Fighting flesh flies: Ontogeny of aggressive behavior in Sarcophaga crassipalpis

We have determined previously that male flesh flies, under lab conditions, maintain a signficantly greater inter-individual distance among themselves than do females. What are the behavioral interactions that lead to this spacing behavior? Male flesh flies were collected on the day of emergence and kept in individual isolation chambers. Pairs of same-age (1-, 2-, 3-, 4-, and 6-day-old), socially naive flies then were placed in a circular arena and video recorded for 1 hour. The resulting ethogram was used to (1) confirm the existence of aggressive behaviors, (2) determine that the behavioral repertoire, including both aggressive and non-aggressive activites, varies with age, and (3) show that the timing of these ontological changes coincide with the onset of reproduction.