- Author: Kathy Keatley Garvey
https://ucdavis.zoom.us/j/95882849672.
His title: "Using Genomic Data to Understand and Prevent the Spread of Tuta absoluta." He will be introduced by Chiu, professor and vice chair, UC Davis Department of Entomology and Nematology. A pre-seminar coffee will take place from 3:30 to 4:10 in Briggs 158.
T. absoluta, a species of moth in the family Gelechilidae, is a pest of tomato crops in its larval stage. It is also known as a tomato leafminer.
"Tuta absoluta is a serious agricultural pest of tomato plants," Lewald says in his abstract. "While initially discovered in Peru, it has rapidly invaded tomato fields around the world over the past century, causing widespread damage to the industry. The recent affordability of whole genome sequencing of insects opens the door to a wide number of applications to understand and control this pest."
"Using long read sequencing, we produced and annotated a highly contiguous T. absoluta genome assembly. Sequencing of individuals collected across many locations in Latin America allowed us to investigate population structure and diversity levels, as well as identify divergence times and possible migration events occurring between regions. Understanding these historical events can be key to predicting and preventing future invasion events. We also used comparative genomics between morphologically similar gelechiid species to develop efficient molecular diagnostics, allowing field researchers and stakeholders to identify Tuta absoluta rapidly to support quarantine and treatment efforts."
Lewald's research interests include studying population genetics and developing molecular diagnostics of pest insects. He received his bachelor's degree in molecular and cell biology from UC Berkeley in 2016. After studying circadian rhythms in sorghum with UC Berkeley professor Frank Harmon, he became interested in animal clock systems and joined the Chiu Lab in 2018.
He has published his work in several journals:
- Lewald, K. M., A. Abrieux, D. A. Wilson, Y. Lee, W. R. Conner et al., 2021 Population genomics of Drosophila suzukii reveal longitudinal population structure and signals of migrations in and out of the continental United States. G3 Genes|Genomes|Genetics jkab343.
- Lewald, K. M., and J. C. Chiu, 2020 Harnessing Transcriptomics to Study Insect Biology, in Transcriptomics in Entomological Research, CABI, Oxfordshire, UK.
- Tabuloc, C. A., K. M. Lewald, W. R. Conner, Y. Lee, E. K. Lee et al., 2019 Sequencing of Tuta absoluta genome to develop SNP genotyping assays for species identification. Journal of Pest Science.
- Gao, J., J. Sasse, K. M. Lewald, K. Zhalnina, L. T. Cornmesser et al., 2018 Ecosystem Fabrication (EcoFAB) Protocols for The Construction of Laboratory Ecosystems Designed to Study Plant-microbe Interactions. JoVE 57170.
The UC Davis Department of Entomology and Nematology's winter seminars are held on Wednesdays at 4:10 p.m. in 122 Briggs Hall. All are virtual. A pre-seminar coffee is held from 3:30 to 4:10 p.m. in 158 Briggs. Urban landscape entomologist Emily Meineke, assistant professor, coordinates the seminars. (See schedule.) She may be reached at ekmeineke@ucdavis.edu for technical issues.
- Author: Kathy Keatley Garvey
The hybrid meeting (both in-person and virtual) took place Oct. 31-Nov. 3 in Denver.
Several of the UC Davis highlights, as previously featured on the Department of Entomology and Nematology website:
- UC Davis distinguished professor Frank Zalom, integrated pest management (IPM) specialist and a past president of ESA, was celebrated as an Honorary Member of the ESA, an honor bestowed for his “long-term dedication and extraordinary contributions." (See more here.)
- UC Davis doctoral alumnus Kelli Hoover, a Pennsylvania State University professor internationally known for her research on invasive species, including the Asian longhorned beetle, gypsy moth and spotted lanternfly, was honored as a newly elected Fellow of ESA for her excellence in research. (See more here.)
- Danielle Rutkowski, doctoral candidate in the UC Davis Department of Entomology and Nematology, won a President's Prize in a graduate student competition for her 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. (See more here.)Doctoral candidate Danielle Rutkowski with her President's Prize. (Entomological Society of America/ Photography G)
- Maureen Page, with the lab of pollinator ecologist Neal Williams, professor, UC Davis Department of Entomology and Nematology, won the second-place award in a graduate student competition for her presentation on "Optimizing Pollinator-Friendly Plant Mixes to Simultaneously Support Wild and Managed Bees." She competed in the category, Plant-Insect Ecosystems: Pollinators. (See more here.)
