Aggressive honeybees calm down when exposed to floral odours associated with food rewards, finds a study in Nature Communications. This is not because the floral scents overpower other signals such as alarm pheromones, but because the bees respond more strongly to signals containing information about the value of a food source.
Honeybees communicate with one another via chemical signals, for example by releasing alarm pheromones that alert other members of the hive to a source of danger, resulting in aggressive behaviour once they arrive. However, these aggressive encounters come at a high cost, since stinging always results in death of the bee once the stinger becomes detached in the body of its victim.
Morgane Nouvian and colleagues study how the presence or absence of key floral chemicals influences the aggressive behaviour of honeybees once alarm pheromones have been released. By counting the number of sting attacks elicited by a rotating feather disturbing the bees, they find that the compounds linalool and 2-phenylethanol (both commonly found in floral odours) were able to block the aggressive response elicited by alarm pheromones, as did the scent of lavender.
Crucially, they also show that this response is not due to floral scents masking those of the bees' alarm pheromone, but that the calming effect instead correlates with the extent to which the flower scent represents a valuable food reward. This research provides new insights into the sensory conflicts that coordinate decision-making in bees, and may also have a practical application in helping beekeepers keep their hives calm.