You never know what you'll find when you visit a pollinator garden.
Take the case of our visit Nov. 12 to the Sonoma Cornerstone, Sonoma, to see the pollinator garden of Kate Frey, an ardent pollinator advocate, world-class garden designer, and co-author of The Bee Friendly Garden with UC San Francisco professor Gretchen LeBuhn.
The flower-filled Frey garden is a people/pollinator favorite at the Sonoma Cornerstone, and no wonder.
We spotted a yellow-faced queen bumble bee, Bombus vosnesenskii, foraging on Salvia Indigo spires. Normally, you don't see bumble bees this time of year, but this one came out of hibernation temporarily to eat. She appeared famished!
Bombus vosnesenskii is among the bees featured in the University of California-authored book, California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday Press). It's the work of entomologists Gordon Frankie of UC Berkeley and Robbin Thorp of UC Davis, entomologist/photographer Rollin Coville and plant expert Barbara Ertter of UC Berkeley. Thorp, a UC Davis distinguished emeritus professor, also co-authored Bumble Bees of North America: An Identification Guide (Princeton University).
In their book, California Bees and Blooms, the authors call attention to this iconic Bombus species: the yellow hairs on the face and top of head, and the yellow stripe on the abdomen.
Hibernating queen bumble bees are a joy to photograph as they forage for food, buzzing from blossom to blossom to sip nectar. This one seemed to be braking during a winter break.
It's Thanksgiving Day and time to give thanks for NOT what we WANT, but what we HAVE.
And, not for what we OWN, but what we CANNOT.
That includes the yellow-faced bumble bee, Bombus vosnesenskii.
On the morning of Nov. 12, we traveled to the Sonoma Cornerstone, Sonoma, to check the plants and pollinators in Kate Frey's amazing pollinator garden. Kate Frey, co-author of The Bee-Friendly Garden" (with UC San Francisco professor Gretchen LeBuhn), is a world-class garden designer and pollinator advocate.
Flashback to Sept. 23, the last time we visited the Frey garden. We noticed monarch butterflies, painted ladies, honey bees and--one bumble bee, a hungry queen Bombus vosnesenskii, newly emerged from winter hibernation to grab something to eat. Sometimes on warm sunny days, the queens will disrupt their hibernation to search for nectar. They. Are. Hungry.
At 12:30 on Nov. 12, the temperature rose to 62 degrees.
And then we saw her, The Queen. The Queen. Resplendent in gold and black, she buzzed loudly toward the spiked floral purple plant, Salvia indigo spires (Salvia farinacea x S. farinacea). Honey bees quickly moved out of her way as she claimed the nectar, all of it. Her wings glowed in the sunlight and her buzz seemed loud enough to break the sound barrier.
Is there anything more bee-utiful?
One bumble bee. One queen. A royal moment.
The news is disturbing but not unexpected.
Scientists are linking global climate change to one reason why the worldwide population of bumble bees is declining.
An article published Sept. 28 in the journal Ecology Letters by Florida State University (FSU) researchers showed that bumble bees just aren't getting enough floral resources.
For the study, lead researcher and postdoctoral fellow Jane Ogilivie and six colleagues examined three subalpine bumble bee species in Colorado's Rocky Mountains, and found that the changing climate means fewer flowers.
"Knowing whether climate variation most affects bumble bees directly or indirectly will allow us to better predict how bumble bee populations will cope with continued climate change," Ogilivie told the FSU News Service in a press release. "We found that the abundances of all three bumble bee species were mostly affected by indirect effects of climate on flower distribution through a season."
The FSU News Service aptly headlined the research a "Stinging Report."
"When researchers think about flower effects on bees, they typically consider floral abundance to be the most important factor, but we found that the distribution of flowers throughout a season was most important for bumble bees,” Ogilivie said. “The more days with good flower availability, the more bees can forage and colonies can grow, and the bigger their populations become. We now have longer flowering seasons because of earlier snowmelt, but floral abundance has not changed overall. This means we have more days in a season with poor flower availability.”
The researchers wrote in their abstract: "Climate change can influence consumer populations both directly, by affecting survival and reproduction, and indirectly, by altering resources. However, little is known about the relative importance of direct and indirect effects, particularly for species important to ecosystem functioning, like pollinators. We used structural equation modelling to test the importance of direct and indirect (via floral resources) climate effects on the interannual abundance of three subalpine bumble bee species. In addition, we used long-term data to examine how climate and floral resources have changed over time. Over 8 years, bee abundances were driven primarily by the indirect effects of climate on the temporal distribution of floral resources. Over 43 years, aspects of floral phenology changed in ways that indicate species-specific effects on bees. Our study suggests that climate-driven alterations in floral resource phenology can play a critical role in governing bee population responses to global change."
Bumble bee expert Robbin Thorp, distinguished emeritus professor of entomology at the University of California, Davis, long ago sounded the alarm that bumble bees are in trouble. He is the co-author of Bumble Bees of North America: an Identification Guide (Princeton) and California Bees and Blooms: A Guide for Gardeners and Naturalists.
The last bumble bee we saw--the last of the season--was on Sept. 23 at Kate Frey's pollinator garden at the Sonoma Cornerstone, Sonoma. It was a yellow-faced queen bumble bee, Bombus vosnesenskii, nectaring on a spiked floral purple plant, Salvia ‘Indigo Spires' (Salvia farinacea x S. farinacea). The queen had apparently emerged from hibernation to find food on that warm summerlike day.
I knelt to capture some images.
