The exciting research of Takato Imazumi of the University of Washington.
If you read Scientific Reports, you probably remember the piece he co-authored: "Circadian Clocks of Both Plants and Pollinators Influence Flower-Seeking Behavior of the Pollinator Hawkmoth Manduca sexta," published Feb. 12, 2018.
"Most plant-pollinator interactions occur during specific periods during the day. To facilitate these interactions, many flowers are known to display their attractive qualities, such as scent emission and petal opening, in a daily rhythmic fashion. However, less is known about how the internal timing mechanisms (the circadian clocks) of plants and animals influence their daily interactions. We examine the role of the circadian clock in modulating the interaction between Petunia and one of its pollinators, the hawkmoth Manduca sexta. We find that desynchronization of the Petunia circadian clock affects moth visitation preference for Petunia flowers. Similarly, moths with circadian time aligned to plants show stronger flower-foraging activities than moths that lack this alignment."
"Moth locomotor activity is circadian clock-regulated, although it is also strongly repressed by light. Moths show a time-dependent burst increase in flight activity during subjective night. In addition, moth antennal responsiveness to the floral scent compounds exhibits a 24-hour rhythm in both continuous light and dark conditions. This study highlights the importance of the circadian clocks in both plants and animals as a crucial factor in initiating specialized plant-pollinator relationships."
And now, Imazumi will head to the University of California, Davis to present a seminar hosted by the UC Davis Department of Entomology and Nematology. His seminar, titled "Circadian Timing Mechanisms in Plant-Pollinator Interaction," is scheduled for 4:10 p.m., Wednesday, Oct. 30 in 122 Briggs Hall, off Kleiber Hall Drive.
"He will be speaking about his work on circadian clocks of plants and pollinators, and how circadian timing can shape plant-pollinator relationships," said molecular geneticist and physiologist Joanna Chiu, associate professor and vice chair of the UC Davis Department of Entomology and Nematology. Chiu, a UC Davis Chancellor Fellow, will introduce him.
Wait, there's more! "Not So Heartless: Functional Integration of the Immune and Circulatory Systems of Mosquitoes."
This may not be the proverbial heart-stopping seminar, but it promises to be an eye opener by a medical entomologist and captivating speaker.
Julián Hillyer, associate professor of biological sciences, Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, Tenn., will deliver that seminar at 4:10 p.m., Wednesday, Oct. 23, in 122 Briggs Hall, as part of the weekly UC Davis Department of Entomology and Nematology seminars.
"Mosquitoes--like all other animals--live under constant threat of infection," Hillyer says in his abstract. "Viral, bacterial, fungal, protozoan and metazoan pathogens infect mosquitoes through breaches in their exoskeleton and following ingestion. Because these pathogens pose a threat to their survival, mosquitoes have evolved a powerful immune system."
In his seminar, Hillyer will present his laboratory's work characterizing the circulatory and immune systems of the African malaria mosquito, Anopheles gambiae. "Specifically," he says. "the talk will describe the structural mechanism of hemolymph (insect blood), circulation in different mosquito life stages, and the role that immune cells, called hemocytes play in the killing of pathogens by phagocytosis, melanization and lysis. Then I will describe the functional integration of the circulatory and immune systems a process that is manifested differently in larvae and adults. Specifically, the infection of an adult mosquito induces the aggregation of hemocytes at the abdominal ostia (valves) of the heart--where they sequester and kill pathogens in areas of high hemolymph flow--whereas the hemocytes of larvae aggregate instead on respiratory structures that flank the posterior in current openings of the heart."
"This research," Hillyer explains, "informs on the physiological interaction between two major organ systems and uncovers parallels between how the organ systems of invertebrate and vertebrate animals interact during the course of an infection."
What does the mosquito heart look like? Check out former Vanderbilt graduate student Jonas King's prize-winning image--a fluorescent image of the heart of a mosquito. It won first place in Nikon's "Small World'" photomicrography competition in 2010. King's image shows a section of the tube-like mosquito heart magnified 100 times. At the time he was a member of Hillyer's research group and is now an assistant professor at Mississippi State University.
In a piece by David Salisbury of Vanderbilt News, Hillyer related that "Surprisingly little is known about the mosquito's circulatory system despite the key role that it plays in spreading the malaria parasite. Because of the importance of this system, we expect better understanding of its biology will contribute to the development of novel pest- and disease-control strategies.”
"The mosquito's heart and circulatory system is dramatically different from that of mammals and humans," wrote Salisbury in the Oct. 15, 2010 piece. "A long tube extends from the insect's head to tail and is hung just under the cuticle shell that forms the mosquito's back. The heart makes up the rear two-thirds of the tube and consists of a series of valves within the tube and helical coils of muscle that surround the tube. These muscles cause the tube to expand and contract, producing a worm-like peristaltic pumping action. Most of the time, the heart pumps the mosquito's blood—a clear liquid called hemolymph—toward the mosquito's head, but occasionally it reverses direction. The mosquito doesn't have arteries and veins like mammals. Instead, the blood flows from the heart into the abdominal cavity and eventually cycles back through the heart."
