- 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 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
The laboratory of Professor Phil Ward, UC Davis Department of Entomology and Nematology, will provide live ants, specimens, information, and engage in one-on-one discussions about ant species at the Bohart Museum of Entomology open house from 1 to 4 p.m., Sunday, May 21.
The event, free and family friendly, will take place in Room 1124 of the Academic Surge Building, 455 Crocker Lane. The family arts-and-crafts activity will be to create paper ant headbands. "The current version has serrated mandibles, but people can go free form, too," said Tabatha Yang, education and outreach coordinator. "We're hoping for a colony of visitors with red headbands."
Among the Ward lab scientists scheduled to participate are doctoral candidates Jill Oberski and Zach Griebenow (both are expected to receive their PhDs this year), and third-year doctoral student Ziv Lieberman.
Griebenow and Oberski are veterans of UC Davis teams that won national championships in the Entomological Society of America's Entomology Games or "Bug Bowls." (See news story) UC Davis teams won national championships in 2022, 2018, 2016 and 2015.
The Bohart Museum featured Ward, a noted ant systematist, in a video, "All About Ants II" shown at the 2021 UC Davis Biodiversity Museum Day. It is posted on YouTube at https://youtu.be/d8eRNsD8dxo.
Ward offered an hour-long, introductory presentation on ants and answered scores of questions, drawing viewers from as far away as Virginia. He illustrated his talk with ant images taken by his former doctoral student Alex Wild (PhD from UC Davis in 2005), curator of entomology at the University of Texas, Austin, and a noted macro photographer (http://www.alexanderwild.com).
Ants originated about 120 million years ago (early Cretaceous), evolving from "wasp-like creatures," Ward said. They are members of the order Hymenoptera, and their closest relatives include honey bees, cockroach wasp and the mud daubers.
Ward related that live in long-lived colonies with (1) cooperative brood care (2) overlapping generations and (3) reproductive division of labor, the hall marks 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)
"Ants have occupied almost all of the world's land surfaces, from deserts to rain forests," Ward said in the video. "There's a few places they're absent. They're not in Antarctica, no surprise! They haven't colonized the Arctic and a few very high elevation tropical mountains, but apart from that, almost any place you go on land you'll see our friends, the ants. And they have assumed a quite a diverse array of ecological roles. Some of them are predators, others are scavengers, and some are seed collectors, and these habits vary tremendously among different species in different parts of the world."
Ants communicate largely by chemical (pheromones) and tactile means, Ward said. Their vision is "not particularly acute." He pointed out that that they lay a trail pheromones from the source of food back to the nest. They have alarm pheromones, causing other workers to act defensively. Chemicals also help ants distinguish their nest mates.
Some ants, like the Argentine ants, are pests. These invaders from South America "form super colonies, which means different colonies don't fight each other; they're all cooperating. And the other downside of Argentine ants is that they tend to eliminate native ants. So over the years I've lived in Davis, I have certainly noticed that native ants have declined as the Argentine ants have expanded. And they expand not just in, say, urban areas, but along certain natural habitats and one that they really like is the riparian habitat. So if you look along rivers and streams that are near urban areas, they're getting invaded by Argentine ants. And when they do, most native ants just disappear. This is a very tough aggressive ant and the mellow California ants can't handle an aggressive invader from South America. So they just disappear."
The Bohart Museum, directed by UC Davis distinguished professor Lynn Kimsey, houses a global collection of eight million insect specimens, plus a petting zoo (including Madagascar hissing cockroaches, stick insects and tarantulas) and a gift shop, stocked with insect-themed t-shirts, hoodies, jewelry, posters, books, and collecting equipment.
Founded in 1946, the Bohart is open to the public Mondays through Thursdays, from 8 a.m. to noon, and 1 to 5 p.m. More information is available on the Bohart website at https://bohart.ucdavis.edu or by emailing bmuseum@ucdavis.edu.

- Author: Kathy Keatley Garvey
Brazilian-born scientist Mônica Antunes Ulysséa, a postdoctoral fellow in the laboratory of Corrie Moreau, Cornell University, will speak on "Morphology for Assessing Species Diversity and Previously Unknown Biological Traits of the Ant Genus Hylomyrma" at a virtual seminar at 4:10 p.m., Wednesday, Dec. 7.
