- Author: Kathy Keatley Garvey
The top honors went to:
- Doctoral candidate Shawn Christensen and doctoral student Alexia "Lexie" Martin, both of the lab of associate professor and community ecologist Rachel Vannette, vice chair of the department; and
- Doctoral student Iris Quayle of the lab of professor and arachnologist Jason Bond, the Evert and Marion Schlinger Endowed Chair and associate dean, College of Agricultural and Environmental Sciences.
Christensen competed in the Plant-Insect Ecosystems (P-IE) Section, Apiculture; Martin in the P-IE Section, Pollinator Biology; and Quayle in the Systematics, Evolution, and Biodiversity (SysEB) Section, Biogeography.
Shawn Christensen. Christensen presented "Bee Specific! Solitary Bee (Anthophora bomboides) Hosts a Specialized Core Microbiome through Development."
His abstract: "Host-microbe interactions are important for the development and fitness of many macroorganisms. While social bees are dependent on a vertically transmitted gut microbiome, solitary bees, which comprise the vast majority of species diversity within bees, lack a specialized gut community. We explored the microbiome associated with the complete life cycle of the ground-nesting polylectic solitary bee Anthophora bomboides standfordiana, including bacterial and fungal composition and abundance. In contrast to expectations, we found that immature stages of this solitary bee maintain a distinct core microbiome consisting of Actinobacteria and one yeast species. Stage-specific shifts in microbial abundance and community composition occur most notably during bee diapause, during which the abundance of bacteria and fungi increased dramatically. We tested two adaptive hypotheses regarding the role of the microbiome in bee ecology. First, isolated brood cell Streptomyces strains were found to inhibit growth of multiple often pathogenic filamentous fungi, suggesting a role in pathogen protection during the long period of diapause. Second, sugar alcohol composition changed in tandem with major changes in microbial abundance suggesting links with bee metabolism or overwintering biology. Our results suggest that this Anthophora species hosts a conserved core microbiome that may provide key fitness advantages through larval development and overwintering. Much work remains to examine the nature of bee-microbiome ecology, but our study reframes the conditions thought to promote the evolution and maintenance of symbiosis."
Co-authors: Rachel Vannette and Sriram Srinivas, UC Davis; Quinn McFrederick, UC Riverside; Bryan Danworth, Cornell University; and Stephen Buchmann, University of Arizona
Her abstract: "Bees interact with and in some cases benefit from a diverse community of microbes, which can be obtained through intraspecific interactions or the environment. Due to differences in sociality, bee species vary in their main route of microbial acquisition and their dependence on microbes. Despite the observation that intraspecific transmission of microbes is imperfect and environmental microbes are nearly ubiquitous in flowers, the potential impacts of intraspecific versus floral microbes on overall pollinator health have not been evaluated. This study uses two model bee species - one social (Bombus impatiens) and one solitary (Osmia lignaria)--to assess the establishment and health impacts of floral and intraspecific microbes. 2x2 factorial experiments were performed on B. impatiens microcolonies and O. lignaria females to selectively introduce intraspecific microbes and/or floral microbes. Survivorship and reproduction were measured to assess bee health and fitness, and DNA extractions and amplicon sequencing were performed on bee guts to evaluate microbial establishment. The results of this study will inform how microbes from different acquisition routes establish in the host, shape the gut microbiome, and affect host health. Since many macroorganisms encounter both intraspecific and environmental microbes, this study provides a framework for similar work in other organisms."
Co-author: Rachel Vannette, UC Davis
Her abstract: "In the Namib Desert, one of the largest and oldest deserts, the genus Onymacris contains a rarity for darkling beetles (Tenebrionidae) – the presence of eight species with striking ‘white' elytra (ranging from stark white to tan/striped). This study seeks to examine the phylogenetic relationships among white Onymacris species to test whether multiple derivations of white elytra is due to convergence or introgression. Population genomic data (3RAD) was generated from all white species of Onymacris with intraspecific sampling for four widespread species (O. marginipennis, O. bicolor, O. candidipennis, O. langi cornelii). Phylogenetic trees were inferred from 995 loci using concatenated and coalescent-based methods. The analyses supported two clades: langi and bicolor each of which contain species with pure white elytra. Variational autoencoder (VAE) clustering analysis shows a pattern of genetically isolated populations (bicolor) and gene flow indicating introgression (langi). These analyses also infer a potential new Angolan species sister to O. marginipennis in need of evaluation. Ancestral character state and biogeographic reconstruction resolve the timing of white species' color expression against the backdrop of sand sea emergence and increased aridity in the Namib, a landscape renown for ‘pocket speciation' and an impressive amount of darkling beetle diversity accounting for nearly 80% of the known endemic beetle fauna. Dynamic coloration provides a fascinating system through which to examine the role of ecological pressures and evolutionary mechanisms but requires a phylogenetic framework to understand organisms' potential adaptations to extreme environments, which is increasingly vital in the face of global trends aridity trends."
