Sound and vibrational signals in the dance language of the honeybee, Apis mellifera

Summary

Sound and vibrational signals exchanged by honeybees during the performance of wagging dances were simultaneously recorded by means of a microphone and a laser vibrometer. Previous descriptions of the 280-Hz sounds emitted by the dancing bee were confirmed, and no vibrational (substrate-borne) component could be detected. In contrast, the 320-Hz “begging signals” (emitted by bees following a dancer and used as a request for food samples from the dancer) do vibrate the comb with peak-peak displacement amplitudes up to 1.5 μm. Artificially-generated comb vibrations of sufficient amplitude cause bees standing on the comb to “freeze”. The threshold for obtaining a detectable freezing response was measured for frequencies between 100 Hz and 3 kHz. At 320 Hz it is just below the amplitude of the natural begging signals. Thus it seems likely that these signals are received by the bees as vibrations of the comb. The propagation velocity of waves, damping, and mechanical input impedance of honeybee combs were studied. These results, combined with the observed amplitudes of the begging signals, support the assumption that the begging signals are generated with the flight muscles. The begging signal propagates as a bending wave. The attenuation of the begging signal with distance is relatively small, so the amplitude of the signal probably needs to be carefully adjusted in order to restrict the range of the communication.