- Kyle Lewald, with the College of Biological Sciences and the Integrated Genomics and Genetics Graduate Group, but a member of the lab of molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the UC Davis Department of Entomology and Nematology, won second-place in a graduate student competition for his presentation on "Assembly of Highly Continguous Diploid Genome for the Agricultural Pest, Tuta absoluta." (See more here.)
At the ESA's annual meetings, students are offered the opportunity to present their research and win prizes. There are several components to the competition: 10-minute papers (oral), posters, and 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.
"Each year approximately 3,500 entomologists and other scientists gather to exchange scientific information," ESA says on hits website. "A program of symposia, conferences, submitted papers, and continuing education seminars provides attendees the opportunity to hear and present research results. The meeting also provides a chance to interact informally with peers and prospective employers."
ESA, founded in 1889 and headquartered in Annapolis, Md.,, is the world's largest organization serving the professional and scientific needs of entomologists and others in related disciplines. Its 7000 members are in educational institutions, health agencies, private industry, and government. Michelle Smith of Corteva Agriscience served as the 2021 president. The newly elected president is Jessica Ware, assistant curator of Invertebrate Zoology at the American Museum of Natural History.
Below are several images shared by Photography G of Denver at the ESA meeting. More images from the ESA meeting are on Flickr.









- Author: Kathy Keatley Garvey
Three UC Davis doctoral students won major awards in the highly competitive 10-minute student speech competitions at the Entomological Society of America's annual meeting, held Oct. 31-Nov. 3 in Denver. The event involves graduate students presenting their papers or ongoing research, in collaboration with their major professors or co-authors.
Danielle Rutkowski, with the lab of community ecologist Rachel Vannette, associate professor, UC Davis Department of Entomology and Nematology, won the first-place award, the President's Prize, in her category, Plant-Insect Ecosystems: Ecology 3, with her presentation on "Fungicide Impacts on Bumble Bees Are Mediated via Effects on Bee-Associated Fungi." Her co-advisor is community ecologist Rick Karban, professor, UC Davis Department of Entomology and Nematology. Taking home second place was Kassie Hollabaugh of the University of Tennessee, Knoxville.
Maureen Page, with the lab of pollinator ecologist Neal Williams, professor, UC Davis Department of Entomology and Nematology, scored second place for her presentation, "Optimizing Pollinator-friendly Plant Mixes to Simultaneously Support Wild and Managed Bees." She competed in the category, Plant-Insect Ecosystems: Pollinators. Hannah McKenzie of Ohio State University won first place, the President's Prize.
Kyle Lewald, with the College of Biological Sciences and the Integrated Genomics and Genetics Graduate Group, but a member of the lab of molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the UC Davis Department of Entomology and Nematology, won second in his category, Systems, Evolution and Biodiversity: Genetics and Molecular Biology, with his speech on "Assembly of Highly Continguous Diploid Genome for the Agricultural Pest, Tuta absoluta." Amanda Markee of the University of Florida took home first place, the President's Prize.
Danielle Rutkowski's abstract
Maureen Page's abstract
Kyle Lewald's abstract
Tuta absoluta represents one of the largest threats to tomato production worldwide. While initially contained to South America throughout the 20th century, T. absoluta were detected in Spain in 2006 before rapidly spreading throughout Europe and Asia over the next decade. To facilitate study of pesticide resistance, adaptation, and control strategies, researchers require a high quality, highly contiguous, and well-annotated genome assembly. The currently published genome assembly was generated using short-read technology for the purpose of developing molecular markers and studying population genetics; however, due to the genome's large size, heterozygosity, and repetitiveness, the assembly was highly fragmented, making it unsuitable for annotation or functional genomic studies. To address this, we extracted DNA from a single T. absoluta individual for sequencing with long-read PacBio HiFi technology to avoid assembly issues expected due to high genetic diversity and repetitiveness. We have now successfully created a diploid assembly that contains 98% of complete BUSCO groups and 99% of initial raw reads, with an N50 of 6Mb. The genome is 3% heterozygous, and is 60% composed of repeat elements, explaining the fragmented nature of the previous assemblies. By annotating this assembly with previously published RNAseq, protein, and repeat-element datasets, we expect this resource to advance efforts in understanding and developing control strategies for this invasive moth. (Paper co-authored with Joanna Chiu)
At the ESA's annual meetings, students are offered the opportunity to present their research and win prizes. There are several components to the competition: 10-minute papers (oral), posters, and 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.
