- Author: Kathy Keatley Garvey
Seminar coordinator and associate professor Brian Johnson has announced the list of UC Davis Department of Entomology and Nematology seminars for the winter quarter, from Jan. 8 through March 11.
All seminars will be on Mondays at 4:10 p.m. in Room 122 of Briggs Hall and also will be on Zoom.The Zoom link: https://ucdavis.zoom.us/j/95882849672.
No seminar will take place on Monday, Jan. 15, which is Martin Luther King Jr. Day, a university holiday.
Adler Dillman
Professor of parasitology and nematology, and chair of the Department of Nematology, UC Riverside
Title: "Nematode Parasitism of Insects with Toxic Cardenolides"
Abstract: (Partial) "Target-site insensitivity (TSI) is an important mechanism of animal resistance to toxins. TSI evolved in parallel in the monarch butterfly and other insects that specialize on milkweeds and is thought to have facilitated sequestration of cardiac glycosides (CGs) that may protect these insects from predation and parasitism....Our results suggest that a molecular evolutionary cascade of parallel substitutions across hosts and parasites, last sharing common ancestry 600 million years ago, may shape multitropic interactions across plant communities."
Biography: He holds a bachelor's degree in microbiology from Brigham Young University (2006) and a doctorate in genetics (2013) from the California Institute of Technology.
William Ja
Associate professor, Herbert Wertheim Scripps UF Institute for Biomedical Innovation and Technology in Jupiter, Florida.
Title: "Eat, Excrete, & Die: Regulation of Homeostatic Behaviors and Aging in Drosophila"
Abstract: "The Ja lab uses the fruit fly, Drosophila melanogaster, as a model organism for uncovering the genetic and neuronal mechanisms that drive aging, behavior, and disease. Recently developed tools allow us to track fly feeding behavior with unparalleled resolution. These tools facilitate the identification of genes and circuits that regulate food intake at diverse time scales, including studies of: 1) meal intake; 2) daily (circadian) feeding rhythms; and 3) compensatory feeding in response to high or low quality food. Our studies of feeding behavior and nutrition also inform aging interventions, including a novel caloric restriction paradigm and an intermittent fasting regime that extends fly life through the stimulation of circadian-regulated autophagy. Overall, our fly studies shed light on basic neurobiological principles that drive animal behavior, providing insights that potentially inform the development of conserved therapeutic strategies."
Biography: Ja received his chemistry degree at UC Berkeley, working with Richard Mathies and Alex Glazer on DNA sequencing technologies. He pursued doctoral studies at the California Institute of Technology with Rich Roberts, utilizing mRNA display technology to identify modulators of G protein signaling. Ja remained at Cal Tech as a postdoctoral scholar to work with Seymour Benzer on developing longevity ‘drugs' in Drosophila. His laboratory focuses on aging and nutrition, animal behavior, and host-microbiome interactions.
Todd Johnson
Assistant professor of forest entomology, Louisiana State University
Title: "Characterizing Ecological Interactions of Arthropods in Forests under Global Change'
Abstract: "Forests cover approximately 30% of the Earth's landmass and provide important ecosystem services that include food, fuel, and timber, as well as habitat for diverse organisms. Threats posed to forests by invasive and pestiferous species are rapidly growing. Global change, an umbrella term that includes may human-mediated processes such as climate change and international trade, is altering the structure and functioning of forests. Our recently formed research group studies how natural variation impacts the outcomes of interactions between trees, herbivores, and the natural enemies of herbivores. My seminar will provide an overview of our ongoing and developing studies to better understand how variation in chemistry across the landscape shapes the fitness of woodboring insects, and how this variation can be harnessed to optimize management of forest ecosystems."
Biography: His research group studies the behavioral and chemical ecology of forest arthropods, with an emphasis on building fundamental knowledge that can further our understanding and management of natural and managed ecosystems. Johnson received his bachelor's degree in biology from Moravian College, his master's degree in entomology from the University of Wisconsin-Madison, and his doctorate from the University of Illinois at Urbana-Champaign. Prior to accepting his position at LSU in the fall of 2022, he was a postdoctoral research associate at the University of New Hampshire.
