- Author: Kathy Keatley Garvey
Take that, you aphids! That'll teach you to suck the lifeblood out of my plants!
"Aphids are small, soft-bodied insects with long slender mouthparts that they use to pierce stems, leaves, and other tender plant parts and suck out fluids," according to the UC Statewide Integrated Pest Management website on how to manage aphids. "Almost every plant has one or more aphid species that occasionally feed on it."
Aphids are major agricultural and garden pests. What's it like to be an aphid? How much stress can they handle?
Enter postdoctoral scholar Jessica Kansman of the Department of Entomology, Pennsylvania State University. She's the next speaker in the UC Davis Department of Entomology and Nematology's winter seminar series. She'll speak on "To Be an Aphid in a Cruel World: How Abiotic and Biotic Stressors Influence Plant-Insect Interactions" from 4:10 to 5 p.m., Wednesday, Feb. 24. To register and attend the Zoom seminar, access this Google form link.
"Whether it is combating the ever-changing host-plant conditions, or keeping careful watch for hungry predators and parasites--aphids have a stressful experience," Kansman says in her abstract. "My research has focused on figuring out just how much stress aphids can handle. Specifically, how plant water stress influences aphids and their natural enemies, and whether predator odors are as stressful for aphids as the predators themselves."
Kansman holds a bachelor's degree in entomology (2015) from Michigan State University, East Lansing, and a doctorate in plant, insect and microbial sciences (2020) from the University of Missouri, studying with Deborah Finke. As a doctoral student, she received a $116,859 grant from the U.S. Department of Agriculture "to study the effect of drought on aphid performance and behavior, indirect effects of drought on natural enemies, and how these effects cascade up to influence insect communities." The Agriculture and Food Research Initiative (AFRI) of USDA's National Institute of Food and Agriculture (NIFA) awarded the grant.
Kansman has given such presentations as "Plants vs. Insects: A Tale of Spines, Spit and Assassins." In one YouTube video on "Decoding Science," she describes aphids as "devastating agricultural pests. They feed by piercing a needlelike mouthpart into the plant tissue and they use it as a straw to suck up the sap of the plant." Aphids stunt growth and transmit viruses.
For a list of Department of Entomology and Nematology seminars, click here.
- Author: Kathy Keatley Garvey
Professor Gary Felton, head of the Department of Entomology, Pennsylvania State University, will speak on "Herbivore-Associated Microbes Mediate the Intersection of Herbivore and Plant Immunity" at the UC Davis Department of Entomology and Nematology's seminar at 4:10 p.m., Wednesday, May 9 in 122 Briggs Hall. This is a Storer Endowment-sponsored seminar.
Felton, who received his doctorate in entomology at UC Davis in 1988, writes in his abstract: "The lateral transfer of microbial genes from bacteria, baculoviruses, polydnaviruses and fungi has shaped the genomes of herbivores such as Lepidoptera. Such transfer has enabled herbivore speciation and the successful colonization of host plants among other impacts on fitness. In present time, herbivore-associated microbes play an exceedingly important role in mediating phenotypic variation in herbivores. Using the example of one highly polyphagous herbivore, the tomato fruitworm (Helicoverpa zea) we will show how herbivore associate microbes strongly impact the phenotype of the herbivore and its impact on induced defenses in the host plant."
"Herbivore cues found in their saliva are recognized by plants to turn on anti-herbivore defenses," Felton says. "Microbes associated with these herbivores including bacteria, fungi, baculoviruses, and polydnaviruses impact the composition of these salivary cues and ultimately mediate the ability of the host plant to mount their anti-herbivore defenses."
Overall, he says of his research on his website: "My research program uses molecular, proteomic and physiological approaches to investigate insect-plant interactions. My main interests are investigating the counter measures herbivores use in overcoming host plant defenses. Particular interest is on the role of herbivore salivary signals in suppressing the induced defenses of host plants. The role of saliva of blood feeding arthropods in suppressing the defenses of their vertebrate hosts has been comparatively well studied; however, very little is known about how the saliva of herbivores may interfere with plant defensive responses. Our projects focus primarily on the saliva of caterpillars. Recent findings indicate that saliva is enriched with an array of molecules that function in defense against microbial infection, digestion of plant tissues, and in suppressing induced defenses of plants. We employ a variety of surgical and genetic approaches (e.g., RNA interference) to examine function(s) of saliva."
Felton, who has served as professor and head of the Penn State Department of Entomology since 2000, received his bachelor of science degree from UC Irvine in 1975, followed by his master's degree from the University of Kentucky, Lexington, in 1983. He then enrolled in the UC Davis entomology graduate school program, studying with Sean Duffey.
After receiving his doctorate from UC Davis in 1988, he did postdoctoral work at UC Davis from 1988 to 2000, and then joined the University of Arkansas, Fayetteville, as an assistant professor in 2000. He was promoted to associate professor in 1994, and to professor in 1998. He left the University of Arkansas in 2000 to accept the professor and department chair position at Penn State.
Want to know more about the tomato fruitworm, also called the cotton bollworm and corn earworm? See the UC Statewide Integrated Pest Management website. "Management of tomato fruitworm requires careful monitoring for eggs and small larvae."
The seminars are coordinated by assistant professor Rachel Vannette; doctoral candidate Brendon Boudinot of the Phil Ward lab, and Extension apiculturist Elina Lastro Niño.