- Author: Kathy Keatley Garvey
The seminar also will be on Zoom. A pre-seminar coffee will take place from 3:30 to 4:10 p.m. in 158 Briggs.
"Ants of the genus Dorymyrmex, the 'pyramid ants,' exhibit an intriguing distribution that is most concentrated not near the equator, but instead in dry temperate regions of the Americas, such as deserts, shrublands, and beaches, and including Davis, California," Oberski writes in her abstract. "Although these ants are common, widespread, and ecologically significant, their diversity and evolutionary history are still poorly understood. My dissertation research introduces Dorymyrmex to modern phylogenomics and concerted biogeographic study by integrating classic and cutting-edge approaches: I performed targeted genomics with UCEs, inferred Bayesian phylogenies and fossil-calibrated divergence dates, and also employed traditional methods like morphometrics and visual species description."
"My work (1) characterizes the major lineages of Dorymyrmex, which are morphologically diverse in the Neotropics but actively peciating (and superficially similar) in North America; (2) illustrates an intercontinental range expansion that occurred millions of years ago; and (3) characterizes the Nearctic fauna, nearly doubling the number of Dorymyrmex species in North America. Ultimately, this research contributes to our knowledge of both local biodiversity and global dispersal patterns, and reveals Dorymyrmex is a unique system for studying rapid evolutionary radiations."
"I've been fascinated by insects as long as I can remember," Jill said. "As a kid, I learned the names of the major taxonomic orders and created a small pinned collection, but I didn't realize it could be anything more than a hobby, so I shifted my sights toward becoming a medical doctor. But when I went to college, I met a professor who actually does study biodiversity and discover new arthropod species for a living. So after getting my start in research at Macalester College, and a year as an intern at University of Wisconsin-Madison, I started searching for suitable research programs across the country where I could train as a grad student doing those same things—biodiversity, evolution, and biogeography of insects or arachnids."
"I was open to almost any insect/arachnid study system because generally, the more I learn about a group, the cooler I find it, and that turned out to be very true for ants. They're amazing little underappreciated creatures with societies all their own, and I'm so happy to be a myrmecologist."
Oberski is a past president of the UC Davis Entomology Graduate Student Association, and served in leadership roles in the Girls' Outdoor Adventure in Leadership and Science (GOALS).
Oberski received a five-year Dean's Distinguished Graduate Fellowship award in 2017. In May of 2022, she was selected for a Professors for the Future Fellowship (PFTF) award, described by PFTF as "a year-long competitive fellowship program designed to recognize and develop the leadership skills of outstanding graduate students and postdoctoral scholars who have demonstrated their commitment to professionalism, integrity, and academic service. The program is designed to prepare UC Davis doctoral students and postdoctoral scholars for an increasingly competitive marketplace and a rapidly changing university environment." For her project, she recorded a series of interviews about mental and chronic illnesses and how they impact academic professional development.
Oberski, who plays tenor saxophone at community events, performed in an entomology band at the 2018 UC Davis Picnic Day as Jill “Jillus Saximus” Oberski. She dressed as a “generalized heteropteran,” which she described as “most likely a member of the family Acanthosomatidae (shield bug) or Pentatomidae (stink bug). My family and friends have called me Jillybug, so I came to be the band's representative of Hemiptera.” (See news story on Entomology website, and feature in Entomology Today, published by ESA)
Future plans? After receiving her doctorate on June 15 in a UC Davis ceremony, Oberski will be moving to Washington, D.C. this summer for a brief stint as a visiting researcher at the Smithsonian Museum of Natural History. Then, in January 2024, she will start a three-year independent postdoctoral research position in Frankfurt, Germany.
The Oberski seminar is the last of the spring seminars, all coordinated by urban landscape entomologist Emily Meineke, assistant professor. For technical issues regarding Zoom connections, she may be reached at ekmeineke@ucdavis.edu.
