- Author: Kathy Keatley Garvey
A member of the Microbiology Graduate Group and the laboratory of community ecologist Rachel Vannette, associate professor and vice chair of the UC Davis Department of Entomology andNematology, he will deliver the Merton Love seminar from 3 to 4:30 p.m., Friday, May 24 in Room 1230 of Walker Hall. The Zoom link:
https://ucdavis.zoom.us/j/99429777483.
The award memorializes Robert Merton Love (1909-1994), emeritus professor of agronomy and range science, who served on the UC Davis faculty from 1940-1976.
“Shawn's thesis work spans microbiology, ecology and evolutionary biology, combined with careful natural history, to document novel species interactions between hosts and microbial communities,” said Vannette, who nominated him for the award. “Each chapter has broad implications for the ecology and evolution of host-microbe interactions. Shawn's work has already reframed the conditions under insect-microbe interactions are thought to hold relevance and evolve. His research has highlighted the utility of natural history observations of microbes and sampling understudied life history stages (overwintering developing insects).”
“Overall, Shawn's dissertation is an example of how detailed observations combined with fearless experimental dissection of interesting phenotypes can yield novel descriptions of species interactions that change the field's perception of when and where microbial communities are important,” she said.
“Shawn's first chapter describes adaptations of a flower specialist bacteria to acquiring resources from pollen—a nutrient source specific to flowers,” Vannette said. “Our lab was interested in the ecology of the flower-dwelling bacteria Acinetobacter, but Shawn took a new look at this bacterium, examining its growth morphology in nectar and in association with pollen. He noticed that this bacterium co-localized with pollen and grew exponentially more in the presence of pollen. To explore this phenotype, he designed new media and assays (microwaving pollen) to determine that Acinetobacter benefits the most from live pollen via stimulating pollen to germinate (within minutes!), then digesting it. Shawn then designed a series of experiments to examine if this ability was unique to this bacterial clade or shared among many floral microbes (it seems to be specific to Acinetobacter).”
“He collected brood cells (nectar and pollen balls along with developing larvae) from these locations at multiple points through bee development and examined not only the bacteria and fungal community composition through insect development, but also examined changes in microbial abundance at each life stage,” Vannette said. “In contrast to my (and the literature's) predictions, Shawn showed that microbial abundance peaks during larval overwintering, when solitary bees and other holometabolous insects are predicted to have voided their microbial gut communities. Instead, healthy A. bomboides hosts the highest abundance of fungi and bacteria during the fall—a wet season where pathogen abundance is also highest.”
Christensen received accolades and widespread media coverage for the first chapter of his dissertation, “Nectar Bacteria Stimulate Pollen Germination and Bursting to Enhance Microbial Fitness,” published in July 2021 in Current Biology. His second thesis chapter on the microbes associated with Anthophora bomboides, has just been accepted for publication by the International Society of Microbial Ecology (ISME).
And more good news: Christensen is a" co-principal investigator on a newly awarded grant by JGI to sequence the genome of the yeast," Vannette said, "and explore its functional potential in renewable energy and is applying to continue to leverage this system's potential in antifungal chemistry and evolution of pathogen defense.”
Every time we see the nests of Anthophora bomboides stanfordiana on the sand cliffs at Bodega Head, we think of the scientists, including Shawn Christensen and Rachel Vannette, who study them. The late Robbin Thorp, UC Davis distinguished emeritus professor, UC Davis Department of Entomology and Nematology, researched them decades ago.
Check out PBS' Deep Look video, "This Bee Builds Sandcastles at the Beach," and you'll never go to Bodega Bay without thinking of these digger bees.
- Author: Kathy Keatley Garvey
Get ready...it's happening...the annual World Bee Day...
Monday, May 20 is World Bee Day, as declared by the United Nations "to raise awareness of the importance of pollinators, the threats they face, and their contribution to sustainable development."
"The goal is to strengthen measures aimed at protecting bees and other pollinators, which would significantly contribute to solving problems related to the global food supply and eliminate hunger in developing countries," the website points out. "We all depend on pollinators and it is, therefore, crucial to monitor their decline and halt the loss of biodiversity."
Lately we've been noticing multiple species of bumble bees in our pollinator garden in Vacaville. One of them appears to be Bombus bifarius.
The bumbles we've seen over the years in our pollinator garden--B. californicus, B. melanopygus, B.vosnesenskii and B. bifarius--especially like Coreopsis, a genus of flowering plants in the aster family, Asteraceae. It's also called tickseed.
Now that's not a good name for such a showy flower!
- Author: Kathy Keatley Garvey
In the human world, we recognize Mother's Day as a special day to celebrate all mothers. It's a day that Anna Jarvis of Grafton, West Va., established on May 10, 1909 with a worship service at St. Andrew's Methodist Church, Grafton.
Lady beetles, aka ladybugs, are mothers, too. The female lays a batch of eggs, from 10 to 50, at one time, and can lay about 1000 eggs in her lifetime, scientists say.
Beneficial insects! Yes, but in their larval form they eat even more.
Mature lady beetles will feed on 20 to 25 aphids per day, but their late-stage larvae will consume 10 times that number, making them far more effective predators, according to Whitney Cranshaw, a professor and Extension entomologist with Colorado State University (now emeritus), in a July 2018 article in Phys.Org.
