- Author: Kathy Keatley Garvey
He will deliver his seminar at 4:10 p.m., Monday, Jan. 29 in 122 Briggs and on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/95882849672.
"Forests cover approximately 30 percent of the Earth's landmass and provide important ecosystem services that include food, fuel, and timber, as well as habitat for diverse organisms," Johnson writes in his abstract. "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."
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.
For Zoom technical issues, contact seminar coordinator Brian Johnson, associate professor, at brnjohnson@ucdavis.edu. See complete list of seminars for the winter quarter.
- Author: Kathy Keatley Garvey
The research, “Circabidian Rhythm of Sex Pheromone Reception in a Scarab Beetle,” published in the Jan. 18 edition of Current Biology, marks the first sex pheromone receptor identified in Coleoptera, the order of beetles.
While most insects exhibit a 24-hour circadian rhythm that regulates their behavior and physiology, the large black chafer beetle, Holotrichia parallela, operates on a 48-hour clock, said Leal, a global expert on insect olfaction and communication. A professor in the Department of Molecular and Cellular Biology, he is a former professor and chair of the UC Davis Department of Entomology, now the Department of Entomology and Nematology.
“Insects smell with their antennae,” said Leal, who has unraveled the molecular mechanisms of mosquitoes, true bugs, long horned beetles, moths and other insects. “They have a sophisticated olfactory system and can selectively detect minute amounts of odorants.”
The female H. parallela emerges from the soil every other night, after sunset, climbs the canopy of the host plant, and seeks a mate by releasing a sex pheromone. Leal wanted to know if the males are also on a 48-hour rhythm clock, and he wanted to identify the elusive male gene in the pheromone receptor that allows the male to scent the female's pheromone.
The answers: “yes” and “yes.”
“I have been waiting for almost three decades to answer these questions,” Leal said. “I identified the sex pheromone of this beetle species in 1993 while working for the Ministry of Agriculture and Forestry of Japan. At that time, I found for the first time a very unusual sex pheromone, which is derived from an amino acid. Now similar sex pheromones have been identified from many species of beetles.”
“Also, we showed that females produce the sex pheromone every other night,” Leal said. “The burning question in biology is what males do about sensing or smelling the female sex pheromone. Back then, we had no idea how insects sense smell. With the advancements in sequencing, we identified all potential receptors and identified which one senses the sex pheromone. COVID happened and delayed our research collaboration. Finally, we found that the receptor is expressed every other day.”
“This is remarkable,” Leal said. “How do they know when it is a 'date night' or a non-calling night? It is still a mystery, but we will find out one day.”
Leal and Yin and their team pointed out that virtually all life on Earth experiences a 24-hour circadian rhythm, which affects almost all behaviors, including sexual activity and mating.
Leal, a native of Brazil, received his Ph.D. in applied biochemistry from the University of Tsukuba, Japan, with subsequent postdoctoral training in entomology and chemical ecology at the National Institute of Sericultural and Entomological Science and Cornell University, respectively. He was the first non-Japanese person to earn tenure at Japan's Ministry of Agriculture, Forestry, and Fisheries.
Leal, who joined the UC Davis faculty in 2000, is a newly elected trustee of the Royal Entomological Society, the first UC Davis scientist to be elected a trustee. He chaired the UC Davis Department of Entomology in 2006-2008 before accepting a position in 2008 as professor of biochemistry in the Department of Molecular and Cellular Biology. His many honors include Fellow of the Entomological Society of America (2009), American Association for the Advancement of Science (2005), and the National Academy of Inventors (2019).
Other co-authors of the Current Biology paper: Yinliang Wang, Huanhuan Dong, Yafei Qu, Jianhui Qin, Kebin Li, Yazhong Cao and Shuai Zhang, Chinese Academy of Agricultural Sciences, Beijing; Yuxin Zhou and Bingzhong Ren, Northeast Normal University, Changchun, China; and Chen Luo, Beijing Academy of Agriculture and Forestry Sciences.
The research drew financial support from the National Key R&D Foundation of China; National Natural Science Foundation, China; and the Natural Science Foundation of Beijing.
Resources:
- For This Beetle, ‘Date Night' Comes Every Other Day, Jan. 18, 2024, Andy Fell, UC Davis News and Media Relations
- Walter Leal Elected Trustee of Royal Entomological Society, Sept. 5, 2023
- Author: Kathy Keatley Garvey
Kaya, who joined the UC Davis faculty in 1976 and retired in 2010, has known Lynn and her husband, Robert "Bob," for more than four decades. Both the Kimseys received their bachelor and doctoral degrees in entomology from UC Davis.