- Author: Kathy Keatley Garvey
"The world's primary arboviral vector, Aedes aegypti, was reintroduced into California in 2013," Kelly says in her abstract. "Its re-establishment throughout the state appears to be due, in part, to the failure of pyrethroid insecticides applied for adult mosquito control. My dissertation work examines 1) population dynamics within the state 2) how mosquito metabolism is impacted by pyrethroid exposure and 3) how a pyrethroid susceptible reference strain of Aedes aegypti differs physiologically from a wild California Ae. aegypti population. This research describes a successful story of ˆexclusion and generated novel hypotheses about the physiological underpinnings of the fitness costs and tradeoffs observed in insects withthepyrethroid resistance phenotype. Additionally, I explore novel targets for insecticide synergism."
Kelly is president of the Entomology Graduate Student Association (EGSA), and served two terms as president of the UC Davis Equity in STEM and Entrepreneurship (ESTEME).
Active in the Entomological Society of America, Kelly was a member of the UC Davis team that won the national Entomology Games championship in 2022. The UC Davis team included three other doctoral candidates from the Department of Entomology and Nematology: Zachary Griebenow of the Phil Ward lab, captain; Jill Oberski of the Ward laboratory; and Madison “Madi” Hendrick of the Ian Grettenberger lab.The event is a lively question-and-answer, college bowl-style competition on entomological facts played between university-sponsored student teams. The question categories include biological control, behavior and ecology, economic and applied entomology, medical, urban and veterinary entomology, morphology and physiology, biochemistry and toxicology, systematics and evolution integrated pest management and insect/plant interactions.
Other academic highlights:
- Kelly was selected the recipient of the 2022 Student Leadership Award from the Pacific Branch of ESA, which encompasses 11 Western states, parts of Canada and Mexico and several U.S. territories. (See news story)
- She won a first-place award at the 2021 Entomological Society of America (ESA) meeting with her poster, “Metabolic Snapshot: Using Metabolomics to Compare Near-Wild and Colonized Aedes aegypti.”
Taylor, who joined the Attardo lab in 2018, holds a bachelor of science degree in biology, with a minor in chemistry, from Santa Clara University, where she served as president of the campuswide Biology Club and led STEM projects, encouraging and guiding underrepresented students to seek careers in science, technology, engineering and mathematics (STEM).
Her future plans? "I'm pursuing vector ecologist positions within California vector control programs!"
(Editor's Note: For the Zoom password, contact associate professor Geoffrey Attardo at gmattardo@ucdavis.edu or Taylor Kelly at etkelly@ucdavis.edu.)
- Author: Kathy Keatley Garvey
The open house, free and family friendly, is set for 1 to 4 p.m. in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus. “He will give a brief introduction to the field at the start of the event in the wildlife classroom (next door) and then we will move into our regular one-on-one, question-and-answer format,” announced Tabatha Yang, education and outreach coordinator.
Kimsey, who received his bachelor's degree and doctorate from UC Davis, focuses his research on public health entomology, arthropods of medical importance, and zoonotic disease, as well as the biology and ecology of tick-borne pathogens, and tick feeding behavior and biochemistry.
Kimsey staffs the annual “Dr. Death” booth at Briggs Hall during the campuswide UC Davis Picnic Day. He pin-mounts and identifies flies from various cases and research efforts, and displays studies on the sequence of development of individual maggots, calling attention to the development and sequence of communities of insect maggots. "By these means, approximations about how long a person has been dead can be made," he told the crowd. He also discussed recently adjudicated cases.
Kimsey wears a number of hats. He's the master advisor of the Animal Biology major; an assistant adjunct professor, UC Davis Department of Entomology and Nematology; and the faculty chair of the department's Picnic Day. He's also the advisor to the UC Davis Entomology Club and that includes guiding students to such venues as Alcatraz Island to see the flies and other insects.
Known as an outstanding teacher, advisor and mentor, Kimsey won the 2020 top faculty academic advising award from the international NACADA, the “global community for academic advising.”
