Honeybees Fight Colony Collapse Disorder: Honey is Medicine for Bees

Honeybees are in trouble. Their colonies are collapsing across the United States as thousands of insects go missing and die. Now, researchers trying to find a way to help these bees may have found part of the solution. They've discovered that the honeybee diet, including honey, influences the insects' ability to withstand harmful conditions.

Researchers have long suspected that Colony Collapse Disorder (CCD) is caused by a variety of factors. These include everything from pests and pathogens to pesticides. Despite knowing what might cause the condition, bees continue to disappear.  On average,more than 30 percent of honeybees vanish each spring. Yet this year, the disappearing bees have reached a new level. More than half of all the honeybees in the U.S. have died almost at once.

In order to investigate this phenomenon and learn more about honeybees in general, researchers decided to examine the insects' diet. Many organisms use a group of enzymes called cytochrome P450 monooxygenases to break down foreign substances such as pesticides and compounds found naturally in plants, known as phytochemicals. However, honeybees have relatively few genes dedicated to this detoxification process in comparison to other insects.

In order to understand exactly which of the P450 genes in honeybees are used to metabolize constituents of pesticides and their natural diet, the researchers fed bees a mixture of sucrose and powdered sugar. Called bee candy, this substance was then mixed with different chemical components in extracts of honey. In the end, they identified p-coumaric acid, a major component in honey, as the strongest inducer of the detoxification genes.

"We found that the perfect signal, p-coumaric acid, is in everything that bees eat--it's the monomer that goes into the macromolecule called sporopollenin, which makes up the outer wall of pollen grains," said May Berenbaum, the study leader, in a news release. "It's a great signal that tells their systems that food is coming in, and with that food, so are potential toxins."

So what does this mean exactly? The p-coumaric acid turns on genes that detoxify substances. In addition, it can turn on honeybee immunity genes that code for antimicrobial proteins. Because many beekeepers feed their bees honey substitutes such as high-fructose corn syrup or sugar water, they may be discouraging the "switch" that turns on genes that can help bees.

"If I were a beekeeper, I would at least try to give them some honey year-round," said Berenbaum in a news release. "Because if you look at the evolutionary history of Apis mellifera, this species did not evolve with high fructose corn syrup."

The findings are published in the journal Proceedings of the National Academy of Sciences.