If you like melons, you won't like these beetles.

But if you're Jasmin Ramirez Bonilla, a UC Davis graduate student in entomology, you're seeking to control these agricultural pests through more effective integrated pest management (IPM) strategies.

Jasmin, who plans to complete her master's degree in the spring of 2022, recently presented her thesis proposal, “Advancing Integrated Pest Management Strategies for Cucumber Beetles in California,” to the UC Davis Department of Entomology and Nematology at a Zoom session.

“The beetle of focus for my thesis is the Western striped cucumber beetle, Acalymma trivittatum,” said Jasmin, who studies with major professor and agricultural entomologist Ian Grettenberger, a Cooperative Extension specialist in the UC Davis Department of Entomology and Nematology. “A second species, the Western spotted cucumber beetle, Diabrotica undecimpunctata undecimpunctata--a milder pest but still a pest of melons-- is also part of my project but not the primary subject of my studies.”

Her thesis project consists of three objectives: 

1. Characterize the non-crop and overwintering habitat
2. Clarify short-distance dispersal dynamics after harvest
3. Evaluate the utility of the aggregation pheromone, vittatalactone

Both species feed on muskmelons, Cucumis melo. “These include honeydew melon, cantaloupe, crenshaw, and cassava,” she said. “However, Acalymma is the specialist.” Cucumber beetles are pests of plants in the Cucurbitaceae family,which includes melons, gourds, cucumbers,  squash and pumpkin. 

Of key concern is “the lack of effective IPM tools for the management of cucumber beetles, especially the western striped cucumber beetle,” she said.  “There is a critical need to visit this system and revisit the ecology to have a clearer understanding of the non-crop habitat uses and dispersal dynamics to improve and optimize the scouting and monitoring strategies. In addition, one way to monitor and manage insect pests is using semiochemicals such as aggregation pheromones and kairomones—for example, cucurbit blossom volatiles--which are of interest to be combined and studied their efficacy attraction.”

Preliminary data for one of her experiments indicates that the synthetic aggregation pheromone, vittatalactone, attracts the western striped cucumber beetle and the spotted cucumber beetle. “This pheromone was mimicked from airborne volatiles produced by male beetles, Acalymma vittatum, the cousin of the western striped cucumber beetle,” Bonila related. “This pheromone is a potential monitoring tool for managing these beetles and minimize the intensive applications of insecticides on the field.”  

What sparked her interest in entomology? When she worked as a field research assistant for six months in 2017 with the UC Cooperative Extension in Woodland and sampled Lygus damage in sunflower fields.

 “After this field assistant position, I worked as a junior specialist on an alfalfa weevil project to improve management in alfalfa,” Jasmin related. This was a research grant of the late Larry Godfrey (1956-2017), an Extension entomologist based in the UC Davis Department of Entomology and Nematology. Godfrey, the principal investigator of the grant, worked with co-principal investigator Yolo County Farm Advisor Rachael Long until his death in April.  

Long invited Jasmin to apply for the position. “That increased my interest in bugs,” Jasmin said. “There were so many different species and I was constantly collecting plethora of insects in each sample!”

A native of Guatemala, Jasmin moved to the United States at age 15 with her family. “Even though I wasn't born here, I still consider myself Guatemalan,” she related. “My family lives in Los Angeles and I attended Reseda High School in the San Fernando Valley.”

Jasmin, who received her bachelor's degree in earth system science at UC Merced in 2016,  worked as a vegetation and ecological restoration intern with the National Park Service before enrolled in the UC Davis graduate program.   

But it's the insects—particularly cucumber beetles—that fascinate her. 

In commemoration of National Moth Week, the Bohart Museum of Entomology is planning a Virtual Moth Open House from 1 to 2 p.m. on Saturday, July 25.

The Bohart Museum will live-stream the free open house on Facebook.  Entomologist Jeff Smith, who curates the 500,000 Lepidoptera  (butterflies and moths) collection, will show specimens and answer questions. 

Due to the COVID-19 pandemic, this is the Bohart Museum's first-ever Virtual Moth Open House.

“We started holding a moth-themed open house near Mother's Day in May, because people who are enthusiasts for moths are called moth-ers,” said Tabatha Yang, education and outreach coordinator for the Bohart Museum. “We then switched our programming to align with National Moth Week. This year's Moth Week is July 18-26. The annual event is celebrated throughout the world with private and public events.  

Bohart Museum officials are preparing videos on black-lighting and how to spread and pin moths. 

During the Facebook Live program, viewers can type in their questions on moths. 

Smith is expected to answer questions such as:

• What is the largest moth?
• How do butterflies and moths differ?
• What is so unique about moths?
• Why should we be concerned with moth diversity?

