Which one is the most popular? Initially, it was the tropical milkweed, A. curassavica. We collected the first five caterpillars there. The A. fascicularis yielded the rest.
So, the count: narrowleaf milkweed, 11; tropical, 5; and showy, a no-show.
To date this year, we have released six monarchs back into the garden. The others went for university research. Elizabeth Pringle's laboratory at the University of Nevada, Reno, needed male and female monarchs to rear a colony, and the UC Davis laboratory of Louie Yang needed some tachinid flies.
Unfortunately for us--and fortunately for the Yang lab--tachinid flies infested two of our "11-piece collection." The adult flies are parasitoids that lay their eggs in immature monarchs (among other hosts). The fly larvae hatch and eat their host from the inside out. In a chrysalid, you can tell a tachnid fly infestation by the large tell-tale "dented" brown spot, it looks somewhat like a rotten spot on an apple. In a caterpillar? Think withered and discolored. Then a bungee-like white string appears, and the larvae (maggots) slide down--probably gleefully--like a kid on a Goliath Slide at the county fair.
Tachinids, however, are considered beneficial insects. They lay their eggs in or on such pests as cabbage loopers, cutworms, cabbage worms, gypsy moths, hornworms, harlequin bugs, lygus bugs, cucumber beetles, earwigs and the like. (See Bug Squad blog for close-up images of the tachinid larvae and pupae.)
2016: A Very Good Monarch Year
The year 2016 was a very good year for monarchs in our pollinator garden; we reared and released 60-plus. Sadly, the numbers fell drastically in 2017, 2018 and 2019. Last year, no eggs, no caterpillars and no chrysalids, and only a few monarchs passed through. In fact, in 2019 we did not see our first monarch until Aug. 9.
This year we're noticing a comeback of sorts. We spotted the first monarch on May 24. We now see:
- Males patrolling our yard and chasing the females--morning, noon and evening
- Females laying their eggs on the narrowleaf milkweed that's beneath the honeysuckle vine or the tropical milkweed that's beneath the roses
- Both males and females nectaring on milkweed, butterfly bush (Buddleia davidii), and Mexican sunflower (Tithonia rotundifolia), napping in the branches of the cherry laurels, and greeting any guests with flutter fanfare.
Life is good.
Sometimes the Gulf Fritillaries, Agraulis vanillae, that are hanging out on their host plant, the passionflower vine, mistake them for one of their own species and a pursuit begins.
Yes, the predators are out there: the California scrub jays, praying mantids, spiders, European paper wasps and yellow jackets. So are the tachinid flies and parasitoid wasps.
Would it be too much to ask them to...um....leave our monarchs alone? Yes.
Everybody eats in the garden. The menu choice is theirs.
But there's much more to it than that. What's in that floral nectar and pollen?
Think plant-pollinator-pathogen webs.
Rebecca Irwin, professor of applied ecology at North California State University, Raleigh, is traveling to UC Davis to present a seminar on "The Role of Floral Traits in Pollination and Bee Disease Transmission."
Her seminar, hosted by the UC Davis Department of Entomology and Nematology, is set for 4:10 p.m., Wednesday, Oct. 16 in 122 Briggs Hall. Community ecologist Rachel Vannette, assistant professor and coordinator of the weekly seminars, will introduce her.
"Secondary compounds play a critical role in plant defense against herbivores," says Irwin in her abstract. "Although these compounds can increase plant resistance to herbivore feeding, they can also benefit herbivores by reducing parasitism. There is now widespread evidence that these same secondary compounds are also found in floral nectar and pollen."
"I will share multiple lines of evidence from a variety of collaborative projects in the lab and field suggesting that floral secondary compounds can reduce parasitism in bees, and that bees may be able to selectively forage on flowers with these compounds when they are parasitized," Irwin says. "Because floral secondary compounds alter pollinator behavior, they also have the potential to affect patterns of pollen movement and plant fitness. However, evidence suggests different effects across plant species. Finally, I will share with you results exploring the degree to which secondary compounds and other floral traits affect pollinator disease transmission in the field. Taken together, this seminar will provide empirical evidence into the diversity of roles that secondary compounds, and floral traits more generally, can play in plant-pollinator-pathogen webs."
Irwin, who received her doctorate from the University of Vermont, says on her website that the Irwin lab combines "concepts and techniques from studies of plant-pollinator and plant-herbivore interactions to understand the ecological and evolutionary consequences of pollination mutualisms and how they will respond to environmental change. We also study the disease ecology and transmission biology of bees and their pathogens."
Irwin also shares her expertise on bee condos or bee hotels. "From humble coffee cans to fancier hotels with a roof, there are many ways to get creative with the design. Here, we provide a brief introduction into building a simple first time bee hotel."
And, she says, "hotels work better when facing southeast."
if you want to build your own bee housing units, check out the information on her website.
She spoke on "The Importance of People in Pollinator Conservation" to a capacity crowd gathered July 18 in the ARC Ballroom.
“Who needs to act?" she asked. "Farmers, governments, conservationists, researchers, the general public and businesses.”
