- 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
Professor Thorp (1933-2019), a 30-year member of the Department of Entomology and Nematology and a worldwide authority on bees, was a tireless advocate of bumble bee conservation. During his retirement, he co-authored Bumble Bees of North America: An Identification Guide (Princeton University, 2014) and California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday, 2014).
And every summer from 2002 to 2018, Thorp volunteered his time and expertise to teach at The Bee Course, an annual workshop sponsored by the American Museum of Natural History and held at the Southwestern Research Station, Portal, Ariz.
Thorp also served as the regional co-chair of the Wild Bee Specialist Group of the International Union for Conservation of Nature (IUCN) and sounded the alarm about bumble bee declines, including Franklin's bumble bee, Bombus franklini, found only in its narrow distribution range of southern Oregon and northern California. Thorp last saw it near Mt. Ashland in 2006 and it is is now feared extinct or at the brink of extinction. The bee inhabits--or did--a 13,300-square-mile area confined to five counties--Siskiyou and Trinity counties in California; and Jackson, Douglas and Josephine counties in Oregon.
Enter the California Bumble Bee Atlas (CBBA), a collaboration of the California Department of Fish and Wildlife (CDFW), Sacramento, and the Xerces Society for Invertebrate Conservation, headquartered in Portland, Ore. Launched in March 2022, the Atlas is a "collaborative community science effort to track and conserve the state's native bumble bee species," according to Dylan Winkler, bumble bee scientific aide for the CDFW's Wildlife Diversity Program.
Back in September 2021, the U.S. Fish and Wildlife Service announced that the American bumble bee, "whose populations have plummeted by nearly 90 percent, may warrant Endangered Species Act protection." The announcement kicked off a one-year status assessment of the species. (See news story)
If you're interested in bumble bee conservation, take note. Winkler will lead a "Bumble Bee Walk" from 10 a.m. to noon on Saturday, May 28 in the UC Davis Arboretum and Public Garden. The goal is to teach interested participants how to survey bumble bees. You can pre-register at https://arcg.is/0PDyO4. Organizers plan to cap attendance at 20 people. Details about this Atlas event and several more scheduled in June:
- Saturday, May 28: UC Davis Arboretum, Davis, CA (Yolo County), parking at Putah Creek Lodge Parking Lot, Garrod Drive, Davis, CA 95616. Tour of the native plant gardens and the forest along Putah Creek from 10 a.m. to noon.
- Saturday, June 4: The Gardens at Lake Merritt, 666 Bellevue Avenue, Oakland, CA (Alameda County). Tour of the gardens from 9 a.m. to 11 a.m.
- Sunday, June 5: College of Marin at Kentfield (Marin County), parking at covered Lots 6/7 off College Ave, Kentfield, CA 94904. Details: Meet at bridge over Corte Madera Creek. Tour of the campus native plants from 10 a.m. to noon.
- Saturday, June 18: Soil Born Farms, Rancho Cordova, CA (Sacramento County), parking at Soil Born Farms: American River Ranch, 2140 Chase Drive, Rancho Cordova, CA 95670. As part of National Pollinator Week, the group will tour the gardens from 10 a.m. to noon. Closed-toed shoes required.
Of the 50 species of bumble bees found in North America, an estimated 25 inhabit California. Overall, a quarter is at risk, according to the Atlas website. The decline is attributed to "loss or fragmentation of habitat, pesticide exposure, climate change, overgrazing, competition with honey bees, low genetic diversity, and perhaps most significant of all, the introduction and distribution of pathogens through commercial honey bee and bumble bee colonies used for crop pollination. All of these factors likely interact, increasing pollinator vulnerability. To support bumble bees, it is critical to protect existing habitat while creating and maintaining new habitat."
Winkler says "we will be using butterfly nets to catch bees, then move them to small vials, and chill them in coolers with ice, so we can take ID'able photographs of them before releasing." The full protocol is at https://www.cabumblebeeatlas.org/point-surveys.html
What bumble bees might you see May 28 in the Arboretum? Bombus vosnesenskii, the yellow-faced bumble bee, and B. melanopygus, the black-tailed bumble bee. "There is a record of B. crotchii at the arboretum from last year around the same date, which is rare and would be amazing to see!" Winkler said.
The project is funded by the U.S. Fish and Wildlife Service through the Wildlife and Sport Fish Restoration Fund. Funding is also provided by the Bureau of Land Management and several private foundations. Read more about the project and the list of coordinators here.
