- Author: Kathy Keatley Garvey
"As a result, pest outbreaks are less likely in diverse landscapes," said Paredes, who analyzed a 13-year government database of diversified landscapes encompassing more than 1300 olive groves and vineyards in Spain. The database documented pests and pesticide applications.
The paper, “The Causes and Consequences of Pest Population Variability in Agricultural Landscapes,” appears in the Ecological Society of America journal, Ecological Applications. Co-authors are UC Davis distinguished professor Jay Rosenheim of the Department of Entomology and Nematology, and Daniel Karp, associate professor, Department of Wildlife, Fish, and Conservation Biology. The research is online at https://bit.ly/3a64WRN.
Pest variability: an understudied but critical topic
Although population variability is often studied in natural systems, the need for long-term pest population data collected across many farms has largely prevented researchers from studying pest variability in agricultural systems, said Paredes, a postdoctoral fellow in the Karp lab.
What causes a pest population to be variable?
Having shown that more pest-population variability is more likely to cause problems for farmers, the researchers then set out to discover what farmers could do to manage variability.
One key factor that emerged was the type of landscape the crops were grown in, specifically whether the landscape was dominated by vast fields of a single crop variety or more diversified. Pest populations were both more abundant and more variable in crop monocultures.
However, while landscape type influenced both pest population sizes and variability, this was not always the case for other variables. “This research shows that the factors that promote high overall mean pest density are not necessarily the same factors that promote high variability in pest density,” Rosenheim said. “So, mean densities, which is what researchers have been studying for decades and decades, are only part of the story. Variation in density, and in particular unpredictable severe outbreaks, need to be studied separately.”
The take-away message?
“In Spain, planting multiple crops and retaining natural habitats would help stably suppress pests and prevent outbreaks,” said Paredes, a native of Spain who holds a doctorate in environmental sciences (2014) from the University of Granada. “Diversifying agricultural may be a win–win situation for conservation and farmers alike.”
"Therefore, we encourage agricultural stakeholders to increase the complexity of the landscapes surrounding their farms through conserving/restoring natural habitat and/or diversifying crops," the researchers wrote in their abstract.
Tapping into other large datasets such as this one, will be key to understanding whether diversified landscapes also help mitigate pest variability and outbreaks in other areas, they said.
This project was funded by the National Science Foundation with funds from the Belmont Forum via the European Biodiversity Partnership: BiodivERsA. It was also supported by the USDA National Institute of Food and Agriculture.
- Author: Kathy Keatley Garvey
The Zoom link is https://ucdavis.zoom.us/j/92038151658, ID 920 3815 1658. (Contact Page at mpage@ucdavis.edu for the passcode.)
Page will present her dissertation research that investigates the impacts of increasing honey bee abundance on plant-pollinator interactions and plant pollination. Her work suggests that honey bees reduce pollen and nectar availability in flowers, leading to competitive displacement of native bees.
"Competitive displacement of native bees may in turn decrease plant pollination because native bees are often more effective than native bees as pollinators," Page says. "My research suggests that such changes are already occurring for Camassia quamash (small camas) following honey bee introductions in the Sierra Nevada."
Page is scheduled to receive her doctorate in entomology in June 2022 and then begin a postdoctoral fellowship with assistant professor Scott McArt at Cornell University, where she will investigate patterns of interspecific pathogen transmission and how more sustainable beekeeping practices might mitigate the negative effects of competition. McArt recently delivered a seminar hosted by the UC Davis Department of Entomology and Nematology on "Pesticide Risk to Pollinators: What We Know and What We Need to Know Better."
Page holds a master's degree in entomology (2019) from UC Davis and a bachelor's degree in biology (2016), cum laude, from Scripps College, Claremont, Calif.
