- Author: Kathy Keatley Garvey
DAVIS--Ecologist Rick Karban, professor in the UC Davis Department of Entomology and Nematology, is featured in the Dec. 23-30 edition of The New Yorker in Michael Pollan’s piece, “The Intelligent Plant: Scientists Debate a New Way of Understanding Plants.”
Karban studies volatile (chemical) communication between plants that affect their defenses against herbivores. Pollan wrote that he met Karban in Vancouver, British Columbia, last July when Karban was presenting a paper on “Plant Communication and Kin Recognition in Sagebrush” at the sixth annual meeting of Society for Plant Neurobiology, now the Society for Plant Signalling and Behavior.
For The New Yorker feature, Pollan interviewed scientists on a number of plant intelligence topics, including decision-making. “Plants perceive competitors and grow away from them,” Karban told Pollan. “They are more leery of actual vegetation than they are of inanimate objects, and they respond to potential competitors before actually being shaded by them.”
Pollan wrote that “Plants speak in a chemical vocabulary we can’t directly perceive or comprehend. The first important discoveries in plant communication were made in the lab in the nineteen-eighties, by isolating plants and their chemical emissions in Plexiglas chambers, but Rick Karban, the U.C. Davis ecologist, and others have set themselves the messier task of studying how plants exchange chemical signals outdoors, in a natural setting.”
Pollan toured Karban’s sagebrush study plot at the UC Sagehen Creek Field Station, near Truckee. Karban has been researching the plant/herbivore interactions since 1999.
Karban recently drew widespread scientific and media attention with research that he and four colleagues published in February 2013 in the Proceedings of the Royal Society B: Biological Sciences. Their research showed that kin have
distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors,” he said in a news release published by the UC Davis Department
of Entomology and Nematology.
“When sagebrush plants are damaged by their herbivores, they emit volatiles that cause their neighbors to adjust their defenses,” Karban said in the news release. “These adjustments reduce rates of damage and increase growth and survival of the neighbors.”
“Why would plants emit these volatiles which become public information?” he asked. “Our results indicate that the volatile cues are not completely public, that related individuals responded more effectively to the volatiles than did strangers. This bias makes it less likely that emitters will aid strangers and more likely that receivers will respond to relatives.”
The research, “Kin Recognition Affects Plant Communication and Defense,” was co-authored by two scientists from Japan and two from UC Davis: Kaori Shiojiri of the Hakubi Center for Advanced Research, Kyoto University, and Satomi Ishizaki of the Graduate School of Science and Technology, Niigata University; and William Wetzel of the UC Davis Center for Population Biology, and Richard Evans of the UC Davis Department of Plant Sciences.
To simulate predator damage, the researchers “wounded” the plants by clipping them and then studied the responses to the volatile cues. They found that the plants that received cues from experimentally clipped close relatives experienced less leaf damage over the growing season that those that received cues from clipped neighbors that were more
distantly related.
“More effective defense adds to a growing list of favorable consequences of kin recognition for plants,” they wrote.
Karban is a fellow of the American Association for the Advancement of Science (AAAS) and has published more than 100 journal articles and two books.
Links:
Kin Recognition Affects Plant Communication and Defense
- Author: Kathy Keatley Garvey
Zalom will be presiding over the 2014 meeting in Portland, Ore. His theme is "Grand Challenges Beyond Our Horizons." He will become the second UC Davis entomologist to head the international organization, which is comprised of members in educational institutions, health agencies, private industry and government. The first was Donald McLean, former professor and chair of the UC Davis Department of Entomology, who was elected ESA president in 1984. The department is now the UC Davis Department of Entomology and Nematology.
Some 3000 researchers, professors, graduate and undergraduate students, extension service personnel, administrators, research technicians, consultants, and others from around the globe gathered for four days of science, networking and fun, according to ESA spokesman Richard Levine. "This is the most important annual conference anywhere in the world for the science of entomology," he said, prior to the conference. The 2013 theme was “Science Impacting a Connected World."
Zalom has been heavily involved in research and leadership in integrated pest management (IPM) activities at the state, national and international levels. He directed the UC Statewide IPM Program for 16 years (1988-2001) and is currently experiment station co-chair of the Association of Public and Land-Grant Universities (APLU) National IPM Committee.
The IPM strategies and tactics Zalom has developed include monitoring procedures, thresholds, pest development and population models, biological controls and use of less toxic pesticides, which have become standard in practice and part of the UC IPM Guidelines for these crops.
