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.)
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!
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 firstname.lastname@example.org.
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.
The University of California, Davis, is the place to "bee" on Saturday, April 7.
There's a plant sale at the UC Davis Arboretum Nursery on Garrod Drive from 9 a.m. to 1 p.m., and there's an open house and plant sale at the Häagen-Dazs Honey Bee Haven from 11 a.m. to 2 p.m. on Bee Biology Road.
And they are within several miles of one another.
At the one-acre Arboretum Nursery, you'll find what the officials are calling "an incredible selection of Arboretum All-Stars, California natives and thousands of other attractive, low-water plants perfect for creating a landscape alive with environmentally important pollinators." You'll find drought-tolerant, easy-care plants. Look for the inventory here. Members receive discounts, and you can join online, at the gate. Credit cards are accepted.
At the bee haven, operated by the UC Davis Department of Entomology and Nematology, you're likely to find asters, California fuchsia, salvia, ceanothus, manzanita, coffeeberry and currant. Favorites include Salvia "Bee's Bliss" and Ceanothus "Valley Violet." Check out the plant list here. Payment is cash only.
As the temperatures soar to 80 degrees, and the ground warms up, the green thumbs are emerging! So are the honey bees, native bees and other pollinators...
The competition is open to all graduate students throughout the country involved in pollinator research, Luu says. Judging criteria? Objectives, methodology, results, research significance, conclusions, appearance, and presentation and interaction with the judges. The winner receives $1000, while the second-place award is $750; third place, $500; and fourth place, $250.
The poster competition is a traditional part of the daylong symposium, hosted by the UC Davis Honey and Pollination Center and the UC Davis Department of Entomology and Nematology. Keynote speaker is bee scientist/professor/author Tom Seeley of Cornell University, Ithaca, N.Y., who will discuss "Darwinian Beekeeping." Seeley is the Horace White Professor in Biology, Department of Neurobiology and Behavior, where he teaches courses on animal behavior and researches the behavior and social life of honey bees. He is the author of three major books, Honeybee Ecology: A Study of Adaptation in Social Life(1985), The Wisdom of the Hive: the Social Physiology of Honey Bee Colonies (1995), and Honeybee Democracy(2010), all published by Princeton University Press. His books will be available for purchase and signing at the symposium.
The 2017 poster competition drew 14 posters throughout the country. Phillipp Brand, a graduate student in the Santiago Ramirez lab, UC Davis Department of Evolution and Ecology, and a member of the Population Biology Graduate Group, won the competition for his research on "The Evolution of Sex Pheromone Communication in a Pair of Sibling Species of Orchid Bees." He received $1000.
Brand, who joined the Ramirez lab in 2013, obtained his bachelor's degree in biology from the University of Dusseldorf, Germany, and then went on to pursue his master's degree there, studying the evolutionary history and the patterns of selection of olfactory receptor genes in a pair of sister lineages of euglossine bees.
"Pheromone communication has long been known to play a central role in the origin and evolution of species diversity throughout the tree of life," he wrote in the introduction on his poster. "What are the underlying genetic and molecular mechanisms that control pheromone variation and signal detection?"
Other 2017 winners were:
- Second place, $750; Jacob Peters, Harvard University, “Self-Organization of Collective Nest Ventilation by Honey Bees”
- Third place, $500; John Mola, UC Davis, “Fire-Induced Change in Flowering Phenology Benefits Bumble Bees"
- Fourth place, $250; Devon Picklum, University of Nevada, Reno, “Floral Visitation and pollen Deposition Bombus- Pollinated Dodecatheon Apinum and Pedicularis Groenlandica in the Sierra Nevada”
The fourth annual UC Davis Bee Symposium: Keeping Bees Healthy is designed for beekeepers of all experience levels, including gardeners, farmers and anyone interested in the world of pollination and bees," said Amina Harris, director of the Honey and Pollination Center. "In addition to our speakers, there will be lobby displays featuring , the latest in beekeeping equipment, books, honey, plants, and much more." Registration is underway.
The conference begins with registration and a continental breakfast at 8:30 a.m., with welcomes and introductions at 9 a.m., by Amina Harris and Neal Williams, UC Davis professor of entomology and faculty co-director of the center. See more at http://honey.ucdavis.edu/events/2018-bee-symposium./span>