Orie Shafer
Professor of biology and cognitive neuroscience, City University of New York
Title: "Circadian and Homeostatic Regulation of Fly Sleep"
Abstract: "Sleep-like states are ubiquitous in the animal kingdom and are regulated by two distinct forms of regulation, circadian and homeostatic. Homeostatic mechanisms promote increases in sleep pressure during prolonged wakefulness. Circadian mechanisms determine the likelihood of sleep, increasing or decreasing its probability across the day. Though the molecular and neural mechanisms of circadian timekeeping are relatively well-understood, much less is known about the mechanistic basis of sleep homeostasis. The fly Drosophila melanogaster is a powerful model organism for the studying of sleep regulation. In this talk I will describe recent work from my lab examining how circadian timekeeping and sleep homeostasis operate in this fly and how these two regulatory processes converge to produce the proper timing and amount of sleep."
Biography: He received his doctorate in biology from the University of Washington, and served as a postdoctoral researcher at Washington University School of Medicine, St. Louis.
Peter Piermarini
Professor and associate chair of entomology, The Ohio State University, Wooster
Title: "Discovery of Novel Chemical Tools for Controlling the Most Dangerous Animals on Earth"
Abstract: "Mosquitoes are considered the most dangerous animals on Earth due to the deadly pathogens they transmit to humans. Controlling the transmission of mosquito-borne diseases often relies on chemical tools that prevent mosquitoes from biting humans (e.g., insecticides, repellents). However, the evolution of resistance in mosquitoes to commonly used control agents with similar modes of action has generated a need to discover novel chemistries for killing and/or repelling mosquitoes. To address this need, my lab is engaged in collaborative research that is discovering synthetic small molecules to disrupt novel physiological targets in mosquitoes and screening natural products for insecticidal and repellent activity against mosquitoes. My talk will summarize examples for each of these approaches and their potential for development into novel mosquito control tools."
Biography: He received his bachelor's degree in biology from James Madison University and doctorate in zoology from the University of Florida, before completing postdoctoral training at the Yale University School of Medicine and Cornell College of Veterinary Medicine. His laboratory studies the molecular physiology and toxicology of mosquitoes with the goal of discovering and developing insecticides with novel modes of action.
Monday, Feb. 26
Professor and director of graduate programs, Department of Entomology and Plant Pathology, North Carolina State University
Title: "“Advances and Innovations in the Characterization of Molecular Interactions Between
Frankliniella occidentalis and Tomato Spotted Wilt Virus.”
Biography: Dorith (pronounced Doreet) Rotenberg received three degrees from the University of Wisconsin-Madison: bachelor of science degree in biochemistry and her master's and doctorate in plant pathology. She is a professor in the Department of Entomology and Plant Pathology at North Carolina State University (NCSU) and the director of Graduate Programs in Plant Pathology. She co-directs the NCSU Plant Virus Vector Interactions Lab. Her foundational research initiatives center on the long-range goal of identifying and characterizing insect vector determinants of plant virus transmission to crop plants using a combination of ecological and genomics-based tools. Her research program has provided to the international science community vector genome, transcriptome, and proteome sequence resources to dig deeply into commonly-shared questions revolving around insect evolution, development, and transmission biology.
Abstract: "Arthropod-transmitted plant pathogens cause crippling monetary losses to U.S. and global economies. Tomato spotted wilt virus (Order Bunyavirales, family Tospoviridae, genus Orthotospovirus) is one of those pathogens, and it is transmitted in a circulative-propagative manner by Frankliniella occidentalis, the principal thrips vector. The overarching goal of my research program is to contribute fundamental knowledge towards developing alternative, effective and innovative tools for diminishing vector-transmitted crop diseases. My lab has been on the forefront of generating and sharing vector ‘omics resources to enable the identification and characterization of molecular determinants of vector competence as a means to specifically disrupt the virus transmission cycle. Using a combination of proteomic, transcriptomic and functional tools developed by my team and collaborators for F. occidentalis and TSWV, we aim to drill down on gut proteins associated with thrips host response to virus activities (indirect interactions) and/or gut proteins that physically interact with the viral attachment protein (GN) (direct). My talk will cover research advances made towards identifying and functionally characterizing two promising gut-expressed proteins, and new tools to interrogate F. occidentalis genes associated with virus transmission."
