- Author: Kathy Keatley Garvey
And education, curiosity, determination, and collaboration.
UC Davis doctoral student Alexandria “Allie” Igwe, advised by community ecologist and assistant professor Rachel Vannette of the UC Davis Department of Entomology and Nematology, has received a prestigious $138,000 National Science Foundation Postdoctoral Fellowship to work on soil microbial communities and develop novel online tools to increase interest in ecology.
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.”
Igwe plans to use “culture-based isolation techniques, qPCR, whole-genome sequencing, and manipulative greenhouse and field surveys to: (1) Quantify the abundance of Microvirga spp. in serpentine and nonserpentine soils and explore the relative influence of edaphic factors, elevation, and climate on bacterial abundance. (2) Identify the presence of ecotypic variation in serpentine- and non-serpentine-isolated Microvirga spp. using functional assays and genome-wide sequencing, and (3) Determine the effect of Microvirga spp. on non-leguminous plant survival and development.”
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!"
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.”
Born in Stockton but raised in Houston, Allie remembers how her mother, a registered nurse, “imparted on me the importance of education from a young age and did a lot to make sure I had access to the best public educational opportunities Houston had to offer.
“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.
Congrats, Allie! We're looking forward to seeing more of your achievements.
- Author: Kathy Keatley Garvey
There's more to Sonoma County's Bodega Head than the stunning views, crashing waves, nesting seabirds, and bursts of flora and fauna.
The sand cliffs are also the home of a digger bee, a bumble bee mimic known as Anthophora bomboides stanfordiana.
"The species name indicates that it is a bumble bee mimic," the late Robbin Thorp, a global authority on bumble bees and a UC Davis distinguished emeritus professor of entomology, told us several years ago. "These bees need a source of fresh water nearby. Females suck up water, regurgitate it on the sandstone bank surface, then dig away at the soft mud. They use some of the mud to build entrance turrets, presumably to help them locate their nests within the aggregation of nests."
"The female," Thorp said, "sucks up fresh water from nearby, stores it in her crop (like honey bees store nectar) for transport to the nest. She regurgitates it on the sandstone, and excavates the moistened soil. She carries out the mud and makes the entrance turret with it."
On multiple trips to Bodega Bay over the years, we watch in fascination as the bees excavate their homes, zip in and out of their turrets, and nectar on nearby flowers.
This time (June 24) we photographed an ant and bee encounter on a turret. The ant? Formica transmontanis, according to ant specialists Phil Ward, professor of entomology at UC Davis, and UC Davis alumnus Brendon Boudinot, who recently received his doctorate from UC Davis, studying with Ward.
"The species nests on the bluffs," Ward told us.
And about that bee-ant encounter? Commented Boudinot: "I suspect the little lady was alarmed by the big bee. These ants and their relatives are rather passive scavengers except during the brooding season, when fresh meat is an order. Most entomeat for Formica tend to be free-walking insects than barricaded larvae, as probably for the bee. For these reasons I think that the encounter may be coincidental!"
Scores of UC Davis entomologists have engaged in research at Bodega Bay. Rachel Vannette, assistant professor, UC Davis Department of Entomology and Nematology, is currently researching Anthophora bomboides stanfordiana and its nests as part of a National Science Foundation grant. Her project on solitary bee provision microbiome includes investigating the diverse community of bacteria and fungi in the provisions and brood cells.
While COVID-19 mandates and precautions hamper her research team's efforts (she's done some preliminary sampling this year and the entire team is planning to do research next year), the digger bees of Bodega Head keep digging, crafting turrets, nectaring on the nearby flora--and encountering ants.
They're all in this together.
- Author: Kathy Keatley Garvey
You're in luck. You can access (for free) the newly uploaded UC Davis Department of Entomology and Nematology's fall and winter seminars, 2019-2020. Each spans about an hour long.
Community ecologist Rachel Vannette, assistant professor, coordinated the seminars. Thanks also to Hyun Suk Shin and George Terry and crew for videoing them and/or uploading them on the web.
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
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
The UC Davis Department of Entomology and Nematology's seminar on Wednesday, Feb. 26 will feature six “Faculty Flash Talks” on topics ranging from honey bees to tsetse flies to digger bees to trapdoor spiders to fruit flies.
The seminar, set from 4:10 to 5 p.m. in 122 Briggs Hall, will include Joanna Chiu, Jason Bond, Geoffrey Attardo, Rachel Vannette, Julia Fine, and Arathi Seshadri.
Associate professor Joanna Chiu, vice chair of the department, will present “results from a project in which we study the mechanisms by which insects sense environmental changes (temperature and photoperiod) to regulate their seasonal physiology. Our lab has identified a protein that can track seasonal changes in temperature and photoperiod to promote winter physiology. Without this protein, insects don't know winter is coming!”
Her laboratory research interests include molecular genetics of animal behavior, Circadian rhythm biology, and posttranslational regulation of proteins.
Capsule information:
Jason Bond, Schlinger Chair in Insect Systematics, is a global expert on spiders. His research interests include systematics, taxonomy, and evolution of terrestrial arthropods with an emphasis on arachnids and myriapods. "We employ molecular, morphological, and ecological approaches to study questions related to evolutionary diversification at multiple hierarchical levels (populations – higher taxa)," he says. (See recent grant.)
Geoffrey Attardo, a medical entomologist/geneticist, focuses his research on insect disease vectors, insect reproduction, vector/parasite interactions, reproductive physiology, male seminal secretions, symbiosis, lactation, nutrition, lipid metabolism, transcriptional regulation, comparative genomics, transcriptomics, proteomics and metabolomics. His research on tsetse flies was recently featured on KQED's Deep Look (see news story on Deep Look). (See news story on landmark research.)
