- Author: Kathy Keatley Garvey
Crowley-Gall's project, “Examining Pathogen-Induced Changes in Floral Chemistry and Assessing Impacts on Plant-Pollinator Interactions,” will focus on the effects of a plant pathogen on chemical signals that pollinators use when foraging. “Specifically, I will examine changes in nectar chemistry and floral volatile cues as a result of infection and resulting effects on pollinator behavior,” she said. “This proposal will utilize the Erwinia-pear system and the commercially utilized pollinator, honey bees.”
In his project, “The Role of Nectar Trait Plasticity and Nectar-Inhabiting Microbes in Sunflower Pollination,” McMunn will explore the interaction among sunflowers, nectar-inhabiting microbes, and bees in determining sunflower pollination success. “The results of this project will reduce the cost of sunflower production by testing new management strategies involving the introduction of beneficial nectar microbes,” he predicts.
Amber Crowley-Gall
“Globally approximately 16 percent of crops are lost a year due to pathogens,” Crowley-Gall wrote in her project proposal summary. “Plant pathogens can manipulate chemical cues emitted from their hosts to attract potential vectors. Pollinator insects rely heavily on these chemical cues when selecting potential host plants and there is evidence that pollinators can contribute to pathogen spread in agricultural systems. Pollination is widely used in agricultural systems and even crops that are not commercially supplied with pollinators are often exposed to some level of pollination. However, little is known about the effects of pathogens on pollinator behavior or the role of pollinators in pathogen transmission in agricultural systems.
“The purpose of this proposal is to examine the effects of pathogen infection on plant chemical cues and associated effects on pollinator behavior,” she wrote. This proposal will focus on Erwinia amylovora a widely spread pathogen that causes fire blight disease in Rosaceous plants. Effects of Erwinia across plant species will be experimentally tested using in vitro assays to examine effects on nectar chemistry and volatiles as well as pollinator neurophysiological and behavioral responses. Pathogen effects in natural systems will be examined in pear, an agricultural crop valued at $429 million in 2018 in the United States. Changes in nectar chemistry as well as nectar/floral volatiles will be characterized throughout the asymptomatic period of blossom infection. Pollinator behavioral responses and contribution to pathogen transmission will be assessed. This proposal will provide an increased understanding of pathogen affects on pollination in agricultural systems and enhance current pollinator management.”
Crowley-Gall, who joined the Vannette lab in 2019 as a postdoctoral researcher, has published her work in Journal of Hereditary, Ecology and Evolution, and Proceedings of the Royal Society B, among others. She guest-lectured this year in Vannette's chemical ecology course.
A native of Cincinnati, Ohio, Amber holds a bachelor of science degree in biological sciences in 2012 from Wright State University, Dayton, Ohio, where she focused on nematodes for her honor thesis, “Genetic Analysis of Hybrid Male Lethality in Caenorhabditis." The University of Cincinnati awarded her a doctorate in 2019: her dissertation: “Mechanisms Underlying Host Shift in Cactophilic Drosophila. Amber also received the J. Robie Vestal Award for Outstanding Doctoral Student.
Marshall McMunn
“Production of many crop plants remains dependent on insect pollination, which occurs as a result of insect attraction to the nectar and pollen within flowers,” McMunn related. “Recent advances in pollination biology have demonstrated that nectar traits are frequently altered by nectar-inhabiting microbes (bacteria and yeast), leading to changes in bee visitation rates. Despite the central role of nectar traits in crop pollination, there is limited information on nectar traits that have known effects on bee preference.”
“The goal of this project is to explore the interaction among sunflowers, nectar-inhabiting microbes, and bees in determining sunflower pollination success,” he said. This will be accomplished through three objectives:
- characterize sunflower nectar traits and nectar-inhabiting microbes using a comparative field study
- assay bee preference for microbially inoculated nectar in a lab study and
- measure change in sunflower nectar traits and bee visitation following microbial inoculation in an experimental field study. The results of this project will reduce the cost of sunflower production by testing new management strategies involving the introduction of beneficial nectar microbes.
As a National Science Foundation Postdoctoral Research Fellow in Biology (August 2018 to July 2020) at UC Santa Cruz and UC Davis, McMunn is co-advised by faculty members Rachel Vannette of UC Davis, and Stacy Philpott of UC Santa Cruz.