A salute to lady beetles and their larvae on Mother's Day!
- Author: Kathy Keatley Garvey
Being bothered by mosquitoes and troubled about the risk of diseases?
Mosquitoes are not just annoying. They can be deadly.
The seminar, titled "Natural Mosquito Control," is part of the California Farm Academy Speaker Series, and will take place from 4:30 to 7:30 p.m. at CLBL, located at 40140 Best Ranch Road, Woodland. The event begins with pizza and mingling, “until about 5:30, and then the presentation,” said spokesperson Julia Hobbs Thomas. Reservations can be made on Eventbrite.com at this link.
The event is billed as "a discussion about both native and invasive species, what diseases they can spread, and how healthy ecosystems can create habitats that keep them in check. Agriculture can play a big role, because pesticide use can damage populations of beneficial insects like dragonflies. You'll also pick up a few tips to avoid being bitten!"
Wood-fired pizza and beverages will served beneath the canopy of a century-old valley oak, she added. Attendees can also bring food or beverages to enjoy or share.
Said Attardo: “I will be focusing on educating people about the most imminent risks of mosquito-borne diseases in California coming from West Nile Virus—due to native Culex mosquitoes predominantly—and Aedes aegypti vectored diseases such as dengue, Zika, Chikungunya, and yellow fever. I'll discuss places these mosquitoes breed in suburban and urban habitats, as well as ways people can eliminate and prevent creation of breeding sites.“
Attardo specializes in medical entomology, reproductive physiology, molecular biology and genetics. He recently hosted a UC Davis symposium, sponsored by the Deaprtment of Entomology and Nematology and the Pacific Southwest Center of Excellence in Vector-Borne Diseases, on “Tule and Cattail: A Tale of the Marsh Economy and Its Role in Human Health and Wellbeing” that aimed "to advance the land management aims of local tribal communities and provide a platform to educate about the importance of maintaining wetland biology for climate change, ecological and human health, and vector control." Attardo addressed the symposium with collaborator Diana Almendariz, a traditional ecological knowledge specialist and a cultural practitioner of Maidu/Wintun, Hupa/Yurok traditions, heritage, and experiences.
A global expert on vectorborne diseases, and renowned for his groundbreaking work on tsetse flies, Attardo received the Medical, Urban, and Veterinary Entomology Award in 2022 from the Pacific Branch, Entomological Society of America. (See news story)
He joined the UC Davis Department of Entomology and Nematology in 2017 from the Yale School of Public Health, where he served as a research scientist studying the reproductive biology of tsetse flies. Attardo holds a doctorate in genetics (2004) from Michigan State University, studying with Alexander Raikhel.
For more information on the May 15 seminar, contact Thomas at julia@landbasedlearning.org or 415-271-0090.
- Author: Kathy Keatley Garvey
It was all the buzz.
Thousands of bee and honey enthusiasts made a beeline for the California Honey Festival, held last Saturday on the Yolo County Fairgrounds.
The annual festival, relocated this year from the streets of downtown Woodland to the fairgrounds due to a weather forecast cautioning heavy rain and wind, drew scores of smiles beneath the arched umbrellas.
Beekeeper Rick Moehrke, a retired Vacaville teacher, answered questions about bees in the Sacramento Area Beekeepers' Association booth.
American Honey Queen Kaelyn Sumner of Cecil, Wisc., a beekeeper and a senior at Kansas State University discussed queen bees, worker bees and drones. She is majoring in agricultural education and minoring in food science and entomology.
Charles McMaster, a U.S. Army veteran from Copperas Cove, Texas, headed the Hives for Heroes booth. The national non-profit service organization focuses on sustainability, conservation, and providing a healthy transition from service: "Through our national network of beekeepers, we provide connection, purpose, and healthy relationships, through access, resources, and funding for Active Duty, Veterans, and First Responders.">
Steve Hays, retired sheriff's deputy, Sacramento County and founder of Second Chance Beekeeping Reentry Service, chronicled the history of his program and how inmates are learning beekeeping and getting "a second chance." (See news story)
Amina Harris, retired founding director of the UC Davis Honey and Pollination Center and now the "Queen Bee" of her family's Woodland-based Z Food Specialty and The HIVE, offered guests "a taste of honey" from all over California. They also sold honey, including a family favorite, starthistle. Harris co-founded the California Honey Festival in 2017 with the City of Woodland.
Attendees tasted and purchased Hawaiian honey, with such varietals as Eucalyptus, macadamia, mango, Christmas bush, tropical blossom and wildflower, from "Queen Bee" Inna Eyrih, business owner of Hawaiian Honey AT&S, a company based in Hawaii (Keaau) and California.
GATEways horticulturist Rachel Davis of the UC Davis Arboretum and Public Garden discussed pollinator gardening, focusing on native bees, butterflies, moths, hoverflies, and hummingbirds.
This year's California Honey Festival lived up to its mission: to emphasize the importance of bees and to promote honey and bee products. The annual festival, co-sponsored by UC Davis, features educational presentations, kids' center activities, honey tasting, cooking demonstrations, a beer and mead garden, live music, vendors and more.
