Effects of Female fruit-marking Pheromones on Oviposition, Mating, and Male Behavior in the Neotropical Species Rhagoletis conversa Bréthes and Rhagoletis brncici Frías (Diptera: Tephritidae)

Sex pheromones produced by females of Rhagoletis conversa Bréthes and Rhagoletis brncici Frías are deposited on the surface of fruits after the eggs are laid. These pheromones repel other females, preventing repeated oviposition on the same fruit. They also attract males, thus assisting mating. Observations were made on wild populations, and cross-species behavioral tests were performed on males. The pheromone released by females was significantly more attractive for males of the same species. The two species showed remarkable differences in mating behavior, in the duration of oviposition, and in the number of circuits made around the fruit after eggs were laid. A morphological analysis of flies collected from their respective host plants indicated great host fidelity and the reproductive isolation of the two species. Possibly, the specific male-arresting effect of this pheromone was important for the sympatric speciation and evolution of these sibling species.