Optimal Integrated Control of Univoltine Pest Populations with Age Structure

A procedure is presented for calculating optima integration and timing of biological, chemical and cultural methods for control of a univoltine pest population in a random environment. The procedure describes a system of high dimension by two nested models: a stochastic dynamic programming problem with four state variables and a more detailed differential equation model describing the effect of management and weather on population demography and crop yield. A computational algorithm is presented which reduces computation requirements for the population model from about 10¹³ operations to 10⁶ operations for a typical example. Results are presented from the application of the method to control the alfalfa weevil by a combination of insecticide applications, early harvesting, and biological control provided by a parasite.