Smith received a 2015 Friend of the College Award from the UC Davis College of Agricultural and Environmental Sciences for saving the museum some $160,000 over a 27-year period through his volunteer service. 

Lynn Kimsey, director of the Bohart Museum and UC Davis professor of entomology, nominated Smith for the award. “You could not ask for a better friend than Jeff Smith,” she said, noting that he has “brought us international acclaim and saved us $160,000 through donations of specimens and materials, identification skills and his professional woodworking skills. This does not include the thousands of hours he has donated in outreach programs that draw attention to the museum, the college and the university.”

Kimsey, who has directed the museum since 1989, remembers when Smith joined the museum. “When Jeff was working for Univar Environmental Services, a 35-year career until his retirement in 2013, he would spend some of his vacation days at the museum. Over the years Jeff took over more and more of the curation of the butterfly and moth collection. He took home literally thousands of field pinned specimens and spread their wings at home, bringing them back to the museum perfectly mounted. To date he has spread the wings on more than 200,000 butterflies and moths. This translates into something like 33,000 hours of work!”  The numbers have since increased.

“About a decade ago, Jeff began helping us by assembling specimen drawers from kits that we purchased,” Kimsey related. “This substantially lowered our curatorial costs, from $50/drawer to $16/drawer. We use several hundred drawers a year to accommodate donated specimens, research vouchers and specimens resulting from research grants and inventories. More recently, he's been accumulating scrap lumber and making the drawers from scratch at no cost to us. Overall, he has made more than 2000 drawers. Additionally, he makes smaller specimen boxes with the leftover scrap wood, which are used by students taking various field courses in the department. We simply could not curate the collection without his contributions.”  

Kimsey praised Smith for completely reorganizing the butterfly and moth collection. “It's no small feat to rearrange this many specimens, housed in roughly one thousand drawers,” she said. “Many thousands of the specimens needed to be identified, and the taxonomy required extensive updating and reorganization.”

The Bohart Museum, located in Room 1124 of the Academic Surge Building, Crocker Lane, UC Davis campus,  houses a global collection of nearly eight million specimens. It is also the home of the seventh largest insect collection in North America, and the California Insect Survey, a storehouse of the insect biodiversity. Noted entomologist Richard M. Bohart (1913-2007) founded the museum.

Bohart Museum is the home of a “live” petting zoo featuring Madagascar hissing cockroaches, walking sticks and tarantulas, and a gift shop, stocked with T-shirts, sweatshirts, books, jewelry, posters, insect-collecting equipment and insect-themed candy. 

Link:
Spreading Wings: The Amazing Work of Bohart Museum Associate Jeff Smith

UC Davis third-year student Naomi Murray, a researcher in the laboratory of ecologist Rick Karban, professor in the UC Davis Department of Entomology and Nematology, is now a Goldwater Scholar. 

Murray, who anticipates receiving her bachelor of science degree in evolution, ecology and biodiversity in June 2021, is one of 396 students selected from a national pool of 5000 sophomores and juniors to receive a scholarship from the Barry Goldwater Scholarship and Excellence in Education Foundation, a federally endowed agency honoring the late senator and “designed to foster and encourage outstanding students” who are pursuing research careers in natural sciences, engineering and mathematics.

The honor includes a monetary prize of $7500. “Goldwater Scholars have impressive academic and research credentials that have garnered the attention of prestigious post-graduate fellowship programs,” according to a foundation spokesperson. Goldwater Scholars have received 93 Rhodes scholarships, 146 Marshall scholarships, 170 Churchill scholarships, 109 Hertz fellowships, and numerous other distinguished awards, including National Science Foundation Graduate Research Fellowships.

Murray, who joined the Karban lab in 2018, is a member of the campuswide Research Scholars Program in Insect Biology (RSPIB), founded and directed by three UC Davis Department of Entomology and Nematology faculty members (Jay Rosenheim, distinguished professor; Joanna Chiu, vice chair and associate professor; and Louie Yang, associate professor) to provide "academically strong and highly motivated undergraduates" with multi-year experience in biological research.  The program pairs students with faculty mentors. 

In the Karban lab, Murray designs and conducts independent research on plant development, flowering, and communication. She generates questions, creates protocols, collects and analyzes data.  

“Naomi has initiated several innovative research questions during the time that she has been in the lab,” said Karban, who teaches field ecology and community ecology. "She is unusually creative and is driven to moving science forward and making a difference in the world.” Karban focuses his research on the population regulation of animal species and the interactions between herbivores and their host plants. He authored the landmark plant-communication book,  Plant Sensing and Communication (University of Chicago Press).

