- Author: Kathy Keatley Garvey
Remember those "long lost" silver digger bees found last week at the San Francisco Presidio? They hadn't been seen in large aggregations for nearly a century.
And yet there they were in the newly restored sand dunes at the Presidio, a former military post now owned and operated by the National Park Service.
UC Davis entomologist Leslie Saul-Gershenz lent her expertise when a volunteer discovered the thriving colonies of bees. An authority on digger bees, she confirmed that they are Habropoda miserabilis and were probably common in the sandy dunes of that area as late as the 1920s. When non-native ivy, eucalyptus and ice plants took over their habitat, the bees disappeared.
“The discovery of a thriving native bee colony on the western side of the Presidio is the latest example of how the removal of invasive plants and the restoration of dunes and grasses at the former military base have helped bring back coastal habitat that thrived in San Francisco for tens of thousands of years before the city was built,” said Saul-Gershenz, who received her doctorate in entomology from UC Davis and is now associate director of research for the Wild Energy Initiative, John Muir Institute of the Environment, on campus.
“I am very happy to see this nest site at the Presidio,” she said. She's worked on the biology, chemical ecology and parasite interactions of this group of bees in the genus Habropoda for many years--on research trips that have taken her to the Oregon coast and the Mojave desert, among others.
“This nest parasite M. franciscanus was originally described from the dunes in San Francisco near Lake Merced by Van Dyke in 1928,” Saul-Gershenz said. “It is presumed to be locally extirpated in San Francisco due to habitat alteration. However its host bee, H. miserabilis appears to have finally found a suitable nest location in a sand dune area being restored by the Presidio Trust in the Presidio National Park. The resiliency of nature provides hope for the future.”
In a news story published in the San Francisco Chronicle on March 29, science reporter Peter Fimrite quoted the UC Davis entomologist as saying that the silver digger bees were “all but gone” by the mid-20th century. However, Saul-Gershenz has kept looking for them. In fact, she collected one near Baker Beach in 1998.
With restoration, comes hope for the return of native plants and insects.
"Biologists have reported a more than tenfold increase in the number of native plants in the Presidio, including at least four that are federally listed endangered or threatened, among them the Presidio clarkia," wrote Fimrite. "The Franciscan manzanita, which was believed to be extinct in the wild, was discovered in the Presidio in 2009. It was the first of its kind seen in its native San Francisco since the old Laurel Hill Cemetery was bulldozed in 1947 and paved over for homes."
Brian Hildebidle, stewardship coordinator for the Presidio Trust, discovered the colonies while surveying a dune restoration project. Jonathan Young, wildlife ecologist for the Presidio Trust, was also included in the news story.
Gershenz and collaborator Jocelyn Millar of UC Riverside and others deciphered the sex attraction of Habropoda miserabilis and the deceptive mimicking blend used by its nest parasite Meloe franciscanus working with a population on the coast of Oregon (Saul-Gershenz et al. 2018). They documented a new parasite-host location system while conducting research on related species in the same genus Habropoda pallida found in the Mojave and Sonoran Desert (Saul-Gershenz and Millar 2006).
The comeback of silver digger bees is not limited to San Francisco. Fimrite related that several other areas in California are are witnessing comebacks, including Bodega Marine Reserve in Bodega Bay and Lanphere Dunes in the Humboldt Bay National Wildlife Refuge.
We remember seeing volunteers at Dillon's Beach, Bodega Bay, last summer removing ice plants by the bird sanctuary, and in the process, giving native plants, native insects and related wildlife a chance to thrive. We remember beachcombers asking "Why? Why are they doing that? Those ice plants are so PRETTY."
The discovery at the Presidio is why.
As Saul-Gershenz points out, there are 1600 native bee species in California, but scientists know little about many of them.
They are all pollinators. And all life is connected. As naturalist/environmental philosopher John Muir (1838-1914) wrote in My First Summer in the Sierra: "When we try to pick out anything by itself, we find it hitched to everything else in the Universe."
So it is with the silver digger bees. That's why they're gold.
- Author: Kathy Keatley Garvey
They range in topics from fruit flies to spider glue to an African odysssey.
The seminars take place at 4 p.m. every Wednesday in Room 122 of Briggs Hall, beginning April 3 and ending June 5.
