Pesticide resistance, population dynamics, and invasive species management

In agriculture, invasive species represent a unique challenge for public policy makers and for economists analyzing optimal pest control policies. In order to accurately evaluate policies involving invasive species, economic models must describe the inter-temporal features of producer responses to invader biology, to seasonal changes in demand, and to the policies themselves. In addition, responses to externalities from pest control, such as pesticide resistance or pest movement, complicate finding the optimal policy and must be accounted for. The overall goal of this dissertation, therefore, is to develop a theoretical and empirical approach for measuring the costs and benefits of invasive species management policy.; In this dissertation, invasive pest management is modeled as a part of a dynamic bioeconomic system. I develop a calibrated simulation model that represents the important biological, economic, and regulatory features of managing the effects of a specific invasion: the late 1990s invasion of California strawberries by the greenhouse whitefly, Trialeurodes vaporariorum , and the pesticide use restrictions imposed by California regulators in order to manage the development of pesticide resistance. The two biological components of this model are a model of the population dynamics of the greenhouse whitefly and a model of the effect of the whitefly on strawberry yields. Detailed scientific data are used to construct each biological component. The economic component of the model captures the grower's objective of maximizing profits from strawberry production subject to the biological constraints of the agricultural system, market prices, and constraints imposed by government regulation. The model is used to calculate optimal grower pesticide application choices (timing and frequency) over a one and six-year period, in order to assess the efficiency of regulations in the short-run, and in the long-run when the development of resistance is considered. The regulations are binding in the short-run, but are only binding in the long-run under certain conditions.; The role of spatial relationships among host crop growers on policy success is also considered. I use the bioeconomic model to assess the influence of whitefly migration timing, market conditions, and pesticide regulations on private- and regionally-optimal regional invasive species management strategies. The circumstances of the strawberry/whitefly case make a central authority unnecessary.; Overall, this dissertation demonstrates the importance of considering both economic and biological features of invasive species management when developing environmental policies, even when limited data are available, and develops a methodology for doing so. The long-run goal of any invasive species management policy should be to maximize total economic benefits. This dissertation advances the ability of government agencies to conduct regulatory impact analyses for invasive species in agricultural systems, by providing an economic and biological framework within which to model invasive species management. In particular, my analysis provides a method for identifying and quantifying the types of benefits and costs associated with pesticide use policies created to preserve the effectiveness of chemical pesticides after the arrival of an invasive species in an agricultural system.