- Author: Kathy Keatley Garvey
Seen any bumble bees lately?
No? Me, neither.
It's almost the first day of spring, and bumble bees are as scarce as the proverbial hen's teeth. (Hens have no teeth, y'know.)
We've been watching our nectarine tree bloom. It's drawing honey bees, but no bumble bees.
Back on March 18, 2018, we spotted a number of bumble bees, including Bombus melanopygus, also known as the black-tailed bumble bee. This is one of the 27 species of bumble bees in California. We frequently see the yellow-faced bumble bee, Bombus vosnesenskii, and sometimes Bombus californicus, aka the California bumble bee.
Our March 18, 2018 "poster child" on our nectarine tree, Bombus melanopygus, appeared to be nesting nearby, due to her frequent visits.
National Public Radio reported on Feb. 6, 2020 that bumble bees are declining because of the extreme heat: "Extreme temperatures are driving a dramatic decline in bumble bees across North America and Europe, according to a new study, in yet another way climate change is putting ecosystems at risk.
"Researchers looked at half a million records showing where bumble bees have been found since 1901, across 66 different species. They found that in places where bumblebees have lived in North America, you're about half as likely to see one today. The decline is especially pronounced in Mexico, where bumble bees once lived in abundance."
Pesticides and habitat loss are also key factors. Says National Geographic in a Feb. 6, 2020 article titled Bumble Bees Are Going Extinct in a Time of 'Climate Chaos': "Climate change is not the only factor behind the insects' decline. They are also threatened by pesticides like neonicotinoids—which are extremely toxic to all bees—destruction of habitat by development and conversion of wildlands into agriculture, the spread of pathogens, and the release of non-native bees for commercial pollination."
If you're interested in learning more about bumble bees, check out the book, California Bees and Blooms: a Guide for Gardeners and Naturalists, the work of UC Davis and UC Berkeley scientists, including Robbin Thorp (1933-2019), distinguished emeritus professor of entomology at UC Davis, who also co-authored Bumble Bees of North America: an Identification Guide.
And if you see any bumble bees in your backyard in your yard between July 23 and Aug. 1, join the Third Annual Backyard Bumble Bee Count at https://www.inaturalist.org/projects/backyard-bumble-bee-count
As inaturalist.org says on its website: "Each bumble bee record submitted during the Backyard Bumble Bee Count helps researchers learn more about how bumble bees are doing and how to protect them and the environment we share. All observations collected July 23- August 1 will be included. For more information, including instructions, go to: https://backyardbbcount.wixsite.com/bumblebeecount."
- Author: Kathy Keatley Garvey
“Nature is more a world of scents than a source of noise.”
So said renowned organic chemist Wittko Francke (1940-2020) of the University of Hamburg, Germany, when he presented a UC Davis Department of Entomology and Nematology seminar at Briggs Hall on Dec. 8, 2010.
He was quoting Jacques Le Magnen (1916-2002), who pioneered research on olfaction and taste.
Professor Francke said that insects communicate in a chemical language or chemical signals. Scientists have long known that methods that can attract or repel insects have important applications for agricultural pests and medical entomology.
He told the crowd how a queen bee secretes compounds that regulate development and behavior of the colony, and how an orchid releases the scent of a female wasp to attract male wasps—activities that result in pollination. He also touched on the “calling cards” of a number of other insects, including bumble bees, wasps, pea gall midges, stingless bees, bark beetles and leafminers, and pointed out that plants, too, send chemical signals.
Sadly, Francke passed away Dec. 27, 2020 at age 80.
"The scientific community loses a very productive and passionate researcher, a great colleague, mentor and friend," wrote former student Jan Bergmann of the Pontifica Universidad Católica de Valparaíso, Chile, a past president of the Latin American Association of Chemical Ecology. Bergmann's tribute appears on one of @ALAEQ2 tweets.
And sadly, the chemical ecologist who introduced Francke at the UC Davis seminar--Steve Seybold of the USDA Forest Service, Pacific Southwest Research Station, Davis, and an affiliate of the UC Davis Department of Entomology and Nematology--died Nov. 15, 2019 at age 60.
No stranger to UC Davis, Francke collaborated with chemical ecologist Walter Leal, a UC Davis distinguished professor of molecular and cellulary biology and former chair of the entomology department, on attractants for navel orangeworm. In his talk, Francke mentioned Leal's discovery of a sophisticated mechanism for the isolation of the chemical communication channels of two species of scarab beetles.