Salil Bidaye
Research Group Leader, Max Planck Florida Institute for Neuroscience
Title: "How Flies Control How They Walk by Knowing When and How to Stop"
Abstract: "Walking is a complex motor program involving coordinated and distributed activity across the brain and the spinal cord. Halting appropriately at the correct time is a critical but often overlooked component of walking control. While recent studies have delineated specific genetically defined neuronal populations in the mouse brainstem that drive different types of halting, the underlying neural circuit mechanisms responsible for overruling the competing walking-state neural activity to generate context-appropriate halting, remain unclear. Here, we elucidate two fundamental mechanisms by which Drosophila implement context-appropriate halting. The first mechanism (“walk-OFF” mechanism) relies on GABAergic neurons that inhibit specific descending walking commands in the brain, while the second mechanism (“brake” mechanism) relies on excitatory cholinergic neurons in the nerve-cord that lead to an active arrest of stepping movements. Using connectome-informed models and functional studies, we show that two neuronal types that deploy the “walk-OFF” mechanism inhibit distinct populations of walking-promotion neurons, leading to differential halting of forward-walking or steering. The “brake” neurons on the other hand, override all walking commands by simultaneously inhibiting descending walking promoting pathways and increasing the resistance at the leg-joints leading to an arrest of leg movements in the stance phase of walking. We characterized two ethologically relevant behavioral contexts in which the distinct halting mechanisms were used by the animal in a mutually exclusive manner: the “walk-OFF” pathway was engaged for halting during feeding, and the “brake” pathway was engaged for halting during grooming. To our knowledge, this represents the first mechanistic understanding of halting in fruit-flies and hence a major step in our larger goal of uncovering the fundamental principles governing walking control in animals."
Biography: Bidaye studies neuronal control of locomotion."While a graduate student in Barry Dickson's lab in the beautiful city of Vienna, Austria, as I observed fruit-flies chasing each other during courtship, I got hooked on to the intricate control that comprises insect walking. This fascination kindled by powerful fly genetic tools, has led me to persistently device new behavioral assays and neural recording techniques, aimed at elucidating the fundamental control mechanisms that underlie the exquisite locomotor control that is commonplace in all animals."
Inga Zasada
Research plant pathologist, USDA-ARS Horticultural Crops Research Laboratory, Corvallis, Ore.
Title: "How an Applied Nematologist Uses Genomic Tools to Address Plant-Parasitic Nematode Research"
Abstract: "Advancements in molecular plant pathology have created an environment in which applied, field-based research programs have the opportunity to utilize genomic tools in their programs. There are potential rewards for incorporating genomics into a research program including enhanced nematode diagnostics, population genetics of infestations, and novel biological discoveries. However, along with these rewards come many considerations including cost, tempered expectations, and the capacity to generate and analyze data. A cautionary tale of such a journey will be presented. Efforts to characterize the nematode microbiomes from a diversity of plant-parasitic nematodes, understand the population genetics of a potato cyst nematode infestation, and sequence and annotate nematodes genomes will be presented to highlight the rewards and challenges of this type of research. Underpinning all of these efforts is the need to establish and maintain productive collaborations with scientists with diverse backgrounds."
Biography: Inga Zasada is a research plant pathologist with USDA-ARS. She received her doctorate in plant pathology from UC Davis. She has spent her entire career with USDA-ARS, first in Beltsville, MD and now in Corvallis, OR. Her research program focuses on the management of plant-parasitic nematodes in raspberry, wine grapes, potatoes and other high value crops.
For Zoom technical issues, contact seminar coordinator Brian Johnson, associate professor, at brnjohnson@ucdavis.edu.
- Author: Kathy Keatley Garvey
The Equity in Science, Technology, Engineering, Math and Entrepreneurship (ESTEME) facilitates the after-school science program for middle school students.
The students, representing fifth to eighth grades, and ranging in age from 10 to 14, learned about insect science, the importance of insect collections, and played “Bug Bingo.”
