Backyard Orchard News
The "honey bee reproductive ground plan" hypothesis that originated two dec
Page, emeritus professor of entomology at UC Davis and now founding director of the School of Life Sciences at Arizona State University, and his collaborator Gro Amdam, are featured in the Oct. 23rd edition of Science, a publication of the American Association for the Advancement of Science.
Writing in the behavior ecology section in an article headlined, "Sex and Social Structure," journalist Elizabeth Pennisi related that the scientists' research "has shown that reproductive traits help shape a honey bee worker's role in life and that ovaries are active players in the process-even if they play little role in reproduction in worker bees."
The specialized tasks "have their basis in what Amdam and Page call a reproductive ground plan," she wrote. Their work has provided a framework and tools to study division of labor, which now "converges on two genes that may explain both ovary size and behavior."
Page and Amdam, an associate professor in the School of Life Sciences and Norwegian University of Life Sciences, believe that genes and hormones likely control social roles as well as longevity.
Their research centers on the role of the ovary in honey bee colonies, and how the worker bees partition the labor of the colony with duties that include rearing young bees, constructing the nest, foraging for pollen and nectar, and processing the food.
Page, a pioneer in the field of evolutionary genetics and social behavior of bees, has long marveled at how highly social bees are. Worker bees, or infertile females, instinctively divide up their roles to run the hive, freeing the queen to lay eggs.
The worker bees serve as nurse maids, nannies, royal attendants, architects, builders, foragers, guards and undertakers.
But why are some colonies high-pollen collectors and hoarders, while others aren't?
His research on high and low pollen hoarding strains that began two decades led to the "reproductive ground plan" hypothesis. Page continues to keep his specialized bee stock, managed by bee breeder-geneticist M. Kim Fondrk, at UC Davis.
This is exciting research.
As Page told us: "The reproductive ground plan research is integrating developmental biology into insect sociobiology. It is completing the synthesis by looking for the signatures of levels of selection above the organism, at the level of the genes, physiology, and embryogenesis. It is substantiating the superorganism."
UC Davis is the hub for the development and maintenance of the high and low pollen hoarding strains of bees "that have been fundamental in testing the reproductive ground plan hypothesis and understanding how selection on colonies affects different levels of biological organization from genes to societies," he said.
Page, who received his doctorate in entomology from UC Davis, retired from UC Davis in 2004 to develop the School of Life Sciences in the College of Liberal Arts and Sciences at Arizona State University.
Page and Amdam are the co-principal investigators on a federally funded project directed by UC Davis entomology professor James R. Carey. Carey directs the Biodemographic Determinants of Lifespan, a National Institutes of Health/National Institute of Aging-funded program involving scientists from UC Davis, UC Santa Barbara, UC Berkeley, Stanford and seven other academic institutions in the United States, the United Kingdom, and Greece.See more information on the UC Davis Entomology Web site.
Hives of International Interest
There's something so magical and captivating about the metallic green sweat bee.
Shouldn't it be yellow? No.
Is it a bee? Yes.
Does it attract attention? Definitely.
We spotted this male green sweat bee, Agapostemon texanus, on what is commonly known as a Seaside daisy, Erigeron glaucus Wayne Roderick. This is a lavender-petaled flower with a yellow center.
The location: the Mostly Natives Nursery, Tomales.
Wayne Roderick (1920-2003) who developed many cultivars, served as head of the California Native Section at the UC Berkeley Botanical Garden for some 24 years. He retired as director of the East Bay Regional Parks Botanic Garden at Tilden.
His name is legendary among horticulturists.
So is the Erigeron glaucus Wayne Roderick--especially when a metallic green sweat bee visits it.
Green Metallic Sweat Bee
The Eyes Have It
Chemical ecologist Walter Leal, professor and former chair of the UC Davis Department of Entomology, and his postdoctoral researcher Zain Syed have done it again.
In August of 2008, they discovered the secret mode of the insect repellent, DEET. In groundbreaking research published in the Proceedings of the National Academy of Sciences (PNAS), they found that DEET doesn't mask the smell of the host (that would be you and me), nor does DEET jam the insect's senses.
Mosquitoes CAN indeed smell DEET. They avoid it because they don't like the odor.
Then on Monday, Leal and Syed published more groundbreaking research, also in PNAS. They identified the dominant compound that attracts Culex mosquitoes to both birds and humans.
It's a compound called nonanal, naturally produced in birds and humans. This not only explains the host shift from birds to humans, but paves the way for key developments in mosquito and disease control.
Infected Culex mosquitoes transmit life-threatening diseases, including West Nile virus. Since 1999, the Centers for Disease Control and Prevention has recorded 29,397 human cases and 1,147 fatalities in the United States alone.
“Nonanal is how they find us,” Leal said. “The antennae of the Culex quinquefasciatus are highly developed to detect even extremely low concentrations of nonanal.”
Researchers from throughout the country this week praised their work.
Yale University professor John Carlson, a leading scientist in insect olfaction, described the study as “exciting with important implications for the intriguing question of how mosquitoes find the humans they bite.”