To celebrate the life and legacy of Francke and his work, Leal is organizing an online symposium set for 10 a.m. (Pacific Time) on Saturday, April 3. Register to participate or attend at https://tinyurl.com/3jsfcub7
Francke was one of the great pioneers shaping chemical ecology and the International Society of Chemical Ecology (ISCE), said Leal, an ISCE past president.
Born Nov. 28, 1940 and raised in Reinbek, near Hamburg, Germany, Francke studied chemistry at the University of Hamburg, obtaining his doctorate there in 1973. His thesis: "The Aggregation Pheromone of the Bark Beetle, Xyloterus domesticus. He was appointed professor of the Institute of Organic Chemistry of the University of Hamburg in 1985 and had served there until after his retirement.
A colleague once called him "The Mozart of Molecules," which Bergmann noted, "summarizes eloquently the admiration of many had for his work, which is documented in more than 450 scientific publications." Among Francke's many global honors: the 1995 ISCE Silver Medal.
Francke was not only an "outstanding, hard-working scientist" but a "loving husband, father of two children and grandather of four grandchildren," Bergmann wrote. "He was also a person with incredible kindness and generosity....He enjoyed bringing people together and deeply cared about his students, many of which stayed in touch with him long after they left his research group. His legacy will live on in those of us he has inspired and guided in so many ways."
Former Francke student Stefan Schulz, a professor at the Institute of Organic Chemistry, Germany, an ISCE past president, wrote on the symposium's registration page: "Even in his early years, he showed some characteristics many associates with him, such as energy, determination, imagination, and creativity. Despite several offers, he stayed his whole academic career at the University of Hamburg, where he finally became a Full Professor and served different functions, including Dean of Chemistry. He always liked to teach, which he did happily even in his later years."
Max Planck Institute for Chemical Ecology tweeted Dec. 29, 2020: "Wittko Francke's death is a severe loss for the field of Chemical Ecology. He was not only a great chemist, but he also had a large influence on the development of our institute being a key member of the advisory committee that set up our institute."
On April 3, the scientific and personal world of Professor Francke will come together to remember his life and legacy and pay tribute to "The Mozart of Molecules."
- Author: Kathy Keatley Garvey
The species has now reached at least 17 California counties and its successful spread may be linked to its resistance to pyrethroids, according to newly published UC Davis research examining genetic markers of resistance at five state locations.
The work, published in the current edition of Parasites & Vectors, a BioMed Central open-access medical journal, focuses on “determining how informative well-established genetic markers of resistance to pyrethroids are in predicting the resistance phenotype of individual mosquitoes of Aedes aegypti within a population,” said Attardo, the lead author.
“Specifically, we generated mosquito colonies from invasive A. aegypti populations from four locations in the Central Valley (Dinuba, Clovis, Sanger and Kingsburg) and from collections in the Greater Los Angeles Area,” he said. “Mosquitoes from these populations have all demonstrated resistance to pyrethroid-type insecticides and we think this may be part of the reason why these mosquitoes have been so successful in spreading throughout California.”
A. aegypti transmits such viruses as dengue, Zika, chikungunya, and yellow fever. Despite California's aggressive surveillance and treatment efforts, this species presents a “significant challenge to local control agencies,” the nine-member team wrote in their research paper, “Frequency of Sodium Channel Genotypes and Association with Pyrethrum Knockdown Time in Populations of Californian Aedes aegypti.“
The paper is online and publicly accessible at https://bit.ly/3vmUxXR.
“What was interesting was that while all the mosquitoes from California show resistance to pyrethroids, there is a lot of variability from one individual to the next in terms of the level of resistance, even when they are carrying genetically identical resistance mutations,” Attardo said. “In particular, there seem to be two levels of resistance in these populations. The two levels seem to represent a resistant group and a super resistant group. However, the proportions of resistant/super-resistant differ in the sampled mosquitoes from population to population.”
Of particular interest was that mosquitoes carrying the resistance mutations at all five genetic locations were very resistant, he said. “However, there was also a large amount of unexplained variability in terms of the knockdown phenotypes demonstrated by mosquitoes of the same age and rearing conditions. We compared the knockdown times of mosquitoes positive for all five resistance mutations from different populations and found that these mutations account for only a proportion of the observed level of resistance. We believe that the unexplained variability is likely being mediated by the presence or absence of an undefined resistance mechanism.”
Although A. aegypti was first detected in California in 2013, researchers believe that its arrival involved multiple introductions. Populations in Southern California are thought to have crossed the border from Mexico, while Central Valley populations may have been introduced, in part, from the southeastern United States.