Highly recognized for her work, Page received a three-year $115,000 National Defense Science and Engineering Graduate Fellowship, funded by the Department of Defense. She was one of 69 recipients out of more than 3600 applicants. She earlier won a campuswide 2016-17 Graduate Scholars Fellowship of $25,200; a Vansell Scholarship in both 2018 and 2019; and Davis Society Botanical grants in 2017, 2018 and 2019. A 2018 Duffey-Dingle Research Fellowship also helped fund her research (optimizing pollinator plant mixes to simultaneously support wild and managed bees).
Active in the Entomological Society of America and the Ecological Society of America, Page scored a second-place award for her project, "Optimizing Wildflower Plant Mixes to Support Wild and Managed Bees" in a 2021 student competition hosted by the Entomological Society of America. She also presented “Impacts of Honey Bee Introductions on the Pollination of a Sierra Wildflower" at the August 2020 meeting of the Ecological Society of America, and "Can Visitation and Pollen Transport Patterns Predict Plant Pollination?" at the April 2019 meeting of the Pacific Branch, Entomological Society of America.
A strong supporter of community outreach and STEM, Page has been active in the summer program, Girls Outdoor Adventure and Leadership (GOALS) since August 2017. The free program is targeted for teens underrepresented in STEM. Page has served as a program co-organizer, mentor and lecturer. Part of her work included helping organize the 2021 summer program, leading a lecture on introductory data analysis, and helping students with their community science project (identifying pollinators in urban gardens).
Page was also active in Center for Land-Based Learning, serving as a mentor in the Student and Landowner Education and Watershed Stewardship. She mentored high school students, engaging them in hands-on conservation science at Say Hay Farm in Yolo County, and teaching them about how wildflower plantings benefit bees.
In July 2019, Page collaborated with colleagues at Cornell and the University of Minnesota to present a workshop on the intersections of science and social justice, aiming to make science more open and accessible.
Page and postdoctoral researcher Charlie Casey Nicholson of Williams lab recently co-authored the cover story, A Meta-Analysis of Single Visit Pollination Effectiveness Comparing Honeybees and other Floral Visitors, in the American Journal of Botany
- Author: Kathy Keatley Garvey
Her seminar begins at 4:10 p.m. The Zoom link: https://ucdavis.zoom.us/j/99515291076
"My lab studies the ecology and evolution of host-symbiont interactions," Wood says. "We're especially interested in the causes and consequences of conflicts that arise as hosts navigate interactions with multiple partners. I will talk about three recent projects in my lab that explore how antagonists affect host-symbiont interactions in the model mutualism between legumes and nitrogen-fixing bacteria."
As an evolutionary biologist, Wood is interested in the evolutionary ecology and evolutionary genetics of species interactions. Her research interests include ecology and biodiversity, plant biology, evolution and genetics, epigenetics and genomics.
Wood holds a bachelor of arts degree in English literature (2008) from Swarthmore (Penn.) College. She received her doctorate in biology from the University of Virginia in 2015. Her dissertation: "The Consequences of Environmental Heterogeneity for Fitness, Selection, and Inheritance."
Wood served as a postdoctoral fellow at the University of Toronto from 2015 to 2018 before accepting a faculty position at the University of Pittsburgh. She joined the University of Pennsylvania faculty in July 2020. (See profile)
Nematologist Shahid Siddique, who coordinates the UC Davis Department of Entomology and Nematology seminars, will introduce Wood. For any technical issues involving the Zoom presentation, he may be reached at ssidique@ucdavis.edu.
The remaining spring seminars:
Wednesday, May 25 (virtual and in-person at 122 Briggs Hall)
James R. Carey, UC Davis distinguished professor
UC Davis Department of Entomology and Nematology
Title: "The Conceptual Sweep of a Mathematical Discovery in Insect Demography: From Estimation of Medfly Population Age Structure to an Historical Analysis of U.S. Congress Incumbency Distributions, 1785-2000”
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
Wednesday, June 1 (virtual and in-person at 122 Briggs Hall)
Isgouhi Kaloshian, Divisional Dean, Agricultural and Natural Resources
UC Riverside
Title: "Root-Knot Nematode Perception and Immune Signaling in Arabidopsis"
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
- Author: Kathy Keatley Garvey
Siddique served as an invited speaker and chaired a nine-presentation session on nematode-plant interactions. He also was elected to the governing board member of the European Society of Nematology (ESN), and will serve a four-year term.