Marshall, a native of Jackson, Mich., received his doctorate in population biology in June 2018 from UC Davis, and his bachelor's degree in ecology and evolutionary biology in 2009 from the University of Michigan, Ann Arbor. A 2018 UC Davis Professors for the Future Fellow, he has published his work in the journals Environmental Entomology, Arthropod-Plant Interactions, Ecological Entomology, and Ecology, among others. He served as a UC Davis teaching assistant for four years, and in 2016, taught at the UC Davis Bio Bootcamp 2.0, a weeklong research summer camp for high school students.
Vannette, a community ecologist, assistant professor and Hellman fellow, now has three graduate students, two postdoctoral scholars (another to start in September) and three undergraduates and a junior specialist working in her lab. (See their projects here.)
- Author: Kathy Keatley Garvey
Igwe who joined the UC Davis doctoral program in 2015, anticipates receiving her PhD in microbiology in September 2020. Her thesis: “Microbial Community Contribution to Plant Abiotic Stress Tolerance: A Case Study in Serpentine Soils.” Igwe focuses her research on plant-microbe associations, microbial ecology, environmental microbiology and bioinformatics.
“Plant-microbe associations impact plant phenotype, distribution and biodiversity and range in their effects on a continuum from costly parasitic to beneficial mutualistic interactions,” she wrote in her successful proposal. “These mutualistic relationships also range from loose and facultative to endosymbiotic and obligate. The relationship between nitrogen-fixing bacteria and plants is especially important ecologically. Research into these associations have traditionally focused on endosymbiotic relationships within the nodules of legumes. I propose to explore the impact of strong selective soil pressures on microbial local adaptation and mutualism using free-living nitrogen-fixers and non-legumes.“
“My study,” she wrote, “will utilize serpentine ecosystems because serpentine soils are naturally high in heavy metals and deficient in plant nutrients which contributes to low plant productivity and presents strong selective pressures. The system also includes a free-living nitrogen-fixer, Microvirga spp., and plants that can grow on both serpentine and nonserpentine soils (serpentine-indifferent), allowing tractable manipulations across stress environments. Research with this system can be useful for disentangling the relative influence of soil and plant type on the establishment of mutualistic relationships and its impact on plant performance.”
She seeks a career as an environmental microbiologist to “scientifically and commercially address problems related to environmental degradation and food security.”
“Allie has initiated exciting research directions during her time in the lab: examining how rhizosphere microbes influence plant survival and growth on serpentine soils,” said Vannette, a UC Davis Hellman Fellow. “She has funded this work through several successful grant applications during her graduate career at UC Davis. Her creative research suggests previously unrecognized ways that plants are able to successfully establish and grow on harsh soils. She has also found that the composition of soil microbes can affect seedling establishment and also change when plants flower!"
“Her findings are novel and they are already making an impact on the field,” Vannette pointed out. “Allie has published a first-author paper and co-authored two additional papers on how soil microbial communities are shaped by soil characteristics and plant species Allie has taken an active role in mentoring students in our lab. She has worked closely with and trained at least five undergraduate students in techniques ranging from DNA extraction and library prep, isolating and identifying soil bacteria, bioinformatics analysis and root imaging analysis. She has accompanied students to national meetings and supported their career goals even after they had left the lab.“
Vannette, who joined the UC Davis Department of Entomology and Nematology in 2015 after serving as a postdoctoral fellow at Stanford University's biology department, also praised Allie for “taking an active role in mentoring students in our lab. She has worked closely with and trained at least five undergraduate students in techniques ranging from DNA extraction and library prep, isolating and identifying soil bacteria, bioinformatics analysis and root imaging analysis. She has accompanied students to national meetings and supported their career goals even after they had left the lab.”
“Allie has not only strong academic achievements, excellent leadership ability and but also the ability to translate these skills into meaningful research, impactful mentoring, and effective recruitment and retention of underrepresented students,” Vannette said. “Allie has accomplished a lot here at Davis and I am excited to watch her career unfold. Her achievements have been recognized with a prestigious NSF Postdoctoral fellowship.”
“I am the first to go to graduate school and will be the first doctor in the family, although not the type they likely expected,” she quipped. “I've always been interested in the natural world and participated in science fairs growing up. My first project was a survey of all the bugs in my front yard. My mom and I collected, identified, and mounted them. She told me that she could always find me in some mud or looking under a rock or collecting snails. I always had an interest in the environmental field--it just took a little nudge from amazing mentors for me to pursue it.”