In Bug Bingo, the students answered such questions as:
- A bug that eats other bugs
- A bug that migrates
- A bug that lives in water
- A bug that is hairy
- A bug that is a pest
- A bug that you think looks silly
- A bug that is a pollinator
- Two bugs that look alike
- A bug you don't like
“Once they got Bingo, they won a prize,” Edwards said.
Each student also "invented" a bug, pinned it with toothpicks, and labeled it. Edwards and Lippey also shared insect collections borrowed from the Bohart Museum of Entomology, home of eight million insect specimens.
Edwards studies with medical entomologist-geneticist Geoffrey Attardo, associate professor of entomology, while Lippey's major professors are insect ecologist Jay Rosenheim, UC Davis distinguished professor, and urban landscape entomologist Emily Meineke, assistant professor.
ESTEME, established in 2017, is sponsored by the UC Davis Student Recruitment and Retention Center and the UC Davis College of Biological Sciences' Initiative. Diversity, Equity and Justice (DEIJ Grant.
CC Edwards. In her graduate studies, Edwards investigates the physiological mechanisms underlying pyrethroid resistance in Aedes aegypti, the yellow fever mosquito. She was a McNair scholar at Baylor University, where she completed her undergraduate degree in cell and molecular biology in May 2021. "I got interested in the mosquito field through my undergraduate research of studying the sensory and oviposition responses of Aedes aegypti in relation to the compound geosmin," she says on the Attardo lab website. "I went on to do my masters at Texas Tech University under the advisement of Dr. Corey Brelsfoard. I graduated in the summer of 2023. I investigated the effects of microplastics in relation to the mosquitoes Aedes aegypti and Aedes albopictus (the Asian tiger mosquito)."
"Though my research interests are broad," Lippey writes, "they generally center around the complexity of global change ecology and how insect interactions have responded to a rapidly changing world in the Anthropocene. I'm specifically intrigued by changes in ecological processes over various spatial and temporal scales, and how multiple simultaneous spatial and temporal dynamics further complicate the changes we observe across insects."
In her graduate studies, Lippey is exploring "insect responses to interactions between multiple global change drivers such as land use change (agricultural intensification and urbanization) and other anthropogenic drivers like warming climate, extreme climate events, and pesticide use."
Lippey was recently featured in a UC Davis article titled "Scientists and Their Science Tattoos" in which UC Davis professors and graduate students shared their tattoos with science news intern Malia Reiss of UC Davis Strategic Communications. Lippey's tattoos include Japanese rhinoceros beetles, a centipede, backwimmer, Madagascar hissing cockroach, cicada (emerging), a worm and a Darwin moth. "I did the worm myself," she said.
- Author: Kathy Keatley Garvey
The Bohart Museum of Entomology is sponsoring its fourth annual Robbin Thorp Memorial First-Bumble Bee-of-the-Year Contest, which begins at 12:01, Jan. 1, 2024. The first person to photograph a bumble bee in either Yolo or Solano and email it to the sponsor, the Bohart Museum, will receive a coffee cup designed with the endangered Franklin's bumble bee, the bee that Thorp monitored on the California-Oregon border for decades.
Contest coordinator Lynn Kimsey, director of the Bohart Museum, said the image must be taken in the wild and emailed to bmuseum@ucdavis.edu, with the time, date and place.
The contest memorializes Professor Thorp (1933-2019), a global authority on bees and a UC Davis distinguished emeritus professor of entomology, who died June 7, 2019 at age 85. A 30-year member of the UC Davis faculty, he retired in 1994 but continued working until several weeks before his death. Every year he looked forward to seeing the first bumble bee in the area.
The 2023 winner was Ria deGrassi of Davis, who spotted and videoed a black-tailed bumble bee Bombus melanopygus, foraging on a prized ceanothus plant on Sunday afternoon, Jan. 8 in her backyard in Davis.
“I was doing clean-up in my backyard after Saturday night's rain and a 50-plus mile-per-hour windstorm,” said de Grassi, now an agricultural policy consultant. “The wind had subsided to a breeze by then. As I walked past my Ray Hartman ceanothus—which I purchased from a UC Davis Arboretum plant sale years ago when I did a garden makeover to be pollinator-friendly—I noticed some extra-long ceanothus branches that needed to be pruned, including some with super-early blooming flowers.”
