- 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)
- Author: Kathy Keatley Garvey
Yes, according to UC Davis community ecologist and doctoral candidate Danielle Rutkowski and her colleagues in their newly published research in the Royal Entomological Society's Journal of Ecological Entomology.
The research, “Bee-Associated Fungi Mediate Effects of Fungicides on Bumble Bees,” provides direct evidence that fungi can benefit both survival and reproduction in two species of bumble bees, Bombus vosnesenskii, and B. impatiens. The research also suggests that yeast, commonly found in the gut of bumble bees, may be more important than originally thought.
“Bumble bees are important pollinators that face threats from multiple sources, including agrochemical application,” said Rutkowsi, the lead researcher-author. “Declining bumble bee populations have been linked to fungicide application, which could directly affect the fungi often found in the stored food and gastrointestinal (GI) tract of healthy bumble bees.”
“I tested if fungicides commonly applied in orchard systems affected yeasts and the health of their bee hosts, and if feeding those bees their fungi after fungicide exposure could rescue them,” said Rutkowski, who studies with major professors Rachel Vannette and Richard Karban, community ecologists in the Department of Entomology and Nematology.
“Bombus vosnesenskii (commonly known as the yellow-faced bumble bee), is native to California and we reared colonies of it from wild-caught queens,” Rutkowski said. “In this species, we observed strong negative effects of fungicide and the ability of bee-associated fungi to rescue bees from these negative effects. The other species, Bombus impatiens, is native to the eastern United States, but is commonly produced and sold commercially for pollination. In this species, we did not find any negative impacts of fungicide, but the addition of yeasts was very beneficial for bee survival and offspring production.”
“Although most previous work on bee microbiomes has focused on bacteria and their role in bee health, Danielle's work suggests that yeasts --which are commonly found in association with bumble bees--may be more important than previously thought,” Vannette said. “This has been hinted at in the literature but rarely tested directly.”
Rutkowski examined the interactive effects of the fungicide propiconazole and fungal supplementation on the survival, reproduction and microbiome composition of microcolonies (queenless colonies) using the two species.
Both B. vosnesenskii and B. impatiens benefitted from fungal addition but in different ways. fungicide exposure decreased survival in B. vosnesenskii, while fungal supplementation mitigated fungicide effects. For B. impatiens, fungicide application had no effect, but fungal supplementation improved survival and offspring production.
“Because the effect of fungicides on yeasts and bees takes a few weeks to observe, it is not detected in short term LD50 trials,” Vannette said, “and therefore could be an unrecognized threat to bumble bees and their symbionts.”
Other co-authors of the paper are entomologist Eliza Litsey and environmental scientist Isabelle Maalouf.
More research is planned to determine the mechanism by which yeasts can affect bee health, and which fungicides affect bee-associated yeasts.
“I'm currently working on a project to determine the mechanisms behind the positive effects of yeast addition that we observed,” Rutkowski said. “In some bees and other insects, fungi can produce nutritionally important compounds for their host, and I'm currently trying to determine if this is the case for bumble bees as well.”
“Additionally, I'm planning on following up some of the interesting results on differences between bumble bee species by determining how associated microbial communities differ between wild and commercially-reared bumble bees,” Rutkowski said. “In this current paper, we found that the fungal communities associated with the commercially-sourced bees were less diverse and less abundant, and I'm hoping to determine if that's a common pattern.”
Rutkowski, who joined the UC Davis doctoral program in 2018, won the President's Prize (first-place) in her category for her graduate student research presentations at the 2017 and 2021 Entomological Society of America meetings. A 2018 graduate of Cornell University, summa cum laude, she holds a bachelor of science degree in entomology and biological sciences, with a concentration in ecology and evolution.
Rutkowski's research drew support from her three-year USDA National Institute of Food and Agriculture grant.


- Author: Kathy Keatley Garvey
Kathy Keatley Garvey, communications specialist for the UC Davis Department of Entomology and Nematology, wrote the news article on "An Amazing Doctoral Opportunity Few Receive,” in March of 2021. The article won the “writing for newspapers” category. (See https://bit.ly/3MfuaLn)
“When five-year-old Rebecca Jean “RJ” Millena entered her kindergarten class in Concord, Calif., she immediately settled on a career choice: entomology,” Garvey began.
“An ‘About Me' poster hanging in her childhood home in Concord confirms it: ‘When I grow up, I want to be an entomologist.'
“She did and she is.”
Millena, who over a two-year-period worked as a student researcher in the laboratory of UC Davis distinguished professor Jay Rosenheim, studied the bizarre Strepsiptera endoparasites that attack their hosts, the Ammophila (thread-waisted) wasps. Millena went on to receive her bachelor's degree in entomology in 2021, and a rare four-year, full-ride doctoral fellowship from the American Museum of Natural History.