Allie received her bachelor's degree in biology in 2013 from Howard University, Washington, D.C., where she submitted her honors thesis: “Elemental Defense in Alyssum murale: Effects on Plant-Herbivore Interactions.” She holds a master of science degree in soil science in December 2015 from Texas A&M (TAMU), where she presented her thesis on “Phytoremediation of Hydrocarbon-Contaminated Soil Using Phenolic-Exuding Horticultural Plants.”
At TAMU, Allie designed greenhouse experiment to identify rhizosphere microbial composition of horticulture plants growing in soil contaminated with polycyclic aromatic hydrocarbons.
The UC Davis doctoral student co-authored “Organic Management Promotes Natural Pest Control through Altered Plant Resistance to Insects,” published May 15 in the journal Nature Plants, with Vannette and several other co-authors.
Igwe served as the lead author of the Igwe-Vannette research, “Bacterial Communities Differ Between Plant Species and Soil Type, and Differentially Influence Seedling Establishment on Serpentine Soils,” published June 26, 2010 in the journal Plant and Soil.
At UC Davis, she has helped other students succeed. She served as a teaching assistant from September 2016 to- December 2019 in the UC Davis Career Discovery Group. She mentored a group of 10-20 freshmen in career exploration activities and professional communication. In addition, she recruited industry professionals to participate in student networking events, and coordinated on-site visits with working professionals for career exploration trips. Igwe also was a success coach in the UC Davis Success Coaching and Learning Strategies for a year.
- Author: Kathy Keatley Garvey
Keating, a member of the Class of 2020, will receive his bachelor's degree in entomology in June. Usually the award is presented at a separate ceremony hosted by the department, but due to the coronavirus pandemic, the presentation is pending.
"Garrett is working on interactions between the solitary bee Osmia lignaria and microbes that are found in the larval provisions,” said Vannette, an assistant professor. “Larvae of this bee feed on the stored nectar and pollen provision, during which time the fungi and bacteria from collected nectar and pollen grow on these stored resources.”
“Garrett is examining how bacterial and fungal composition changes over time as the provisions age--and larvae grow--so this is a study in microbial community succession in bee food,” she added. “We are interested to see if microbes in stored nectar and pollen (provisions) affect the provision itself and if they end up in the gut of larval bees. He has already performed the sampling and is finishing up bioinformatics and analysis right now.”
His project is a collaboration between the Vannette lab and Neal Williams lab.
Keating, who joined the Vannette lab in 2019, plans to spend the summer working in the lab, and then next year “working at a nature-based outdoor education program in Sonoma,” he said. “After that I hope to return to entomology research.”
“I've been interested in entomology ever since I was a kid,” Keating said. “I grew up playing with spiders in my backyard and watching ants fight termites. My dad helped me set up science fair projects with pill bugs and water striders.”
Keating, from the East Bay city of Piedmont, enrolled at UC Davis after transferring from UC Riverside from 2016-2018. "In 2017-2018 I worked in Jessica Purcell's lab, studying socially polymorphic ants," he said, "and in the summer of 2018 I conducted a independent research project in Switzerland, studying bumble bee diversity along an elevational gradient. This was done through the UC study abroad program."
He graduated from Naropa University, a private university in Boulder, Colo., where he was involved in the Naropa LeapYear Gap Experience Program. During his freshman year, he earned semester credit while studying, working and doing internships in the United States and abroad.
Keenly interested in the environment, Keating served as a volunteer in a UC Berkeley professor's project in 2015 to stop the growth of Sudden Oak Death. Also in 2015, he engaged in a 100-hour project at The Presidio, San Francisco, to preserve wildlife and remove invasive species.
Keating completed an internship in 2016 with the Volunteer Initiative Nepal, where he worked on a water research project in Kathmandu, Nepal. His other work experiences range from cabin leader to camp counselor to head counselor for youth outdoor education programs from 2012 to 2018.
An avid volunteer, Keating engaged in a variety of projects with Amor Ministries from 2012 to 2015; in 2012 and 2013, he built houses for needy families in San Juan, Mexico. In the summer of 2014, he volunteered with Amigos de las Américas in Oaxaca, Mexico, and also conducted a summer program there to teach children the importance of amaranth as a grain or pseudocereal.