The 7000-member Entomological Society of America, founded in 1889 and headquartered in Annapolis, Md.,, is the world's largest organization serving the professional and scientific needs of entomologists and others in related disciplines. Its members are in educational institutions, health agencies, private industry, and government.
- Author: Kathy Keatley Garvey
A total of 10 entomology graduate students will deliver presentations in the 10-minute oral student competitions, and two will present posters. The events are scheduled Monday, Nov. 1.
10-Minute Student Speech Competitions:
- Jill Oberski, doctoral candidate who studies with major professor Phil Ward
Category: Systematics, Evolution and Biodiversity: Phylogenetics and Phylogenomics
Title: "Arid-Adapted Pyramid Aants (Formicidae: Dorymyrmex) Show an Amphitropical Distribution and an Ongoing Radiation." - Zachary Griebenow, doctoral candidate who studies with major professor Phil Ward
Category: Systematics, Evolution and Biodiversity: Parasites and Symbionts
Title: "Discovery of a Putative Troglomorphic Ant (Hymenoptera: Formicidae: Leptanillinae)"
- Lacie Newton, doctoral candidate who studies with major professor Jason Bond
Category: Systematics, Evolution and Biodiversity: Phylogentics and Phylogenomics
Title: "Establishing a Robust Combined-Evidence Phylogeny of the Trapdoor Spider Genus Aptostichus (Araneae: Mygalomorphae: Euctenizidae)" - Lindsey Mack, PhD student who studies with major professor Geoffrey Attardo
Category: Medical, Urban and Veterinary Entomology: Mosquitoes, Biting Midges and Flies
Title: "Gene Expression Temporal Analysis of Pyrethroid Response in Californian Aedes aegypti" - Danielle Rutkowski, PhD student who studies with major professor Rachel Vannette
Category: Plant-Insect Ecosystems: Ecology 3
Title: "Fungicide Impacts on Bumble Bees are Mediated via Effects on Bee-Associated Fungi" - Maureen Page, doctoral candidate who studies with major professor Neal Williams
Category: Plant-Insect Ecosystems: Pollinators
Title: "Optimizing Pollinator-friendly Plant Mixes to Simultaneously Support Wild and Managed Bees" - Xavier Zahnle, PhD student who studies with major professor Jason Bond
Category: Systematics, Evolution and Biodiversity: Evolution
Title: "Deep Homology Influences Llocalized Postembryonic Metamorphosis in Male Genitalia of the Flat-Backed Millipede Pseudopolydesmus serratus (Myriapoda, Diplopoda,Polydesmida,Polydesmidae)" - Erin T. Kelly, doctoral candidate who studies with major professor Geoffrey Attardo
Category: Physiology, Biochemistry and Toxicology: Molecular Biology, Cellular Biology and Biochemistry
Title: "Using Metabolomic Analysis to Generate Insights into Pyrethroid Metabolism and Resistance in California Aedes aegypti" - Jasmin Ramirez Bonilla, master's student who studies with major professor Ian Grettenberger
Category: Plant and Insect Ecosystems: Field Crops 3
Title: "Stripes and spots: Evaluating an Aggregation Pheromone, vittatalactone, for Western Striped (Acalymma trivittatum) and Western Spotted (Diabrotica undecimpunctata undecimpunctata) Cucumber Beetles" - Madison Hendrick, PhD student who studies with major professor Ian Gettenberger
Category: Plant and Insect Ecosystems: Field Crops 1
Title: "Clarifying Pyrethroid Resistance and Exploring Interactions with Insecticide Use in California Alfalfa Weevil"
Posters:
- Mia Lippey, PhD student who studies with major professors Jay Rosenheim and Emily Meineke
Poster in the Plant-Insect Ecosystems Section, Behavior and Ecology: "Effects of Surrounding Landscapes on the Fork-tailed Bush Katydid (Scudderia furcata) in California Citrus" - Gabriel "Gabe" Foote, PhD student who initially studied with (the late) Steve Seybold and is now advised by Hugh Safford Region 5 Regional Ecologist/Affiliate Faculty (UC Davis).
