If you like learning about trapdoor spiders, be sure to read the newly published research from the arachnology laboratory of Professor Jason Bond, University of California, Davis.

Bond wears several hats: he is the Evert and Marion Schlinger Endowed Chair, UC Davis Department of Entomology and Nematology; director of the Bohart Museum of Entomology; associate dean, UC Davis College of Agricultural and Environmental Sciences; and president-elect of the American Arachnological Society. 

The Bond lab research paper, involving a new genus of California trapdoor spiders, calls attention to not only the diversity of trapdoor spiders in the state, but a new species they named for national civil rights activist Fred Toyosaburo Korematsu, a San Francisco Bay area native who resisted incarceration in the Japanese-American concentration camps during World War II.

The paper, “Microgeographic Population Structuring in a Genus of California Trapdoor Spiders and Discovery of an Enigmatic New Species (Euctenizidae: Promyrmekiaphila korematsui sp. nov.), appears in the journal Ecology and Evolution. The link: https://doi.org/10.1002/ece3.10983.

“This paper summarizes a herculean effort by our entire lab spanning many years of field, bench, and bioinformatics work and truly reflects an integrative approach that synthesizes genetic, ecological, and morphological data to delineate species,” Bond said. "While it demonstrates, what I think is the new and truly scientific nature of 'modern' taxonomy, it also reminds us again, with the description of a new species, just how remarkable the state of California is and that there are always new discoveries waiting just around the corner. And, it was particularly poignant to name this spider species for Korematsu. He and his legacy are well known to many residents of Davis.”

The Fred T. Korematsu Elementary School, Davis, bears his name, as do several schools in the Bay Area. Born in Oakland in 1910 to Japanese immigrants, Korematsu resisted President Franklin D. Roosevelt's Executive Order and was convicted of evading internment. A federal court in San Francisco overturned his conviction in 1983, and in 1988, the U.S. officially apologized “for its discriminatory wartime actions and granted reparations to all those who were being interned,” according to Wikipedia. Korematsu received the U.S.  Presidential Medal of Freedom in 1998 from President Clinton in recognition of his life-long dedication as a civil rights activist. Korematsu died in Marin County in 2005 at age 86.

Co-Authors of Paper. Co-authors of the paper with Bond are James Starrett, project scientist; Xavier Zahnle, who recently received his doctorate; doctoral candidate Emma Jochim and doctoral student Iris Quayle.

Trapdoor spiders are so named because they construct their burrows with a corklike or wafer trap door made of soil, vegetation and silk.

“In this study, we generate sub-genomic scale data to investigate phylogenetic relationships and population structure in Promyrmekiaphila and explore deep phylogenetic breaks hypothesized to occur across the genus,” they wrote. “We employ multiple approaches to test species delimitation hypotheses and test for gene flow to assess reproductive isolation in divergent lineages. We measure an array of female somatic morphological characters to evaluate if species diverge morphologically in potential sympatry, as well as in allopatry with divergent ecological niches. Our goal is to address at what point in the speciation process morphologically conserved taxa can be declared cryptic species rather than simply divergent population groups. We describe a new speciesPromyrmekiaphila korematsuisp. nov. Ultimately, we reject dividing the most geographically widespread species,P. clathrata, into multiple species, and instead interpret genetic breaks as deeply structured populations that are not fully reproductively isolated or may have undergone historical gene flow.”

The paper's abstract:
tr“The recognition and delineation of cryptic species remains a perplexing problem in systematics, evolution, and species delimitation. Once recognized as such, cryptic species complexes provide fertile ground for studying genetic divergence within the context of phenotypic and ecological divergence (or lack thereof). Herein we document the discovery of a new cryptic species of trapdoor spider, Promyrmekiaphila korematsui sp. nov. Using subgenomic data obtained via target enrichment, we document the phylogeography of the California endemic genus Promyrmekiaphila and its constituent species, which also includes P. clathrata and P. winnemem. Based on these data we show a pattern of strong geographic structuring among populations but cannot entirely discount recent gene flow among populations that are parapatric, particularly for deeply diverged lineages within P. clathrata. The genetic data, in addition to revealing a new undescribed species, also allude to a pattern of potential phenotypic differentiation where species likely come into close contact. Alternatively, phenotypic cohesion among genetically divergent P. clathrata lineages suggests that some level of gene flow is ongoing or occurred in the recent past. Despite considerable field collection efforts over many years, additional sampling in potential zones of contact for both species and lineages is needed to completely resolve the dynamics of divergence in Promyrmekiaphila at the population–species interface.”

