals do not fully align with the central agency survey objective. The methodology can be adapted to explore governance hierarchies in other regions and political jurisdictions. • We find optimal levels of cooperation between two levels of governments in pest survey campaigns. • Our model finds optimal cost-sharing strategy between a biosecurity agency and regional governments. • We demonstrate the approach for delimiting surveys of hemlock woolly adelgid in Ontario, Canada. • The approach can be adapted to improve a governance of biosecurity projects in other regions.