Uncertainty in pest control thresholds: Application to chemical control of corn earworm on soybean

Abstract

Uncertainty and risk are important components of chemical spray decisions. In this paper, we define an action threshold using the decision analytic approach (based on axioms of rational choice under uncertainty) of minimizing expected loss. The concept of loss is defined in terms of the cost of making an incorrect treatment decision. Expected loss implies integrating the loss function over probability distributions used to describe the relevant uncertainties. This concept of the action threshold is applied to control of corn earworm on soybean crops, using a time-dependent threshold function previously developed (Yu et al., 1992). The main source of uncertainty in this application is the time of onset of influx of adult moths. This approach to defining the threshold provides a framework for explicit consideration of uncertainties and also, through the use of multi-attribute loss functions, inclusion of cost factors other than monetary.