An Extension program incorporating biological control into decision-making for management of sweetpotato whitefly in cotton

The Sweetpotato whitefly, (Bemisia tabaci Middle East Asia Minor 1) is a key pest in the Arizona cotton system that reduces lint quality. Whiteflies are currently managed within an Integrated Pest Management framework that involves frequent sampling, action thresholds, and the use of selective chemistries that preserve natural enemy abundance. This program has successfully reduced insecticide use and helped increase yields in Arizona, but uses a pest-centric sampling system that does not explicitly consider natural enemies in decision-making. In this same system, a suite of arthropod predators is known to regulate whitefly populations under certain circumstances. Incorporating the effects of these natural enemies in decision-making has the potential to reduce, delay, or optimize insecticide applications. Based on three years of research we have identified and estimated predator : prey ratios that indicate the level at which biological control functions. Without added sampling costs, pest managers can use these ratios to measure and incorporate biological control into whitefly spray decisions. Our objective is to leverage this research to develop an Extension program that works directly with Pest Control Advisors (PCAs) in the Arizona and California cotton systems. Through a series of dedicated workshops, Extension meetings, and commercial demonstrations we will promote the adoption of predator : prey ratios in decision-making and measure their impacts on whitefly control. Our efforts focus on usability, validation and demonstration while advancing the core IPM concept of Integrated Control, as proposed by Stern et al. (1959).