In his three decades with the UC Davis entomology department, Zalom has published more than 300 refereed papers and book chapters, and more than 360 technical and extension articles. The articles span a wide range of topics related to IPM, including introduction and management of newer, soft insecticides, development of economic thresholds and sampling methods, management of invasive species, biological control, insect population dynamics, pesticide runoff mitigation, and determination of host feeding and oviposition preferences of pests.
The Zalom lab has responded to six important pest invasions in the last decade, with research projects on glassy-winged sharpshooter, olive fruit fly, a new biotype of greenhouse whitefly, invasive saltcedar, light brown apple moth, and the spotted wing Drosophila.
Zalom is a fellow of ESA, American Association for the Advancement of Science, and the California Academy of Sciences.
Highly honored for his work, Zalom received the Entomological Foundation’s 2010 “Award for Excellence in IPM,” an award sponsored by Syngenta Crop Protection and given for “the most outstanding contributions to IPM.” In 2008 he was was part of a team receiving an International IPM “Excellence Award” at the sixth International IPM Symposium. Also in 2008, Zalom was part of the seven-member UC Almond Pest Management Alliance IPM Team that received the Entomological Foundation’s "Award for Excellence in IPM.” Zalom was awarded the C. W. Woodworth Award from the Pacific Branch of the ESA in 2011.
Michael Parrella, professor and chair of the UC Davis Department of Entomology, served as the Pacific Branch’s representative to the ESA governing board for the past six years and will be succeeded on the board in 2014 by Douglas Walsh, professor at Washington State University who received his doctorate in entomology from UC Davis. Walsh received the "Excellence in IPM" award at 2013 meeting.
Zalom, Parrella and McLean are among 15 UC Davis entomologists elected as ESA fellows, an honor bestowed to a maximum of 10 persons per year. Richard Bohart (1913-2007), for whom the Bohart Museum of Entomology is named, received the honor in 1947, followed by Donald McLean, 1990; Harry H. Laidlaw Jr. (1907-2003), 1991; John Edman, 1994; Robert Washino, 1996; Bruce Eldridge, 2001; William Reisen, 2003; Harry Kaya, 2007; Michael Parrella and Frank Zalom, 2008; Walter Leal, 2009, Bruce Hammock and Thomas Scott, 2010; and James Carey and Diane Ullman, 2012.
At the Austin conference, Byrony Bonning, a former doctoral research associate at UC Davis in the Bruce Hammock lab who went on to become a noted professor in Iowa State University’s Department of Entomology and director of the National Science Foundation's Center for Arthropod Management Technologies, was inducted as an ESA Fellow.
Another UC Davis affiliate honored at the ESA meeting was Cornell University professor Anurag Agrawal, who received his doctorate in population biology from UC Davis while studying with major professor Rick Karban. He is the recipient of the Entomological Society of America’s 2013 Founders’ Memorial Award.
In addition, many UC Davis entomologists and graduate attended and presented their researech. See ESA schedule.
UC Davis doctoral candidate Matan Shelomi, who studies with Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis, received the John Henry Comstock award (Pacific Branch). (See archived news story.) Shelomi captained the UC Davis Linnaean Team, which went to the finals, and also served on the UC Davis Debate Team. The Debate Team won the national championship.
The Debate Team, captained by Mohammad-Amir Aghaee and advised by Michael Parrella, also included graduate students Matan Shelomi, Danny Klittich and Irina Shapiro. The Linnaean Team, captained by Matan Shelomi and coached by Larry Godfrey, included Rei Scampavia, Jenny Carlson and Danica Maxwell.
For his 10-minute talk, Mohammad-Amir Aghaee received a first-place award in the President's Prize competition and Rosanna Kwok, a second-place prize. See news story.
See Frank Zalom's Video on Extending Orchard IPM Knowledge in California
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- Author: Kathy Keatley Garvey
Agrawal, a professor of ecology and evolutionary biology at Cornell with a joint appointment in the Department of Entomology, will deliver the Founders’ Memorial Award lecture at the ESA’s 61st annual meeting set Nov. 10-13 in Austin, Texas.
The recipient of this annual award addresses the conferees to honor the memory and career of an outstanding entomologist. Agrawal has selected Dame Miriam Rothschild (1908-2005), best known for her work with mimicry, and a pioneer in the area of insect chemical ecology.
Agrawal researches plant-insect interactions, including aspects of herbivory, community ecology, phenotypic plasticity, chemical ecology and coevolution. Research projects include work on local biodiversity, ecology of invasive plants, the biology of Monarch butterflies, and the evolution of plant defense strategies.