“I fumbled to retrieve my cell phone from my pocket to record, just to get in on the fun,” said de Grassi. “These bumbles dart around a lot, they don't stay put for photo ops.”
De Grassi knew Thorp from her professional work with the California Farm Bureau Federation and from her friendship with bee scientists Timothy Lawrence and Susan Cobey, formerly of UC Davis.
DeGrassi, a former director of federal policy, livestock, animal health and welfare for the California Farm Bureau Federation, credits the storm, the UC Davis Arboretum and Public Garden and her working relationships with bee scientists, including Thorp, as having a hand in either her find and/or her interest in plants and pollinators.
The three previous winners (2022 was a tie) each photographed a bumble bee in the 100-acre UC Davis Arboretum. Coincidentally, de Grassi bought her prized ceanothus at an Arboretum plant sale.
Postdoctoral researcher Charlie Casey Nicholson of the Neal Williams lab and the Elina Lastro Niño lab, UC Davis Department of Entomology and Nematology, won the 2021 contest by photographing a B. melanopygus at 3:10 p.m., Jan. 14 in a manzanita patch in the Arboretum.
UC Davis doctoral candidate Maureen Page of the Neal Williams lab and horticulturist Ellen Zagory, retired director of public horticulture for the Arboretum, tied for first in the 2022 contest by each photographing a bumble bee foraging on manzanita (Arctostaphylos) in the Arboretum at 2:30 p.m., Saturday, Jan. 1.
Page, who now holds a doctorate in entomology, photographed a B. melanopygus, while Zagory captured an image of the yellow-faced bumble bee, Bombus vosnesenskii.
Thorp, a tireless advocate of pollinator species protection and conservation, co-authored two books in 2014, during his retirement: Bumble Bees of North America: An Identification Guide (Princeton University,) and California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday). Every year he looked forward to finding or seeing the first bumble bee in the area.
Thorp co-taught The Bee Course from 2002 to 2019. An intensive nine-day workshop affiliated with the American Museum of Natural History and held annually at the Southwestern Research Station, Portal, Ariz., it draws participants from around the world, includkng conservation biologists, pollination ecologists, and other biologists who want to gain greater knowledge of the systematics and biology of bees.
For years, Thorp monitored Franklin's bumble bee, found only in a small range in Southern Oregon and Northern California, and now feared extinct. He last spotted it in 2006.
The bumble bee contest originated in 2012 with the "Bombus posse" of Thorp, Allan Jones, Gary Zamzow, Kim Chacon and Kathy Keatley Garvey, who engaged in a friendly contest to see who could find the first bumble bee of the year in the two-county area. The first bumble bee to emerge in the area is usually the black-tailed bumble bee. B. melanopygus, Thorp used to say. Another early bumble bee is the yellow-faced bumble bee, B. vosnesenskii.
- Author: Kathy Keatley Garvey
Nieh will present his seminar at 4:10 p.m., Monday, Dec. 4 in Room 122 of Briggs Hall and also on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/95882849672
"Karl von Frisch referred to the waggle dance as the 'magic well' for the insights that it provides not only on honey bees, but on the general cognitive complexity that social insects are capable of," Nieh writes in his abstract. "New research demonstrates that the neurotransmitter, dopamine, the 'pleasure molecule' plays a similar hedonic role in honey bees as it does in many vertebrates, regulating the perception of danger and the anticipation of food rewards as revealed in the excitatory waggle dance and the associated, inhibitory stop signal. I will also discuss new data showing that the honey bee waggle dance is partially learned and has elements that may be culturally transmitted. Together, these findings, demonstrate that the waggle dance can teach us a great deal about shared cognitive mechanisms and the importance of social learning across taxa."
In an article titled "Unlocking Secrets of the Honeybee Dance Language--Bees Learn and Culturally Transmit Their Communication Skills," and published March 9, 2023 in The Conversation, Nieh described the waggle dance as "one of the most complicated examples of nonhuman communication. They can tell each other were to find resources such as food, water, or nest sites with a physical 'waggle dance.' this dance conveys the This dance conveys the direction, distance and quality of a resource to the bee's nestmates."
