- Author: Kathy Keatley Garvey
There's a way for a bear to outsmart a fox.
A teddy bear bee, that is.
We just witnessed a male Valley carpenter bee, Xylocopa sonorina, aka "the teddy bear bee," buzz up to a patch of foxgloves, Digitalis purpurea.
Then he engaged in the foraging behavior known as nectar-robbing. That's when a carpenter bee or bumble bee drills a hole at the base of the corolla--or finds a hole already drilled--and "robs" the nectar, bypassing the flower's reproductive parts that lead to pollination.
Hey, I'm not going through the front door! I'm not! I'm taking the back door.
We usually see female Valley carpenter bees drilling the holes and robbing the nectar. This time, though, it was a male. The late Robbin Thorp, UC Davis distinguished emeritus professor of entomology, always referred to the males as "teddy bear bees," adding "boy bees don't sting."
This particular teddy bear lingered a bit, sipped some nectar, and then took flight.
That's how a "bear" outsmarts a fox.
By the way, sexual dimorphism is pronounced in X. sonorina. The male is a green-eyed blond, while the females are solid black.
In our garden, other plants popular for nectar robbing include the salvias, ‘Hot Lips' Sage (Salvia ‘Hot Lips'), and California fuchsia (Epilobium canum). Sometimes you'll see a honey bee following a carpenter bee or bumble bee around to gain easy access to the nectar. She "knows the drill."
Scientists have known about nectar-robbing for more than two centuries. German naturalist Christian Konrad Sprengel observed bumble bees perforating the corollas of flowers as early as 1793, according to Wikipedia. Sprengel recorded this phenomenon in his book, The Secret of Nature in the Form and Fertilization of Flowers Discovered. Charles Darwin observed nectar robbing (by bumble bees) in 1859 and published his observations in his book The Origin of Species.
- Author: Kathy Keatley Garvey
Have you ever pulled up a chair in your garden and watched honey bees foraging?
They are so intent on their "bees-ness" that they don't know you're there. It's a great opportunity to photograph them.
Sometimes, if you're lucky, they'll buzz over your head on their way back to their colony, and you'll see:
- The three main body parts: head, thorax and abdomen
- The two pairs of wings
- The three pairs of legs
- The pair of antennae
Such was the case in Vacaville this week when we were watching honey bees forage in our African blue basil, a bee magnet that we plant annually. We first learned of African blue basil, (Ocimum kilimandscharicum × basilicum 'Dark Opal'), through Gordon Frankie, UC Berkeley professor and the late Robbin Thorp, distinguished emeritus professor of entomology at UC Davis. They co-authored the book, California Bees and Blooms: a Guide for Gardeners and Naturalists (Heyday Books) with Rollin Coville and Barbara Ertter, also affiliated with UC Berkeley.
Want to know more about honey bees? Be sure to read the newly published The Art of the Honey Bee; Shaping the Environment from Landscapes to Societies (Oxford University Press) by noted bee geneticist and biologist Robert E. Page Jr., who maintains strong ties to UC Davis and Arizona State University (ASU). Also learn about honey bee anatomy on ASU's web page, "Ask a Biologist."
Page, who holds a doctorate in entomology from UC Davis, is a former chair of the UC Davis Department of Entomology. In 2004, Arizona State University (ASU) recruited him for what would become a series of top-level administrative roles. He advanced from director of the School of Life Sciences to dean of Life Sciences; vice provost and dean of the College of Liberal Arts and Sciences; and university provost. Today he holds the titles of provost emeritus of ASU and Regents professor emeritus, as well as UC Davis department chair emeritus, professor emeritus, and UC Davis distinguished emeritus professor.
Tool Kit
Did you know a bee has a tool kit? Page lists the tool kit in his book, The Art of the Bee: a compass, an odometer and a path integrator.
'As 'central place foragers,' bees fly out from the nest site and explore the surrounding environment in search of food resources," writes Page, renowned for his research on honey bee behavior and population genetics, particularly the evolution of complex social behavior. "They return to the nest with the resources they collect. To do this, they need to be able to navigate out and find their way back. To aid them, they have a toolkit of navigation mechanisms."
One tool in their tool kit is their internal compass that depends on the location of the sun.