- Author: Kathy Keatley Garvey
If you've ever been to Bodega Head in Sonoma County, you may have marveled at the waves crashing and the whales surfacing.
But have you ever seen the digger bees, Anthophora bomboides stanfordiana, aka bumble bee mimics, that nest in the sandstone cliffs?
They're there. They're foraging on flowers, excavating their nests, and rearing young.
These digger bees are not easy to photograph. On our May 9th trip, we got lucky: our 200mm macro lens picked up a digger bee warming its flight muscles.
"The species name indicates that it is a bumble bee mimic," the late Robbin Thorp (1933-2019), a global authority on bumble bees and a UC Davis distinguished emeritus professor of entomology. "These bees need a source of fresh water nearby. Females suck up water, regurgitate it on the sandstone bank surface, then dig away at the soft mud. They use some of the mud to build entrance turrets, presumably to help them locate their nests within the aggregation of nests."
"The female," Thorp said, "sucks up fresh water from nearby, stores it in her crop (like honey bees store nectar) for transport to the nest. She regurgitates it on the sandstone, and excavates the moistened soil. She carries out the mud and makes the entrance turret with it."
Thorp, a 30-year member of the Department of Entomology and Nematology, studied these bees. (See his presentation at the Proceedings of the Symposium on Biodiversity of Northwestern California, Santa Rosa, delivered in October 1991.)
Today, community ecologist and associate professor Rachel Vannette from the same department, is among scientists engaged in the research of these fascinating bees.
- Author: Kathy Keatley Garvey
The open-to-the-public competition involved searching for the first-of-the-year bumble bee in the two-county area of Yolo or Solano; photographing it; and emailing the image to the Bohart Museum at bmuseum@ucdavis.edu.
The first bumble bee to emerge in this area is usually the black-tailed bumble bee, Bombus melanopygus, but another bumble bee, the yellow-faced bumble bee, Bombus vosnesenskii,is out early as well.
Both are considered "spring bees" because that is when their population is the highest, according to Thorp. Then their numbers "tail" the rest of the year.
Lynn Kimsey, director of the Bohart and a UC Davis distinguished professor, Department of Entomology and Nematology, announced Saturday that "we have the winners."
Not one winner, but two. No one species, but two.
Coincidentally, they each took their photos at exactly 2:30 p.m., Jan. 1 in the 100-acre UC Davis Arboretum and Public Garden as the bees foraged on manzanita.
And fittingly, they both knew and worked with Robbin Thorp (1933-2019), a global authority on bees and a UC Davis distinguished emeritus professor of entomology.
The event also marked the second consecutive year that a member of the Williams lab won. Last year postdoctoral researcher Charlie Casey Nicholson of the Williams lab and the lab of Elina Lastro Niño, claimed the prize by photographing a B. melanopygus at 3:10 p.m., Jan. 14 in a manzanita patch in the Arboretum.
As the 2022 winners, Page and Zagory will each receive a coffee cup designed with the endangered Franklin's bumble bee, a bee that Thorp closely monitored in its small range at the California-Oregon border. The cup features the image of the bee specimen, photographed by Bohart scientist Brennen Dyer, and designed by UC Davis doctoral alumnus Fran Keller, professor at Folsom Lake College.
The television program, Good Day Sacramento, featured the contest on Jan. 3. (See it here.)
Worldwide Collection. The Bohart Museum houses a worldwide collection of 8 million insect specimens, including 112 species of bumble bees, Kimsey said. Thorp spend much of his time at the Bohart where he identified bees and helped colleagues with their research.
Thorp, a 30-year member of the UC Davis faculty, retired in 1994 but continued his work on bees until his death at age 85 at his home in Davis. Known as a tireless advocate of pollinator species protection and conservation, he co-authored two books in 2014: Bumble Bees of North America: An Identification Guide (Princeton University) and California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday).
Said Zagory: “I indeed knew Robbin Thorp, one of the most generous and kind people I have ever met. Dr. Thorp invited me to do a page for their book (California Bees And Blooms: A Guide for Gardeners and Naturalists) about the UC Davis Arboretum All-Stars (pages 230 -232) and he edited a publication we created at the UC Davis Arboretum called Ten Bees and Ten Plants they Love that can be downloaded from the website at https://arboretum.ucdavis.edu/pollinator-gardening.