Nieh related exactly how the bees perform the waggle dance. "Essentially, the dancer points recruits in the correct direction and tells them how far to go by repeatedly circling around in a figure eight pattern centered around a waggle run, in which the bee waggles its abdomen as it moves forward. Dancers are pursued by potential recruits, bees that closely follow the dancer, to learn where to go to find the communicated resource."
"Longer waggle runs communicate greater distances," Nieh wrote, "and the waggle angle communicates direction. For higher-quality resources such as sweeter nectar, dancers repeat the waggle run more times and race back faster after each waggle run."
Nieh noted that "The Greek historian Herodotus reported over 2,000 years ago on a misguided forbidden experiment in which two children were prevented from hearing human speech so that a king could discover the true, unlearned language of human beings.
"Scientists now know that human language requires social learning and interaction with other people, a property shared with multiple animal languages. But why should humans and other animals need to learn a language instead of being born with this knowledge, like many other animal species?"
Nieh went on to point out that "This question fascinates me and my colleagues and is the basis for our recent paper published in the journal Science. As a biologist, I have spent decades studying honeybee communication and how it may have evolved."
Nieh received his bachelor's degree from Harvard University in 1991 and his doctorate from Cornell University in 1997. He completed a postdoctoral fellowship funded by NSF-NAT0 (National Science Foundation, North Atlantic Treaty Organization) at the University of Würzburg, Germany. He served as a Harvard Junior Fellow from 1998-2000
Seminar coordinator is Brian Johnson, associate professor, UC Davis Department of Entomology and Nematology. For Zoom technical issues, he may be reached at brnjohnson@ucdavis.edu. The list of seminars is posted here.
Resources:
- Social Signal Learning of the Waggle Dance in Honey Bees, March 9, 2023, Science
- Bees Can Teach Their Young to Dance, March 9, 2023, Washington Post
- The Waggle Dance, PBS documentary on YouTube
- Author: Kathy Keatley Garvey
Dag will present his seminar at 4:10 p.m. in Room 122 of Briggs Hall. It also will be on Zoom: the Zoom link:
https://ucdavis.zoom.us/j/
"Tree crops belonging to the Rosaceae, such as almond, pear, apple, and sweet cherry, depend on cross-pollination by insects to set fruit," Dag says in his abstract. "The primary pollinator of the crops is the honey bee (Apis mellifera). However, due to harsh climatic conditions during flowering, limited movement of bees between cultivars, low preference of the bees for flowers of the target crop, and limited overlap in flowering between the cultivars, pollination is a primary factor limiting yield. Our group has tested multiple approaches to mitigate this problem: Using 'Pollen dispensers,' sequential introduction of beehives to the orchards, selection of honeybee strains with higher preference for the target crop, introduction of bumblebee (Bombus terrestris) colonies and phosphorous fertilization to increase nectar secretion and improve crop-flower attractiveness. I will summarize the effects of those methods on fruit set and yield in apples, almonds, and pears."
A native of Moshav Lachish, Israel, Dag received his bachelor's degree (1990) and master's degree (1992) in life sciences at the Faculty of Life Sciences, Tel Aviv University. His master's thesis: "Improving the Honey Bee Efficiency of Melon Pollination in Greenhouses." He obtained his doctorate in agriculture at the Horticulture, Faculty of Agriculture at Hebrew University of Jerusalem. His thesis: "Pollenizers, Pollinators and Pollination in Mango." He held postdoctoral positions at both Tel Aviv University and the Hebrew University of Jerusalem.
Dag's research interests include fruit tree physiology, olive biology and cultivation, reproductive biology of fruit trees, crop pollination, pomology in semi-arid conditions and "developing guava as an export crop."
He served as an Extension specialist in beekeeping from 1991 to 2003 for the Israeli Ministry of Agriculture.
Seminar coordinator is Brian Johnson, associate professor, UC Davis Department of Entomology and Nematology. For Zoom technical issues, he may be reached at brnjohnson@ucdavis.edu. The list of seminars is posted here.
