Honey, Bees, Better Sleep & Memories

April 24, 2010

“A TEASPOON OR TWO of honey before bed insures a restorative sleep,” writes Reese Halter in his informative little book, The Incomparable Honeybee & The Economics of Pollination. “A human liver stores about eight hours of glycogen – an important brain food. If you eat supper at 7 pm, by about 3 am your brain releases a stress hormone called cortisol. Cortisol scavenges the body, melts muscle tissue and converts it into glycogen to feed the brain. When released, cortisol causes the heart to beat faster and raises glucose insulin levels in the blood. Elevated cortisol can lead to obesity, diabetes, coronary disease and autoimmune breakdown. A teaspoon of honey at night fuels the liver with glucose and fructose, which is absorbed slowly – thus providing a restful sleep and preventing the release of cortisol.”

Perhaps honey also helps bees with their sleep?

In the 27 March 2010 Philosophical Transactions B of the Royal Society, researchers Timothy C. Roth and Vladimir V. Pravosudov at the University of Nevada, Reno, and Niels C. Rattenborg at the Max Planck Institute in Germany “examine the ecological relevance of sleep” for “memory/learning and hypothermia/torpor to conserve energy.” Sleep, it seems, is still a somewhat mysterious function. However, sleep in honeybees and other animals lends itself to ecological and experimental study.

Honeybee sleep is not exactly the hottest research topic on the planet at the moment. But that may change as the links between honeybee sleep, pathogen spread, and diseases are further explored. At past Entomological Society of America (ESA) meetings, Barrett Klein, who is finishing his Ph.D. in Ecology, Evolution and Behavior at the University of Texas in Austin, has attracted more attention for his entertaining role in insect art symposia.

At the Biozentrum in Wurzburg, Germany, Klein used an infrared camera to measure temperature changes and map sleep patterns of Carniolan bees (Apis melifera carnica) as they aged and changed tasks over time. Young worker bees progress from cleaning hive cells to nursing to food storage to foraging as they age.

Older forager bees sleep mostly at night, outside of cells, close to the edge of the hive where it is coldest. Younger cell cleaning bees sleep day and night, mostly inside cells where it is warmest. Foraging honeybees are the caste most likely to bring pathogens back to the hive. Thus, sleeping at night in the cold near the edge of the hive away from the warm brood reduces the potential for pathogen spread to the rest of the hive.

In the journal Learning & Memory, researchers in Germany used a web camera to “address the question if sleep in bees, like in other animals, improves memory consolidation.” Indeed, the webcam revealed that sleep deprivation had some negative effects on honeybee memory. At the ESA, Edgar Hernandez of the University of Missouri in St Louis described some of the work with “clock genes” and “clock proteins” playing a role in determining when bumble bees sleep.

With honeybees in trouble due to colony collapse, bumble bees and native bees are getting more attention. Nancy Adamson of Virginia Tech reported to the ESA that the honeybee situation has become so worrisome that the Virginia State Legislature voted to support research “aiming to provide information to Virginia farmers interested in supporting a broad spectrum of pollinators on their crops.” This includes providing harborage and habitat for bumble bees and other native bees.

“North America boasts over 4,000 species of native bees, many of which could serve as crop pollinators,” said Ann Fraser of Michigan’s Kalamazoo College. Native bees and bumble bees can pollinate crops on cloudy days and in cooler weather when honeybees are less active. Indeed, New Jersey and Pennsylvania watermelons are pollinated by 46 native bee species. In New York pumpkin fields, more bumble bee visits means heavier pumpkins, said Cornell’s Derek Artz.

Native bees and bumble bees can also be part of urban renewal. According to Ohio State University’s Scott Prajzner, vacant land within the city centers of Akron and Cleveland now supports community gardens and urban farms. This has boosted populations of native squash bees (Peponapis sp) and long-horned bees (Melissodes sp).

Perhaps we will all sleep better and have a more sustainable food supply by getting back to the basics: Honeybees for honey production, and letting bumble bees and native bees handle more crop pollination.