Contextual Chemical Ecology: Male to Male Interactions Influence European Corn Borer¹ Male Behavioral Response to Female Sex Pheromone in a Flight Tunnel

The responses of European corn borer, Ostrina nubilalis (Hübner), males in a flight tunnel to sex pheromone, [11-tetradecenyl acetate (97:3, Z:E)] was dependent upon the context in which the males were exposed to the stimulus. Males, held individually in isolation before being exposed to pheromone, flew upwind in the pheromone plume and landed on the pheromone source significantly more often than males caged with other males before exposure to the pheromone. When groups of males were simultaneously exposed to female sex pheromone, they responded, on a permale basis, with significantly more upwind flights to pheromone and intense behavior near the pheromone source than did males exposed to the pheromone individually. Heightened intensity of male response in group flight was independent of whether the males were individually isolated or caged with other males before being exposed to the pheromone. The enhanced behavioral output of males responding to pheromone in groups may represent an evolutionary adaptive advantage in instances where several males are simultaneously pursuing a single calling female.