“Upon detection in 2013, the Consolidated Mosquito Abatement District implemented an integrated vector control management strategy which involved extensive public education, thorough property inspections, sanitation, insecticide treatment at larval sources and residual barrier spraying with pyrethroids,” the authors wrote. Despite their efforts, the species successfully overwintered and continued to spread, implicating that it arrived in California with genetic mutations “conferring resistance to the type I pyrethroid insecticides applied for vector control in California.”
The co-authors include former UC Davis mosquito researcher Yoosook Lee, now at the University of Florida-Florida Medical Entomology Laboratory, Vero Beach; research entomologist Anthony Cornel and staff research associate Katherine Brisco of the Mosquito Control Research Laboratory, Kearney Agriculture and Extension Center and UC Davis Department of Entomology and Nematology; and Lindsey Mack, Erin Taylor Kelly, Katherine Brisco, Kaiyuan Victoria Shen, Aamina Zahid, and Tess van Schoor, all with the UC Davis Department of Entomology and Nematology.
For more information and photos, see news story on "UC Davis Researches Examine Pyrethroid Reistance in Spread of Aedes aegypti," on the UC Davis Department of Entomology and Nematology's website.
- Author: Kathy Keatley Garvey
If you're a beekeeper, a food retailer, in honey production or just want to know more about honey adulteration and food authenticity and what you can do about it, this one's for you.
An online Honey Adulteration Symposium, hosted by the UC Davis Honey and Pollination Center and featuring keynote speaker Michael T. Roberts of the Resnick Center for Food Law and Policy at the UCLA School of Law, will take place Thursday, April 22 from 9 to 11:30 a.m.
Registration for the 2.5-hour symposium ($30 per ticket) is underway here. The last day to register is April 18.
Amina Harris, director of the Honey and Pollination Center, said the symposium is an opportunity "to learn how honey adulteration affects our food system and an opportunity to take action. Honey is the world's third most adulterated food, right after milk and olive oil."
The symposium, she said, is geared toward "educating specialty food retailers who actively educate their consumers." Presenters will address issues of pollination, economic adulteration and threats to beekeeping. A panel of specialty food retailers will discuss how they source and select products and educate and inspire their customers.
According to his website: "Roberts entered the field of food law when, in 2000, he left his law practice and enrolled in the LL.M. program on agricultural law at the University of Arkansas School of Law, the only such program in the U.S. Since then, Roberts has engaged in a variety of professional capacities related to food law and policy. A few years after completing the LL.M. program, he was invited to join the University of Arkansas School of Law as a Research Professor of Law and as the Director of the National Agricultural Law Center. Roberts has broad experience in practicing food law, including being of counsel in Washington D.C. with Venable LLP, as a member of the firm's food and agricultural law practice group. He was also a visiting scholar and consultant to the FAO in Rome."
Roberts teaches two courses at UCLA Law: "Introduction to Food Law and Policy" (for second- and third-year law students) and "Emerging Scholarship in International Food Law" (a "modes" class for first-year law students). He has also been instrumental in the organization of a UCLA food studies certificate graduate program and was the co-instructor of the program's Introduction to Food Studies course.
The Resnick Center performs cutting-edge legal research and scholarship in food law and policy to improve health and quality of life for humans and the planet, according to its website.
Also, at the UC Davis symposium, five retailers will discuss the ways they educate their customers. The speakers are:
- Amelia Rappaport, Woodstock Farmers' Market, Woodstock, Vermont
- Danielle Vogel, Glen's Garden Market, Washington, DC
- Grace Singleton, Zingerman's Deli, Ann Harbor, Mich.
- Kendall Antonelli, Antonelli Cheese Shop, Austin, Texas
- Ralph Mogannam, Bi-Rite Family of Businesses, San Francisco
Among the other speakers will be Chris Hiatt, vice president, American Honey Producers Association, and a third-generation beekeeper at Hiatt Honey, Madera, Calif., who will share his insights.
Lead sponsor is Nature's Nate, but other sponsors are needed, Harris said. She may be contacted at aharris@ucdavis.edu for more information.
The Honey and Pollination Center, affiliated with the UC Davis Department of Entomology and Nematology and the College of Agricultural and Environmental Sciences, is located in the Robert Mondavi Institute on Old Davis Road, UC Davis campus.
- Author: Kathy Keatley Garvey
The event, the Eric Conn Memorial Biochemistry Games, not only memorialized a UC Davis plant biochemist, but offered “ZOOM fatigue relief” for UC Davis undergraduate students and Cardiff University students studying biochemistry, said organizer and moderator Walter Leal, UC Davis distinguished professor of molecular and cellular biology.
