Ever seen honey bees engaging in washboarding?
It's a behavior so named because they look as if they're scrubbing clothes on a washboard or scrubbing their home.
It occurs near the entrance of the hive and only with worker bees. They go back and forth, back and forth, a kind of rocking movement. No one knows why they do it. It's one of those unexplained behaviors they've probably been doing for millions of years.
Bee breeder-geneticist Susan Cobey of the University of California, Davis and Washington State University, has witnessed washboarding scores of times. Last week the unusual behavior occurred on two of her hives at the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis. She hypothesizes that these bees are in the "unemployment line." It's a time when foraging isn't so good, so these bees are "sweeping the porch" for something to do, she speculates.
Emeritus professor Norman Gary of UC Davis Department of Entomology writes about it in his chapter, Activities and Behavior of Honey Bees, in the Dadant publication The Hive and the Honey Bee.
"They stand on the second and third pairs of legs and face the entrance. Their heads are bent down and the front legs are also bent," wrote Gary, who has kept bees for more than six decades. "They make 'rocking' or 'washboard' movements, thrusting their bodies forward and backward. At the same time they scrape the surface of the hive with their mandibles with a rapid shearing movement, sliding over the surface as if cleaning it."
They pick up some material and then clean their mandibles.
Gary thinks that "these rocking movements probably serve as a cleaning process by which the bees scrape and polish the surface of the hive."
Like most people, professor/biologist/bee researcher James Nieh of UC San Diego has never seen this behavior. Nieh, who recently presented at seminar at UC Davis, later commented "It is an interesting behavior that would be particularly fascinating to observe in natural colonies in trees. It does seem to involve some cleaning behavior, although it is possible that bees are depositing some olfactory compound while they are rubbing the surface with their mandibles. We are currently conducting research in my lab on the effects of bee mandibular gland secretions on foraging orientation behavior. A new set of experiments will involve examining the effect of mandibular gland secretions on bee behaviors at the nest. I will definitely consider looking at how this potential pheromone affects washboarding."
We managed to capture the behavior with our Iphone and posted it on YouTube.
It's interesting that of the some 25 research hives at the Laidlaw facility, occupants of two of Cobey's hives exhibited washboarding last week.
So, what are washboarding bees doing? Cleaning their home where pathogenic organisms might congregate, per a theory by Katie Bohrer and Jeffrey Pettis of the USDA-ARS Bee Research Lab?
Or are they just creating "busy work"--"sweeping the porch" for something to do?
It would be interesting to find out!
If you want to take photos of honey bees in flight, do so early in the morning. They don't move as fast and the lighting is to die for.
This morning we stepped out in our yard, steaming coffee in hand, and watched the honey bees foraging among the lavender blossoms. Against the backdrop of red pomegranate blossoms and spring green leaves, they crawled up and down the lavender and then took off for the next blossom.
So smoothly. So effortlessly. So tirelessly.
You don't always have to stop the action with a flash. We took this with a Nikon D700 with a 105mm macro lens. No flash. We set the aperture (f-stop) at 8, the shutter speed at 1/800th of a second, and the ISO at 800.
The blurring of the wings added to the feeling of speed.
Indeed, the honey bees seem a little more frantic now as they rush to bring back nectar, pollen, propolis and water to the hive. With the queen bee laying about 2000 eggs a day now, everyone has to pitch in.
Just call this "The Lavender Blossom Special."
It was a pomegranate kind of day. Red, bright and wonderful.
The papery-thin reddish blossoms in our yard draw both beneficial and pestiferous insects. Honey bees are there for the pollen and nectar; ladybugs are there for the pesky aphids. Occasionally we see another pest, the spotted cucumber beetle (which prefers cucurbits).
The pomegranate, an ancient fruit native to Persia (what is now Iran), is a long-lived tree. Indeed, some pomegranate trees in Europe are more than 200 years old. One in our yard spans 85 years.
Spanish settlers introduced the pomegranate into California in 1769, and today, the state leads the nation in the production of pomegranates. Agricultural statistics show that in 2010, California's San Joaquin Valley alone blossomed with an estimated 22,000 acres of pomegranates. That's about 200 trees per acre.