Rachel Vannette, community ecologist and assistant professor who coordinates the department's seminars, says: "All plants are colonized by microorganisms that influence plant traits and interactions with other species, including insects that consume or pollinate plants. I am interested in the basic and applied aspects of microbial contributions to the interaction between plants and insects. I also use these systems to answer basic ecological questions, such as what mechanisms influence plant biodiversity and trait evolution." (See recent research)
Arathi Seshadri and Julia Fine, who recently joined the USDA-ARS lab on Bee Biology Road, UC Davis, aim to improve honey bee survival and beekeeping sustainability in California and nationwide. They collaborate with federal, university, non-governmental and industry partners. (See news story on opening of the facility.)
Seshadri, a pollination biologist with expertise in honey bee behavior and plant reproductive strategies, is working with beekeepers and farmer stakeholders to develop projects aimed at finding solutions to the ongoing pollination challenges. Also trained as an evolutionary biologist, she has applied principles of plant-pollinator mutualism, specifically the impact of phytochemicals in pollen and nectar on honey bee health and colony performance. Her contributions to pollinator conservation include enhancing the sustainability of all pollinators, including native bees on farms and urban areas. She also has expertise in agroecosystem-based approaches and citizen science programs to promote pollinator diversity and abundance.
Fine, an entomologist with expertise in insect toxicology, honey bee physiology, reproduction and development, focuses her research on identifying how stressors impact honey bee behavior, health and fecundity. She uses both established and novel laboratory techniques. Her previous projects involved investigating how agrochemical and viral stressors interact to affect the development and survival of honey bee brood and how nutritional stress affects honey bee queen fecundity. In engaging with beekeepers and growers, Fine is researching how realistic biotic and abiotic stressors affect honey bee reproduction, longevity and pollination services, and she is identifying techniques and strategies to overcome these effects.
The seminar is open to all interested persons. For more information, contact Vannette at rlvannette@ucdavis.edu.
- Author: Kathy Keatley Garvey
They draw the attention of curious kids--some poke them with a stick, stomp on them, or race their bicycles over them. Some peer into the holes, trying to see the insects inside.
When Corrie Moreau was a young girl, she no doubt was one of the kids who peered inside.
She's now a noted evolutionary biologist and entomologist (specialty myrmecology, the study of ants).
Moreau will present a UC Davis Department of Entomology and Nematology seminar, "Piecing Together the Puzzle to Understand the Evolution of the Ants: Macroevolution to Microbiomes" from 4:10 to 5 p.m., Wednesday, Jan. 15 in 122 Briggs Hall, Kleiber Hall Drive.
Moreau is the Moser Professor of Biosystematics and Biodiversity, Departments of Entomology and Ecology and Evolutionary Biology at Cornell, University, Ithaca, N.Y. and the curator of the Cornell University Insect Collection.
"Moreau and colleagues were the first to establish the origin of the ants at 140 million years ago using molecular sequence data (40 million years older than previous estimates), and that the diversification of the ants coincided with the rise of the flowering plants (angiosperms)," according to an entry in Wikipedia. "In addition, Moreau and Charles D. Bell showed that the tropics have been and continue to be important for the evolution of the ants. Moreau and colleagues have demonstrated the importance of gut-associated bacteria in the evolutionary and ecological success of ants through targeted bacterial and microbiome sequencing, including showing that bacterial gut symbionts are tightly linked with the evolution of herbivory in ants."
Her honors are many and widespread. In 2018 she was elected a fellow of the American Association for the Advancement of Science. Also in 2018, she was featured in National Geographic as a "Woman of Impact." In 2015, she was included in "15 Brilliant Women Bridging the Gender Gap in Science."
A native of New Orleans, Moreau holds degrees (bachelor and master's) from San Francisco State University and a doctorate in biology from Harvard University (2007). At Harvard, she studied with major professors E. O. Wilson and Naomi Pierce. Wilson featured her in his 2013 book, Letter to a Young Scientist.
"There was no bravado in Corrie, no trace of overweening pride, no pretension," Wilson wrote. "The story of Corrie Saux Moreau's ambitious undertaking is one I feel especially important to bring to you. It suggests that courage in science born of self-confidence (without arrogance!), a willingness to take a risk but with resilience, a lack of fear of authority, a set of mind that prepares you to take a new direction if thwarted, are of great value – win or lose."
Moreau will cover a lot of ground in her UC Davis talk. "To fully understand the macro evolutionary factors that have promoted the diversification and persistence of biological diversity, varied tools and disciplines must be integrated," she says in her abstract. "By combining data from several fields, including molecular phylogenetics/phylogenomics, comparative genomics, biogeographic range reconstruction, stable isotyope analyses, and microbial community sequencing to study the evolutionary history of the insects, we are beginning to understand the drivers of speciation and the interconnectedness of life. Comparative phylogenetic analysis reveals the interconnectedness of ants and plants and that ants diversified after the rise of the angiosperms. Comparative genomics has permitted the exploration of the role of symbiosis on genome evolution and behavioral gene evolution demonstrating that Red Queen dynamics are at play in obligate mutualisms..."
"Microbial contributions to ants are not limited to diet enrichment," she says, "and we find evidence for their role in cuticle formation. These multiple lines of evidence are illuminating a more complete picture of ant evolution and providing novel insights into the role that symbiosis plays to promote biological diversity."
UC Davis graduate student Marshall McMunn of the Phil Ward lab is the host. Community ecologist Rachel Vannette, assistant professor (rlvannette@ucdavis.edu), coordinates the weekly seminars. See seminar schedule.