“They had so much fun,” said Leal, a former chair of the UC Davis Department of Entomology. “Ten years from now, most of these students will be in another field and professions unrelated to biochemistry. Those not remaining in biochemistry will probably forget everything they learned this quarter. However, all students who participated will never forget this experience. In the middle of a pandemic and suffering from ZOOM fatigue, they made new friends across the pond. Eric Conn would be happy to see undergraduate students having this experience.”
UC Davis won the event, but “UC Davis had a competitive advantage because this was their second game,” Leal noted. “Everything was new for Cardiff. Additionally, the contents of our syllabi differ.”
Catherine Rodriguez, a microbiology major, captained the six-member UC Davis Team, known as the Ironic Bonds. Fellow team members: Kelly Brandt (biochemistry and molecular biology major), Jiaying Liu (biological sciences), Aly Lodigiana (cellular biology), Efrain Santos (neurobiology, physiology and behavior) and Mary Aina (psychology).
The Cardiff team: spokesperson Jessie Vaughan, and members Marianna Gisdaki, Kia Blackburn, Ellie Whitworth, Alice Pike, and Anastasia Rouchota.
The event also cemented friendships. “A student from UC Davis reached out to become an electronic pen-pal with Cardiff students,” Leal said, adding that “both Cardiff and UC Davis parents wrote direct emails indicating how pleased they were with the event.”
The deans will exchange hoodies. Also, all participants will receive certificates.
UC Davis Chancellor Gary May delivered the welcoming address. While the students were answering questions, Dr. Dean Blumberg of UC Davis Health fielded questions on COVID-19 vaccines.
Nearly 300 logged-in to see the three games: two preliminary games with UC Davis students competing for slots on the final team, and the UC Davis/Cardiff game. The Ironic Bonds defeated the Gibbs Team in the preliminary. “Every student who played on Wednesday will receive a gift card,” Leal said.
Other judges were Cardiff faculty member D. Dafydd Jones; UC Davis emeritus professor Charles Gasser, and UC Davis distinguished research professor Clark Lagarias, a member of the National Academy of Sciences.
Professor Conn also enjoyed close ties with Professor Gasser. “It was Eric who persuaded Charles, then in the private sector, to apply for a position at UC Davis,” Leal related. “Then when Charles joined UC Davis faculty, Eric gave him his lab, which he used until his retirement.”
Two Cardiff faculty members with links to UC Davis assisted with organizing the event and reading the questions:
- Mark Young, a senior lecturer, lived in Davis as a child while his father Thomas Young, taught brewing at UC Davis
- Wynand van der Goes van Naters, a lecturer, is an associate of Leal's, spanning back to when they both lived and worked in Japan. “His research is also focused on insect olfaction,” Leal said. “He was the person I reached out to make the initial contact.”
Some of the Questions Asked
Some of the questions the students answered at the event:
Question: “What is one of the ways that humans adapt to high altitudes by virtue of what happens to hemoglobin?”
Answer: “Increase production of a compound named 2,3-BPG that leads to increase delivery of oxygen.”
Question: “Which portion of the spike protein moves up and down to either evade the immune system or allow virus entry to the host cell to occur?”
Answer: “The receptor-binding domain.”
Question: “A1c is a blood test that measures your average blood sugar levels over the past 3 months. The A1c test measures the percentage of your red blood cells that have sugar-bound hemoglobin. Which ligand binds to hemoglobin as your blood sugar does, albeit in a reversible fashion?”
Answer: “Carbon dioxide”
Question: “Why can crocodiles stay underwater for such a long time without drowning?”
Answer: “Their hemoglobin binds to bicarbonate and reduces affinity for oxygen (at the tissues).”
Question: “In the so-called UK variant of the SARS-CoV-2 virus the amino acid residue asparagine in the receptor-binding domain at position 501 is replaced by which amino acid?”
Answer: “Tyrosine”
Question: “Why the change of a single amino acid, glutamic acid to valine, in hemoglobin leads to sickle cell disease?”
Answer: “It causes aggregation of hemoglobin due to hydrophobic interactions.”
A poll of the viewers indicated 80 percent felt “very satisfied” with the event. Due to EU regulations, the event will not be posted on YouTube for public viewing.
Professor Conn (1923-2017) was a fellow of the National Academy of Sciences. A member of the UC Davis faculty for 43 years, he was the third recipient of the UC Davis Prize for Teaching and Scholarly Achievement. Described as an excellent teacher and researcher, he received the Academic Senate's Distinguished Teaching Award in 1974 and the Academic Senate's highest honor, the Faculty Research Lecturer Award, in 1977. He won the UC Davis Prize for Undergraduate Teaching and Scholarly Achievement in 1989. See https://youtu.be/TdwJkcjQvbw.