- Author: Kathy Keatley Garvey
Community ecologist Rachel Vannette, assistant professor, coordinated the seminars. Credit: Videos were created and uploaded to the website, thanks to the work of recorders Hyun Suk Shin and Alex Cardenas and information systems analyst George Terry. Alfred Chan serves as the Phoenix Information Technology Support Manager (Department of Entomology and Nematology, as well as the Department of Plant Pathology.)
Fall Quarter, 2019
Sept. 25, 2019
James Nieh, professor, Section of Ecology, Behavior and Evolution, Department of Biological Sciences, UC San Diego
Topic: "Animal Information Warfare: How Sophisticated Communication May Arise from the Race to Find an Advantage in a Deadly Game Between Honey Bees and their Predators" (See lab website)
Host: Brian Johnson, associate professor, Department of Entomology and Nematology
Link to Seminar
Oct. 2
Nathan Schroeder, assistant professor, Department of Crop Sciences, University of Illinois, Urbana-Champaign
Topic: "Endless Worms Most Beautiful"
Host: Shahid Saddique, assistant professor, Department of Entomology and Nematology
Link to Seminar
Oct. 9
John Mola, doctoral candidate, Neal Williams lab, Graduate Group in Ecology
Exit seminar: "Bumble Bee Movement Ecology and Response to Wildfire." Mola specializes in bee biology, pollinator ecology and population genetics.
Host: Neal Williams, professor, Department of Entomology and Nematology
Link to Seminar
Oct. 16
Rebecca Irwin, professor of applied ecology, North Carolina State University, Raleigh, N.C.
Topic: "The Role of Floral Traits in Pollination and Bee Disease Transmission." She specializes in the ecology and evolution of multiple-species interactions, pollination biology, and species invasions
Host: Rachel Vannette, assistant professor, Department of Entomology and Nematology
Link to Seminar
Oct. 23
Julián Hillyer, director of the program in career development and associate professor of biological sciences, Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, Tenn.
Topic: "Not So Heartless: Functional Integration of the Immune and Circulatory Systems of Mosquitoes"
Host: Olivia Winokur, graduate student, Chris Barker lab
Link to Seminar
Oct. 30
Takato Imaizumi, professor, Department of Biology, University of Washington, Seattle
Topic: "Circadian Timing Mechanisms in Plant-Pollinator Interaction"
Host: Joanna Chiu, associate professor and vice chair of the Department of Entomology and Nematology
Link to Seminar
Nov. 13
Don Cippollini, director of environmental sciences and professor, Department of Biological Sciences, Wright State University
Topic: "The Potential for Host Switching via Ecological Fitting in the Emerald Ash Borer-Host Plant System"
Link to Seminar
Winter Quarter, 2019-2020
Dec. 4, 2019
Jackson Audley, doctoral candidate who studied with the late Steve Seybold
Topic: "Semiochemical Interruption of Host Selection Behavior of the Invasive Walnut Twig Beetle, Pityophthorus juglandis."
Link to Seminar
Wednesday, Jan. 8, 2020
Karen Menuz, University of Connecticut, Storrs
Topic: "Molecular Basis of Insect Olfaction"
Host: Walter Leal, distinguished professor, Department of Molecular and Cellular Biology and a former chair of the entomology department
Link to seminar
Wednesday, Jan. 15
Corrie Moreau, Cornell University, Ithaca, N.Y.
Topic: "Piecing Together the Puzzle to Understand the Evolution of the Ants"
Host: Marshall McMunn, graduate student
Link to seminar
Wednesday, Jan. 22
Sebastian Eves-van den Akker, University of Cambridge, UK
Topic: Effector Gene Birth in Plant-Parasitic Nematodes: Furnishing the Immunity and Development-Altering 'Tool Box'
Host: Shahid Siddique, assistant professor
Link to Seminar
Wednesday, Jan. 29
Elizabeth Crone, Tufts University, Medford, Mass.
Topic: "Why Are Monarch Butterflies Declining in the West?"
