The seminar takes place from 4:10 to 5 p.m., Wednesday, Oct. 28. Access this site for the Zoom link. Host is Cooperative Extension specialist and agricultural entomologist Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology. He is coordinating the department's fall seminars.
"The research in our lab focuses on understanding how chemical compounds mediate interactions among microbes, plants, herbivores, and herbivore natural enemies," Helms says. "We combine analytical chemistry and behavioral ecology in laboratory and field-based research to investigate how organisms use chemistry to navigate, communicate, and defend themselves. This seminar will discuss some of our ongoing projects examining how plants and insect herbivores use chemical information from their environment to assess their risk of attack and how herbivore natural enemies use such information to find potential prey."
Helms, an assistant professor, holds two degrees from Pepperdine University, Malibu, Calif., both awarded in 2009: a bachelor of science degree in biology and a bachelor of arts degree in biochemistry. She received her doctorate in ecology in 2015 from The Pennsylvania State University, State College, Penn. While in the John Tooker lab, Helms studied the chemical ecology of plant-insect interactions, especially how plants defend themselves against insect herbivores. She investigated how plants use olfactory cues to predict impeding herbivore attacks and the molecular mechanisms involved.
In addition to the general field of chemical ecology, Helms' research interests include plant-insect interactions, tritrophic interactions, belowground chemical ecology, chemical communication, and plant defense.
Her most recent publications:
Helms, A.M., Ray, S., Matulis, N.L.*, Kuzemchak, M.C.*, Grisales, W.*, Tooker, J.F., Ali, J.G. Chemical cues linked to risk: Cues from belowground natural enemies enhance plant defences and influence herbivore behaviour and performance. Functional Ecology. 33, 798-808 (2019). DOI: 10.1111/1365-2435.13297
Acevedo, F.E., Smith, P., Peiffer, M., Helms, A.M., Tooker, J.T., Felton, G.W. Phytohormones in fall armyworm saliva modulate defense responses in plants. Journal of Chemical Ecology. (2019). https://doi.org/10.1007/s10886-019-01079-z
Yip, E.C., Sowers, R.P.*, Helms, A.M., Mescher, M.C., De Moraes, C.M., Tooker, J.F. Tradeoffs between defenses against herbivores in goldenrod (Solidago altissima). Arthropod-Plant Interactions. 13, 279-287 (2019). DOI: 10.1007/s11829-019-09674-3
For any technical issues regarding the seminar, contact Grettenberger at email@example.com.
Global change ecologist Amanda Koltz, a senior scientist with the Department of Biology, Washington University, St. Louis, will speak on "Species Interactions and Ecosystems in a Changing World" at the UC Davis Department of Entomology and Nematology's virtual seminar at 4:10 p.m., Wednesday, Oct. 14.
"Biological communities and species interactions are changing rapidly as a result of global change," she says in her abstract. "These changes are likely to have cascading effects on ecosystems, but we still have limited understanding of the extent to which organismal responses to global change may also drive ecosystem responses to it. In this talk, I will present some of my work on the potential feedbacks between global change, communities, and ecosystem functioning from two different study systems. First, I will discuss how warming can alter the cascading effects of spiders in the Arctic tundra, and then I will discuss my recent efforts at characterizing the potential consequences of shifting interactions among ruminant hosts and their parasites. The common theme throughout the talk will be the importance of considering species interactions in efforts to understand ecosystem responses to global change."
Koltz describes herself as a "global change ecologist interested in how species interactions influence community composition and ecosystem function in the context of environmental change. I use common, widespread organisms that are sensitive to change-- like wolf spiders, mosquitoes and gut worms--to better understand how the animals in our everyday lives impact the ecosystems we live in. My recent work focuses on two fundamental questions: (1) How do biological communities respond to changes in the environment? and (2) What are the consequences of changes in species interactions for the cycling of energy and nutrients within ecosystems?"
Cooperative Extension specialist and agricultural entomologist Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology, coordinates the fall series of virtual seminars. They are held on Wednesdays at 4:10 p.m.