While at UC Davis, Millena studied Ammophila specimens at the Bohart Museum of Entomology, which houses a worldwide collection of more than 30,000 Ammophila (among the Bohart's eight million specimens). As larvae, members of the order Strepsiptera, known as “twisted wings,” enter theirs hosts, including wasps and bees, through joints or sutures.
Millena drew information and inspiration from UC Davis alumnus Arnold Menke, a global authority on Ammophila and author of "The Ammophila of North and Central America (Hymenoptera, Sphecidae).
“Strepsiptera are very unusual among parasites in that the parasite is visible on the outside of the host's body,” Rosenheim explained. “The head of the parasite protrudes between the sclerites on the abdomen. Looking across a growing list of species, RJ has shown that Ammophila species where mothers have more extended contact with their young--because they provision their nests with many, small caterpillars instead of one giant caterpillar-- are at much greater risk of acting as inadvertent vectors of strepsipteran parasites to their young.”
“RJ has shown that this one feature explains something like 90 percent of the total variation across Ammophila species in the risk of parasitism,” Rosenheim said. “Ecology virtually never works in such a predictable way; this is one truly exceptional counterexample of nature being highly predictable. Anyway, RJ's work shows that sometimes parental care can be a double-edged sword; we usually think of parental care as providing enhanced protection of offspring from predators and parasites. In this case, it proves to be the reverse.”
Also quoted in the news story was Lynn Kimsey, director of the Bohart Museum and a UC Davis distinguished professor of entomology: “RJ is one of those rare students that is focused, task-oriented and simultaneously creative. She was great fun to have working in the museum.”
Entomology Photo Series Award
Garvey also won the ACE silver award (second-place) for her picture story on “The Flight of the Bumble Bee,” posted June 14, 2021 on her daily (Monday through Friday) Bug Squad blog on the UC Agriculture and Natural Resources website. (See https://bit.ly/3xuoPLN)
Garvey captured in-flight images of a yellow-faced bumble bee, Bombus vosnesenskii, foraging on lupine at Bodega Bay. In her blog, she drew attention to two books: California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday, 2014), the work of University of California scientists Gordon Frankie, Robbin Thorp, Rollin Coville and Barbara Ertter; and Bumble Bees of North America: An Identification Guide (Princeton University, 2014), co-authored by Thorp (1933-2019), a UC Davis distinguished emeritus professor of entomology.
ACE, an international association of communicators, educators and information technologists who focus on communicating research-based information, will present the communication awards at its 2022 conference, set June 12-14, in Kansas City, MO.


- Author: Kathy Keatley Garvey
Mola, a U.S. Geological Survey Mendenhall Postdoctoral Fellow based at the Fort Collins Science Center, Colorado, and a former member of the Neal Williams laboratory, UC Davis Department of Entomology and Nematology, authored the research review article with colleagues Jeremy Hemberger, a postdoctoral researcher in the Williams lab; Jade Kochanski of the University of Wisconsin, Madison; Leif Richardson of the Xerces Society for Invertebrate Conservation; and UC Davis alumnus Ian Pearse of the Fort Collins Science Center.
Photographer Diego Delso took the cover image showing a Bombus terrestris, a buff-tailed bumble bee that is one of the most numerous bumble bee species in Europe. He captured the image on a pink mulla mulla, Ptilotus exaltatus, in Estonia.
The abstract:
"Declines of many bumble bee species have raised concerns because of their importance as pollinators and potential harbingers of declines among other insect taxa. At present, bumble bee conservation is predominantly focused on midsummer flower restoration in open habitats. However, a growing body of evidence suggests that forests may play an important role in bumble bee life history. Compared with open habitats, forests and woody edges provide food resources during phenologically distinct periods, are often preferred nesting and overwintering habitats, and can offer favorable abiotic conditions in a changing climate. Future research efforts are needed in order to anticipate how ongoing changes in forests, such as overbrowsing by deer, plant invasions, and shifting canopy demographics, affect the suitability of these habitats for bumble bees. Forested habitats are increasingly appreciated in the life cycles of many bumble bees, and they deserve greater attention from those who wish to understand bumble bee populations and aid in their conservation."
They pointed out that "Bumble bee conservation and management has garnered considerable attention because of bees' role as pollinators of economically and ecologically important crops and wild plants. The precipitous decline of several bumble bee species has been documented in the twenty-first century, raising alarm about the viability of these charismatic species (Cameron and Sadd 2020). Because of this, bumble bees have become a focal taxon for understanding and preventing the loss of insect biodiversity more broadly (Goulson and Nicholls 2016, Wagner et al. 2021). Threats to bumble bee populations include habitat loss, novel pathogen exposure, climate change, and pressures from intensive agriculture, such as pesticide applications (Cameron and Sadd 2020). One of the primary tasks for bumble bee conservation is developing a greater understanding of the habitat requirements of species throughout their life cycle and incorporating that knowledge into restoration and management plans." See more here.
