The Slow the Spread (STS) Project is a large IPM project directed at the gypsy moth. The project, under the aegis of the US Forest Service, involves several administrative agencies at both state and federal levels. Participating states include Indiana, Illinois, Kentucky, Michigan, North Carolina, Ohio, Virginia, West Virginia, and Wisconsin.

• Demonstrate that new and current technology can slow the rate at which gypsy moth populations are currently spreading
• Assess the technological, economic, ecological, and environmental viability of implementing an operational STS program.
• Integrate STS technology into a national strategy for suppression of the gypsy moth.

While traditional approaches to gypsy moth management address potentially defoliating populations occuring in generally infested areas, the STS project focuses on populations in the area between that of general infestation and generally uninfested. In this transition zone, populations are low and somewhat discontinuous. Male moths are the primary population indicators, and other life stages are rarely found. The project attempts to meet its goals by conducting intensive monitoring with pheromone-baited traps in order to detect isolated or low-level populations in the transition zone. Although all available tactics to control gypsy moth populations will be considered, emphasis is placed upon the most environmentally benign tactic which meets management objectives.

The STS Project is composed of two types of management areas: the Action Area, where STS management strategies are applied, and the Evaluation Area, where normal state and federal management strategies are maintained. Data from the Evaluation Area, along with data from surrounding state gypsy moth surveys, will be used to assess the efficacy of STS management strategies in the Action Area. Intensive monitoring within the Action Area is the foundation of the project and provides the trap catch data used in a decision-making algorithm to determine the appropriate management activities.