The Zoom link: https://ucdavis.zoom.us/j/95882849672. Host is doctoral candidate Jill Oberski of the Phil Ward laboratory.
"Hylomyrma is a Neotropical ant genus of small to midsized ants, cryptic inhabitants of the leaf-litter of wet and dry environments, with a remarkable body sculpture," she says in her abstract. "They occur from sea level to 3,600m, from Mexico to northern Argentina and southern Brazil; its higher diversity is in the Amazon. Out of the 30 recognized species, 11 have females whose external morphology combines morphological traits of workers and queens, and at least three of them present female specimens with queen-like traits. These mosaic specimens sent me back to fieldwork to investigate more about the genus biology. I went to Serra do Cipó, Brazil, to find nests of the endemic Hylomyrma primavesi. Hence, for the first time, the H. primavesi nest architecture and the colony size were documented, the ergatoid queen, male and immatures were collected, and the behavior of the forage workers and their feeding preferences based on field and lab observations were recorded."
Ulyssea specializes in myrmecology, taxonomy, phylogeny, systematics, curatorial practices, and science dissemination. She received a 2018-2023 postdoctoral fellowship at Zoology Museum of University of Sao Paulo (2018-2023) to study in the Moreau lab. Professor Moreau, who teaches arthropod biosystematics and biodiversity, directs and curates the Cornell University Insect Collection.
Ulyssea's resume includes:
- Doctorate from the Zoology Museum of University of Sao Paulo, Brazil, Graduate Program in Systematics, Animal Taxonomy, and Biodiversity (2013-2017)
- Internship at Sorbonne University, Pierre and Marie Curie Campus, Paris/France (2015-2016).
- Master's degree in zoology, Graduate Program in Zoology at the State University of Feira de Santana, BA/Brazil (2010-2012).
- Bachelor and licentiate in biological sciences at Federal University of Santa Catarina, Florianópolis, SC/Brazil (2002-2008)
Urban landscape entomologist Emily Meineke, assistant professor, coordinates the department's seminars. This is the last of the fall seminars. For further information on the seminars or technical difficulties with Zoom, contact Meineke at ekmeineke@ucdavis.edu.
- Author: Kathy Keatley Garvey
This was Rutkowski's second consecutive President's Prize.
Doctoral candidate Lindsey Mack and doctoral student Adelaine “Addie” Abrams scored second-place for their research presentations in the highly competitive program.
Their topics ranged from bumble bees (Rutkowski) and ants (Griebenow) to mosquitoes (Mack) and thrips and aphids (Abrams).
At the Entomological Society of America (ESA) annual meetings, students are offered the opportunity to present their research and win prizes. They can compete in 10-minute papers (oral), posters, or infographics. The President's Prize winners receive a one-year paid membership in ESA, a $75 cash prize, and a certificate. Second-winners score a one-year free membership in ESA and a certificate.
Danielle Rutkowski
Danielle Rutkowski, who studies with community ecologists Rachel Vannette, associate professor, and distinguished professor Richard “Rick” Karban, spoke on “The Mechanism Behind Beneficial Effects of Bee-Associated Fungi on Bumble Bee Health,” at her presentation in the category, Graduate School Plant-Insect Ecosytems: Pollinators.
Her abstract: "Bees often interact with fungi, including at flowers and within bee nests. We have previously found that supplementing bumble bee colonies with these bee-associated fungi improves bee survival and increases reproductive output, but the mechanisms behind these effects are unclear. This research aimed to determine the mechanisms underlying positive impacts of fungal supplementation in the bumble bee, Bombus impatiens. We tested two hypotheses regarding possible nutritional benefits provided by bee-associated fungi. These included the role of fungi as a direct food source to bees, and the production of nutritionally important metabolites by fungi. To test these mechanisms, we created microcolonies bumble bees and exposed each microcolony to one of four treatment groups. These four treatments were created based on the presence of fungal cells and the presence of fungal metabolites. We found that bee survival and reproduction were unaffected by treatment, with trends of decreased survival and reproduction when fungi were present. This contradicts previous results we've found using this bumble bee species, where fungi had a positive impact. It is possible that this disparity in results is due to differences in pathogen pressure between the two experiments, as bees in the first experiment were exposed to large amounts of pathogen through provided pollen, including Ascosphaera and Aspergillus. This pollen was sterilized for subsequent experiments, reducing pathogen load. Therefore, it is possible that bee-associated fungi benefit bees through pathogen inhibition, and future work exploring this hypothesis is necessary to fully understand the role of these fungi in bumble bee health."