An invited participant on the Western Bumble Bee Species Status Assessment Expert Group and the Native Bee Monitoring Research Coordination Network, Mola is also an organizing member (since 2020) of BOMBUSS: Building Our Methods by Using Sound Science.
Mola, who holds a bachelor of science degree in environmental studies from Florida State University, and a master's degree in biology from Humboldt State University, received his doctorate in ecology in 2019 from UC Davis. He presented his exit seminar on "Bumble Bee Movement Ecology and Response to Wildfire."
Mola also was a UC Davis Professors for the Future Fellow, receiving a year of professional development and pedagogical training. His honors also include a 2013-2018 National Science Foundation Graduate Research Fellowship of $133,500 and a 2014-2016 UC Davis Graduate Group in Ecology Fellowship of $43,000. He won the graduate student research poster competition at the 2018 UC Davis Bee Symposium for his work on "Bumble Bee Movement and Landscape Genetics."

- Author: Kathy Keatley Garvey
She and other recipients of the prestigious President's Prize, (the first-place award), each held up an empty picture frame lettered with "Student Competition Winner."
Images from the ESA meeting are online on Flickr at https://www.flickr.com/photos/
Rutkowski delivered her 10-minute presentation on "Fungicide Impacts on Bumble Bees are Mediated via Effects on Bee-Associated Fungi" in the category, Plant-Insect Ecosystems: Ecology 3." She studies with community ecologist Rachel Vannette, associate professor, and is also advised by community ecologist and professor Rick Karban.
At the ESA's 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. First-place winners receive a one-year free membership in ESA, a $75 cash prize, and a certificate. Second-winners score a one-year free membership in ESA and a certificate.
Rutkowski's abstract:
"Native bees including bumble bees are important pollinators but face threats from multiple sources, including agrochemical application. Declining bumble bee populations have been linked to fungicide application, which could directly affect the fungi often found in the stored food and GI tract of healthy bumble bees. Here, we test the hypothesis that fungicides impact bee health by disrupting bumble bee -fungi interactions. Using two species, Bombus vosnesenskii and B. impatiens, we test the interactive effect of the fungicide propiconazole and fungal supplementation on the survival, reproduction, and microbiome composition of microcolonies (queenless colonies). We found that both bee species benefitted from fungi, but were differentially affected by fungicides. In B. vosnesenskii, fungicide exposure decreased survival while fungal supplementation mitigated fungicide effects. For B. impatiens, fungicide application had no effect, but fungal supplementation improved survival and offspring production. Fungicides altered fungal microbiome composition in both species, and reduced fungal abundance in B. vosnesenskii microcolonies, but not in B. impatiens, where instead fungal addition actually decreased fungal abundance. Our results highlight species-specific differences in both response to fungicides and the nature of fungal associations with bees, and caution the use of results obtained using one species to predict the responses of other species. These results suggest that fungicides can alter bee- fungi interactions with consequences for bee survival and reproduction, and suggest that exploring the mechanisms of such interactions, including interactions within bee-associated fungal communities, may offer insights into bumble bee biology and bumble bee conservation strategies. (Paper co-authors are associate professor Rachel Vannette, Eliza Litsey and Isabelle Maalouf)
Rutkowski completed her bachelor's degree at Cornell University, where she studied how the relationship between mycorrhizal fungi and their host plants impacts insect herbivores. On the Vannette lab website, she specifies that she studies "how bumble bees interact with the microbes, particularly fungi, in their environment, and how these relationships impact bee health."
Vannette describes her lab as "a team of entomologists, microbiologists, chemical ecologists, and community ecologists trying to understand how microbial communities affect plants and insects (sometimes other organisms too). We often study microbial communities in flowers, on insects or in soil. We rely on natural history observations, and use techniques from chemical ecology, microbial ecology and community ecology. In some cases, we study applied problems with an immediate application including pathogen control or how to support pollinators. Other questions may not have an immediate application but are nonetheless grounded in theory and will contribute to basic knowledge and conservation (e.g. how can dispersal differences among organisms affect patterns of abundance or biodiversity?)"
Related Information:
- Three UC Davis Graduate Students Win Top Awards at ESA Competition (Danielle Rutkowski, President's Prize; Maureen Page, second-place; and Kyle Lewald, second-place)
- UC Davis Graduate Students Present Their Research in ESA Competitions (Jill Oberski, Zachary Griebenow, Lacie Newton, Lindsey Mack, Danielle Rutkowski, Maureen Page, Xavier Zahnle, Erin Taylor Kelly, Jasmin Ramirez Bonilla, Madison Hendrick, Mia Lippey, and Gabriel Foote)