The schedule:
Wednesday, April 3
Alistair McGregor, Oxford Brookes University, England
Topic: "Differences in Tartan Underlie the Evolution of Male Genital Morphology Between Drosophila Species"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
Wednesday, April 10
Monique Rivera, UC Riverside
Topic: "How Agriculture Influences the Structure of Belowground Communities"
Host: Elvira de Lange, postdoctoral fellow, UC Davis Department of Entomology and Nematology"
Wednesday, April 17
Bert Hölldobler, Arizona State University
Topic: "The Superorganism: Communication, Cooperation and Conflict in Ant Societies"
Host: Robert Page, distinguished emeritus professor, UC Davis Department of Entomology and Nematology and provost emeritus, Arizona State University
Wednesday, April 24
Sarah Stellwagen, University of Maryland
Topic: "Towards Spider Glue: From Material Properties to Sequencing the Longest Silk Family Gene" (Link)
Hosts: Hanna Kahl, doctoral student in entomology, and Jason Bond, the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology
Wednesday, May 1
Andrew Nuss, University of Nevada, Reno
Topic: "Breaking Insecticide Resistance: Novel Strategies for Insect Pest Management"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
Wednesday, May 8
Colin Orians, Tuffs University, Massachussetts
Topic: "Mitigating the Effects of Climate Change on Tea Agroecosystems in China"
Host: Rachel Vannette, assistant professor, UC Davis Department of Entomology and Nematology
Wednesday, May 15
Erin Wilson-Rankin, UC Riverside
Topic: "Ecological Factors Underlying Diet Shifts in California Pollinators"
Host: Rachel Vannette, assistant professor, UC Davis Department of Entomology and Nematology
Wednesday, May 22
James R. Carey, distinguished professor of entomology, UC Davis Department of Entomology and Nematology
Topic: African Odyssey: Natural Wonders, Wildlife Adventures, and Indigenous Peoples"
Wednesday, May 29
Laurence Packer, York University, Canada
Topic: "Extreme Bees in Extreme Environments: Bee Biogeography in the Atacama Desert"
Hosts: Leslie Saul-Gershenz, associate director of research, Wild Energy Initiative, John Muir Institute of the Environment, UC Davis, and Steve Nadler, professor and chair, UC Davis Department of Entomology and Nematology
Wednesday, June 5
Immo Hansen, New Mexico State University
Topic: "Toward Implementation of Mosquito Sterile Insect Technique"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
More information is available from Attardo at gmattardo@ucdavis.edu.
/span>- Author: Kathy Keatley Garvey
What native California plants are best for attracting pollinators?
Now for answers.
Three pollination ecologists from the University of California, Davis, have just published their research, “Identifying Native Plants for Coordinated Habitat Management of Arthropod Pollinators, Herbivores and Natural Enemies,” in the Journal of Applied Ecology. It details what plants proved most attractive to honey bees, wild bees and other pollinators, as well as what drew such natural enemies as predators and parasitic wasps.
“I hope this study can inform selection of plants that support pollinators and natural enemies without enhancing potential pests,” said lead researcher and first author Ola Lundin, a former postdoctoral fellow in the Neal Williams lab, UC Davis Department of Entomology and Nematology and now a postdoctoral fellow in the Department of Ecology, Swedish University of Agricultural Sciences, Uppsala.
He and co-authors Williams, professor of entomology and a Chancellor's Fellow at UC Davis; and project specialist Kimiora Ward of the Williams lab conceived the ideas and developed the methodology for the research project.
“Planting wildflowers is a key strategy promoted nationally to support wild and managed bees,” said Williams. “Successful adoption of these plantings in agricultural landscapes will require that they not only support pollinators but that they also avoid supporting too many pests. Plant selection going forward will need to balance multiple goals of pollinators pest management and other functions. This research is a first step on the path to identifying plants that will meet these goals."
The trio established 43 plant species in a garden experiment on the grounds of the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis. They selected plant species that were drought-tolerant; native to California (except for buckwheat, Fagopyrum esculentum, known to attract natural enemies and widely used in conservation biological control); and, as a group, covered a range of flowering periods throughout the season.
“For early season bloom, Great Valley phacelia (Phacelia ciliata) was a real winner in terms of being attractive for both wild bees and honey bees,” Lundin said. “Elegant Clarkia (Clarkia unguiculata) flowers in late spring and was the clearly most attractive plant for honey bees across the dataset. The related Fort Miller Clarkia (C. williamsonii) was also quite attractive for honey bees and had the added benefit that a lot of minute pirate bugs visited the flowers.”
Lundin said that common yarrow (Achillea millefolium) “attracted “attracted the highest numbers of parasitic wasps but also many herbivores, including Lygus bugs.”
“In general a lot of parasitic wasps were found on Asteraceae species (the daisy family) and this was a somewhat surprising result considering that they have narrow corollas, and for parasitic wasps relatively deep corollas that can restrict their direct access to nectar. Under the very dry conditions in late summer, Great Valley gumplant (Grindelia camporum) and Vinegarweed (Trichostema lanceolatum) both performed well and attracted high numbers of wild bees.”
The team found that across plant species, herbivore, predator and parasitic wasp abundances were “positively correlated,” and “honey bee abundance correlated negatively to herbivore abundance.”
The take-home message is that “if you're a gardener or other type of land manager, what you'd likely prefer would be a mix of some of the most promising plant species taking into account their individual attractiveness for these arthropod groups, plus several more factors including costs for seed when planting larger areas,” Lundin said.
“Plant choice can also depend on how you weigh the importance of each arthropod group and whether you are interested in spring, summer or season-long bloom,” Lundin added. Those are some of the questions that the Williams lab plans to explore in future projects.