The research drew funding from a National Science Foundation grant and the Evert and Marion Schlinger Foundation.

Katydids are incredibly fascinating.

Just ask UC Davis entomology student Sol Wantz, who will present a talk on katydids (her favorite insect), grasshoppers and crickets at the Bohart Museum of Entomology open house, set from 1 to 4 p.m., Sunday, March 3 in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus. It's free and family friendly.

We remember a crab spider that also found a katydid "incredibly fascinating." Umm, make that "nutritious." The spider grabbed the katydid on a Mexican sunflower (Tithonia rotundifola) in our garden, paralyzed it with a venomous bite, and then dragged it beneath the petals to eat it.

It's all about the cycle of life. Everything eats in the garden.

Sol Wantz triples as a curator intern at the Bohart Museum of Entomology, a student researcher in the lab of pollination ecologist and professor Neal Williams, and as president of the UC Davis Entomology Club.

“I'll be giving a overview of all of the major and most interesting--in my opinion--families of Orthoptera," she said. The order includes some 20,000 species worldwide.

Did you know that "the katydid genus Supersonus produces the highest frequency sound of any known animal, up to 150 kHz!" she asks. "For reference, humans can hear only between 0 and 20 kHz."

The Bohart Museum, directed by Professor Jason Bond, is located in Room 1124 of the Academic Surge Building, 455 Crocker Lane. It houses a global collection of eight million insect specimens, plus a live petting zoo (Madagasgar hissing cockroaches, stick insects, tarantulas and more) and an insect-themed gift shop stocked with T-shirts, hooded sweatshirts, books, posters, jewelry and insect-collecting equipment.

For more information, access the Bohart website at https://bohart.ucdavis.edu or contact bmuseum@ucdavis.edu.

You won't want to miss this Bohart Museum of Entomology open house!

Themed "Grasshoppers, Crickets and Katydids," the open house will take place from 1 to 4 p.m., Sunday, March 3 in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus. It's free and family friendly. Parking is also free.

UC Davis third-year entomology major Solea “Sol” Wantz, who triples as a curator intern at the Bohart Museum of Entomology, a student researcher in the lab of pollination ecologist and professor Neal Williams, and as president of the UC Davis Entomology Club, will discuss “Grasshoppers, Crickets and Katydids."

She'll deliver her presentation at 1 p.m., and questions and answers will follow. The venue: a classroom of the Museum of Wildlife and Fish Biology, located next to the Bohart Museum. 

“I'll be giving a overview of all of the major and most interesting--in my opinion--families of Orthoptera," she said. The order includes some 20,000 species worldwide.

A few factoids she related:

• The katydid genus Supersonus produces the highest frequency sound of any known animal, up to 150 kHz! For reference, humans can only hear between 0 and 20 kHz. 
• The family Myrmecophilidae, the “ant-loving crickets” are tiny, wingless crickets that live only in ant nests. “We even have these here in Davis, but they're hard to find unless you're digging through ant colonies,” Wantz says.
• Jerusalem crickets, also known as "potato bugs," have a unique method of sound production. "Rather than using their wings (they are actually wingless, she says) or another sound-producing organ, these crickets thump their abdomen against the ground to produce a surprisingly loud noise. Their thumping patterns can be used to identify their species."

And did you know that grasshoppers spit or produce what some folks call “tobacco juice?

“It's actually a grasshopper defense mechanism!” Wantz says. “When under stress--usually when they are grabbed, especially around the thorax-- grasshoppers vomit a foul-smelling/tasting liquid to ward off whatever predator is attacking them.”

Orthoptera (in ancient Greece, “ortho” means "straight,” and “optera” means "wings") is an order that includes grasshoppers, crickets, locusts and katydids. Grasshopper belong to the suborder Caelifera, and crickets and katydids to Ensifera.

Wantz, who decided at age 6 that she wanted to become an entomologist, is currently re-curating and reorganizing the Bohart's collection of several thousand specimens of Orthoptera.

"After finishing my undergraduate degree at UC Davis, I aim to enter a graduate program, potentially to explore my newfound interest in systematics. Ultimately, I hope to become a professor of entomology and lead my own research lab. This appeals to me because it presents the opportunity to weave together my knowledge of wild bee ecology and conservation, love of Orthoptera and museum work, and emphasis on professional outreach and public engagement."

