Mating behavior and sound production in harvester ants (Pogonomyrmex, Formicidae)

1. Stridulation sound production was investigated in sexuals of the harvester ants Pogonomyrmex barbatus, P. rugosus and P. maricopa of the SW United States during preparation and take-off for nuptial flight, as well as during mate selection, copulation and postcopulatory behavior on the mating leks, and competition in the process of colony foundation. 2. The structures of the stridulatory organs and the characteristics of air-borne and of substrate-borne signals of the three species are described (Tables I and II). There are no prominent interspecies differences in the distress signals. 3. Stridulatory communication is not involved in the control of preflight warm-up and take-off for the nuptial flight. Further, it does not play a role in the selection of species and sex of the mates, or in the competition among males for females. 4. Females of all species stridulate regularly when prevented by males from leaving the lek after several copulations. It is assumed that this «female liberation signal» communicates the female's non-receptivity to approaching males and makes them let the female go. 5. Founding queens stridulate regularly when competing for founding burrows, especially if physical fights are involved. Nevertheless, our experimental results do not substantiate a communicatory function for this behavior.