Page is a 2018 alumnus of The Bee Course, which Thorp co-taught from 2002-2018. The nine-day intensive workshop, geared for conservation biologists and pollination ecologists and considered the world's premiere native bee biology and taxonomic course, takes place annually in Portal, Ariz. at the Southwestern Research Station, part of the American Museum of Natural History, N.Y. (The 2021 winner--Charlie Casey Nicholson--is a 2015 alumnus of The Bee Course.)
Page said she was “also lucky enough to participate in a "Bumble Bee Blitz" organized by Thorp and the U. S. Fish and Wildlife Service in July 2016 on Mt. Ashland, where we searched for Bombus franklini and Bombus occidentalis-- two very rare West Coast bee species. We unfortunately did not find Bombus franklini, which is now recognized as an endangered species under the Endangered Species Act.”
Brilliant Scientist. “Robbin was a brilliant scientist and a dedicated advocate for bumble bee conservation,” Page said. “His death was a great loss and I wish more of my career could have overlapped with his time in Davis.”
As a doctoral candidate in entomology, Page researches and investigates “whether European honey bees compete with native bees for floral resources and how we can use well-planned floral enhancements to mitigate negative effects of competition."
How rare is it find Bombus vosnesenskii on Jan. 1?
In an email today, UC Davis doctoral alumnus and Thorp protégé Kim Chacon, said she has seen B. vosnesenskii near San Luis Obispo since Dec 26. She is a lecturer at California Polytechnic University (Cal Poly). "I think it is a very opportunistic species. In my research, that was one of the first emergers, the 6th genus actually. Robbin Thorp had an interesting theory about bumble bees dealing with a virus or other illness which was shifting the dominant species to vosnesenskii. I'm so happy both Ellen and Maureen won-- they are both awesome!"
"My congratulations, too," said bumble bee enthusiast/photographer Allan Jones of Davis, a friend of Thorp's. "I did not even go out considering the chilly weather. I expected it to be on the second day when we got up into the sixties, and with the ground so damp and cold, too. Hats off, brrrr."
Both bumble bee species have also been sighted and photographed in recent years on Dec. 31 and Jan. 1 in Benicia, Solano County.
- Author: Kathy Keatley Garvey
If you're thinking about taking a walk in Yolo or Solano counties to celebrate the new year--or just to get some exercise in keeping with your New Year's Resolution (you did make one, didn't you?)--bring your camera.
You might find and photograph the first bumble bee of the year in a contest sponsored by the Bohart Museum of Entomology and memorializing bumble bee expert Robbin Thorp (1933-2019), UC Davis distinguished emeritus professor of entomology.
Participants are to capture an image of a bumble bee in the wild in either of the two counties and email the image to bmuseum@ucdavis.edu, with the details of time, date and place. The image must be recognizable as a bumble bee, said contest coordinator Lynn Kimsey, director of the Bohart Museum and a UC Davis distinguished professor of entomology.
The first bumble bee to emerge in this area is the black-tailed bumble bee, Bombus melanopygus, according to Thorp, who co-authored Bumble Bees of North America: An Identification Guide (Princeton University) and California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday).
Thorp launched the first unofficial bumble-bee-of-the-year contest several years ago with a small group of bumble bee enthusiasts/photographers: Allan Jones and Gary Zamzow of Yolo County, and yours truly of Solano County. Kim Chacon, then a UC Davis doctoral candidate and a Thorp protégé, joined us later. She is a 2019 alumnus of The Bee Course (co-taught by Thorp from 2002-2018). The nine-day intensive workshop, geared for conservation biologists and pollination ecologists and considered the world's premiere native bee biology and taxonomic course, takes place annually in Portal, Ariz. at the Southwestern Research Station, part of the American Museum of Natural History, N.Y.
Nicholson photographed B. melanopygus, in a manzanita patch at 3:10 p.m., Thursday, Jan. 14, 2021 in the UC Davis Arboretum and Public Garden to claim the honor. He is a researcher in the UC Davis Department of Entomology and Nematology labs of Professor Neal Williams, a pollination ecologist, and Extension apiculturist Elina Lastro Niño.
His prize? A coffee cup designed with the endangered bumble bee that Thorp closely monitored—Franklin's bumble bee, Bombus franklini, known to exist in a small area by the California-Oregon border. UC Davis doctoral alumnus Fran Keller, a professor at Folsom Lake College and a Bohart Museum scientist, designed the cup. Bohart scientist Brennen Dyer photographed the specimen from the Bohart collection.
The 2022 winner also will receive that prized coffee cup.
So, take a walk. Invite your camera. Keep that New Year's Resolution.
Game on!