When Worker Bees Get a Promotion

The New York Times/Science     By James Gorman   September 8, 2014

The honeybee hive would not seem to be the place to look for individuality, flexibility in job duties and social mobility. But by using new techniques for analyzing bee behavior, researchers at the University of Illinois at Urbana-Champaign, recently found that the life of a bee is less rigidly determined than had been thought.

They first discovered that an elite 20 percent of foragers do 50 percent of all the foraging, and then found that membership in this group was surprisingly flexible. When the elite bees were removed from the hive, less hard-working bees raised the level of their activity and a new elite emerged.

Gene E. Robinson, the director of the Institute for Genomic Biology at the university, said he and other researchers set out to look at the behavior of bees in a new way partly because of “an increasing appreciation of the role of the individual in social insects.”

Teasing out the differences in individual levels of foraging activity required some new tools, both for observing the bees and for analyzing the data.

To work on the first part of the problem, Dr. Robinson said, Paul Tenczar, a retired computer entrepreneur and enthusiastic citizen scientist, joined the lab. He worked with scientists to devise a kind of E-ZPass system for bees involving tiny electronic ID tags, entry and exit tubes for a hive, and laser scanners to track the bees as they passed through the tubes (think toll plazas).

But even with the technology functioning at a high level to track the bees’ activity, analytical tools had to be developed to understand and interpret the data, Dr. Robinson said.

The results, which the team of scientists reported in the September issue of Animal Behaviour, showed first that there was an elite group among the foraging bees.

Then, by removing those top performers, the team found that other bees took their place. It was, said Dr. Robinson, “elitism with a populist streak.”

They also found, in mining the data, that over the life of an individual bee, patterns of foraging activity fluctuated and that individual bees had different life histories.

The approach to studying behavior using so-called big data is like that used by Internet companies to track people’s shopping behavior. Such new techniques, Dr. Robinson said, showed the power of “massive amounts of surveillance” to “reveal previously inaccessible data about individual behavior” in insects. And just when bees thought Facebook had ignored them.

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Scientists Track Gene Activity When Honey Bees Do and Don't Eat Honey

The following is brought to us by ABJ Extra    July 18, 2014  

CHAMPAIGN, Ill. — Many beekeepers feed their honey bees sucrose or high-fructose corn syrup when times are lean inside the hive. This practice has come under scrutiny, however, in response to colony collapse disorder, the massive -- and as yet not fully explained -- annual die-off of honey bees in the U.S. and Europe. Some suspect that inadequate nutrition plays a role in honey bee declines.

In a new study, described in Scientific Reports, researchers took a broad look at changes in gene activity in response to diet in the Western honey bee (Apis mellifera), and found significant differences occur depending on what the bees eat.

The researchers looked specifically at an energy storage tissue in bees called the fat body, which functions like the liver and fat tissues in humans and other vertebrates.

"We figured that the fat body might be a particularly revealing tissue to examine, and it did turn out to be the case," said University of Illinois entomology professor and Institute for Institute for Genomic Biology director Gene Robinson, who performed the new analysis together with entomology graduate student Marsha Wheeler.

The researchers limited their analysis to foraging bees, which are older, have a higher metabolic rate and less energy reserves (in the form of lipids stored in the fat body) than their hive-bound nest mates -- making the foragers much more dependent on a carbohydrate-rich diet, Robinson said.

"We reasoned that the foragers might be more sensitive to the effects of different carbohydrate sources," he said.

The researchers focused on gene activity in response to feeding with honey, high-fructose corn syrup (HFCS), or sucrose. They found that those bees fed honey had a very different profile of gene activity in the fat body than those relying on HFCS or sucrose. Hundreds of genes showed differences in activity in honey bees consuming honey compared with those fed HFCS or sucrose. These differences remained even in an experimental hive that the researchers discovered was infected with deformed wing virus, one of the many maladies that afflict honey bees around the world.

"Our results parallel suggestive findings in humans," Robinson said. "It seems that in both bees and humans, sugar is not sugar -- different carbohydrate sources can act differently in the body."

Some of the genes that were activated differently in the honey-eating bees have been linked to protein metabolism, brain-signaling and immune defense. The latter finding supports a 2013 study led by U. of I. entomology professor and department head May Berenbaum, who reported that some substances in honey increase the activity of genes that help the bees break down potentially toxic substances such as pesticides.

"Our results further show honey induces gene expression changes on a more global scale, and it now becomes important to investigate whether these changes can affect bee health," Robinson said.

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