Hosts: Neal Williams, professor; Rachel Vannette, assistant professor
Link to Seminar
Wednesday, Feb. 5
Andrew Young, postdoctoral scholar at California Department of Food and Agriculture, Pest Diagnostic
Topic: "The Natural History of Syrphidae: From Pollinators To Parasitoids"
Host: Lynn Kimsey, professor and director of the Bohart Museum of Entomology
Link to seminar
Wednesday, Feb. 12
Kevin Rice, University of Missouri, Columbia
Topic: "Lasers, Drones, and Growth Promoting Fungus: New Technologies for IPM"
Host: Ian Grettenberger, assistant professor
Link to Seminar
Wednesday, Feb. 19
Mercedes Burns, University of Maryland, Baltimore County
Topic: "Reproductive Diversity And Sexual Conflict: Opilionid Mating From The Female Perspective"
Host: Jason Bond, professor and Schlinger Chair in Insect Systematics
Link to Seminar
Wednesday, Feb. 26:
Faculty Flash Talks (featuring series of faculty members, including Rachel Vannette, Ian Grettenberger, Shahid Siddique, Geoffrey Attardo, Jason Bond)
Link to Seminar
Wednesday, March 4
Brendon Boudinot, doctoral candidate, Phil Ward lab, exit seminar
Topic: "Morphology and Evolution of the Insects, and the Ancestors of the Ants"
Host: Phil Ward, professor
Link to Seminar
Wednesday, March 11
Mary Salcedo, postdoctoral researcher, Virginia Tech
Topic: "Hydraulics in an Insect Wing: How Venation Pattern Affects Circulation"
Host: Rachel Vannette, assistant professor
Link to Seminar
- Author: Kathy Keatley Garvey
Viewers may log in (access information will be provided each week).
The seminars, coordinated by community ecologist Rachel Vannette, assistant professor, UC Davis Department of Entomology and Nematology, are held on Wednesdays from 4:10 to 5 p.m.
The schedule:
Wednesday, April 1
Javier Ceja-Navarro, research scientist, Biological Systems and Engineering, Biosciences, Berkeley
Topic: (He researches multitrophic interactions in ecosystems such as digestive tracts of insects and soil)
Host: Rachel Vannette, assistant professor, UC Davis Department of Entomology and Nematology
Wednesday, April 8
Reginald “Rex” Cocroft, professor of biology, University of Missouri
Topic: (He researches plants as receivers of insect sound and vibration)
Host: Rick Karban, professor, UC Davis Department of Entomology and Nematology
Thomas and Nina Leigh Distinguished Alumni Seminar (to be determined)
Michael Hoffmann, emeritus professor, Cornell University
Topic: “Our Changing Menu: What Climate Change Means to the Foods We Love and Need”
Host: Steve Nadler, professor and chair, UC Davis Department of Entomology and Nematology
Wednesday, April 22
(To be announced)
Wednesday, April 29
Dhruba Naug, professor, Department of Ecology and Evolutionary Biology, Colorado State University
Topic: (He combines his interests in behavioral and cognitive ecology to understand the functioning of individuals and social groups. His research involves experimental work in behavior and physiology complemented by approaches based on individual based modeling.)
Host: Rachel Vannette, assistant professor, UC Davis Department of Entomology and Nematology
Wednesday, May 6
Xianhui "Nitrol" Liu, Joanna Chiu lab, UC Davis Department of Entomology and Nematology
Topic: Exit seminar (title pending)
Host: Joanna Chiu, associate professor and vice chair, UC Davis Department of Entomology and Nematology
Wednesday, May 13
Andre Kessler, chemical ecologist and professor Cornell University
Topic: (He is chemical ecologist whose research focuses on the mechanisms, ecological consequences and the evolution of plant induced responses to herbivore damage)
Host: Rick Karban, professor, UC Davis Department of Entomology and Nematology
Wednesday, May 20
Shalene Jha, University of Texas, Austin
Topic: "Plant-Insect Interactions in the Face of Global Change"
Host: Charlie Nicholson, Neal Williams lab, UC Davis Department of Entomology and Nematology
Wednesday, May 27
Rebecca Godwin, doctoral candidate, Jason Bond lab, UC Davis Department of Entomology and Nematology
Topic: Exit seminar (title pending)
Host: Jason Bond, Schlinger Chair in Insect Systematics, UC Davis Department of Entomology and Nematology
Wednesday, June 3
Esther Ngumbi, assistant professor of entomology and African-American studies, University of Illinois
Topic: (Pending)
Host: Elvira DeLange, Christian Nansen Lab, UC Davis Department of Entomology and Nematology
For more information, contact Rachel Vannette at rlvannette@ucdavis.edu. The winter seminars just concluded.
