Lab members

Rachel Vannette, Assistant Professor 2015-present   

Postdoc, Stanford University, Department of Biology

Ph.D., University of Michigan, Ann Arbor, Department of Ecology and Evolutionary Biology, 2011

Bachelor’s degree, Calvin College, 2006

Department of Entomology and Nematology

University of California, Davis

I am a community ecologist interested in understanding and predicting how microbial communities influence interactions between plants and insects.

Follow me on Twitter @rachelvannette

Google Scholar Site

ResearchGate Profile


Postdoctoral scholars

Amber Crowley-Gall, USDA Postdoctoral Fellow  2019-current

PhD. University of Cincinnati

Amber is a chemical ecologist with an interest in understanding the role of sensory systems in insect host choice. Her PhD dissertation focused on examining how variation in the olfactory system contributes to host specialization in cactophilic Drosophila. She is currently interested in exploring the role of microbes in insect host selection. She is particularly interested in understanding how plant-microbe interactions, especially plant pathogens, can alter the chemical signatures that insects are exposed to, as well as how these interactions can influence host choice and the impacts of time and environmental conditions. As a member of the Vannette lab she hopes to examine microbe-pollinator interactions, with a focus on plant pathogens and their potential microbial antagonists.

Jacob Francis, Postdoctoral researcher 2020-current

B.S: University of North Carolina at Asheville,                Ph.D. :University of Nevada Reno

Jake Francis is a behavioral and community ecologist interested in how pollinator behavior drives processes in co-flowering plant communities. For his doctoral work, he explored how floral reward nutrition shapes bees’ foraging behavior with downstream effects on patterns of pollen movement among plant species. In the Vannette lab he plans to explore the intersection of plant, pollinator, and microbial ecology with a focus on how floral traits mediate these interactions.Google Scholar, Jake’s Website

Marshall McMunn, USDA Postdoctoral Fellow 2018-current

B.S. University of Michigan 2009                                       Ph.D. University of California, Davis 2018

Marshall is a community and insect ecologist interested in behavior, physiology, and how insects cope with variable temperatures. As a member of the Vannette lab, Marshall is studying gut microbes within the Arizona turtle ant. His Google Scholar page.

Visiting researcher

Alexandria Igwe,  PhD  Microbiology Graduate Group (2020)A. Igwe

Email: aigwe at ucdavis dot edu

Twitter: @an_igwe

Allie is interested in understanding how microbial community composition and functions contribute to plant phenotypes. She finished her undergraduate degree in Biology at Howard University where her honor’s research focused on the role of nickel as a defense against herbivory. While studying at Texas A&M, Allie focused on microbial community dynamics in hydrocarbon-contaminated soil as a function of plant root exudation and earned a MS in Soil Science. Her PhD work focused on understanding how plant growth promoting bacteria contribute to the survival of California wildflowers on serpentine and non-serpentine soil. Allie completed her PhD in the Microbiology Graduate Group at UC Davis in 2020 and is currently a National Science Foundation Postdoctoral Fellow working with Michelle Afkhami at the University of Miami.

Graduate students

Danielle Rutkowski, PhD Student in the Entomology Graduate Group

Email: dmrutkowski ‘at’ ucdavis ‘dot’ edu

Co-advised with Rick Karban

Danielle is an entomology PhD student interested in the relationships between bees and microbes. She completed her bachelor’s degree at Cornell University, where she studied how the relationship between mycorrhizal fungi and their host plants impacts insect herbivores. At UC Davis, she studies how bumble bees interact with the microbes, particularly fungi, in their environment, and how these relationships impact bee health.


Shawn Christensen, PhD Student in the Microbiology Graduate Group

Email: smchristensen ‘at’ ucdavis ‘dot’ edu

Twitter: @pollenmicrobes

Shawn is an evolutionary biologist turned microbiologist, broadly interested in microbial interactions/symbioses with plant-pollinator systems, weird evolutionary traits, and crosswords. They obtained a BS from University of Wisconsin-Madison in Evolutionary Biology, where they did research on reducing ecological impacts of phosphorus runoff, ethnobotany and domestication traits in Brassica rapa, botanical field excursions of all kinds, and the evolution of chemical sets in the early origins of life. In the Vannette lab, Shawn is currently studying nectar-dwelling Acinetobacter and other nectar microbes and their potential influences on pollen for nutrient procurement, as well as the metabolomics of solitary bee pollen provisions.