From the ESA site:
"Dr. Agrawal’s research accomplishments cover the key areas of arthropod community genetics, real-time evolution of plant defense against insects, phylogenetic ecology, plant neighborhood-insect interactions, and insect colonization and induced defense. Over the course of his career to date, he has published more than 100 peer-reviewed papers in high-profile journals such as PNAS, Science, and Nature, and he has edited two key books on insect ecology."
"In the relatively new area of arthropod community genetics, he has addressed natural selection on milkweed defensive traits and how plant genetic variation in these traits influences insect community structure and coexistence. In the area of real time evolution of plant defenses against insects, he has shown that the suppression of insect damage causes the evolution of decreased plant resistance and increased competitive ability. His work in the area of phylogenetic ecology uses a comparative biology approach to address problems ranging from the controls on the success of invasive species to phylogenetic signatures of coevolution. And in the area of plant neighborhood-insect interactions, his ongoing research seeks to partition the relative importance of direct, associational, and trait-mediated effects of competing plants on milkweed and its insect fauna."
Rothschild, a British natural scientist and a leading authority on fleas. authored a book on parasitism, Fleas, Flukes and Cuckoos. Her father was entomologist Charles Rothschild, whose collection of fleas is in the Rothschild Collection at the British Museum.
"She is best known for her work with mimicry, and she conducted classic studies on the role of carotenoids in insect mimicry," according to information posted on the ESA website. "In addition to her work cataloging the famous Rothschild flea collection, Dame Rothschild was also a pioneer in the area of insect chemical ecology. Her work in particular on mimicry and sequestration of toxic compounds by insects was outstanding. Nature conservation was extremely important to her, and she lobbied strongly in favor of nature reserves."
Agrawal was at UC Davis in January of 2012 to deliver a seminar on "Evolutionary Ecology of Plant Defenses." His abstract: "In order to address coevolutionary interactions between milkweeds and their root feeding four-eyed beetles, I will present data on reciprocity, fitness tradeoffs, specialization and the genetics of adaptation. In addition to wonderful natural history, this work sheds light on long-standing theory about how antagonistic interactions proceed in ecological and evolutionary time."
Nearly 3,000 entomologists are expected to attend Entomology 2013. ESA, which has some 6500 members, is the world's largest organization serving the professional and scientific needs of entomologists and people in related disciplines. It was founded in 1889.
- Author: Kathy Keatley Garvey
The research, involving 900 butterfly and moth species and 459 non-native plants in Europe, may lead to better screening of potential invasive plants, risk assessment, and pest management strategies, said researchers Ian Pearse and Florian Altermatt.
“Despite the growing prevalence of non-native plants, there are few effective tools for predicting the fate of non-native plants or their impacts on native communities,” they wrote in newly published research, “Predicting Novel Trophic Interactions in a Non-Native World,” in Ecology Letters. “We demonstrated that novel interactions between herbivores and non-native plants can be predicted based on plant evolutionary relationships and properties in the native herbivore-plant food web.”
“My work has asked why some non-native plants are attacked by native herbivores while others are not,” said Pearse, who completed the research while studying for his doctorate degree in entomology at UC Davis. He teamed with Altermatt, then a UC Davis postdoctoral scholar with UC Davis Department of Environmental Science and Policy. Pearse is now a postdoctoral researcher in the Cornell Lab of Ornithology, and Altermatt is with the Swiss Federal Institute of Aquatic Science and Technology in Zurich, Switzerland.
“We noticed that many non-native plants were included as hosts of native moths in that food web,” Pearse said, “and we thought that we could use some of the ideas that I had been working on to explain which moths have started to eat which non-native plants.”
“Herbivores, by in large, are not very adventurous in what they eat,” Pearse said. “So, when a non-native plant enters their habitat, they tend to colonize those that are similar to the ones that they already eat. Plant evolutionary relationships are one of the best ways of looking at similarity between plants.”
They successfully predicted the majority of novel interactions between herbivores and non-native plants. “When non-native plants enter a new ecosystem, their success and effects are mostly unpredictable,” Pearse said. “However, we showed that one very predictable aspect of a non-native plant is which native herbivores can colonize it.”
For instance, the larvae of the cinnabar moth (family Tyriajacobaeae), are a biocontrol agent of ragworts (Senecio), a native of Europe, but they also will colonize other plants. A geometrid moth, Eupithecia virganreata feeds on various ragworts but over the last decades, has extended its diet to invasive goldenrods (Solidago canadensis and S. gigantea).
