A control theoretic analysis of the cotton aphid: an economics approach

The cotton aphid is an important pest affecting the profitability of cotton production. We study the problem of the optimal timing of pesticide application to control the aphid. The problem is complicated by the presence of a significant predator insect. The predator serves as a natural control of the aphid and is adversely affected by application of pesticide. Observation of the system is costly. We determine optimal state dependent rules for application of pesticide. We show that the first application of pesticide is a switching time between two dynamic systems.