In addition, Naomi works with UC Davis Professor Jay Stachowicz at the Bodega Marine Laboratory, where she does independent research on seagrass disease ecology, specifically herbivore-plant-pathogen interaction. She formerly worked as a full-time undergraduate researcher on seagrass ecology in the Stachowicz lab.

Native of San Diego
Naomi was born and raised in San Diego and is the first scientist in her family. Her father holds a bachelor of science degree in engineering and works as a home inspector and her mother is a newly retired lawyer.

 “My interest in ecology started in high school, when I interned at the San Diego Zoo,” Naomi related. “Before the internship, I knew I loved animals and the environment, but I had no idea how I could turn those passions into a career--I thought if I liked animals, my only options were to be a zookeeper or a vet. The internship exposed me to a lot of other professionals and researchers working to protect nature, which was really my first glimpse into ecology and conservation."  

"When I selected ecology, evolution, and biodiversity as my major, I intended to be primarily animal-focused, but that changed when I went to the Botanical Conservatory on UC Davis Biodiversity Museum Day my freshman year. I absolutely fell in love with it, and I interned there that spring. It turned into employment and since then, my love for plants has really grown; they're the main subject of my research now!” 

Naomi is one of two Goldwater Scholars from UC Davis; the other is Jayashri Viswanathan, who seeks a doctorate in neuroscience and plans to teach biological sciences at the college level. They are among 32 recipients statewide. 

Career in Forest Ecology
Naomi is leaning toward a research career in forest ecology, studying how trees affect community function and resilience “with the goal of minimizing the impacts of climate change.”  She worked three weeks as a field technician on a project monitoring tree mortality in the forests of Yosemite Valley, where she tent-camped without running water or electricity, and collected data for 10 hours a day. 

She acknowledged that after a few days there, she didn't know if she could meet the challenges. “But as the days passed, I realized that even when I was at my most uncomfortable, I was asking questions about the system, proposing new hypotheses for old phenomena, and marveling at the beauty of the forest,” she wrote in her essay, part of the Goldwater Scholarship application. 

 “As the world changes and becomes increasingly interconnected, we are in desperate need of critical thinkers, synthesizers, and people able to approach complex problems with broad, interdisciplinary perspectives,” Murray wrote. “I am working to become one of these pioneers and intend on pursuing a career in research to monitor, track, and minimize the impacts of climate change. Specifically, I plan to focus on forest ecology and how patterns of resource allocation and carbon storage among trees affect community function and ecosystem resilience.” 

After receiving her bachelor's degree, Naomi plans to pursue a doctorate in ecology. “My current major prepares me with a strong foundation in basic science, and I have taken it upon myself to seek out diverse research experiences in both field and lab settings to develop a multi-dimensional perspective on critical issues in ecology,” she noted. “My time as a field technician has prepared me for ecological field work. Living as a full-time undergraduate researcher gave me a glimpse into conducting research as a career and made me familiar with work beyond the field. Additionally, participation in the Research Scholars Program in Insect Biology, a long-term pairing of undergraduates with faculty mentors to conduct research, has fostered connections instrumental in my path towards a successful research career. Perhaps most importantly, my independent design and execution of three experiments has taught me how to ask and test scientific questions.” 

Murray earlier received a UC Davis Provost's Undergraduate Fellowship of $1200, a Regents Scholarship of $30,000, and a Bodega Marine Lab Undergraduate Research Fellowship of $5000, among other honors and awards.

Active in SEEDS
The Goldwater Scholar is active in Strategies for Ecology Education, Diversity, and Sustainability (SEEDS), an offshoot of the Ecological Society of America, and serves as an officer of the Davis SEEDS Chapter. The group seeks to make ecology more accessible to underrepresented groups of students. The club fosters science exploration and guidance through career panels and research facility tours. 

“When I attended the 2018 SEEDS National Field Trip, the student group was mainly women of color,” Murray related in her essay. “I listened to them speak about the racism that structures this nation and its higher institutions, creating foundational issues of access to opportunity, mentorship, and funding. It was a wake-up call, making me aware of my privilege and inspiring me to deconstruct the walls that exist in my academic sphere.”

“I became an officer for the UC Davis SEEDS chapter. Through the club, I work to organize graduate student and career panels, amplifying underrepresented stories and connecting students with mentors who have similar backgrounds. I plan field trips and study sessions, and promote campus opportunities. And I help apply for funding to make all our activities equal access. Moving forward in my career I will continue this work, grateful that SEEDS has pushed me to become an active participant in scientific advancement through social justice.” 

UC Davis researchers led by molecular geneticist and physiologist Joanna Chiu, vice chair of the Department of Entomology and Nematology, have identified a key driver in how animals “sense” seasonal changes.   

