In today’s Academic Minute, Dr. Gene Robinson of the University of Illinois at Urbana-Champaign reveals why not all honey bees are mindless drones without individual personality traits.
Gene Robinson is a professor of entomology and Director of the University of Illinois Bee Research Facility at the University of Illinois at Urbana-Champaign. His research group uses the Western honey bee, Apis mellifera, to understand the evolution and mechanisms of social behavior. Robinson has made a wide range of fundamental advances in elucidating the endocrine, neural, and genetic regulation of behavior at the individual and whole-colony levels in honey bees. He holds a Ph.D. from Cornell University.
Dr. Gene Robinson – Bees and Individual Personality
People used to think that the honey bee hive was a highly regimented colony of interchangeable workers, most of them doing more or less the same tasks. Now, however, we have learned that individual honey bees actually differ in their desire or willingness to perform certain tasks for the hive. Some bees, for example, are much more likely than others to scout for new patches of flowers. This unusual trait – less than 15 percent of the honey bees in a colony act as scouts – involves striking out into the unknown to find a resource that is vital to the hive.
When we looked at what was going on in these adventurous bees’ brains, we found patterns of gene activity in molecular pathways known to be associated with thrill-seeking in humans. In humans, thrill-seeking is a component of personality. We wondered whether some honey bees, too, might have adventurous personalities.
A personality trait is a behavioral tendency that persists in different contexts, so we decided to test whether the food scouts also were more likely to be adventurous in a different context: scouting for a new nest site. We found that nest scouts were on average more than three times as likely as their peers to also become food scouts.
Some of the molecular pathways we identified as more active in the honey bee scouts’ brains are known to be involved in novelty-seeking and responding to reward in other animals, including humans. To test whether the brain chemicals involved in these pathways actually caused the novelty seeking, we subjected the bees to treatments that would increase or inhibit these chemicals in the brain. We found that treatments with two potent signaling molecules, glutamate and octopamine, increased scouting in bees that had not scouted before. Blocking another brain signaling molecule, dopamine, decreased scouting behavior.
These results demonstrate that novelty seeking in humans and other vertebrates has parallels in an insect.