Insect communities are well known to exhibit social behavior, often accomplishing in groups extraordinary tasks of building and cooperation far disproportionate to their individual size and brainpower.
One such insect community—bees—has been in decline for nearly a decade. The reasons for bees’ population decrease are unclear, but scientists have pointed to viruses, habitat loss, climate change, and extensive pesticide use as potential causes. The danger of this decrease is not exclusive to bees: the mass deaths of such prolific pollinators put the health of food crops at risk, too. And along with risking global food supply, bee death threatens many research programs on the fascinating and complex arrangement of insect social life—research that informs human society in many ways.
Only a few kinds of bees are social, said Gene Robinson, director of the Bee Research Facility at the University of Illinois, Urbana-Champaign. Though all are pollinators to some extent, the more social bees are those that pollinate many different kinds of plants, including many of the crops humans eat.
Those bees evolved social mechanisms to coordinate their activities, including labor-sharing and extensive communication. Those mechanisms are necessary, Robinson said, because it’s hard to derive a community’s nutrition singly from plants.
“If you could follow them, you would follow them back to the hive. They live with about 40,000 other individuals. They live with a queen. They live with a generation of baby bees, the brood. And all of them are interacting constantly in order to be able to make a living in a very complex world.”
This cooperation is essential not only to bees’ survival, but to ours, said James Carrington, president of the Donald Danforth Plant Science Center. One-third of all the food we eat is the result of insect pollination, adding up to an agricultural value of $29-30 billion a year. Without bee pollination, almonds, peaches, oranges, sunflowers, blueberries, squash, and scores of other crops would see significant decline.
It is to our own benefit, then, to attempt to understand how bees work the way they do, Robinson said.
“Bees are unique in that they are important for their own sake—so, what we learn about the bee brain and its behavior can be applied to the agricultural context,” Robinson said—“and also, they serve as a model for understanding social behavior in general.”
Honeybees have tiny brains, he explained, that nonetheless produce significantly intricate—and recognizable—behaviors. “It’s a grass seed with a million neurons; our brain is billions and billions of neurons.”
But in that grass seed are genes that cause bees to respond to social challenges and threats. These genes have also been found in other species, including mice and stickleback fish. Robinson said these kinds of discoveries are important in the treatment of human mental illnesses in which systems of threat identification and reaction go awry.
Those genes responsible for honeybees’ social lives also contribute in some way to the species’ apparent decline. “Because the colony works in such an integrated and intricate manner, where the actions of some bees affect the other bees, [stress] puts a demand on the entire colony until you finally get a crash in the population.”
Robinson was referring to colony collapse disorder, a catch-all term for a collection of losses in bee population. When the disorder first became known, Robinson said, it was because bees appeared to be disappearing—whole hives vanishing in the space of months or years.
Now, science has a better understanding of what may be causing bees’ decline. It’s a combination of factors including pesticides, parasites, pathogens, and poor nutrition. Analyses of honey and beeswax in abandoned hives have found chemicals in proportions harmful to bees.
“Nature has a bounty, and it’s very important to pay attention to different species,” Robinson said. Without that attention, humanity may suffer not only a loss of food crops but a loss of insight into our own strange, social behaviors.
Danforth Plant Science Center Presents “Understanding the Roots of Social Life"
- Thursday, August 27, 2015
- 6:00 p.m.; reception at 5:15 p.m.
- AT&T Auditorium, Danforth Plant Science Center
- 975 N. Warson Rd, St. Louis, Missouri 63132
St. Louis on the Air discusses issues and concerns facing the St. Louis area. The show is produced by Mary Edwards and Alex Heuer and hosted by veteran journalist Don Marsh. Follow us on Twitter: @STLonAir.