- Author: Kathy Keatley Garvey
Her dissertation proposal also will be virtual. The Zoom link:
https://ucdavis.zoom.us/j/99327991233.
“In the proposed research, I will study the effectiveness of both automated precision spray applications and drone-mediated releases of biological control agents for the suppression of lettuce aphid and western flower thrips in several contexts," she says in her abstract. "I hope that the results of the proposed research will contribute to the development of best-use practices to guide the use of both technologies."
"I will generate novel data that fill existing knowledge gaps regarding the use of precision insecticide applications and drone releases of natural enemies in lettuce production systems. This will advance the adoption of these new pest management tools and contribute to a more sustainable integrative pest management system for lettuce."
Addie received her bachelor's degree in molecular environmental biology from UC Berkeley in 2011 and her master's degree in horticulture and agronomy from UC Davis in 2018. Before enrolling at UC Davis, she worked as a researcher under research chemist Spencer Walse at the USDA Agricultural Research Service (ARS) laboratory in Parlier, CA (2019-2021) and the UC Davis Contained Research Facility in Davis, CA (2012-2019), studying postharvest integrated pest management (IPM) of quarantine pests.
Active in the Entomological Society of America (ESA), Abrams received a second-place or runner-up award for her student research presentation at the 2022 ESA meeting, a joint meeting of the Entomological Societies of America, Canada, and British Columbia held in Vancouver, B.C., Nov. 13-16.
In her abstract, she noted that "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."
At the 2019 Pacific Branch of ESA meeting, Abrams delivered a presentation on Rearing methods for brown marmorated stink bug, Halyomorpha halys, on live host plants. She has authored or co-authored several publications on stink bugs.
- 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
That's the title of a virtual seminar to be presented Wednesday, Feb. 24 by postdoctoral scholar Jessica Kansman of the Department of Entomology, Pennsylvania State University as part of the weekly winter seminars hosted by the UC Davis Department of Entomology and Nematology.
Kansman will speak from 4:10 to 5 p.m. To register and attend the Zoom seminar, access this Google form link.
"Whether it is combating the ever-changing host-plant conditions, or keeping careful watch for hungry predators and parasites--aphids have a stressful experience," Kansman says in her abstract. "My research has focused on figuring out just how much stress aphids can handle. Specifically, how plant water stress influences aphids and their natural enemies, and whether predator odors are as stressful for aphids as the predators themselves."
On her website, she says: "I am broadly interested in plant-insect interactions, abiotic/biotic stress interactions, insect ecology, and multi-trophic interactions. I am passionate about science communication, science policy, and inspiring a love of insects in children, in the college classroom, and with just about anyone I come across."
Kansman holds a bachelor's degree in entomology (2015) from Michigan State University, East Lansing, and a doctorate in plant, insect and microbial sciences (2020) from the University of Missouri, studying with Deborah Finke. As a doctoral student, she received a $116,859 grant from the U.S. Department of Agriculture "to study the effect of drought on aphid performance and behavior, indirect effects of drought on natural enemies, and how these effects cascade up to influence insect communities." The Agriculture and Food Research Initiative (AFRI) of USDA's National Institute of Food and Agriculture (NIFA) awarded the grant.
Kansman has given such presentations as "Plants vs. Insects: A Tale of Spines, Spit and Assassins." In one YouTube video on "Decoding Science," she describes aphids as "devastating agricultural pests. They feed by piercing a needlelike mouthpart into the plant tissue and they use it as a straw to suck up the sap of the plant." Aphids stunt growth and transmit viruses.
Cooperative Extension specialist Ian Grettenberg is the seminar host and coordinates the seminars. For technical issues, he may be reached at imgrettenberger@udavis.edu.
For a list of Department of Entomology and Nematology seminars, click here.
- Author: Kathy Keatley Garvey
(Editor's Note: This seminar initially set for Wednesday, May 2 at 4:10 p.m. in 122 Briggs Hall has been cancelled.)
Tory Hendry, an assistant professor of microbiology at Cornell University, Ithaca, New York, will present a seminar on bacteria that infect and kill pea aphids at 4:10 p.m., Wednesday, May 2 in 122 Briggs Hall, as part of the weekly spring seminars hosted by the UC Davis Department of Entomology and Nematology.
Her seminar is titled “Life and Death in the Phyllosphere: Epiphytic Bacteria Influence Aphid Survival and Behavior.”