The Bohart Museum, directed by Professor Jason Bond, houses a global collection of eight million insect specimens, plus a live petting zoo (Madagascar hissing cockroaches, stick insects, tarantulas and more) and an insect-themed gift shop stocked with T-shirts, hooded sweatshirts, books, posters, jewelry and insect-collecting equipment.

For more information, access the Bohart website at https://bohart.ucdavis.edu or contact bmuseum@ucdavis.edu.

What a catchy title for a seminar: "How Flies Control How They Walk by Knowing When and How to Stop."

Meet Salil Bidaye, Research Group Leader, Max Planck Florida Institute for Neuroscience, Jupiter, Fla.

He studies neuronal control locomotion in fruit flies, Drosophila--focusing his research on "understanding how fast and precise locomotor decisions are executed at the level of genetically defined neural circuits."

He will present his seminar, hosted by the UC Davis Department of Entomology and Nematology (ENT), at 4:10 p.m., Monday, March 4 in 122 Briggs Hall and on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/95882849672.

Molecular geneticist and physiologist Joanna Chiu, professor and chair of the ENT department, will introduce him.

"Walking is a complex motor program involving coordinated and distributed activity across the brain and the spinal cord," Bidaye writes in his abstract. "Halting appropriately at the correct time is a critical but often overlooked component of walking control. While recent studies have delineated specific genetically defined neuronal populations in the mouse brainstem that drive different types of halting, the underlying neural circuit mechanisms responsible for overruling the competing walking-state neural activity to generate context-appropriate halting, remain unclear. Here, we elucidate two fundamental mechanisms by which I implement context-appropriate halting."

"The first mechanism ('walk-OFF' mechanism) relies on GABAergic neurons that inhibit specific descending walking commands in the brain, while the second mechanism ('brake' mechanism) relies on excitatory cholinergic neurons in the nerve-cord that lead to an active arrest of stepping movements," he explains. "Using connectome-informed models and functional studies, we show that two neuronal types that deploy the 'walk-OFF' mechanism inhibit distinct populations of walking-promotion neurons, leading to differential halting of forward-walking or steering. The 'brake' neurons on the other hand, override all walking commands by simultaneously inhibiting descending walking promoting pathways and increasing the resistance at the leg-joints leading to an arrest of leg movements in the stance phase of walking. We characterized two ethologically relevant behavioral contexts in which the distinct halting mechanisms were used by the animal in a mutually exclusive manner: the 'walk-OFF' pathway was engaged for halting during feeding, and the 'brake' pathway was engaged for halting during grooming. To our knowledge, this represents the first mechanistic understanding of halting in fruit-flies and hence a major step in our larger goal of uncovering the fundamental principles governing walking control in animals."

Bidaye accepted his Research Group Leader position at the Max Planck Florida Institute for Neuroscience in April 2021. He previously served as a postdoctoral Fellow at UC Berkeley in the lab of Professor Kristin Scott. He obtained his Ph.D. at the Research Institute of Molecular Pathology, Vienna, Austria, working in the Barry Dickson laboratory. 

While a graduate student in Vienna, "I observed fruit-flies chasing each other during courtship," he relates. "I got hooked on to the intricate control that comprises insect walking. "This fascination kindled by powerful fly genetic tools, has led me to persistently device new behavioral assays and neural recording techniques, aimed at elucidating the fundamental control mechanisms that underlie the exquisite locomotor control that is commonplace in all animals."

His publications include: 

• Two Brain Pathways Initiate Distinct Forward Walking Programs in Drosophila, Aug. 20, 2020, journal Neuron
• Six-Legged Walking in Insects: How CPGs, Peripheral Feedback, and Descending Signals Generate Coordinated and Adaptive Motor Rhythms, February 2018, Journal of Neurophysiology
• Neuronal Control of Drosophila Walking Direction, April 4, 2014, Science

Bidaye's seminar is expected to be the last of the winter quarter; the next scheduled speaker, Inga Zasada, a research plant pathologist with the USDA-ARS Horticultural Crops Research Laboratory, Corvallis, Ore., recently canceled her March 11 seminar due to a medical issue in the family.

For any Zoom technical issues, contact seminar coordinator Brian Johnson, associate professor, at brnjohnson@ucdavis.edu. The list of winter quarter seminars is here.