Quoting noted biologist/author E. O. Wilson, Dicks said that insects are “the little things that run the world.”
Dicks began her presentation by chronicling news media accounts of “insectageddon,” which Cambridge fellow Robert Macfarlane defined on Twitter as “the current calamitous population decline of insect species globally, with catastrophic results for life on earth.”
One news story, by environment editor Damian Carrington of The Guardian, warned that "The world's insects are hurtling down the path to extinction, threatening a catastrophic collapse of nature's ecosystems." Carrington, in his Feb. 10, 2019 piece, titled “Plummeting Insect Numbers ‘Threaten Collapse of Nature," wrote that “More than 40 percent of insect species are declining and a third are endangered...The rate of extinction is eight times faster than that of mammals, birds and reptiles. The total mass of insects is falling by a precipitous 2.5% a year, according to the best data available, suggesting they could vanish within a century.”
“Wild insect pollinators have declined in occurrence, diversity, and in some cases, abundance, in Europe and North America,” Dicks told the crowd. “Lack of data for other regions prevents global assessment of status for insect pollinators, but the main drivers of decline are operating everywhere.”
“Why does pollinator decline matter?” she asked. “Eighty-eight percent of wild plant species depend on pollinators. At least half of the crop pollination serves are provided by wild pollinators—half by managed honey bees.”
Farmers, governments, conservationists, researchers, the general public and businesses must get involved, she reiterated.
What Farmers Should Do
For example, she said, farmers should
- Plant flowers for nectar and pollen
- Manage hedges and forest edges for wildlife
- Restore and protect flower-rich native habitats like meadows, scrubland and woodland
- Provide set aside or fallow areas
- Leave field edges and corners to naturally generate
- Provide nesting sites for bees ("bare ground, big old trees and bee hotels")
What the General Public Should Do
The general public's role should be:
- Grow more flowers, shrubs and trees
- Let your garden grow wild
- Cut your grass less often
- Don't disturb insect nest and hibernation spots
- Think carefully about whether to use pesticides
What Governments Should Do
Dicks touched on 10 "pollinator policies" that governments should do:
- Raise pesticide regularly standards
- Promote integrated pest management
- Include indirect and sublethal effects in GM crop risk assessment
- Regulate movement of managed pollinators
- Develop incentives, such as insurance schemes, to help farmers benefit from ecosystem services instead of agrochemicals
- Recognize pollination as an agricultural input in a extension services
- Support diversified farming systems
- Conserve and restore 'green infrastructure” (a network of habitats that pollinators can move between) in agricultural and urban landscapes
- Develop long-term monitoring of pollinators and pollination
- Fund participatory research on improving yields in organic, diversified and ecologically intensive farming
Dicks, in her position at the University of East Anglia, engages in research in entomology, agroecology, management of biodiversity and ecosystem services on farms. (See research profile.)
In addition to addressing pollinator decline and "who needs to act and what should they do," the researcher touched on how to motivate people: "insights from the behavioral sciences; and the importance of local knowledge and culture."
Awareness and Understanding Are Not Sufficient
She offered key insights from behavioral science, noting that "awareness and understanding are not sufficient; decisions are not always rational; social norms are important; peer-to-peer communication within social groups drives behavior change and people must feel ABLE to act in their current context."
Dicks recommended that the attendees become acquainted with the work of the coalition Promote Pollinators (https://promotepollinators.org). An excerpt from the website: "Pollinators play a key role in the conservation of biological diversity, ecosystems, food production and the global economy. The effects of current human activities hamper animal pollination. Promote Pollinators, the Coalition of the Willing on Pollinators, reaches out to potential new partners to develop and implement national pollinator strategies. The coalition believes that country-led politics can foster policy measures and innovative action on protecting pollinators."
She also cited the work of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)
Dicks described pollinator decline as "a complex issue." People--including some politicians--have to change to help protect the pollinators and the ecosystem.
How Some Politicians Use Science
Dicks quoted author Mark Avery, former director of conservation at the Royal Society for the Protection of Birds: "I have rarely seen a policy argument won through logic and science, even though everybody pretends that they are. No, politicians use science like a drunk uses a lamp post--more for support than for illumination."
The conference, “Multidimensional Solutions to Current and Future Threats to Pollinator Health,” covered a wide range of topics in pollinator research: from genomics to ecology and their application to land use and management; to breeding of managed bees; and to monitoring of global pollinator populations. (See agenda.)
Dicks keynoted the conference on Thursday morning, July 18, and Christina Grozinger, distinguished professor of entomology and director of the Center for Pollinator Research, Pennsylvania State University, delivered a keynote address on Friday, July 19, discussing "Bee Nutritional Ecology: From Genes to Landscapes."
Pollination ecologist and professor Neal Williams and Extension apiculturist Elina Lastro Niño, both of the UC Davis Department of Entomology and Nematology, co-chaired the conference. Amina Harris, director of the UC Davis Honey and Pollination Center, and events manager Elizabeth Luu coordinated the four-day event.