"As light from the sun passes through the atmosphere, it becomes polarized," Page writes. "The pattern of polarized light in the sky depends on the angle of the sun relative to where you are looking. Bees have special sensors in their eyes for detecting the polarized light patterns. On cloudy days, they can't see the sky; but they can still locate the sun using ultraviolet light detectors. Ultraviolet light penetrates cloud cover, allowing bees to use the location of the sun as a navigational marker. With heavy clouds, bees can get to and from a resource by relying solely on landmarks that they learn; otherwise, they stay home until the weather changes. However, as the earth turns, the sun is always changing location relative to the horizon, making it an unreliable marker unless you know the time of day, and bees do. They learn the movement of the sun across the sky and reference it to an internal clock. We know they have the clock because we can train them to forage at specific times of day. If you anesthetize a bee, you can stop her clock. When she awakens and takes a foraging trip to a learned foraging station, her flight path will be offset by the amount of time lost. In other words, she will misinterpret the direction based on the current location of the sun by the amount of time she was anesthetized."
"The odometer plus the ability to determine a flight vector (direction and distance) from a given landmark along a resource flight path, using their sun compass and internal clock, give bees the basic tools for navigation," Page writes. "The last tool in the toolkit is a path integrator that combines the compass and odometer information."
It's a fascinating book by Page, whose most salient contributions to science include constructing the first genomic map of the honey bee, which sparked a variety of pioneering contributions not only to insect biology but to genetics at large.
Meanwhile, take the challenge. Pull up a chair in your garden and watch and photograph the bees going about their "bees-ness."
- Author: Kathy Keatley Garvey
Salivating over salvia?
You can see, salivate--and purchase--salvias and more at the spring premiere plant sale sponsored by the UC Davis Arboretum and Public Garden on Saturday, April 6.
They'll offer everything from "Bee's Bliss" to "Black Lace" to "Blaze" to "Brilliance." Among the many others: "Whirly Blue, "Pozo Blue," "Marine Blue," "Little Kiss," "Midnight," "Pink Cadillac" and "Hot Lips."
The plant sale, open to the public, is set from 9 a.m. to 1 p.m. at the one-acre Arboretum Teaching Nursery on Garrod Drive. It's a great place to buy plants to attract our pollinators: bees, butterflies, birds, beetles and bats. Not to mention syrphid flies, aka hover flies/flower flies!
You can download the plant sale inventory on the website. Favorites include the Arboretum All-Stars and California native plants, as well as herbs, perennials, shade plants, bushes, trees, vines and more.
Can't make it on Saturday, April 6? Plant sales are also scheduled Saturday, April 27 and Saturday, May 11.
Happy spring! Happy salivating! And happy/hungry pollinators!
- Author: Kathy Keatley Garvey
Remember receiving valentine cards that read "Bee My Valentine?"
Well, every day can be Valentine's Day when there are bees in your garden.
We captured this image several years ago of a queen bumble bee, Bombus vosnesenskii, nectaring on a spiked floral purple plant, Salvia indigo spires (Salvia farinacea x S. farinacea). She had just emerged from her winter hibernation on a sunny day in November. The site: the Sonoma Cornerstone pollinator garden of Kate Frey. She's the co-author of The Bee-Friendly Garden (with UC San Francisco professor Gretchen LeBuhn), and a world-class garden designer and pollinator advocate.
It wasn't Valentine's Day, but then again, yes, it was!
Every day is Valentine's Day when there are bees in your garden.
Bee my valentine!
- Author: Kathy Keatley Garvey
Some folks call them "bumble bees," but they're not.
In size, the female Valley carpenter bee (Xylocopa varipuncta) resembles a bumble bee, but certainly not in color.
The female Valley carpenter is solid black with metallic wings. The male of the species is a green-eyed blond, fondly known as "the teddy bear" bee because it's fuzzy-wuzzy and cannot sting. Entomologists will tell you that the male and female are dramatic examples of sexual dimorphism. Yes, they are!
We've been seeing a lot of female Valley carpenter bees lately on our blue spike salvia, (Salvia uliginosa). They engage in nectar-robbing: this occurs when bees circumvent the usual plant-pollinator relationship and "cheat" by entering a flower from the outside to steal nectar. They drill a hole in the corolla to reach the nectar, thus avoiding pollination or contact with the anthers.
Similar-looking insects include bumble bees, cactus flies and horse flies, according to California Bees and Blooms, a Guide for Gardeners and Naturalists,by UC-affiliated authors Gordon Frankie, Robbin Thorp, Rollin Coville, and Barbara Ertter. "Carpenter bees are shinier and have less hair than fuzzy bumble bees. Carpenter bees have two pairs of wings, and they have long, slender, elbowed antennae, while fly mimics have only one pair of wings, and short stubby antennae."
The Valley carpenter bee is California's largest carpenter bee.
They're large but they're elusive. They usually don't linger long for you to grab a photo. This one did. It was early in the morning, and like a true human morning person, she declined to move fast.
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