- Author: Kathy Keatley Garvey
Native to Southeast Asia, it infests soft-skinned fruits such as strawberries, raspberries, cherries, blueberries, blackberries, peaches and grapes. Scientists first detected it in the United States (central coastal region of California) in 2008.
If you attend UC Davis doctoral candidate Christine Tabuloc's exit seminar at 4:10 p.m., Wednesday, Feb. 15--in-person or virtually--you'll get a grasp of the work she's doing involving D. suzukii, a worldwide pest, and D. melanogaster, a common species used worldwide as a model organism in genetics.
Tabuloc, advised by molecular geneticist and physiologist Joanna Chui, professor and vice chair of the UC Davis Department of Entomology and Nematology, will speak on "Environmental and Anthropogenic Impact on Insect Gene Expression and Physiology" in 122 Briggs Hall Her seminar also will be virtual. The Zoom link:
https://ucdavis.zoom.us/j/95882849672.
Professor Chiu will introduce her. A pre-seminar coffee session is set from 3:30 to 4:10 p.m. in Briggs 158.
"Natural environmental factors and anthropogenic disturbances can modulate gene expression, resulting in
alteration of organismal phenotype," Tabuloc says in her abstract. "In the first part of my thesis project, I used Drosophila melanogaster as an insect model to understand the mechanisms by which 24-hour light-dark cycles can regulate rhythmic changes in the chromatin to generate circadian rhythms of gene expression and orchestrate daily biological rhythms. I observed that two clock proteins, CLOCK and TIMELESS, regulate daily rhythmicity in the binding of BRAHMA, a chromatin remodeler, to DNA spanning clock-controlled genes to facilitate their rhythmic gene expression cycles. Moreover, because TIMELESS degrades in the presence of light, my results provide new insights into how light affects DNA structure and gene expression."
"In the second part of my thesis project, I investigated the impact of insecticide applications on the
fruit pest Drosophila suzukii," Tabuloc said. "Specifically, I performed RNA sequencing analysis on D. suzukii flies that are either susceptible or resistant to common insecticides to determine genetic mechanisms underlying insecticide resistance in this agricultural pest. My results revealed that enhanced metabolic detoxification confers pyrethroid resistance while
spinosad resistance is the result of both metabolic and penetration resistance. Finally, we identified alternative splicing
as an additional mechanism of resistance. These results will facilitate the development of efficient molecular
diagnostics to identify insecticide resistance in the field and enable growers to adjust D. suzukii spray programs to
control this devastating pest more effectively."
Christine received her bachelor of science degree in biochemistry and molecular biology from UC Davis in 2015. She joined the Chiu lab as an undergraduate research assistant in 2012. "Much of my work in the lab has involved different agricultural pests and investigating the molecular aspects contributing to the insect's ability to be an effective pest," she says on the Chiu lab website. "My current focus is to investigate the effects of climatic change on gene expression of an invasive pest and determine whether there is a correlation to resistance and survival. In addition to pest management research, I am also studying a kinase of a core clock protein in Drosophila melanogaster and hoping to dissect its functional contribution to the molecular oscillator."
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. They are coordinated by urban landscape entomologist Emily Meineke, assistant professor. (See schedule.) She may be reached at ekmeineke@ucdavis.edu for technical issues.
- Author: Kathy Keatley Garvey
The project? Fourteen articles in The Journal of Economic Entomology's Special Collection: Research Advances in Spotted-Wing Drosophila suzukii Management, published in the August 2022 edition.
The insect? It's native to Asia and primarily targets soft-skinned fruits in the berry industry, such as raspberries, blackberries, blueberries, strawberries, and cherries. The tiny insect, about 1/12 to 1/8 inch long, invaded the continental United States in 2008.
The authors? They're from eight countries: United States, Austria, Brazil, Canada, Italy, Spain, Sweden, and the United Kingdom and represent perspectives from universities, federal and state laboratories, growers, and pest product companies.
