Research on bumble bees may show whether the brain helps determine societal roles
By Beth Luce
The next time a bumble bee buzzes past in pursuit of a sweet-smelling flower, consider this: That bee has a job to do, just like you when you go to the office or clean up after the kids.
You fulfill certain functions in your social group, and so does the bee. The difference is that you choose most of your roles, such as whether to be an accountant or a musician and whether, at home, you’re the one in the family who vacuums or walks the dog.
In bumble bee society, individuals don’t get to pick their jobs, but somehow they know what they are. Some bumble bees are foragers, some clean the nest, others take care of the young. Nobody knows precisely how or why the bees acquire these different jobs, or how an individual’s role might change if circumstances of the nest change. But Robin Foster, associate professor of psychology, means to find out.
Foster, who has studied social insects for about 15 years, is interested in the factors that determine who does what in insect societies and how that might generalize to other social groups, possibly even human societies.
“It’s a pretty big stretch to go from bumble bees to humans,” she notes. She doesn’t study bees with the intent of making generalizations about humans, but there are principles of social organization that seem to apply to both species. For example, in a small group—either insects or people—individuals tend to be generalists, rather than specialists. The larger the organization, the more likely individuals will specialize, and the narrower the specialties. But why?
Foster spent the summer conducting the first phase of pioneer research to determine whether the makeup of the brain has something to do with social organization.
“There has been a lot of research into genetic influences in denoting which bees get which jobs,” Foster explains. Some bees, for example, may be genetically more predisposed than others to notice that the colony’s supply of pollen is running low.
“I think there’s more to task-specialization than just the genetic mechanism, though, and it definitely involves the brain,” Foster says.
She began her experiments by setting up about 20 bumble bee colonies in three groups.
The first set of colonies reside in a shed on the University of Washington campus, where a colleague is helping with the research. The forager bees from these nests must go out and find their own food sources, gather nectar, and return to the nest—a complicated set of tasks.
The second group lives in Foster’s lab on the Puget Sound campus and must travel about 10 feet to artificial flowers spiked with sugar water that Foster has provided. Finding the food and making it back to the nest is less complicated for the forager bees in this group.
In the third group, which is also in the lab, the forager bees have it pretty easy; to find food they only have to walk (they don’t even have to fly) into a box that adjoins their nest.
With the help of sophomore undergrad assistant Joy Gibson, as well as two other assistants at the UW, Foster set up the colonies, glued a number onto the back of each bee, and videotaped them to discover which individuals worked at which tasks. The next step was to identify the most active forager bees and “house bees” that never left the hive, then compair their brains, which are only slightly bigger than two grains of sand. She will be working this fall with another faculty member, neurobiologist Sue Hannaford, associate professor of biology, in dissecting more than 300 bee brains, which is no small job.
“Granted, a bee brain is much simpler than a human brain,” Foster says, “but there is still a great deal of complexity in a tiny amount of space.”
Foster said that examining the brains will keep her busy for the next five to 10 years. Her work is supported by a Martin-Nelson Junior Sabbatical for the fall term and by a grant from the university Enrichment Committee.
Foster speculated on several possible applications of her research, including modeling the relationship between complex behavior, genes, and the brain. Information about how restricting a bee’s normal behavior affects its brain might have parallels to human disability and occupational therapy. Or her research might have implications in studying the neurobiology of learning.
Although much is known about honey bees, Foster said very few people study bumble bees. The fuzzy black, red, and yellow insects live in smaller groups, which are easier to study, and individuals are more likely to shift roles, which suggests neural plasticity, she explains. Worker bumble bees can even become queens if the need arises, something that honey bees cannot do.
And, Foster happily notes, studying bumble bees has a distinct advantage over honey bees for a scientist who’s also a university professor—bumble bees hibernate during the school year. “It fits my teaching schedule perfectly,” she says.