The paper, appearing online on the website of the Proceedings of the National Academy of Sciences (PNAS), solves a puzzle that scientists have tried to piece together for a long time.   

The Chiu lab did it with the widely used model organism, Drosophila melanogaster, also known as the vinegar fly. 

“This paper advances our understanding of how animals ‘sense' seasonal changes in day length and temperature to modulate their physiology and behavior in order to survive through seasonal variations in their environment,” Chiu said. “Specifically, we identified the protein EYA to be a key driver of seasonal changes in biology. By manipulating the level of EYA protein using transgenic technologies in specific neurons of the vinegar fly Drosophila melanogaster, we were able to disrupt the fly's ability to sense seasonal changes.” 

“We were able to trick them into thinking that it is winter when it is actually summer time and vice versa,” Chiu said. “Interestingly, this protein is very conserved in other animals, including in birds and mammals, suggesting that the mechanism we are studying could be widely used in the animal kingdom.” 

The paper, “EYES ABSENT and TIMELESS Integrate Photoperiodic and Temperature Cues to Regulate Seasonal Physiology in Drosophila,” is the work of the first author and postdoctoral fellow Antoine Abrieux, graduate students Yao Cao and Kyle Lewald, undergraduate researcher Hoang Nhu Nguyen, in collaboration with members of Dr. Yong Zhang's lab at the University of Nevada Reno. Associate Professor Joanna Chiu is the corresponding and senior author. 

“There is still a lot of work to be done in order to understand how the EYA protein regulates seasonal physiology and behavior,” said Chiu, who was named one of 10 UC Davis Chancellor's Fellows in January 2019, “but we are excited that our work opened up a lot of new interesting questions.” 

In their abstract, the seven-member team wrote: “Organisms possess photoperiodic timing mechanisms to detect variations in day length and temperature as the seasons progress. The nature of the molecular mechanisms interpreting and signaling these environmental changes to elicit downstream neuroendocrine and physiological responses are just starting to emerge. Here, we demonstrate that, in Drosophila melanogaster, EYES ABSENT (EYA) acts as a seasonal sensor by interpreting photoperiodic and temperature changes to trigger appropriate physiological responses. We observed that tissue-specific genetic manipulation of eya expression is sufficient to disrupt the ability of flies to sense seasonal cues, thereby altering the extent of female reproductive dormancy. Specifically, we observed that EYA proteins, which peak at night in short photoperiod and accumulate at higher levels in the cold, promote reproductive dormancy in female D. melanogaster.”

“Furthermore, we provide evidence indicating that the role of EYA in photoperiodism and temperature sensing is aided by the stabilizing action of the light-sensitive circadian clock protein TIMELESS (TIM). We postulate that increased stability and level of TIM at night under short photoperiod together with the production of cold-induced and light-insensitive TIM isoforms facilitate EYA accumulation in winter conditions. This is supported by our observations that tim null mutants exhibit reduced incidence of reproductive dormancy in simulated winter conditions, while flies overexpressing tim show an increased incidence of reproductive dormancy even in long photoperiod.” 

Research in the Chiu lab focuses on the regulation of biological rhythms and their control over organismal physiology. Her expertise involves molecular genetics of animal behavior, circadian and seasonal biology, and posttranslational regulation of proteins. 

By using Drosophila melanogaster as a model to study the mechanisms that regulate circadian clocks, Chiu has discovered new insights into the function of key proteins that control animal circadian clocks. She earlier identified new mechanisms that slow down or speed up the internal clock of vinegar flies and mechanisms that allow the internal clock to interpret food as timing cues--research that could help lead the way to alleviate human circadian and metabolic disorders. 

“Besides being indispensable for the control of daily activities in animals, such as the sleep-wake cycle, locomotor activity, hormone circulation and food intake, defects in circadian rhythms and clock genes have also been implicated in a wide range of human disorders, including chronic sleep orders, various forms of depression, metabolic syndromes, as well as susceptibility to cancer and drug and alcohol addiction,” Chiu says. 

D. melanogaster is widely used for biological research due to its rapid life cycle, simple genetics (only four pairs of chromosomes), and its large number of offspring per generation, according to Wikipedia. As of 2017, six Nobel prizes had been awarded for research using Drosophila. 

The fly, a member of the family Drosophilidae, is a nuisance pest found worldwide in restaurants and other places where food is served.

First author and postdoctoral fellow Antoine Abrieux, an international scholar from France, holds a doctorate from Angers University,  France. He joined the Chiu lab in spring 2016 to explore interactions between the clock and endocrine system underlying seasonal adaptation in Drosophila suzukii. He discussed his work at a UC Davis Department of Entomology and Nematology seminar in February 2019 about the molecular mechanisms involved in seasonal adaptation in insects.