Siddique, who joined the UC Davis faculty in March 2019 as an assistant professor after serving as a research group leader for several years at the University of Bonn, Germany, delivered his address on “How Plants Recognize Nematodes: Signals and Signalling.”
Siddique focuses his research on "elucidating interactions between parasitic nematodes and their hosts using molecular and basic applied methodologies." Plant-parasitic nematodes are destructive pests causing losses of billions of dollars, he says on his lab website. "While these pests have been investigated mainly because they pose a major threat to food security globally, they are also intellectually fascinating due to their highly evolved interkingdom interactions with host plants."
Coomer, who recently won a worldwide competition sponsored by the International Federation of Nematology Societies (IFNS) for her three-minute thesis on root-knot nematodes, presented her award-winning video, “Trade-Offs Between Virulence and Breaking Resistance in Root-Knot Nematode.” She received a busary as well as a certificate signed by ICN president Larry Duncan of the University of Florida and conference chair Pierre Abad of France, a senior scientist at INRA, a French public research institute dedicated to agricultural science. Coomer also showcased her work on a life-sized poster.
IFNS annually hosts the three-minute thesis competition “to cultivate student academic and research communication skills, and to enhance overall awareness of nematodes and the science of nematology.” Coomer, a doctoral student in plant pathology with an emphasis on nematology, is working on her dissertation, “Plant Parasitic Nematode Effectors and Their Role in the Plant Defense Immune System.”
The international meeting, themed “Crossing Borders: A World of Nematode Diversity and Impact to Discover" to reconcile the importance of agricultural production with that of environmental conservation, drew 682 nematologists from 57 countries. Among them were 100 student and early career scientist busary recipients. The scientific program of 32 concurrent sessions included 288 oral presentations, 12 workshops, 12 keynote speakers and more than 500 poster presentations.
It was the first in-person meeting in two years due to the COVID-19 pandemic.
- Author: Kathy Keatley Garvey
Grettenberger's project, "Assessing a Biocontrol System for the Management of Tadpole Shrimp in Rice," is one of 10 research grants sharing $3.75 million meant to explore integrated pest management (IPM) tools for urban, non-agricultural and agricultural pest management, according to DPR Director Julie Henderson.
The grant program, funded by the state budget, represents a 617 percent increase from the previous year's funding. In the last decade, DPR has awarded $9,702,819 in research grants.
The grant projects "are critical to developing and expanding innovative practices and biological, non-chemical and physical tools to manage pests in agriculture, urban and other non-agricultural communities,” said Henderson. “The research will support the state's work to accelerate a systemwide transition to safer, more sustainable pest management and better protect human health and the environment.”
"Tadpole shrimp usefully eat some early season weeds but can cause damage to rice later in their life cycle," Grettenberger noted. "To preserve their role in controlling weeds but diminish the shrimp's later impact on the rice harvest, predator mosquito fish will be introduced mid-season to control the shrimp's population when necessary."
The 10 projects comprise two areas of research:
- Research projects funded for urban and agriculture pest management
- Research projects funded for urban and nonagricultural pest management
Grettenberger, who joined the Department of Entomology and Nematology faculty in January 2019, received his bachelor of science degree in biology, with an ecology, evolution and organismal emphasis in 2009 from Western Washington University, Bellingham, Wash., and his doctorate in entomology in 2015 from Pennsylvania State University, State College, Pa. He served as a postdoctoral researcher in the Godfrey lab and later, in the Frank Zalom lab.
His fields of expertise include field and vegetable crops; integrated pest management; applied insect ecology, and biological control of pests.
The California Department of Pesticide Regulation aims to protect human health and the environment "by fostering safer and sustainable pest management practices and operating a robust regulatory system to evaluate and register pesticides and monitor and regulate their sale and use across the state." (See more information about DPR.)
