The beet armyworm pheromone dispenser, Yotoh-con-S, was evaluated for its ability to inhibit mate location and subsequent population growth of beet armyworm in head lettuce. Pheromone dispensers were ineffective at reducing beet armyworm populations the under high population pressure. Under low beet armyworm pressure, pheromone dispenser did significantly reduce beet armyworm populations, but not to the point where insecticide applications could be eliminated.