Williams praised the “uniquely capable team that came together.”
“Ola is an emerging leader in considering integrated management of pests and pollinators and Kimiora is a known expert in developing regionally-relevant plant materials to support pollinators,” Williams said. “They and some talented UC Davis undergraduates--notably Katherine Borchardt and Anna Britzman--compiled a tremendously useful study.”
The overall aim of the study “was to identify California native plants, and more generally plant traits, suitable for coordinated habitat management of arthropod pollinators, herbivores and natural enemies and promote integrated ecosystem services in agricultural landscapes,” the researchers wrote.
More specifically, they asked:
- Which native plants among our candidate set attract the highest abundances of wild bees, honeybees, herbivores, predators, and parasitic wasps,
- If the total abundances of arthropods within these functional groups across plant speacies are related to the peak flowering week, floral area, or flower type of the focal plant species, and
- If the total abundances of arthropods within these functional groups are correlated to each other across plant species.
“A first critical step for design and implementation of multifunctional plantings that promote beneficial arthropods while controlling insect pests is to identify suitable plant species to use,” the authors wrote in their abstract. “We aimed to identify California native plants and, more generally, plant traits suitable for the coordinated management of pollinators (wild bees and honey bees), insect herbivores and arthropod natural enemies (predators and parasitic wasps).”
At the time, the Laidlaw grounds included nearly 50 bee colonies: some 20 to 40 honey bee colonies, and eight managed research colonies of the yellow-faced bumble bee, Bombus vosnesenkii.
The project drew funding from the USDA Resources Conservation Service, USDA Agricultural Marketing Service, USDA National Institute of Food and Agriculture and a Swedish foundation for scientific research, the Carl Tryggers Stiftelse for Vetenskaplig Forskning.
(Note: An upcoming Bug Squad blog will list the 43 plants the researchers used.)
- Author: Kathy Keatley Garvey
When you head over to a nursery, and see bees and butterflies and other pollinators foraging on the plants, that's a good sign.
Buy the plants.
Promise: The pollinators will come.
Many gardeners and would-be gardeners are looking forward to the UC Davis Arboretum and Public Garden Plant Sale--the "first entirely open-to-the-public plant sale of the fall season." It's set from 9 a.m. to 1 p.m., Saturday, Oct. 13 in the Arboretum Teaching Nursery on Garrod Drive, near the School of Veterinary Medicine.
Members of the Friends of the UC Davis Arboretum and Public Garden and the Davis Botanical Society receive 10 percent off their purchases. You can join online, at the door, or call ahead, officials say. New members receive a $10-off coupon as a thank you for joining.
That's a good incentive.
What plants are they offering? Download the inventory.
Meanwhile, summer has ended, fall crept in on Sept. 23, and winter is fast approaching--Dec. 21.
We caught a little sliver left of mellow mornings last weekend in the Kate Frey Pollinator Garden at Sonoma Cornerstone. An anise swallowtail, Papilio zelicaon, fluttered in, touched down to sip some nectar, and soared off. What a sight to see!
Buy a plant (help the UC Davis Arboretum and Public Garden), and promise, the pollinators that will surely come are free!
- Author: Kathy Keatley Garvey
How about wearing a pollinator on your heart?
It's National Pollinator Week.
The UC Davis Entomology Graduate Student Association (EGSA) offers a wealth of t-shirts as part of its year-around fundraising efforts. It's for a good cause. The EGSA, comprised of UC Davis graduate students who study insect systems, is an organization that "works to connect students from across disciplines, inform students of and provide opportunities for academic success, and to serve as a bridge between the students and administration," according to EGSA president Brendon Boudinot, an ant specialist/doctoral student in the Phil Ward lab.
The t-shirts can be ordered online at https://mkt.com/UCDavisEntGrad/, according to medical entomologist and EGSA treasurer Olivia Winokur, a doctoral student in the Christopher Barker lab. She serves as the t-shirt sales coordinator and can be reached at ocwinokur@ucdavis.edu.
One of the favorite bee t-shirts depicts a honey bee emerging from its iconic hexagonal cells. It's the 2014 winner of then graduate student Danny Klittich, who recently received his doctorate in entomology from UC Davis and now works as a California central coast agronomist.
Another "fave" bee shirt--this one showing a bee barbecuing--is by doctoral student and nematologist Corwin Parker, who studies with Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology. It was one of the 2018 winners. (See the three winners on this site.)
Pollinators also include butterflies, birds and beetles.
"The Beetles" t-shirt is EGSA's all-time best seller. Instead of the English rock band John Lennon, Paul McCartney, George Harrison and Ringo Star crossing Abbey Road in single file (that's the iconic image on the cover of their album, Abbey Road), think of The Beetles (four insects) crossing Abbey Road in single file. Beneath the images of the beetles are their family names: Phengogidae, Curculionidae, Cerambycidae and Scarabaeidae. Think glowworm, snout, long-horned, and scarab beetles.
One thing's for certain: Pollinators matter. Not just during National Pollinator Week but every day of the year.