Co-authors: Lisa Chamberland, James Starrett and Jason Bond, UC Davis
The full list of student winners--first, second and third places--is here.
Founded in 1889, ESA is the largest entomological organization in the world. Its more than 7,000 members are affiliated with educational institutions, health agencies, private industry, and government.
- Author: Kathy Keatley Garvey
Professor Bond is serving a 2023-2025 term with president Linda Rayor of Cornell University's Department of Entomology, and then will assume the presidency. Bond specializes in the evolutionary diversification of terrestrial arthropods, specifically spiders, millipedes, and tenebrionid beetles. Rayor, a behavioral ecologist, focuses her research on the evolution of sociality in spiders.
AAS has played a huge role in Bond's career, with lifelong friends, colleagues, and collaborators who extend back nearly 30 years. "I consider it an honor to serve as AAS president."
AAS, founded in 1972, aims “to further the study of arachnids, foster closer cooperation and understanding between amateur and professional arachnologists, and to publish the Journal of Arachnology, according to its website. The journal is published three times a year.
A member of AAS since 1993, Bond co-hosted the 2022 AAS meeting at UC Davis, which included an outreach event, “Eight-Legged Encounters,” at the Bohart Museum of Entomology.
Bond joined the UC Davis faculty in 2018 after a seven-year academic career at Auburn University, Ala. He served as professor of biology, director of the Auburn University Museum of Natural History (2011-2105); chair of the Department of Biological Sciences from January 2016 to July 2018; and as curator of arachnids and myriapods (centipedes, millipedes, and related animals) from August 2011 to July 2018.
Bond also is the co-editor-in-chief of the journal Insect Systematics and Diversity, published by the Entomological Society of America. He and co-editor Hojun Song of Texas A&M began serving their four-year terms in 2022.
A veteran of the U.S. Army, Bond served as a UH-60 Blackhawk helicopter crew chief upon graduation from high school.
Jason received his bachelor's degree in biological sciences, cum laude, in 1993 from Western Carolina University, Cullowhee, and his master's degree in biology in 1995 from Virginia Polytechnic Institute and State University, Blacksburg. He earned his doctorate in evolutionary systematics and genetics in 1999 from Virginia Tech.
Research in his lab currently focuses on the California trapdoor spider fauna, specifically species delimitation, phylogeography, systematics and taxonomy; Bond has described many new spider taxa to include new families, genera, and more than 50 species.
- Author: Kathy Keatley Garvey
Her major professor Jason Bond, then a professor and administrator at Auburn University, Alabama, described and named what is commonly called "The Barack Obama Trapdoor Spider" in 2012.
The article, published in the journal Ecology and Evolution and part of Newton's 2022 doctoral dissertation, is titled "Phylogeography and Cohesion Species Delimitation of California Endemic Trapdoor Spiders within the Aptostichus icenoglei Sibling Species Complex (Araneae: Mygalomorphae: Euctenizidae)."
Co-authors are Professor Bond, who is the Evert and Marion Schlinger Endowed Chair in the UC Davis Department of Entomology and Nematology, and associate dean, College of Agricultural and Environmental Sciences; and Bond lab members, project scientist James Starrett and doctoral candidate Emma Jochim.
"Species delimitation in mygalomorph spiders using only traditional morphological approaches has underestimated species diversity," Newton said, "yet molecular approaches have been shown to overestimate species diversity due to the local population structuring seen as 'species divergence.' Specifically, the Aptostichus icenoglei complex, which comprises the three sibling species, A. barackobamai, A. isabella, and A. icenoglei, exhibits evidence of cryptic mitochondrial DNA diversity throughout their ranges across the California Floristic Province."