“She will be talking about some of her new and very cool work on insect vision and pathogen avoidance,” said co-seminar coordinator Rachel Vannette, assistant professor of entomology. “Her website is here, but briefly, she works on bacterial genome evolution and plant-microbe-insect interactions, and other microbial symbioses.”
In her abstract, Henry writes: “Several diverse strains of plant epiphytic bacteria, such as Pseudomonas syringae, are able to infect and kill pea aphids. P. syringae can be pathogenic to plants, but is also widespread in the environment and a common eipipye. We have found the P. syringae can easily infect aphids and be highly virulent to insects. This interaction is fairly broad, both across P. syringae strains and across hemipteran insect species, suggesting that infection by these bacteria may be common in nature. Aphids may use varied non-immunological defenses against bacterial infection, in particular they are able to avoid feeding when highly virulent bacteria are present on a leaf. We found that up to 80 percent of aphids avoid leaves painted with epiphytic bacteria in favor of feeding on control leaves."
"This interaction is fairly broad, both across P. syringae strains and across hemipteran insect species, suggesting that infection by these bacteria may be common in nature. Aphids may use varied non-immunological defenses against bacterial infection, in particular they are able to avoid feeding when highly virulent bacteria are present on a leaf. We found that up to 80 percent of aphids avoid leaves painted with epiphytic bacteria in favor of feeding on control leaves."
However, says Hendry, "aphids do not avoid all strains, rather avoidance is correlated with strain virulence such that mainly highly virulent strains are avoided. We determined that production of the fluorescent siderophore pyoverdine by P. syringae was necessary for aphid avoidance, and the evidence suggests that aphids use vision to detect the fluorescence of this molecule. Pyoverdine is not responsible for virulence itself, but aphids may use it as a reliable cue of virulence.”
Hendry received her doctorate in ecology and evolutionary biology from the University of Michigan. She held a postdoctoral appointment at the University of Arizona, working with David Baltrus, and was a fellow with USDA's National Institute of Food and Agriculture, working with Nicholas Mills and Steven Lindow at the UC Berkeley.
Co-coordinator of the weekly seminars are Brendon Boudinot, doctoral candidate in the Phil Ward lab, and Extension apiculturist Elina Lastro Niño.
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- Author: Kathy Keatley Garvey
Garden heroes, that is. That include lady beetles, better known as ladybugs.
“Garden Heroes” will set the theme of the Bohart Museum of Entomology's open house from 1 to 4 p.m., Sunday, March 2. The event, free and open to the public, will be held in Room 1124 of the Academic Surge building on Crocker Lane, UC Davis campus.
“This time of year aphids are invading our gardens,” said Tabatha Yang, education and outreach coordinator at the Bohart Museum. “Garden heroes, like lady beetles, help us out.”
Other garden heroes include lacewings, bigeyed bugs, assassin bugs, damsel bugs, and soldier beetles. Family activities, including how to make a bee condo for native bees, are planned.
Another key attraction will be a return appearance of the Budding Biologist, (http://www.buddingbiologist.com/about.html), creator of ecology video games. Budding Biologist is an educational publishing company owned by Kristine Callis-Duehl, who is with the Department of Ecology and Evolutionary Biology at UC Irvine. This game is loosely based on ecological research being conducted by Louie Yang, assistant professor in the UC Davis Department of Entomology and Nematology. Walter Hsiao, the video game developer, will be on hand to answer questions about game design.
The Bohart Museum, directed by Lynn Kimsey, professor of entomology at UC Davis, houses nearly eight million specimens and is the seventh largest insect collection in North America. It is also the home of the California Insect Survey, a storehouse of insect biodiversity. Noted entomologist Richard M. Bohart (1913-2007) founded the museum in 1946.
The year-around gift shop (also online) offers t-shirts, jewelry, insect nets, posters and books, including the newly published children's book, “The Story of the Dogface Butterfly,” written by UC Davis doctoral candidate Fran Keller and illustrated (watercolor and ink) by Laine Bauer, a 2012 graduate of UC Davis. The 35-page book, geared toward kindergarteners through sixth graders, also includes photos by naturalist Greg Kareofelas of Davis, a volunteer at the Bohart.
The museum is located near the intersection of LaRue Road and Crocker Lane. The museum's regular public hours are from 9 a.m. to noon and 1 to 5 p.m., Monday through Thursday. Group tours can be arranged with Tabatha Yang at tabyang@ucdavis.edu or (530) 752-0493. The museum is closed to the public on Fridays, Saturdays and Sundays and UC Davis holidays.