“The mosquito's heart works something like the pump in a garden fountain,” Hillyer told Salisbury.
Hillyer was a Vanderbilt Chancellor Faculty Fellow (2016-2018) and was awarded the 2015 Henry Baldwin Ward Medal by the America Society of Parasitologists. He was elected to the Council of the American Society of Parasitologists, serving from 2012-2016. Other recent awards: the 2011 Jeffrey Nordhous Award for Excellence in Undergraduate Teaching and the 2012 Recognition Award in Insect Physiology, Biochemistry and Toxicology from the Southeastern Branch of the Entomological Society of America.
Hillyer received his master's degree and doctorate from the University of Wisconsin-Madison under the mentorship of Ralph Albrecht and Bruce Christensen, respectively. He completed a postdoctoral fellowship under the mentorship of Kenneth Vernick at the University of Minnesota, now with Institut Pasteur. In 2007, Hillyer moved to Nashville, Tenn. to establish Vanderbilt University's mosquito immunology and physiology laboratory. (See more.)
The Hillyer Lab is interested in basic aspects of mosquito immunology and physiology, focusing on the mechanical and molecular bases of hemolymph (blood) propulsion, and the immunological interaction between mosquitoes and pathogens in the hemocoel (body cavity)," according to his website. "Given that chemical and biological insecticides function in the mosquito hemocoel, and that disease-causing pathogens traverse this compartment prior to being transmitted, we expect that our research will contribute to the development of novel pest and disease control strategies."
Host is Olivia Winokur, doctoral student in the Chris Barker lab. Community ecologist Rachel Vannette, assistant professor, Department of Entomology and Nematology, coordinates the weekly seminars. (See list of seminars)
Scientists, conservationists and citizen scientists were there to discuss "Recovering the Western Monarch Butterfly Population: Identifying Opportunities for Scaling Monarch Habitat in California's Central Valley."
"The western population of the monarch butterfly has garnered widespread attention because of its dramatic decline in recent decades," the Environmental Defense Fund said in its opening statements. "The latest population surveys indicate that monarchs overwintering on the central coast have declined 86% since last winter and now total 0.5% of their historical average. Population declines have spurred greater scientific study, funding, and coordination around the western monarch. California legislators appropriated $3 million in funding to the California Wildlife Conservation Board to establish the Monarch Butterfly and Pollinator Rescue Program."
In his presentation, Shapiro told the group: "As of right now, the monarch is on life support in California, and we are reduced to prescribing placebos. If our patient comes back from the brink—as history suggests it may well—will we convince ourselves that our placebos worked? Probably. And that's not how to do science. That's what philosophers call the fallacy of post hoc, ergo propter hoc." (See Shapiro's other comments)
Shapiro, who has monitored the butterfly populations of central California for more than four decades, posts his research on his website, Art's Butterfly World.
Meanwhile, the widespread interest in monarchs continues to widen. What's happening with the monarchs this year?
If you're a University of California Master Gardener and want an update on the status of Western monarchs, be sure to attend Shapiro's presentation at the UC Master Gardeners' Fall Conference on Saturday, Oct. 26 in the Veterans Memorial Senior Center, 1455 Madison Ave., Redwood City.
The event, to take place from 9:30 a.m. to 3 p.m., includes a talk by Shapiro from 1:15 to 2:45 p.m. on "The Controversy on the Western Monarch Monarch Butterfly."
- 9:30-9:45: Welcome and Introductions, Shirley Melnicoe, president and Kali Burke, new program coordinator
- 9:35-10: Recognition, Ginny Piazza, membership chair
- 10 to 11: Soils Group presentation by Master Gardeners Joe Lees and Nick Landolfi
- 11 to 11:15: Break
- 11:15 to 11:45: Igor Lacan, UC Cooperative Extension Advisor for San Francisco Bay Area, The Odonata Order – The Mystery of Dragonflies
- 11:45 to noon: Sheena Sidhu, staff biologist, San Mateo County Department of Agriculture on Pests and Diseases, Latest Pests & Diseases in San Mateo County
- 12 to 1: Lunch
- 1 to 1:15: Master Gardeners leading some exercises, to be announced
- 1:15 to 2:45: Arthur M. Shapiro, UC Davis distinguished professor of evolution and ecology, The Controversy on the Western Monarch Butterfly
- 2:45-3: Closing comments/wrap-up
The highly respected California Academy of Sciences greeted its 2019 Class of Fellows on Oct. 15, and one of them is a pollination ecologist from the University of California, Davis.
Professor Neal Williams of the UC Davis Department of Entomology and Nematology was inducted into the scientific organization at the annual Bay Area gathering of the Fellows. The group includes more than 450 distinguished scientists who have made notable contributions to science.
Fellows nominate others for the high honor, and then the California Academy of Sciences' Board of Trustees votes on the nominees. James R. Carey, distinguished professor of entomology, nominated Williams, with Claire Kremen of the University of British Columbia, formerly of UC Berkeley, seconding the nomination. Maverakis was nominated by Walter Leal, distinguished professor, UC Davis Department of Molecular and Cellular Biology, and a former chair of the entomology department.