The researchers sampled 62 individuals overall for the three species within the complex, using both specimens from Bond (2012) and new records. "A. barackobamai was collected across its geographic range in northern California for a total of 21 samples, and A. icenoglei was collected throughout its range in southern California for a total of 40 samples," they wrote. "Only one specimen of A. isabella was included in this study due to collecting constraints (i.e., only one individual of this species has ever been collected and a burrow has not yet been found containing this species; Bond, (2012)
Next steps? "We hope to use whole genomes for both reconstructing evolutionary relationships as well as identifying genes that contribute to potential adaptive divergence across the landscape," Newton said. "We also hope to gather more natural history data for each of the species, especially A. icenoglei populations, for general ecological information that may aid in species delimitation."
Born and raised in Eupora, Miss., and a first-generation college student in her family, Lacie holds a bachelor of science degree in biological sciences (2016) from Millsaps College, Jackson, Miss. She then enrolled in the graduate school program at Auburn University, studying with Professor Bond. When he accepted the Schlinger Endowed Chair in 2018, Lacie, along with other lab members, transferred to UC Davis. Newton completed her dissertation on species delimitation in two trapdoor spider groups, Antrodiaetus unicolor complex and Aptostichus icenoglei sister species complex, and evaluation of interspecific relationships within the genus Aptostichus.
The research drew support from a National Science Foundation Grant awarded to Bond and Starrett; the McBeth Memorial Scholarship awarded to Newton; and the Evert and Marion Schlinger Foundation.
- Author: Kathy Keatley Garvey
In lekking, certain species of males in the animal world, including black grouse, peacock and owl parrots, congregate in a courtship ritual to entice females to mate with them. This is unusual because spiders are notoriously solitary and cannibalistic.
Jason Bond, the Evert and Marion Schlinger Endowed Chair in the UC Davis Department of Entomology and Nematology and project scientist James Starrett headed the genetic analysis. The research paper was recently published in the journal, Insect Systematics and Diversity.
“This paper is significant in a number of respects including the discovery of a new species of orb web-weaving spider that is social; most spiders are solitary predators that are cannibalistic,” said Bond, who doubles as associate dean, UC Davis College of Agricultural and Environmental Sciences. “Although additional behavioral studies are needed to confirm, what is particularly interesting about this paper is that we report what is likely the first known observation of lekking behavior in spiders.”
The paper, “Discovery and Genetic Characterization of Single Cohort Adult Colonies With Male Aggregations, and Preliminary Evidence for Lekking in a Malagasy Kite Spider (Isoxya, Gasteracanthinae),” is drawing worldwide attention, including a piece, “Spider Solidarity: Scientists Discover New Species With Unprecedented Social Behavior,” in Entomology Today, a publication of the 7000-member Entomological Society of America.
Ingi Agnarsson, a professor of zoology at the University of Iceland and the Smithsonian Institution, Washington, D.C., headed the international team of researchers.
While looking for bark spiders in the rainforests of Andasibe-Mantadia National Park, the scientists observed large colonies of interconnected webs, built by what they later determined to be a new species.
In examining the webs, the researchers noticed multiple males gathering close together, sometimes touching, in a central, nonsticking line. They counted up to 41 interconnected, single-cohort adult female webs with up to 38 adult males aggregating on a central, single, nonsticky line.
In all, their mile-long research area yielded 22 spider colonies, ranging from 2 to 79 spiders in webs two inches to almost eight inches in size. The spiders are dark gray with black coloring and large protruding spines. The females are about 0.2 inches in size, with “cryptic yellow markings.” The males are smaller but with no yellow markings.
They named the new species Isoxya manangona, derived from the Malagasy verb for “gather” or “aggregate.”
“Spiders are notoriously solitary and cannibalistic, with instances of colonial or social lifestyles in only about 50-60, or ~0.1% of 50,000 described species,” the authors wrote in their abstract. “Population analyses indicate that most colonies consist of multiple cohorts formed by close relatives. Territorial social spiders facultatively form colonies by interlinking individual webs, but further cooperation is infrequent, and only among juveniles or (rarely) females. In spiders therefore, aggregations of males outside of the male-male competition context has been unknown.”