Poster in Plant-Insect Ecosystems Section, Pollinators, "Landscape and Stand Level Factors Affecting Wild Bee Diversity in the Californian Central Sierra Nevada"
Abstracts:
Speech Competition
Jill Oberski
Zachary Griebenow
Xavier J. Zahnle
In the arthropod subphylum Myriapoda, localized modification of walking legs is taxonomically widespread. Male millipedes (class Diplopoda) exemplify this phenomenon, with diverse postembryonic walking leg transformations including clasping organs, reduced or hyper-enlarged leg pairs, and intromittent copulatory genitalia called gonopods. Gonopods are fully formed in adult males, but usually develop internally through several stadia.
Special attention was paid to the origin and insertion points of muscles as potential points of topological continuity preserved through development. Additionally, a series of juvenile male Pseudopolydesmus stadia was imaged using µCT to investigate the structural transformation of the future gonopod appendage pair. Topological continuity of muscles between walking legs and gonopods could be established for only a few muscles. Moreover, the developmental series revealed near-complete obliteration of appendicular muscles before adult gonopod formation begins, disproving the hypothesis that gonopod muscles are physically retained serialhomologs of those in the walking legs. Therefore, the few structural similarities between muscles in walking legs and gonopods are more likely due to the structure being preserved from the ancestral node of gonopod-bearing millipedes (deep homology) than to developmental continuity within the individual. (Co-authors of paper are Professor Jason Bond and Megan Ma.)

Lindsey Mack

Danielle Rutkowski
Maureen Page
Despite the recognized utility of wildflower plantings to support honey bees and wild bees these two goals have largely been pursued separately. Furthermore, pollinator-friendly plant mixes are currently selected using estimates of flower visitation without considering among-plant differences in nutritional quality or how competition among bees might affect plant use. The nutritional composition of pollen and nectar strongly affects bee health and survival and bees use nutritional information to make plant foraging decisions. Additionally, honey bees, which are generally stocked at high densities in crop lands, have been shown to compete with native pollinators for pollen and nectar resources and such competition may lead to changes in plant choice and narrowing of diet breadth. In this study, I use data on flower visitation patterns and the nutritional quality of nectar and pollen from different plant species in conjunction with recently developed optimization models to identify plant mixes that meet the goals of enhancing honey bee nutrition and maximizing support of diverse bee communities while minimizing competition. (Paper co-authored by Professor Neal Williams)


Madison Hendrick
Posters
Mia Uppey

Gabriel Foote
Kyle Lewald, College of Biological Sciences and Member of the Joanna Chiu Lab
Tuta absoluta represents one of the largest threats to tomato production worldwide. While initially contained to South America throughout the 20th century, T. absoluta were detected in Spain in 2006 before rapidly spreading throughout Europe and Asia over the next decade. To facilitate study of pesticide resistance, adaptation, and control strategies, researchers require a high quality, highly contiguous, and well-annotated genome assembly. The currently published genome assembly was generated using short-read technology for the purpose of developing molecular markers and studying population genetics; however, due to the genome's large size, heterozygosity, and repetitiveness, the assembly was highly fragmented, making it unsuitable for annotation or functional genomic studies. To address this, we extracted DNA from a single T. absoluta individual for sequencing with long-read PacBio HiFi technology to avoid assembly issues expected due to high genetic diversity and repetitiveness. We have now successfully created a diploid assembly that contains 98% of complete BUSCO groups and 99% of initial raw reads, with an N50 of 6Mb. The genome is 3% heterozygous, and is 60% composed of repeat elements, explaining the fragmented nature of the previous assemblies. By annotating this assembly with previously published RNAseq, protein, and repeat-element datasets, we expect this resource to advance efforts in understanding and developing control strategies for this invasive moth. (Co-author is Joanna Chiu)
The 7000-member Entomological Society of America, founded in 1889 and headquartered in Annapolis, Md.,, is the world's largest organization serving the professional and scientific needs of entomologists and others in
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