In his letter of nomination, Carey wrote that Williams is “widely known and respected for his excellence in research, extension, outreach, teaching and leadership” and “is not only one of the stars of our campus, and the UC system, but is an internationally recognized leader in pollination and bee biology and strong voice in the development of collaborative research on insect ecology. He has organized national and international conferences, leads scores of working groups, and guides reviews of impacts of land use and other global change drivers on insects and the ecosystem services they provide.”
The UC Davis professor served as co-chair (with Extension apiclturist Elina Lastro Niño) of the seventh annual International Pollinator Conference, a four-day conference held July 17-20 on the UC Davis campus. The global conference focused on pollinator biology health and policy.
In his work--a labor of love--Williams seeks and finds found common solutions for sustaining both wild and managed bees and communicates that information to the public and stakeholder groups. Said Carey: “This is a critical perspective in natural and agricultural lands, but also in urban landscapes in northern and southern California.”
Each year the UC Davis professor speaks to multiple beekeeper, farmer and gardener groups, and provides guidance to governing bodies, including the state legislature, and environmental groups. He and his lab are involved in a newly initiated California Bombus assessment project, which is using both museum and citizen scientist records to understand past, current and future distributions and habitat use by bumble bees. This program will host a series of workshops this spring and summer open to practitioners and the public.
Williams received his doctorate in ecology and evolution in 1999 from the State University of New York, Stony Brook and served as an assistant professor in the Department of Biology at Bryn Mawr (Penn.) College from 2004 to 2009. He joined the UC Davis faculty in 2009, advancing to full professor in 2017.
His honors and awards are numerous. Williams was part of the UC Davis Bee Team that won the Team Research Award from the Pacific Branch, Entomological Society of America (PBESA) in 2013. In 2015, he was named a five-year Chancellor's Fellow, receiving $25,000 to support his research, teaching and public service activities. And then earlier this year, Williams received PBESA's Plant-Insect Ecosystems Award, presented annually for outstanding accomplishments in the study of insect interrelationships with plants.
In addition to Carey, five others affiliated with UC Davis Department of Entomology and Nematology are Fellows of the California Academy of Sciences:
- Professor Phil Ward, ant specialist
- Frank Zalom, integrated pest management specialist and distinguished professor of entomology. He is a past president of the Entomological Society of America
- Robert E. Page Jr., bee scientist and UC Davis distinguished emeritus professor. He is a former chair of the UC Davis Department of Entomology and provost emeritus of Arizona State University
- Walter Leal, distinguished professor, UC Davis Department of Molecular and Cellular Biology, and a former chair of the entomology department; and
- Visiting scientist Catherine Tauber, formerly of Cornell University.
Former Fellows from the UC Davis entomology department include Robbin Thorp (1933-2019), distinguished emeritus professor of entomology, and visiting scientist Maurice Tauber (1931-2014), formerly of Cornell University.
It's commonly called a "passion butterfly," but we call it a Gulf Fritillary (Agraulis vanillaea) or Gulf Frit.
A sure sign of autumn:
- A skeletonized passionflower vine (Passiflora)
- A Gulf Fritillary (Agraulis vanillae) eclosing
- A ravenous caterpillar crawling along a stem, and
- A caterpillar J'ing, about to form a chrysalis.
The orange-reddish butterfly, with its silver-spangled underwings, is a glorious butterfly.
How's the population doing this year?
Butterfly guru Art Shapiro, UC Davis professor of evolution and ecology, who has monitored the butterfly populations of central California for more than four decades and posts his research on Art's Butterfly World, says this year the Gulf Frit population is "spotty; locally abundant but less generally distributed than in recent years."
His 10 field sites stretch from the Sacramento River Delta through the Sacramento Valley and Sierra Nevada mountains to the high desert of the Western Great Basin.
We notice the ups and downs of the Gulf Frit population every year in Vacaville. This spring they were slow to start, Western scrub jays and European paper wasps grabbed what few caterpillars there were. In the summer, the population speeded up. And now caterpillars and chrysalids cover two of our three vines--or what's left of our three vines.
Shaprio says the Gulf Frit was introduced into southern California in the 19th century, in the vicinity of San Diego in the 1870s. It was first recorded in the Bay Area before 1908. "It became a persistent breeding resident in the East and South Bay in the 1950s and has been there since." Once prevalent in the Sacramento area in the 1960s, it "seems to have died out by the early 1970s," he said. Then in 2009, it began making a comeback in the Sacramento area.
Meanwhile, the passionflower vine climbs our fences with reckless abandon, only to be skeletonized by the growing population of Gulf Frits. They eat the leaves, the flowers, the fruit, and then start in on the bark.
More Gulf Frits mate. More eggs, caterpillars, chrysalids and adults appear. The cycle continues until the first frost. The plants die back, and will recover in the spring. A few chrysalids will remain, clinging to the vines like leftover Christmas tree ornaments,
Surprises occur. Several years ago, we saw a Gulf Frit laying an egg on Christmas Day.