One of the primary pomegranate varieties is "Wonderful." The honey bees and ladybugs think so, too!
Our yard is filled with such bee friendly plants as salvia, lavender, catmint and rock purslane.
Lately, however, the honey bees have taken a liking to the sugar-water mixture from our hummingbird feeder. Manufacturers' bee guards are meant to deter them but frankly, we rather like attracting both the hummers and the buzzers.
"The bees are hungry," said bee breeder-geneticist Susan Cobey of the University of California, Davis and Washington State University.
We like watching the honey bees gather at the "red fountain" as the sun sets. They buzz excitedly around the feeder, sip what they think is a nectar of the gods, and head back to their hive. Soon more of their sisters arrive to partake.
So, will the honey bees make red honey from the sugar-water mixture in the hummingbird feeder? No. The honeycomb will be tinted red, but it's not honey, said Extension apiculturist Eric Mussen of the UC Davis Department of Entomology. It's syrup. Sugar syrup.
Bee breeder-geneticist Susan Cobey, who holds a dual appointment at the University of California, Davis and Washington State University (WSU), believes that "increasing the overall genetic diversity of honey bees may lead to healthier and hardier bees that can better fight off parasites, pathogens and pests." Just as stock improvement has served the poultry, dairy and swine industries well, the beekeeping industry needs access “to stocks of origin or standardized evaluation and stock improvement programs,” she says.
You can hear her discuss her research on “Importation of Honey Bee Germplasm to Increase Genetic Diversity in Domestic Breeding Stocks" at the UC Davis Department of Entomology seminar from 12:10 to 1 p.m., Wednesday, May 2 in 122 Briggs Hall.
A UC Davis researcher since May 2007, Cobey is a former student of "Father of Honey Bee Genetics" Harry H. Laidlaw Jr., (1907-2003), for whom the UC Davis bee lab is named. She provided practical application to the Robert Page-Harry Laidlaw Closed Population Breeding Program (CPRP) theory in the development of the New World Carniolan line, in its 31st generation and now an industry standard.
"The many problems that currently face the U.S. honey bee population have underscored the need for sufficient genetic diversity at the colony, breeding, and population levels,” wrote Cobey and colleagues Walter “Steve” Sheppard, professor and chair of the WSU Department of Entomology and David Tarpy of North Carolina State University (formerly a graduate student at UC Davis) in a chapter of the newly published book, Honey Bee Colony Health: Challenges and Sustainable Solutions (Contemporary Topics in Entomology).
European colonists brought a small subset of European bees to America before the U.S. Honey Bee Act of 1922 restricted further importation of Old World honey bees to prevent the introduction of the tracheal mite, Acarapis woodi. These early importations represented "a limited sampling of several subspecies," Cobey said.
“The limited foundation stock has been propagated and expanded to establish the existing U.S. beekeeping industry. In addition, the destruction of a once widespread feral population by parasitic mites and the genetic consequences of large scale queen production practices have contributed to reduce genetic diversity in U.S. honey bee populations. “
Cobey is involved in a number of scientific research projects. She and fellow scientists and beekeepers from UC Davis, WSU and the California Bee Breeders' Association are working together to develop and test protocols for the international exchange of honey bee germplasm and to incorporate imported stocks into established U.S. breeding stocks.
Cobey is also involved in a newly formed international group devoted to preserving the Carniolan honey bee. Research that she co-developed was presented in March at the first International Symposium About the Carniolan Honey Bee in Slovenia. The conference drew scientists, researchers and queen breeders interested in the conservation of Carniolan honey bees (Apis mellifera carnica) and collaboration.
Cobey is known globally for her expertise on the instrumental insemination of queen bees; her classes on queen rearing and instrumental insemination attract students from all over the world.
So it's not surprising that she's in high demand as a speaker. Cobey has lectured throughout the United States, Central and South America, South Africa, New Zealand and Australia, and was recently invited to Cuba for the 3rd Latin-American Beekeepers' Meeting and the 4th Cuban Beekeeping Congress.
Come November, Cobey will be a keynote speaker for the Apimondia Symposium on Honey Bee Breeding in Quebec.
If you're unable to attend the Cobey seminar at UC Davis, not to worry. It's scheduled to be videotaped and posted at a later date on UCTV.