Phase reversal of vibratory signals in honeycomb may assist dancing honeybees to attract their audience.
Forager honeybees dancing on the comb are able to attract dance-followers from distances across the comb that are too remote for tactile or visual signals to play a role. An alternative signal could be the vibrations of the comb at 200-300 Hz generated by dancing bees but which, without amplification, may not be large enough to alert remote dance-followers. We describe here, however, an unexpected property of honeycomb when it is subjected to vibration at around 200 Hz that would represent an effective amplification of the vibratory signals for remote dance-followers. We find that, at a specific distance from the origin of an imposed vibration, the walls across a single comb cell abruptly reverse the phase of their displacement and move in opposite directions to one another. Behavioural measurements show that the distance from which the majority of remote dance-followers are recruited coincides with the location of this phase-reversal phenomenon relative to the signal source. We propose that effective signal amplification by the phase-reversal phenomenon occurs when bees straddle a cell across which the phase reversal is expressed. Such a bee would be subjected to a situation in which the legs were moving towards and away from one another instead of in the same direction. In this manner, remote dance-followers could be alerted to a dancer performing in their vicinity.
Tautz
J
J
Biozentrum, Zoologie II, Am Hubland, 97074 Würzburg, Germany. tautz@biozentrum.uni-wuerzburg.de
Casas
J
J
Sandeman
D
D
D000819:Animal Communication; D000818:Animals; D001516:Bees / Q000502:physiology*; D001522:Behavior, Animal; D006722:Honey; D009043:Motor Activity; D014732:Vibration