The researchers noted that the males were “resting tightly together,” but they found “no evidence” of male-male aggression. “Genetic analyses from RAD sequencing suggest that most colonies consist of unrelated individuals,” they wrote in their abstract. “Furthermore, genetic variability of males was somewhat less than that of females. Single cohort colonies made up purely of adults, and peaceful male aggregations, have not previously been observed in spiders. Although direct behavioral observations are preliminary, we speculate based on the available evidence that these colonies may represent a novel and first case of lekking in spiders.”
Since it was near the end of the field season, the researchers had no opportunity for more observations, and never witnessed mating.
Other co-authors of the paper are Zachary Babbitz of Boston College, Matjaž Gregoric of the Slovenian Academy of Sciences and Arts, Onjaherizo Christian Raberahona of the University of Madagascar; Steven Williams, Oxford Brookes University, UK, and Matjaž Kuntner of the Smithsonian Institution.
Starrett, who joined the Bond lab in 2018, holds a doctorate in genetics, genomics and bioinformatics from UC Riverside. He is a former postdoctoral fellow (2016-2018) in the Jason Bond lab at Auburn University. Professor Bond joined the UC Davis faculty in 2018 from Auburn University, where he directed its Museum of Natural History (2011–2016), and served as professor and chair of the Auburn Department of Biological Sciences (2016–2018).
- Author: Kathy Keatley Garvey
Her seminar also will be virtual. The Zoom link is https://ucdavis.zoom.us/j/95882849672. A coffee social will take place in 158 Briggs from 3:30 to 4:10 p.m.
Chamberland is a member of the laboratory of Jason Bond, associate dean, UC Davis College of Agricultural and Natural Resources, and professor and the Evert and Marion Schlinger Endowed Chair, UC Davis Department of Entomology and Nematology.
“Net-casting spiders (Deinopidae) comprise three genera with enigmatic evolutionary histories. Deinopisand Asianopis, the ogre-faced spiders, are best known for their giant light-capturing posterior median eyes (PME), whereas Menneus does not have enlarged PMEs,” Chamberland says in her abstract. “Molecular phylogenetic studies have revealed discordance between morphology and molecular data. We employed a character-rich, ultra-conserved element (UCE) dataset and a taxon-rich cytochrome oxidase I (COI) dataset to reconstruct a genus-level phylogeny of Deinopidae, aiming to investigate the group's historical biogeography, and examine PME size evolution. Although the phylogenetic results support the monophyly of Menneus and the single reduction of PME size in deinopids, these data also show that Deinopis is not monophyletic. Deinopid biogeographic history reflects the separation of Western Gondwana as well as long-distance dispersal events.”
Chamberland, who studies the evolution and biogeography of spiders, joined the Bond lab in 2021. She holds a doctorate in biology (2020) from the University of Vermont, Burlington, where she studied with Ingi Agnarsson. Her dissertation: "From Gondwana to GAARlandia: Molecular Phylogenetics and Historical Biogeography of Spiders." She received her bachelor's degree in biology and anthropology in 2013 from the University of Vermont.
“As an undergraduate at the University of Vermont, I was introduced to deinopids, the ogre-faced spiders, and it was love at first sight,” Chamberland related. “With a wide range of dispersal propensities and diverse hunting strategies, spiders have been a rich source for me to explore biogeographic and evolutionary questions. I would like to continue my work with historical biogeography and spiders after my postdoc and help foster the upcoming generation of arachnologists. I enjoy teaching, especially through the lens of phylogenetics and systematics, and I am working towards finding a teaching career where I can teach, mentor, and continue to ask evolutionary questions.”
Chamberland is the lead author of “Biogeography and Eye Evolution of the Ogre-faced Spiders," published Oct. 22, 2022 in Scientific Reports and co-authored by Ingi Agnarsson, Iris Quayle, Tess Ruddy, James Starrett and Jason Bond.
Chamberland and Bond co-hosted the 2022 American Arachnological Society Summer Symposium at UC Davis and she also delivered a research presentation at the symposium. At both UC Davis and at the University of Vermont, she has led and taught lab and field techniques, molecular methods and data analyses, and arachnology to high school, undergraduate, and graduate students, resulting in publications on systematics, evolution, and biogeography of spiders.
She earlier served as the invertebrate collections manager at the Zadock Thompson Zoological Collections (2020-2021), University of Vermont.
The department seminars, coordinated by urban landscape entomologist Emily Meineke, assistant professor, are held on Wednesdays through March 15. (See schedule.) Eight of the 10 will be in-person in 122 Briggs Hall, and all will be virtual.