Kimsey is also a 2019 winner of a faculty advising award from the College of Agricultural and Environmental Sciences, the Eleanor and Harry Walker Advising Awards. He previously won the UC Davis Outstanding Faculty Advising Award, and the Distinction in Student Mentoring Award from the Pacific Branch, Entomological Society of America.
The Bohart Museum, home of a global collection of eight million insect specimens, plus a live "petting zoo" and a gift shop, is directed by UC Davis distinguished professor Lynn Kimsey.
- Author: Kathy Keatley Garvey
The three-hour open house included displays of live ants as well as specimens. Ward and newly minted PhDs, Jill Oberski and Zachary Griebenow of the Ward lab, fielded scores of questions. Oberski and Griebenow each wore a "Dr." name tag, presented by Tabatha Yang, Bohart Museum education and outreach coordinator.
"The questions were mostly about the habits and behavior of ants, how many species are there, etc.," Ward related. "And how can I obtain live colonies for my kid? I received almost no queries about 'how do I get rid of them in my kitchen?' and that was refreshing."
"We had live colonies of a centipede-hunting ant (Stigmatomma oregonense) and a generalist omnivore (Aphaenogaster occidentalis)," Ward said. "The displays also included collections of common California ants; the world's smallest ant (Carebara) and the world's largest ant (Myrmecia)."
Griebenow, who recently presented his exit seminar on "Systematic Revision of the Ant Subfamily Leptanillinae (Hymenoptera:Formicidae), Reciprocally Illuminated by Phylogenomics and Morphology," answered questions about his research, and general questions about ant diversity. Griebenow, who holds a bachelor of science degree (2017) in agriculture (entomology), magna cum laude, from The Ohio State University, joined the Ward lab in September 2017.
Oberski, who received her bachelor's degree in biology and a bachelor's degree in German studies (summa cum laude) in 2016 from Macalester College, Saint Paul, Minn., finished her dissertation earlier this month. She will present her exit seminar on "Phylogenetics and Biography of Pyramid Ants" at 4:10 p.m., Wednesday, June 7 in 122 Briggs Hall. It also will be on Zoom.
Questions at the open house? Oberski shared that she received "some great questions about ant diets. What do ants eat? Are ants specialized or generalized in their feeding habits? The answer can vary a lot. Some ants are generalists that eat any food they come across, but others are extremely specific, like ants that are fungus farmers or specialized predators of springtails, spider eggs, or centipedes."
Professor Ward is featured in a Bohart Museum of Entomology video on YouTube at https://youtu.be/d8eRNsD8dxo. Ants, he related, originated about 120 million years ago (early Cretaceous), evolving from "wasp-like creatures." They are members of the order Hymenoptera, and their closest relatives include honey bees, cockroach wasp and the mud daubers. California is home to some 300 species of ants, but thousands more live in the tropics. Globally, there may be as many as 40,000 to 50,000 species of ants, the professor estimated, but only about 14,000 are described.
Also in the video, Ward related that ants live in long-lived colonies with (1) cooperative brood care (2) overlapping generations and (3) reproductive division of labor, the hallmarks of eusocial behavior. He also pointed out:
- A typical ant colony contains a reproductive queen, numerous non-reproductive workers and brood (eggs, larvae, pupae)
- Colonies of ants can be thought of as superorganisms: tightly integrated and cooperative entities with complex systems of communication and division of labor (castes)
The Bohart Museum, directed by UC Davis distinguished professor Lynn Kimsey, houses a global collection of eight million insects and also maintains a live "petting zoo" (Madagascar hissing cockroaches, stick insects, tarantulas and others) and an insect-themed gift shop. The museum is located in Room 1124 of the Academic Surge Building, 455 Crocker Lane.
The next Bohart Museum open house, themed "Insects and Forensics," will be from 1 to 4 p.m., Saturday, June 3. It will feature forensic entomologist Robert "Bob" Kimsey and his work.