Zach Griebenow, who studies with major professor and ant specialist Phil Ward, (Griebenow also captained the UC Davis Entomology Games Team in its national championship win at the Entomology Games or Bug Bowl) explained “Systematic Revision of the Obscure Ant Subfamily Leptanillinae (Hymenoptera: Formicidae), Reciprocally Informed by Phylogenomic Inference and Morphological Data.” His category: Graduate School Systematics, Evolution and Biodiversity: Evolution 1.
His abstract: "Ants belonging to the subfamily Leptanillinae (Hymenoptera: Formicidae) are sister to nearly all other extant ants. Miniscule and subterranean, little is known of their behavior. Contrary to the collecting bias observed in most ants, male leptanilline specimens are acquired more easily than workers or queens. The sexes are almost never collected in association, and many subclades within the Leptanillinae are known from male specimens only. Our comprehension of evolutionary relationships among the Leptanillinae is further obstructed by oft-bizarre derivation in male phenotypes that are too disparate for phylogeny to be intuited from morphology alone. These restrictions plague our understanding of the Leptanillinae with probable taxonomic redundancy. My thesis aims at leptanilline taxonomy that reflects phylogeny, inferred from both genotype and phenotype, and integrates morphological data from both sexes. Here I present the results of (1) phylogenomic inference from ultra-conserved elements (UCEs), compensating for potential systematic biases in these data, representing 63 terminals; and (2) Bayesian total-evidence inferences from a handful of loci, jointly with discrete male morphological characters coded in binary non-additive or multistate fashion. Notably, these analyses identify worker specimens belonging to the genera Noonilla and Yavnella, which were heretofore known only from males. Given such discoveries across the Leptanillinae, the number of valid leptanilline genera is reduced from seven to three in order to create a genus-level classification that upholds monophyly along with diagnostic utility."
Mack, who studies with medical entomologist-geneticist Geoffrey Attardo, assistant professor, covered “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."
Abrams, who studies with Extension agricultural entomologist and assistant professor Ian Grettenberger (she is a member of the Horticulture and Agronomy Graduate Group), titled her research, “Hitting the Mark: Precision Pesticide Applications for the Control of Aphids in California Lettuce" in the category, Graduate School Physiology, Biochemistry and Toxicology: Integrated Pest Management.
Her abstract: "Commercial lettuce production in California's central coast represents 70 percent of the production in the United States. Recent discoveries of some chemistries in ground and surface water in the Salinas valley region have placed the insecticidal chemistries used by the industry at risk of increased regulation. Automated thinner-sprayers use plant-detection sensors to apply chemical sprays directly to individual lettuce plants, so that the same amount of product to plants as a standard broadcast sprayer while potentially reducing the amount of pesticide applied per acre by up to 90 percent. Field experiments testing this technology for the control of western flower thrips (Frankliniella occidentalis) and aphids, lettuce-currant aphid (Nasovonia ribisnigri) and others, were conducted to compare the efficacy of automated sprays to a conventional broadcast application system. Experiments were conducted in conventionally managed organic romaine lettuce fields using a complete randomized block design. Prior to and at regular intervals after treatment, heads were sampled from experimental and control plots to assess pest pressure. Results from this experiment validate the use of the automated sprayers to apply insecticides for the control of aphid and thrips pests in lettuce and will be discussed in the context of developing best-use-practices for this technology."
The 7000-member ESA, founded in 1889, is the largest organization in the world serving the professional and scientific needs of entomologists and individuals in related disciplines. Its members, affiliated with educational institutions, health agencies, private industry, and government, are researchers, teachers, extension service personnel, administrators, marketing representatives, research technicians, consultants, students, pest management professionals, and hobbyists.
(See all of student competition winners on ESA site)