"I never had Lynn in a classroom situation, but she was always helpful in helping others ID insects," Kaya said. He and Lynn worked on a McKnight Foundation potato grant project in Peru for four years. He remembers Bob as a "super student in my insect pathology class."
Lynn, then Lynn Siri, received her bachelor's degree in 1975 and her doctorate in 1979, while Bob received his bachelor's degree in 1977 and his doctorate in 1984. Lynn joined the UC Davis faculty in 1989 and has directed the Bohart Museum since 1990. Bob, a forensic entomologist, joined the UC Davis faculty in 1984 as a lecturer. Both plan to retire this year.
Harry Kaya is internationally recognized for his contributions to insect pathology and insect nematology, which include more than 250 peer-reviewed publications. He co-authored an insect pathology book in 1993; co-edited another insect pathology book in 2012; and co-edited five books in several disciplines including forest entomology, entomopathogenic nematology, and invertebrate pathology.
He was named a fellow of the Entomological Society of America (ESA) in 2007.
At the seminar, co-organizer Lynn Lebeck, then executive director of the Association of Natural Biocontrol Producers, praised him as a top-notch researcher and as "a warm human being." She recalled the "many years of fun times and great research experiences with him." (See news story)
Kaya co-founded the journal Biological Control, and served as the co-editor of the first and second editions of Field Manual of Techniques in Invertebrate Pathology, Application and Evaluation of Pathogens for Control of Insects and other Invertebrate Pests.
Born and raised in Honolulu, Harry received his bachelor's degree in entomology in 1962 from the College of Tropical Agriculture, University of Hawaii (UH). He served in the U.S. Army, and after being discharged as a first lieutenant, earned his master's degree in entomology from UH in 1964, specializing in insect ecology. In 1970, UC Berkeley awarded him his doctoral degree in entomology. with research in insect pathology.
From 1971 to 1976, Kaya worked as an entomologist at the Connecticut Agricultural Experiment Station in New Haven and conducted research on biological control of forest insects. In 1976, he joined the UC Davis faculty as an assistant professor, attaining the rank of full professor in 1984. He became a distinguished professor of entomology in 2008.
Kaya chaired the Department of Nematology from 1994 to 2001. He also served as an officer in the Society of Invertebrate Pathology (treasurer, 1990–1994, vice-president, 2000–2002, and president-elect 2002–2004), and was one of the founding editors of the journal Biological Control.
Highly honored by his peers, Kaya received the 1998 C. W. Woodworth Award, the highest honor presented by the Pacific Branch, ESA. In 2000, he received the 2000 Recognition Award in Entomology from ESA and Fellow of the Society of Nematologists. The Society for Invertebrate Pathology and UH also presented him with several awards.
In honoring him as a Fellow, ESA posted this on its website: "Kaya has mentored many graduate students and post-doctoral researchers who have proceeded to establish their own careers and excel in research and teaching. His laboratory hosted and trained many visiting scientists from other countries who have become leaders in research with entomopathogenic nematodes upon their return to their own countries. These include scientists from Korea, Thailand, Turkey, Mexico, Ukraine, and Peru. Kaya maintains a strong relationship with many of them and he had research projects with scientists from Korea and Turkey."
Kaya's first four PhD students--Raquel Alatorre, Arnold Hara, Phyllis Hotchkin {Weintraub) and Robin Goblin-Davis--are all retired from their faculty and research positions. Arnold Hara died Nov. 18, 2022.
Kaya resides in Davis with his wife, Joanna. He enjoys spending time with his grandchildren and gardening, and used to fish with colleague Les Ehler (1946-2016). "No fishing since Les passed away," he related.
One of his granddaughters, Madelyn Lee, a freshman at UC Riverside, may follow in his footsteps. "She has always been interested in the biological sciences and has become an active member of the Entomology Club at Riverside. She is thinking about being an entomology major."
- Author: Kathy Keatley Garvey
His seminar will be in Room 122 of Briggs Hall and also will be on Zoom. The Zoom link: https://ucdavis.zoom.us/j/95882849672. Associate professor and nematologist Shahid Siddique of the Department of Entomology and Nematology is the host.
Dillman, a professor of parasiotology and nematology, chairs the UCR Department of Nematology. 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.
The abstract of his UC Davis seminar:
Known as an excellent investigator and teacher, Dillman won the 2022 UC Riverside Chancellor's Award for Excellence in Undergraduate Research and Creative Achievement; the 2021 Award for Excellence in Teaching from the Society of Nematologists, and a 2020 Outstanding Investigator Award, Maximizing Investigators' Research Award (MIRA).
His lab page details his research. Recently a guest of an episode on the podcast Something Offbeat, he discussed a scientific article on a case of Ophidascaris robertsi infection in a human brain.
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 here.
- 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.