Thirteen UC Davis scientists or former affiliates are among the authors who contributed.
“All of the papers were by invitation of the co-editors of the special collection—Jana Lee, Cesar Rodrigue-Saona, and me,” said journal editor-in-chief Frank Zalom, a UC Davis distinguished professor emeritus and recall professor in the Department of Entomology and Nematology. Zalom's research includes the insect, Drosophila suzukii.
Lee, formerly with the UC Davis laboratory of the late chemical ecologist Steve Seybold, is a research entomologist with the Horticultural Crops Research Unit, U. S. Department of Agriculture, Agricultural Research Service, Corvallis. Rodriguez-Saona, who received his doctorate from UC Riverside, is an Extension entomologist with the Department of Entomology, Rutgers University, the State University of New Jersey.
One paper, Spatio-temporal Variation of Spinosad Susceptibility in Drosophila suzukii (Diptera: Drosophilidae), a Three-year Study in California's Monterey Bay Region, is from the Zalom lab and includes co-author, molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the Department of Entomology and Nematology.
Since 2008, "D. suzukii has become a key economical pest of raspberries, blackberries, blueberries, strawberries, and cherries in the United States and worldwide," the editors wrote in their introductory remarks. "Not surprisingly, the number of publications has proliferated from 29 publications as of 2010 to 978 additional publications between 2011 and 2021 from a Web of Science search for ‘Drosophila suzukii.' While many publications are available, this special collection will highlight advances in D. suzukii pest management since its U.S. invasion. We solicited papers by open call and received 66 abstracts, and selected 14 papers covering: 1) review, 2) monitoring and risk, 3) behavioral control, 4) biological control, 5) cultural control, and 6) chemical control."
The editors pointed out that “Given that 14 years of research has accumulated since the continental U.S. invasion, it was fitting to include two reviews that provide a different scope than was covered in prior reviews on D. suzukii biological control (Lee et al. 2019, Wang et al. 2020), trapping (Burrack et al. 2020), cultural control (Schöneberg et al. 2021), and chemical ecology (Cloonan et al. 2018). This special collection is anchored by Tait et al. (2021), a review of the most promising methods as part of an Integrated Pest Management (IPM) strategy against D. suzukii across the world since 2008. The effectiveness, impact, sustainability, and present stage of development and implementation are discussed for each of the considered techniques, and insights for continued development are presented.”
The researchers related that the pest is a significant threat to California's berry production industry, which the California Department of Food and Agriculture (CDFA) valued at more than $2.8 billion in 2019. Caneberries, in particular, "are a preferred host of D. suzukii, and California accounts for 89.4 percent of all production in the United States, with the Monterey Bay region producing about half of the state's raspberries and blackberries (CDFA 2020). This pest has now spread to all major berry and cherry growing areas of the United States."
The collection is meant to serve "as a key reference point for entomologists across many institutions (e.g., academia, government, and industry) on important advances in D. suzukii pest management," according to the Entomological Society of America. "The articles in this collection will also provide scientists information on potential research gaps that will help guide future research directions on this important pest. The goal is to preserve and catalog articles on various aspects of D. suzukii pest management, i.e., monitoring, cultural control, chemical control, behavioral control, and biological control, that will be shared among entomologists."
- Author: Kathy Keatley Garvey
"The spotted-wing drosophila, Drosophila suzukii, first invaded California in 2008," says UC Davis postdoctoral researcher Brian Gress, "and has since rapidly spread throughout North America and Europe."
Gress will discuss "Host Selection and Resistance Evolution in Drosophila Suzukii" at a UC Davis Department of Entomology and Nematology seminar at 4:10 p.m., Wednesday, Jan. 9 in 122 Briggs Hall.
He will be introduced by his advisor, integrated pest management specialist Frank Zalom, distinguished professor of entomology, UC Davis Department of Entomology and Nematology, and a past president of the Entomological Society of America.
