Asian hive bees, Apis cerana, modulate dance communication in response to nectar toxicity and demand

Some nectars, such of that of the thunder god vine, Tripterygium hypoglaucum, contain alkaloids that are mildly toxic to honeybees, Apis spp. Given a choice, foragers prefer nontoxic honey to that of T. hypoglaucum, but only if there are no alternative nectar sources. Here we show that foragers of the Asian hive bee collecting T. hypoglaucum honey modulate their recruitment dances depending on the availability of alternatives. When alternative nectar sources were available, dancers decreased the frequency of waggle dances and increased the frequency of tremble dances. Furthermore, the waggle dances were less precise than usual. These changes are likely to reduce recruitment. By contrast, when there were no alternative nectar sources available, foragers collecting T. hypoglaucum honey performed near-normal dances. Because dance behaviour is dependent on the alternative food sources available, changes in the beesʹ behaviour is probably not due to the nectarʹs toxicity per se. We conclude that modulation of in-hive communication serves to protect the colony from death caused by the collection of high quantities of toxic food while preventing starvation when no other food is available.