- Author: Kathy Keatley Garvey
The honor is awarded to those scholars “whose work has been internationally recognized and acclaimed and whose teaching performance is excellent.”
The UC Davis Department of Entomology now has a total of nine distinguished professors: six current faculty--Bruce Hammock, Frank Zalom, Lynn Kimsey, James R. Carey, Jay Rosenheim, and Richard Karban--and three emeriti faculty--Harry Kaya, Howard Ferris and Thomas Scott. (In addition, emeritus professor/chair Robert E. Page Jr. is a UC Davis distinguished emeritus professor, as was the late Robbin Thorp, who died in 2019.)
Karban, whose research interests include the population regulation of animal species and the interactions between herbivores and their host plants, currently focuses his research on two main projects: volatile communication between sagebrush plants that affects resistance to herbivory and factors that control the abundance and spatial distribution of wooly bear caterpillars.
Karban has researched plant communication in sagebrush (Artemisia tridentata) on the east side of the Sierra since 1995. His groundbreaking research on plant communication among kin, published in February 2013 in the Proceedings of the Royal Society B: Biological Sciences, drew international attention. In that study, Karban and his co-researchers found 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.”
On his website, he explains his research on volatile communication: “When sagebrush is experimentally clipped, it releases volatile cues that undamaged branches on the same plant, on different sagebrush plants, and on some other plant species respond to. These volatile cues cause many changes in neighboring plants and some of these changes make the undamaged neighbors better defended against their herbivores. We currently know little about the nature of these cues.
“Blocking air contact between branches makes responses undetectable, indicating the involvement of airborne cues. Methyl jasmonate has the ability to serve as the signal although it remains unclear if it acts in this capacity in nature. I would like to understand the costs and benefits of releasing volatiles cues and of responding to them. I am examining the multiple consequences of emitting cues. For example, cues affect neighboring plants, nearby herbivores, as well as predators and parasites of those herbivores. I am currently examining the long-term fitness consequences for sagebrush of responding to volatile cues.”
On his research on the abundance and distribution of caterpillars, Karban writes: “Many workers define ecology as the science that explains the abundance and distribution of species. Despite a century of work on these questions, our field has only a rudimentary grasp on the factors that are important. I have been censusing populations of wooly bear caterpillars at Bodega Bay for 30 years and have relatively little understanding of the factors that produce patterns in abundance and distribution. The ‘usual suspects' all have relatively little explanatory power: weather, food limitation, and parasitoids all fail to provide much insight. Indeed, caterpillars often recover from the attacks of their tachinid parasitoids and alter their diets when parasitized to increase their chances of surviving. Including a more complete food web in our analysis does not appear to provide more resolution although ants may be unappreciated as predators and food quality may also be important. I am collaborating with Perry de Valpine to attempt to develop new analytical techniques that will account for more of the variance in abundance data. I am collaborating as well with Marcel Holyoak to examine spatial patterns of abundance.”
Karban is the author of landmark book, Plant Sensing and Communication. He is a fellow of the Ecological Society of America (ESA) and the American Association for the Advancement of Science, and the recipient of the 1990 George Mercer Award from ESA for outstanding research.
The UC Davis ecologist is featured in the Dec. 23-30, 2013 edition of The New Yorker in Michael Pollan's piece, The Intelligent Plant: Scientists Debate a New Way of Understanding Plants. Zoe Schlanger featured him in a Nov. 21, 2020 Bloomberg Quint article titled The Botanist Daring to Ask: Do Plants Have Personalities?
Karban received his bachelor's degree in environmental studies from Haverford (Penn.) College in 1977 and his doctorate in biology from the University of Pennsylvania, Philadelphia, in 1982. He served as a lecturer at Haverford College for six months before joining the UC Davis faculty in May 1982 as an assistant professor. He advanced to associate professor in 1988 and to full professor in 1994.
