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)

Abstract

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.

Electrophysiological Responses of Bactrocera kraussi (Hardy) (Tephritidae) to Rectal Gland Secretions and Headspace Volatiles Emitted by Conspecific Males and Females

“…For example, in Bactrocera oleae , sex pheromones are produced by female flies [ 9 , 10 ], while males produce a compound that only acts as a close-range attractant for females [ 11 , 12 ]. Females of Rhagoletis coversa and R. brncici deposit fruit-marking pheromones that also attract males for mating [ 13 ]. It is likely that the historical focus on male-produced compounds has led to an underestimation of the importance of female-produced compounds in fruit fly chemical ecology; both sexes need to be studied for a comprehensive understanding of chemical communication.…”