Host for the Koltz seminar is Emily Meineke, assistant professor of urban landscape entomology, who researches insect-plant interactions.
Grettenberger announced that this is the form to obtain the zoom link:
Koltz's research has appeared in a number of recent publications:
- Small but Mighty: Measuring Parasites' Footprints
- Wolf Spiders May Turn to Cannibalism in a Warming Arctic
- Warming Alters Predator-Prey Interactions in the Arctic
- Bugged Out by Climate Change
- Higher Education Channel: Arctic Wolf Spider's Changing Diet May Help Keep Arctic Cool & Lessen Some Impact of Global Warming
"Insect wings are flexible, dynamic living structures that are composed of long tubular veins, and thin membrane," she says in her abstract. "Veins act as conduits, containing hemolymph (insect blood), oxygen supply (through trachea tubes), and nerves (sensory information in flight). Wings allow an insect to perform a myriad of behaviors such as predation, migration and pollination."
"In my research, I work to understand how wing health and function is maintained, and how that relates to insect development, behavior, and ecosystem. My research program incorporates foundational physiology (wing vein structure, venation pattern active systems) quantifying the biomechanics of flow produced by an insect (circulation, wing expansion, flapping flight), and determining how agricultural practices affect insect health. Here I will discuss how venation pattern affects circulation dynamics in the wings of the North American grasshopper (Schistocerca americana) and how it barely scratches the surface of understanding circulation in insects."
In a First Person piece in Biology Open, the Company of Biologists, Salcedo describes herself as "an insect biomechanist, but perhaps functional morphologist is more accurate. I've studied how insects fly, how their muscles move, how they breathe and circulate hemolymph. My PhD looked into their wing structure at several levels: external, internal and global. Externally, I looked at how wing shapes differ between species and how we might compare them. Within the insect wing vein, I studied how hemolymph is transported across the wing. Overall, I looked at how an insect's multiple hearts contribute to internal circulation."
Salcedo, who received a National Science Foundation Postdoctoral Research Fellowship to investigate fundamental insect physiology, holds three degrees: a bachelor of science in applied and computational math sciences (2012( from the University of Washington; a bachelor of science in molecular, cellular and developmental biology (2012) from the University of Washington, and a doctorate in biomechanics, biology and applied math (2018) from Harvard.
Coordinating the seminars is community ecologist Rachel Vannette, assistant professor, UC Davis Department of Entomology and Nematology (firstname.lastname@example.org). To access the program live, go to https://zoom.us/j/559909612 and enter meeting ID: 559 909 612.
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Meeting ID: 559 909 612
The UC Davis Department of Entomology and Nematology's seminar on Wednesday, Feb. 26 will feature six “Faculty Flash Talks.”
The seminar, set from 4:10 to 5 p.m. in 122 Briggs Hall, will include Joanna Chiu, Jason Bond, Geoffrey Attardo, Rachel Vannette, Julia Fine, and Arathi Seshadri.
Associate professor Joanna Chiu, vice chair of the department, will present “results from a project in which we study the mechanisms by which insects sense environmental changes (temperature and photoperiod) to regulate their seasonal physiology. Our lab has identified a protein that can track seasonal changes in temperature and photoperiod to promote winter physiology. Without this protein, insects don't know winter is coming!”
Her laboratory research interests include molecular genetics of animal behavior, Circadian rhythm biology, and posttranslational regulation of proteins.
Jason Bond, Schlinger Chair in Insect Systematics, is a global expert on spiders. His research interests include systematics, taxonomy, and evolution of terrestrial arthropods with an emphasis on arachnids and myriapods. "We employ molecular, morphological, and ecological approaches to study questions related to evolutionary diversification at multiple hierarchical levels (populations – higher taxa)," he says. (See recent grant.)