"The female D. suzukii possess a unique serrated ovipositor that allows them to cut into ripening fruit, causing major economic losses for berry and cherry producers across the globe," Gress writes in his abstract. "Growers rely heavily on the use of insecticides to control this pest, and spinosad is among the most important materials currently available for protecting susceptible host crops."
Recent reports, however, "have raised concerns that the efficacy of this insecticide is declining in fields near Watsonville, Calif., a major hub of commercial berry production in the United States," Gress says. "In this seminar, I will present a series of studies aimed at assessing the degree of resistance in the population, the evolutionary potential for resistance to increase, and novel strategies for managing resistance in the field."
The spotted-wing drosophila, a major agricultural pest, damages fruit in many California counties, according to the UC Statewide Integrated Pest Program (UC IPM). "The males have a black spot toward the top of each wing. The females have not spots. They have "a very prominent, sawlike ovipositor for laying eggs in fruit."
Gress joined the Zalom lab in January 2017. He lists his research aims as
- understand the evolutionary processes and genetic mechanisms that give rise to insecticide resistance in agricultural pests;
- develop sustainable and cost-effective strategies for managing agricultural pests by disrupting insect mating behavior and reproductive physiology; and
- assess population dynamics and demography of wild insect populations in the field.
Gress holds bachelor of science degrees in biology and psychology, magna cum laude, from Iowa State University, Ames (2011), and a doctorate in biological science from Syracuse (N.Y.) University (2016).
At Syracuse, Gress received the 2016 Alexander Gourevitch Memorial Award, in recognition of research excellence; and the 2016 College of Arts and Sciences Outstanding Dissertation Award. In 2015 he was awarded a National Science Foundation Doctoral Dissertation Improvement Grant of $19,050.
- Author: Kathy Keatley Garvey
Medical entomologist Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology, has compiled a great line-up of speakers for the winter quarter. The Wednesday seminars, to begin Jan. 9 and continue through March 13, will take place from from 4:10 to 5 p.m. in 122 Briggs Hall. They are open to all interested person. Some seminars will be recorded for later posting.
First up on Jan. 9 is Brian Gress, a postdoctoral fellow in the lab of integrated pest management specialist Frank Zalom, distinguished professor of entomology in the UC Davis Department of Entomology and Nematology and a past president of the 7000-member Entomological Association of America. Gress will discuss the fruit fly, Drosophila suzukii: its host selection and resistance evolution.
The spotted-wing drosophila, a major agricultural pest, damages fruit in many California counties, according to the UC Statewide Integrated Pest Program (UC IPM). First discovered here in 2008, "it infests ripening cherries throughout the state and ripening raspberry, blackberry, blueberry, and strawberry crops, especially in coastal areas. It also has been observed occasionally attacking other soft-flesh fruit such as plums, plumcots, nectarines, and figs when conditions are right."
The adults are about 1/16 to 1/8 inch long with red eyes and a pale brown thorax and abdomen with black stripes on the abdomen, UC IPM says on its website. The males have a black spot toward the top of each wing. The females have not spots. They have "a very prominent, sawlike ovipositor for laying eggs in fruit."