Presenters from 15 Countries
Williams said that presenters represented 15 countries: Australia, Thailand, Korea, Japan, Colombia, Brazil, Israel, Mexico, France, Germany, Spain, Sweden, United Kingdom, Canada, and the United States. "And we had at least one attendee from China--although not presenting."
"This was the fourth International Conference on Pollinator Biology, Health and Policy," Williams said. "Each time we try to add new elements that address emerging challenges and new directions in research. This year's sessions felt as fresh and innovative as ever, adding symposia on climate change, innovative monitoring and data collection, and urban bees. By restricting presenters to those who had not presented in the past six years we also added new voices and perspectives."
"We also grew. In the past the conference has been just under 200 attendees. This year it topped 250, and we had to turn away several people because we simply could not fit more into the space. We added a second evening of posters to provide more time to interact. The response was overwhelming with 112 poster presenters!"
Williams said that the conference "also added more explicit policy elements by creating a set of ViewPOINTS documents summarizing key areas in pollinator biology and heath that target policy makers. This has allowed for collaborative interaction across the attendees and a set of deliverable products from our interactions."
The UC Davis Honey and Pollination Center, directed by Amina Harris, coordinated the conference, with events manager Elizabeth "Liz" Luu serving in the lead role.
"It was an amazing team effort pulling it all together," Williams said. "Liz Luu from the UC Davis Honey and Pollination Center (HRC) was in a word, fantastic, keeping every thing and everyone together. The HPC really showed what it can do and what tremendous value it adds to our campus. The organizing committee worked so well together, sharing the load throughout. A great set of colleagues!"
The next International Pollinator Conference will take place at Pennsylvania State University. Grozinger and Rufus Isaacs of Michigan State University launched the conference in 2012. They are held every third year.
(June 17-23 is National Pollinator Week.)
"How many? Does anyone know?"
No one did, but by the end of the Pollination Education Program, sponsored by CAMBP, all 72 youths from the Sutter Creek and Ione area of Amador County did: 20,000.
They also learned that there are 4000 species of bees in the United States, 1600 species in California, and 350 in Yolo County.
And they learned that pollinators include honey bees, bumble bees, butterflies, sweat bees, hummingbirds and syrphid flies.
"Can you all say entomologist?" Mather asked. "Does anyone know what entomology means?"
"Insects," said one youth.
"Yes, entomology is the scientific study of insects," Mather told them. That's what each and everyone of you is today: entomologists! Okay?
She explained the life cycle of a bee: from egg to larva to pupa to adult. "Males are called drones," she said. "Females are called worker bees."
Toward the end of the program, Mather told the students: "You are ready for the university. As soon as you graduate from high school, I hope to see you guys here. You are all excellent, very respectable, responsible and mature scientists. I want you to please take the knowledge that you gathered here today and share it with family and friends."
The Pollinator Education Program (PEP), developed two years ago by CAMPB director and Extension apiculturist Elina Lastro Niño of the UC Davis Department of Entomology and Nematology, along with staff research associate Bernardo Niño, aims to provide a fun, immersive educational experience "to help kids of all ages understand the importance pollinators play in the lives of humans."
At the recent session, Mather shared data on native bees, explained the life cycle of a honey bee, encouraged students to be citizen scientists, and demonstrated how to carefully collect bee specimens with a bee vacuum in a catch-and-release activity.
Volunteer Robin Lowry managed the “Planting for Pollinators” and “Be a Beekeeper” station. Students tried on beekeeping suits and tested the equipment, including a smoker and hive tools.
Volunteer Julia Wentzel introduced the concept of "pollinator specialists" and engaged the students in creating a "pollinator" which they then used to transfer "pollen" to different shaped flowers. Diverse floral sources are integral to honey bee health, she said.
Matthew Hoepfinger, staff research associate in the Niño lab, opened a bee hive (inside a screened tent) and showed the students the queen, workers and drones.
Just before boarding the buses for home, the students sampled several varietals of honey. "This is really good!" a girl said. "I want more."
Ron Antone of the UC Master Gardeners of Amador coordinates the annual program, working with Amador school officials, parents and master gardeners. This year he coordinated two groups:
- Jackson Elementary. 62 third graders, 3 teachers, 2 aides, 3 parents and 2 Master Gardener volunteers from Amador County.
- Ione Elementary. 72 third graders, 3 teachers, 7 parents, 3 Master Gardeners and 3 volunteers from Farms of Amador.
The UC Davis Department of Entomology and Nematology operates the Häagen-Dazs Honey Bee Haven, with Elina Lastro Niño serving as the garden's faculty director and Christine Casey as the manager. Two others from the Niño lab--staff research associate Charley Nye, manager of the Harry H. Laidlaw Jr. Honey Bee Research Facility, and staffer Christine Torres--assisted with the pollinator education programs.
"It takes a village as they say," Mather said.
That it does.
A tip of the bee veil to CAMBP, PEP, the Niño lab, and the UC Master Gardeners of Amador County for their roles in educating youth about pollinators.
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!