SCOTT, M.P.: Hormonally-Mediated Cues for Mate Recognition by Burying Beetles

Individual recognition of a mate or a past enemy has seldom been demonstrated in invertebrates. When recognition cues have been identified, they are usually found to be based on social status or family membership. Burying beetles rear a brood on an unpredictable resource and as a pair, they must defend their young and the resource from conspecific intruders. Thus a mechanism for the identification of a non-mate is necessary for the appropriate aggressive response. Burying beetles appear to match the hormonal state of an intruder to a template based on that of their mate. Unknown individuals at the same reproductive stage were accepted as mates. In addition, aggression by males was significantly reduced towards unknown non-breeding females treated with juvenile hormone or its analogue, methoprene. When mating behavior was examined, the “acceptance threshold” for the comparison of the unknown individual to the template was lower than for aggressive behavior. Males were more likely to mate or attempt to mate with non-breeding, breeding, or treated strangers than with their own mate, as long as trial with the mate preceded the trial with the stranger. Aggression toward unknown non-breeding females treated with an extract of the mate’s cuticular hydrocarbons was reduced. Thus we conclude that recognition cues are provided by contact pheromones.