Junior Specialist

Tobias Mueller

Email: tgmueller at ucdavis dot edu

Tobias Mueller

Tobias is a junior specialist and lab manager interested broadly in community ecology. His current work focuses on how differences in nectar chemistry and the presence of antimicrobial compounds found in nectar impact microbial community formation. Also keeping everyone in the lab safe (from paperwork mostly). He previously researched thrips and IPM in california citrus systems as well as insect communities in alfalfa and cotton.


Tobias is also the campus head steward of UAW5810, the postdoc and academic researchers union – reach out if you’re a postdoc or AR with any questions or concerns!

Undergraduates in the lab

Madeline Handy

Madeline (Maddie) Handy is an undergraduate majoring in Microbiology. She joined the Vannette Lab as part of the Research Scholars Program in Insect Biology. Maddie has a strong interest in how gut microbiota influence host health. In the future, she hopes to be able to apply her research skills and knowledge into the relationship between microorganisms and human systems. In the Vannette lab, Maddie’s research focuses on the Carpenter bee microbiome.



Other awesome undergraduates currently affiliated with the Vannette lab:

Garrett Keating

Dani Virdier

Jeselle-Ann Laxa

Gigi Melone

partial Vannette lab 2019: Jeselle-Ann Laxa, Ivan Munkres, Maddie Handy, Isabelle Maalouf, Danielle Rutkowski, Rachel Vannette, Rachel Dutch, Marshall McMunn, Amber Crowley-Gall, Honey Pathak


some of us are coordinated 🙂

Partial lab group, summer 2018

(L to R: Allie Igwe, Ash Zemenick, Robert Schaeffer, Rachel Vannette, Honey Pathak and Imade Ojo)


Lab photo, Summer 2016

(L to R: Tim Rei, Chela Owens, Rachel Vannette, Ariana Nagainis, Megan Morris, Griffin Hall and Allie Igwe)


Youngest (honorary) lab members:

Sterling Vannette (2013-present) and Corwin Vannette (2017-present)



Previous affiliates


Megan Morris,  JDPE student from Liz Dinsdale’s lab at San Diego State University Vannette lab 2015-2016

2018-2020: Postdoc at Stanford University

2020-current: Postdoc at Lawrence Berkeley National Lab


IMG_3242Griffin Hall, junior specialist  2015-2017

Bachelor’s degree, UC Davis, 2015

Coffee + travel blog

Current: Plant Materials Manager & Assistant Breeder at Frinj coffee


Robert Schaeffer, USDA ELI Postdoctoral Fellow 2016-2018

Assistant Professor at Utah State University

co-advised by R. Vannette, D. Crowder, N. Williams and T. Fukami


Ivan Munkres, junior specialist 2018-2019

Bachelor’s degree UC Davis 2018

Now laboratory assistant working on Bee Toxicology in Minneapolis, MN

Casie Lee, 2017 STAR (Students Training in Advanced Research) Program student.

UC Davis School of Veterinary Medicine, DVM Candidate, Class of 2020, co-advised with Lisa Tell.


Rachel Dutch, Master’s student in Avian Sciences, co-advised by Lisa Tell





Previous undergraduate researchers in the Vannette lab:

Ariana Nagainis (Spring 2016-Fall 2016)

Chela Owens (Spring 2016)

Tim Rei (2016-2017)

Wendy Melendez (2016-2017)

Cody Kiniry (2017-2018)

Anthony Chan (2017-2018)

John Duque (2017-2018)

Isabelle Maalouf (2017-2019)

Honey Pathak (2017-2019)

Eliza Litsey (2018-2019)

High School Student Affiliates

Almas Khan (2018-2019)