- Author: Kathy Keatley Garvey
The Republicans tout their elephants. The Democrats, their donkeys. But UC Davis ecologists believe that their “bears” will successfully predict which political animal will win the U.S. presidential election, as they've done for the past three decades.
Bears? That would be the woolly bear caterpillars, the immature form of the Ranchman's Tiger Moth, Platyprepia virginalis.
Professor Richard “Rick” Karban of the UC Davis Department of Entomology and Nematology and his graduate students study the woolly bear caterpillars that dine primarily on lupine along the cliffs of Bodega Bay. Sometimes the population booms; other times, it's a bust. When the population thrives, a Democrat heads to the White House. When the population dives, the Republicans take over.
The UC Davis scientists, known for their expertise in plant-insect interactions, are now drawing national headlines for their presidential predictions.
“The pollsters and talking heads seem unable to size up this election cycle,” said Karban. “Paul the Octopus had a pretty good run predicting soccer matches in 2012 so perhaps the woolly bears have earned as much credibility at forecasting this presidential election.”
The scientists first announced their findings in a poster displayed at the 2014 Ecology Society of America meeting. On April 25, they expanded on the concept, complete with intricate charts plotted in red and blue, in Lopresti's Natural Musings blog, “The Woolly Bear Presidential Election Outlook 2016,” co-written by scientists in the Karban lab.
Washington Post reporter Karin Bruilliard picked it up and ran with it on April 26 in a piece titled, “These Fuzzy Little Caterpillars Are Better at Predicting Elections Than Most Pundits.”
“Each March, Karban censuses the same patches of lupine that he has for over 30 years,” LoPresti explained in Natural Musings. “The study asks a vexing question: Why are there are so many caterpillars in some years and so few in others? Many insects, including pests cycle like this, therefore it is of keen interest to many. Dozens of papers later, Karban, his students, and his collaborators have answered a great many questions, including how caterpillars deal with parasites, whether population cycles are influenced by rain, whether caterpillars enjoy eating plant hairs, and how caterpillars avoid their predators.”
“A superficial examination suggests that 2016 will be a Republican year – woolly bear abundance is not particularly high,” LoPresti noted. “However, looking a little closer, it may not be. The number of woolly bears per lupine bush in 2016 (0.53) is higher than the average Republican year by 152% and is 36% above the highest Republican year ever recorded (1988). However, it is only 27% of an average Democratic year and still only 36% of the lowest Democratic year (2008). This result is without presidential precedent in the last 30 years.”
So, which party, aka political animal, will occupy the White House come Jan. 1, 2017?
“We suspect that the Republicans have the edge,” the UC Davis scientists surmised. “However, a valid hypothesis would be a third-party winner, such as a right-leaning independent (a logical placeholder in between Democrats and Republicans). Perhaps Donald Trump will take particular interest in our data. Alternately, a contested Republican convention could produce a fractured party and the old Republican woolly bear average would not accurately represent the mean caterpillar abundances seen by this new party.”
Responding to the April 25 blog, someone noticed the resemblance of the hair of a presidential candidate to the hair of the woolly bear caterpillar.
The UC Davis scientists study the caterpillars at the Bodega Marine Reserve above the Bodega Marine Laboratory. The reserve, which surrounds the Bodega Marine Laboratory, is a unit of the University of California Natural Reserve System and is administered by UC Davis.
“Platyprepia virginalis caterpillars are dietary generalists and feed on multiple host species within a single day,” Karban says.
In research, Diet Mixing Enhances the Performance of a Generalist Caterpillar, Platyprepia virginalis, published in February 2010 in the journal Ecological Entomology, “We found that relative growth rates and rates of survival were higher when they fed on mixed diets compared to lupine only,” Karban said. These results were consistent with hypotheses that mixed diets provided balanced nutrition, diluted toxins, and/or allowed recovery from parasitoids, although our data did not allow us to separate these non-exclusive explanations.”
The caterpillar's taste for plants containing alkaloids may help it survive parasitoids, Karban said.