Geoffrey Attardo, a medical entomologist/geneticist, focuses his research on insect disease vectors, insect reproduction, vector/parasite interactions, reproductive physiology, male seminal secretions, symbiosis, lactation, nutrition, lipid metabolism, transcriptional regulation, comparative genomics, transcriptomics, proteomics and metabolomics. His research on tsetse flies was recently featured on KQED's Deep Look (see news story on Deep Look). (See news story on landmark research.)
Rachel Vannette, community ecologist and assistant professor who coordinates the department's seminars, says: "All plants are colonized by microorganisms that influence plant traits and interactions with other species, including insects that consume or pollinate plants. I am interested in the basic and applied aspects of microbial contributions to the interaction between plants and insects. I also use these systems to answer basic ecological questions, such as what mechanisms influence plant biodiversity and trait evolution." (See recent research)
Arathi Seshadri and Julia Fine, who recently joined the USDA-ARS lab on Bee Biology Road, UC Davis, aim to improve honey bee survival and beekeeping sustainability in California and nationwide. They collaborate with federal, university, non-governmental and industry partners. (See news story on opening of the facility.)
Seshadri, a pollination biologist with expertise in honey bee behavior and plant reproductive strategies, is working with beekeepers and farmer stakeholders to develop projects aimed at finding solutions to the ongoing pollination challenges. Also trained as an evolutionary biologist, she has applied principles of plant-pollinator mutualism, specifically the impact of phytochemicals in pollen and nectar on honey bee health and colony performance. Her contributions to pollinator conservation include enhancing the sustainability of all pollinators, including native bees on farms and urban areas. She also has expertise in agroecosystem-based approaches and citizen science programs to promote pollinator diversity and abundance.
Fine, an entomologist with expertise in insect toxicology, honey bee physiology, reproduction and development, focuses her research on identifying how stressors impact honey bee behavior, health and fecundity. She uses both established and novel laboratory techniques. Her previous projects involved investigating how agrochemical and viral stressors interact to affect the development and survival of honey bee brood and how nutritional stress affects honey bee queen fecundity. In engaging with beekeepers and growers, Fine is researching how realistic biotic and abiotic stressors affect honey bee reproduction, longevity and pollination services, and she is identifying techniques and strategies to overcome these effects.
The seminar is open to all interested persons. For more information, contact Vannette at email@example.com.
The title of her seminar is "Mechanisms of Resistance in Poplar Against the Asian Longhorned Beetle and its Gut Symbionts."
Hoover received her doctorate in entomology from UC Davis in 1997.
"Asian longhorned beetle (ALB), Anoplophora glabripennis, is a polyphagous, tree-killing wood borer, reported to attack a broad range of deciduous tree species, including poplar," she writes in her abstract. "Yet in the invasive range of North America and Europe, poplars are usually avoided even when they are abundant. Populus species produce salicinoids (phenolic glycosides) that have properties known to reduce feeding and cause gut lesions in foliage-feeding herbivores such as gypsy moth."
"We hypothesized that these compounds may confer resistance to ALB and help explain the feeding and attack patterns in the field in both the native and introduced range of ALB. Concentrations of salicinoids normally found in bark deterred adult feeding, but low doses of salicinoids did not inhibit feeding and resulted in dramatic effects on beetle fitness. Diversity of gut fungal and microbial symbionts and abundance of the key gut fungal symbiont were affected as well."
"In Southern China, the beetle did not exhibit a feeding preference between willow and maple, but like the invasive populations in the U.S. and Europe, beetles would not feed on and seldom attack poplar, yet in Northern China poplar plantations are often heavily attacked by ALB," Hoover related. "ALB-host interactions appear to be complex and it is possible that there are differences in geographic populations of ALB in tolerance to salicinoids. These studies will be repeated this summer in Northern China and Inner Mongolia. Understanding the mechanistic differences between geographic populations of ALB will contribute to developing control measures for this destructive wood-borer."
The department's winter-quarter seminars, coordinated by assistant professor Christian Nansen, take place every Wednesday through March 15. All are held from 4:10 to 5 p.m. in 122 Briggs Hall. See seminar schedule.