- Author: Kathy Keatley Garvey
Her seminar takes place at 3:30 in 366 Briggs Hall, and also will be on Zoom.
Mack studies Aedes aegypti with a focus on analysis of transcriptomic datasets and 3D imaging datasets. "Throughout my time in graduate school, my projects have considered pyrethroid resistance in Aedes aegypti ;examining the genetic response to this insecticide. As I finish up my dissertation, I hope to pursue a career in industry using the skills I've developed to continue to analyze large datasets!"
Insecticide resistance is a global issue, Mack says in her exit seminar abstract. Ae. aegypti, known as "the yellow fever mosquito," can transmit dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents. The mosquito was first colonized California in 2013 and arrived resistant to pyrethroids. "The pyrethroid target site genotype differs geographically in California and partially infers resistance phenotype, indicating that other mechanisms are at play as well."
"Since their detection in 2013, Aedes aegypti has become a widespread urban pest in California," the co-authors wrote in the abstract. "The availability of cryptic larval breeding sites in residential areas and resistance to insecticides pose significant challenges to control efforts. Resistance to pyrethroids is largely attributed to mutations in the voltage gated sodium channels (VGSC), the pyrethroid site of action. However, past studies have indicated that VGSC mutations may not be entirely predictive of the observed resistance phenotype."
"To investigate the frequencies of VGSC mutations and the relationship with pyrethroid insecticide resistance in California, we sampled Ae. aegypti from four locations in the Central Valley, and the Greater Los Angeles area. Mosquitoes from each location were subjected to an individual pyrethrum bottle bioassay to determine knockdown times. A subset of assayed mosquitoes from each location was then analyzed to determine the composition of 5 single nucleotide polymorphism (SNP) loci within the VGSC gene."
The conclusion:
"Resistance associated VGSC SNPs are prevalent, particularly in the Central Valley. Interestingly, among mosquitoes carrying all 4 resistance associated SNPs, we observe significant heterogeneity in bottle bioassay profiles suggesting that other mechanisms are important to the individual resistance of Ae. aegypti in California."
Mack, who holds a bachelor of science degree (2018) in biology from Creighton University, Omaha, Neb., enrolled in the UC Davis graduate school program in 2018.
Active in the Entomological Society of America, Mack scored second place in student competition at the 2022 joint meeting of the Entomological Societies of America, Canada, and British Columbia, held last November in Vancouver, British Columbia. She entered her presentation, "Three Dimensional Analysis of Vitellogenesis in Aedes aegypi Using Synchrotron X-Ray MicroCT,” in the category, "Graduate School Physiology, Biochemistry and Toxicology: Physiology.
Her abstract: "Traditional methods of viewing the internal anatomy of insects require some degree of tissue manipulation and/or destruction. Using synchrotron-based x-ray phase contrast microCT (pcMicroCT) avoids this issue and has the capability to produce high contrast, three dimensional images. Our lab is using this technique to study the morphological changes occurring in the mosquito Aedes aegypti during its reproductive cycle. Ae. aegypti is the primary global arbovirus vector, present on all continents except Antarctica. Their ability to spread these viruses is tightly linked with their ability to reproduce, as the production of eggs in this species is initiated by blood feeding. Amazingly, this species produces a full cohort of eggs (typically 50-100) in just 3 days' time following a blood meal. This rapid development represents dramatic shifts in physiological processes that result in massive volumetric changes to internal anatomy over time. To explore these changes thoroughly, a time course of microCT scans were completed over the vitellogenic period. This dataset provides a virtual representation of the volumetric, conformational, and positional changes occurring in tissues important for reproduction across the vitellogenic period. This dataset provides the field of vector biology with a detailed three-dimensional internal atlas of the processes of vitellogenesis in Ae. aegypti."
"As for career plans, I am applying to computational biology positions in industry," Mack said. "I'm not filing my dissertation until July so I am still working on this."