The seminars, as of today, Dec. 20:
Wednesday, Jan. 9
Brian Gress, postdoctoral fellow in the Frank Zalom lab, UC Davis Department of Entomology and Nematology
Title: "Host Selection and Resistance Evolution in Drosophila suzukii"
Host: Frank Zalom, distinguished professor of entomology, UC Davis Department of Entomology and Nematology
Wednesday, Jan. 16
Sarah Stellwagen, postdoctoral researcher, University of Maryland
Title: “Toward Spider Glue: From Material Properties to Sequencing the Longest Silk Family Gene”
Hosts: Hanna Kahl, doctoral student in the Jay Rosenheim lab, and Jason Bond, Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology
Wednesday, Jan. 23
Pending
Wednesday, Jan. 30:
Laura Burkle, assistant professor of ecology, Montana State University, Bozeman
Topic: Wild bees, interactions with flowers
Hosts: Pollination ecologist Neal Williams, professor of entomology, and Maureen Page, doctoral student in the Williams lab, UC Davis Department of Entomology and Nematology
Wednesday, Feb. 6
Alan Hastings, theoretical ecologist and distinguished professor, UC Davis Department of Environmental Science and Policy
Title: "Stochasticity and Spatial Population Dynamics"
Host: Hanna Kahl, doctoral student in the Jay Rosenheim lab, UC Davis Department of Entomology and Nematology
Wednesday, Feb. 13
Antoine Abrieux, postdoctoral fellow, Joanna Chiu lab, UC Davis Department of Entomology and Nematology
Title: "Understanding the Molecular Mechanisms underlying Photoperiodic Time Measurement in Drosophila melanogaster"
Host: Joanna Chiu, associate professor and vice chair of the UC Davis Department of Entomology and Nematology
Wednesday, Feb. 20:
Alexander Raikhel, distinguished professor, UC Riverside
Title: "The Role of Hormone Receptors and MicroRNAs in Mosquito Reproduction and Metabolism"
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematolgoy
Wednesday, Feb. 27:
Lauren Esposito, faculty member, San Francisco State University, and assistant curator and Schlinger Chair of Arachnology at the California Academy of Sciences
Title: "Evolution of New World Scorpions and Their Venom"
Host: Jason Bond, Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology
Wednesday, March 6:
Monika Gulia-Nuss, assistant professor, biochemistry and molecular biology, University of Nevada, Reno
Topic: DNA Methylation in Ticks
Host: Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology
Wednesday, March 13:
Pending
Spring Break: March 20-27
For further information on the seminars, contact Geoffrey Attardo at gmattardo@ucdavis.edu.
- Author: Kathy Keatley Garvey
The spotlight is on spotted wing drosophila, a major fruit crop pest that wreaks economic havoc throughout the world.
Native to Southeast Asia, Drosophila suzukii infests soft-skinned fruits such as strawberries, raspberries, cherries, blueberries, blackberries, peaches and grapes. The insect was first detected in the United States in 2008 when scientists identified it in the central coastal region of California. It can cause an estimated $300 million in damage annually to California crops.
Enter Kent Daane, Cooperative Extension specialist at UC Berkeley. He'll present a UC Davis seminar, hosted by the UC Davis Department of Entomology and Nematology, on "Classical Bio-Control of the Spotted Wing Drosophila: Collecting and Processing Parasitoids Through the Quarantine Process" from 4:10 to 5 p.m., Wednesday, April 18 in 122 Briggs Hall, located off Kleiber Hall Drive.
"A classical bio-control program has been undertaken against the olive fly using parasitoids imported from Africa and the spotted wing drosophila, both newly invasive species in California," Daane says. "Drs. Xingeng Wang and Antonio Biondi have been cooperating with other researchers in California, Oregon, Delaware, Hawaii, Italy, China, South Africa, South Korea and France by quarantine screening imported parasitoid species to determine their potential to control these invasive pests without causing any harm to non-target insects. The quarantine work is like the gatekeeper that screens imported material to allow only those natural enemies that will be beneficial into California."
The spotted-wing drosophila was first observed in Japan as early as 1916. The females lay their eggs in ripe and ripening fruit, unlike other Drosophila species known to infest overripe and blemished fruit. The larvae feed on the fruit. The adult is the only stage that can be targeted for control by conventional pesticides, according to integrated pest management specialist Frank Zalom, distinguished professor of entomology at UC Davis. The most commonly used insecticides are organophosphates, pyrethroids and spinosyns.
Daane, who received his doctorate in entomology from UC Berkeley, focuses his research on the development of ecologically-based insect pest management systems. His research studies include classical biological control, augmentation programs, insect-plant interactions, use of least-disruptive insecticides and the biology of natural enemies."
Coordinators of the department's seminars are Rachel Vannette, assistant professor, and Brendon Boudinot, Ph.D candidate, Phil Ward lab.