“Leal and Syed have identified a human odor that is detected with great sensitivity by the antennae of mosquitoes that transmit West Nile virus,” Carlson said. “In addition to its scientific interest, the study may have important practical applications in the control of these mosquitoes and the diseases they carry.”
Chemical ecologist Coby Schal, a professor at North Carolina State University, described the research as representing “some of the best research on insect olfaction that I have ever read. By combining trapping experiments in the field with careful characterization of the response profiles of antennal and maxillary sensilla of Culex mosquitoes, Syed and Leal show not only that the combination of carbon dioxide and nonanal is an important beacon for blood-seeking mosquitoes, but also that a large fraction of the sensilla on the mosquito’s nose (antennae) is dedicated to the detection of nonanal at incredibly low concentration.
“Such high sensitivity of olfactory receptor neurons to nonanal – rivaling the response characteristics of pheromone responsive neurons – suggests that nonanal has played an important role in the evolution of host-finding and host-preferences in Culex mosquitoes,” Schal said. “This is a truly exceptional achievement by the outstanding Syed/Leal team, but in step with their previous outstanding contributions on a wide range of arthropods.”
More information on the Leal lab research is on the Department of Entomology Web page.
Leal, a newly elected Fellow of the Entomological Society of America (he's one of 10 entomologists to be so honored this year) and Syed, named one of the top post-doctoral researchers at UC Davis this year, have indeed done it again.
When you think of all the havoc that mosquito-borne diseases have wreaked, this is the kind of research that definitely deserves a round of applause.
Dr. Leal and Dr. Syed are a highly efficient and effective SWAT team.
Walter Leal and Zain Syed
A bee is a bee is a bee?
Poet Gertrude Stein ("a rose is a rose is a rose") could have said that.
True, there's only one species of honey bee in the United States--Apis mellifera, the Western or European honey bee--but there are several races.
The "gold standard" is Apis mellifera ligustica, also known as the Italian honey bee, the most common bee in America. It's basically your yellow or golden bee.
But among the other popular races is Apis mellifera carnica, aka the Carniolans or "Carnies," a darker bee. It is primarily darkish gray.
We spotted both of them last weekend sharing a lavender--the blond Italian bee on one side and the darker Carniolan bee on the other.
Author Richard E. Bonney writes in his book, Beekeeping: A Practical Guide: "For the most part, they (the races) are the result of evolution in geographic isolation (Italians on the Italian peninsula, for instance) where the specific climate and vegetation influenced their development over the ages. Each race has specific traits that relate to the geographic origin of that race."
At UC Davis, bee breeder-geneticist Susan Cobey, manager of the Harry H. Laidlaw Jr. Honey Bee Research Facility, focuses her research on identifying, selecting and enhancing honey bee stocks that show increasing levels of resistance to pests and diseases. In the early 1980s, Cobey developed her New World Carniolans stock by back-crossing stocks collected from throughout the United States to create a more pure strain.
“Over time, it has proven very productive, winter hardy, well-tempered and more resistant to pests and disease,” says Cobey, who teaches advanced courses on queen bee rearing and queen bee insemination, drawing students from throughout the world.
Genetic diversity, the raw tools for selection, is critical “in maintaining colony fitness and resisting pests and diseases,” she notes.
No matter the races, the honey bees still race for the lavender.
And the other bee friendly plants...
The Italian and the Carniolan
Fran Keller, a doctoral candidate in entomology, and Nanase Nakanishi, a senior animal science major, teamed to create a "Save the Bees" T-shirt, spotlighting the Harry H. Laidlaw Jr. Honey Bee Research Facility and the adjacent Häagen-Dazs Honey Bee Haven.
The newly planted haven is a half-acre bee friendly garden designed to provide a year-around food source for honey bees and an educational experience for human visitors. By spring, it will be well-established and in full bloom.
And the T-shirt? Nakanishi served as the artist, and Keller, the designer.
Nakanishi, a Bohart student employee for the past three years, plans to become a veterinarian.
Keller's Ph.D. work involves tenebrionids or darkling beetles. She studies with major professor Lynn Kimsey, director of the Bohart and professor and vice chair of the Department of Entomology.
In her "spare" time, Keller has created a number of insect posters and T-shirts, all available at the museum.
The bee shirt, which comes in black or yellow, is receiving scores of accolades. "Cute!" is one of them.
The front says "Save the Bees" and is inscribed with the Laidlaw facility name. The back features a photo (taken by yours truly) of a newly emerged bee tucked inside the line drawing of a hive. It is lettered with "Follow me to the Honey Bee Haven Garden!"
Keller said the shirts will sell for $20 for adults and $15 for youths, and range in size from 2XL to small for adults, and XS to large for youths.
All proceeds are earmarked for honey bee research at UC Davis. The shirts are available at the Bohart Museum, 1124 Academic Surge, UC Davis campus, or by accessing the Bohart Web site.
Saving the Bees