"Oh, it's just a bumble bee," scoffed one tourist, casually sipping a glass of wine. "They're everywhere."
Sadly, they're not.
Nice to see you!
That's how we greeted our very last bumble bee of 2016.
The yellow-faced bumble bee, Bombus vosnesenskii, apparently came out of hibernation and started nectaring on mallow Nov. 14 at the Natural Bridges State Park, Santa Cruz. We were at the park to see the overwintering monarch butterflies, but it was definitely delightful to see another insect species as well.
Ms. Bombus buzzed from one mallow to the other, keeping her distance from the two-legged park visitors. Once she nearly collided with an overwintering monarch heading for tropical milkweed blossoms.
B. vosnesenskii, native to the west coast of North America and found from British Columbia to Baja California, is an iconic pollinator and also an important pollinator for such crops as greenhouse tomatoes. It's among the bumble bees featured in the book, Bumble Bees of North America: An Identification Guide (Princeton University), the award-winning work of Paul H. Williams, Robbin W. Thorp, Leif L. Richardson and Sheila R. Colla.
When you click on the Princeton site, you'll hear the familiar buzz of bumble bees. It's just like encountering them in a wildflower meadow and listening to them take flight. It's a sound, unfortunately, that we're not hearing that much any more. The world's bumble bee population is declining, and some species are extinct or critically imperiled.
Speaking of bumble bees, did you see the paper, “Bumble Bees of Montana,” published this week by faculty and students in the Montana State University College of Agriculture in the Annals of the Entomological Society of America (AESA)? The scientists researched and compiled the state's first inventory of bumble bees known to live in Montana.
"The first time a bumble bee was recorded in Montana was in the journals of the Lewis and Clark expedition in 1805," wrote Jenny Lavey of the MSU News Service.
Four scientists co-authored the paper:
- Michael Ivie, associate professor of entomology in the MSU Department of Plant Sciences and Plant Pathology
- Kevin O'Neill, professor of entomology in the MSU Department of Land Resources and Environmental Sciences,
- Casey Delphia, MSU research scientist, and
- Amelia Dolan, former MSU entomology graduate student
"Because of Montana's size, landscape diversity and regional junction of eastern and western geographies, when it comes to bumble bees, Montana hosts a diverse, large and globally relevant community of species,” Ivie said in the news release. “Our research shows 28 different species of Bombus, with four more expected to make the list. That's the largest number of bumble bee species recorded for a state in the entire country."
Said Dolan: "It was amazing because we had people collecting specimens across the state, in varying elevations and diverse ecosystems – areas we alone wouldn't have had access to in the time that we had to complete the project. The number of species is representative of Montana's wild spaces and diverse landscapes that host these bees."
When was Bombus vosnesenskii first recorded in Montana? In 1923 (Frison).
If you want to hear more about bumble bees and other bees (some 1600 species of bees reside in California), be sure to attend a free two-hour presentation on "Bee Aware Bee Cause" at 1:30 p.m., Saturday, Jan. 7 by Robbin Thorp at the Rush Ranch Nature Center, 3521 Grizzly Island Road, Suisun. A worldwide expert on bees, Thorp is a distinguished emeritus professor of entomology at UC Davis who continues his research, writings and bee identification work. (See information on the event on previous Bug Squad blog.)
How it all began: Pollination ecologist Neal Williams, associate professor in the UC Davis Department of Entomology and Nematology and postdoctoral researcher Rosemary Malfi set out to research how the short-term loss of floral resources affects bumble bees, specifically the yellow-faced bumble bee, Bombus vosnesenskii, a common bumble bee native to the West Coast of the United States. Its importance to agriculture, including the pollination of greenhouse tomatoes, cannot be overstated.
So, "the bee team," led by Williams, decided they needed to weigh the bees as part of their research. They engaged mechanical and electrical engineers on the UC Davis campus to see if they could come up with a "bee scale" to weigh individual foragers.
They could and they did. The project is underway in a field west of the central UC Davis campus. The site includes fine-mesh tents filled with wildflowers to contain the bumble bees and an RV converted into a lab.
Fell began his piece with "How do you weigh a bee?"
"That's the question that brought together insect specialists at the University of California, Davis, and two teams of UC Davis engineering students this year, to try and solve what turns out to be a tricky technical problem," Fell wrote. "But the consequences are important: ultimately, understanding how California's native bumble bees respond to changes in the environment and the availability of flowers, and how we can protect these insects that are so vital to both agriculture and wild plants."
The entomologists worked with electrical engineers Anthony Troxell, Jeff Luu and Wael Yehdego, advised by Andre Knoesen, professor in the Department of Electrical and Computer Engineering, and mechanical engineers Lillian Gibbons, Laurel Salinas and Ryan Tucci, advised by Professor Jason Moore.
Fell wrote: "The electrical engineers had to solve the problem of taking the raw signal from the scale and obtaining time-stamped data for individual bees."
“We were working with very small signals, at the low end of the technology, so noise in the data was an issue,” Troxell related in the news story. "A bumble bee weighs between 150 and 200 milligrams, and to get useful information about bee health or how much pollen they are carrying, the scale would need to be accurate to less than one milligram. A conventional laboratory balance averages several readings over a few seconds — but bees are much too fast and jittery for that to work."
Williams described the bee scale as "a great example of interdisciplinary work." And indeed it is.
This project is sure to gain national and international attention. It's not just about the plight of the bumble bees but the unique collaboration between entomologists and engineers and the resulting device they successfully designed and crafted.