On the basis of interactions between native hosts and insects, the researchers found “specific diet extensions of potential European pest insects to plants of forestry or agricultural interest introduced from North America, as well as the diet extension of European insects onto non-native plants that are of invasive concern.”
“The goal of this approach is to correctly identify specific important interactions between a novel plant and native herbivore with the lowest possible false-positive rate, where a null model would result in a 50% false-positive rate,” they wrote. “For example, we predicted that the tussock moth (Calliteara pudibunda) colonizes red oak (Quercus rubra; a common introduced tree throughout Europe) with a false-positive rate of only 0.7%. The tussock moth is an herbivorous insect of forestry concerns, having mass-outbreaks, and it is thus critical to understand its diet extension to novel host plants. Similarly, we predicted that the specialist Sessiid moth Synanthedon tipuliformis colonizes Ribes aureum, a cultivated gooseberry introduced from North America, with a false-positive rate of only 2.0%. S. tipuliformis is known to cause damage in agricultural gooseberry plantations, and an accurate prediction of host switch to introduced agricultural gooseberries is thus economically important.”
Pearse received his doctorate in entomology from UC Davis in 2011, studying with major professor Rick Karban. Pearse's current research at Cornell “is trying to understand masting in oak trees; that is why and how trees produce very large seed sets in some years but small ones in others.”
Feb. 13, 2013
If you're not closely related, communication won't be as effective.
Newly published research in today's Proceedings of the Royal Society B: Biological Sciences shows that kin have distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors,” says lead researcher and ecologist Richard Karban, a professor in the UC Davis Department of Entomology.
For example, fire ants can recognize kin. “Ants will destroy queens that are not relatives but protect those who are,” Karban said.
That ability is less well studied for plants, until now.
“When sagebrush plants are damaged by their herbivores, they emit volatiles that cause their neighbors to adjust their defenses,” Karban said. “These adjustments reduce rates of damage and increase growth and survival of the neighbors.”
The research, “Kin Recognition Affects Plant Communication and Defense,” is co-authored by two scientists from Japan and two from UC Davis: Kaori Shiojiri of the Hakubi Center for Advanced Research, Kyoto University, and Satomi Ishizaki of the Graduate School of Science and Technology, Niigata University; and William Wetzel of the UC Davis Center for Population Biology, and Richard Evans of the UC Davis Department of Plant Science.
To simulate predator damage, the researchers “wounded” the plants by clipping them and then studied the responses to the volatile cues. They found that the plants that received cues from experimentally clipped close relatives experienced less leaf damage over the growing season that those that received cues from clipped neighbors that were more distantly related.
“More effective defense adds to a growing list of favorable consequences of kin recognition for plants,” they wrote.
The researchers performed their field work on sagebrush (Artemisia tridentata) at Taylor Meadow, UC Sagehen Creek Field Station, near Truckee. They conducted four field experiments over three years “that compared the proportion of leaves that were damaged by herbivores over the growing season when plants were provided with volatile cues clipped from a close relative versus cues from a distant relative,” the scientists wrote.
For closely related kin, they snipped stem cuttings (clones), potted them, and then returned the pots to the field. They determined relatedness “by using microsatellites that varied among individual sagebrush clones.”
The result: “Plants responded more effectively to volatile cues from close relatives than from distant relatives in all four experiments and communication reduced levels of leaf damage experienced over the three growing seasons,” they wrote. “This result was unlikely to be caused by volatiles repelling or poisoning insect herbivores.”
Karban, who has studied plant communication among the sagebrush at the site since 1999, likened the plant communication to neighbors “eavesdropping.” They “hear” the volatile cues of their neighbors as predators damage them.
Plants do communicate, Karban said. A basic form of plant communication occurs when it is being shaded and it responds by moving away.
“Some definitions of communication require that both the sender and receiver benefit by engaging in the behavior,” the researchers wrote. “Sagebrush is a long-lived perennial, making estimates of the costs and benefits of communication difficult although plants that responded to volatile cues from damaged neighbors experienced greater survival at the seedling stage and greater production of new branches and inflorescences over 12 years.”
Karban said that the volatiles released by “experimentally damaged plants are highly variable among individuals.”
“In the future we plan to examine this chemical variability to determine which chemicals are active as signals and why they exhibit so much variability,” Karban said. “Ultimately, we would like to be able to understand the chemical nature of the volatile cues, how plants use them to communicate, and whether as agriculturalists, we can control host plant resistance to herbivores.”
The work was supported by grants from the Japan Society for the Promotion of Science (JSPS) and the U.S. Department of Agriculture.
Related Link
Rick Karban's Lab Research