Posts Tagged: Rick Karban
If you're planning to hike the hills around Bodega Head in Sonoma County, watch out for the bears.
The woolly bear caterpillars, that is.
Last Sunday, with the temperature hovering around 70 degrees, the woolly bears were everywhere. They were munching on the gray-green leaves of Lupinus arboreus (yellow bush lupine), not yet blooming. We also spotted them on yellow mustard and wild radish, both members of the Brassicaceae family and both abloom.
If you look closely at these little caterpillars, they seem to be having a bad hair day. They look as if they just encountered a jolt of static electricity.
They're also known as the larvae of Ranchman's Tiger Moth (Platyprepia virginalis). Once they become moths, they do not resemble woolly bears any more.
Rick Karban, professor of entomology at UC Davis, has published a number of research papers on these herbivores.
"Platyprepia virginalis caterpillars are dietary generalists and feed on multiple host species within a single day," he wrote recently in Ecological Entomology. "We conducted field experiments to evaluate their performance on diets consisting of only their primary food, Lupinus arboreus, or diets consisting of L. arboreus plus other acceptable host species."
"We found that relative growth rates and rates of survival were higher when they fed on mixed diets compared to lupine only."
That feeding behavior we saw, too. A lupine lunch, with a touch of mustard and radish.
Close-up of woolly bear caterpillar on yellow lupine on Bodega Head, Sonoma County. (Photo by Kathy Keatley Garvey)
Woolly bear caterpillar on wild radish on Bodega Head, Sonoma County. (Photo by Kathy Keatley Garvey)
It will be like "old-home week" when Anurag Agrawal returns to the University of California, Davis, tomorrow (Jan. 18) to deliver a seminar on "Evolutionary Ecology of Plant Defenses."
Agrawal, who received his doctorate at UC Davis under major professor Rick Karban, UC Davis Department of Entomology, and is now a professor of ecology at Cornell University, Ithaca, N.Y., will give the presentation from 12:10 to 1 p.m., in 122 Briggs. Host is Andrew Merwin of the Michael Parrella lab.
"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," Agrawal said. "In addition to wonderful natural history, this work sheds light on long-standing theory about how antagonistic interactions proceed in ecological and evolutionary time."
Agrawal does research on plant-insect interactions, including aspects of herbivory, community ecology, phenotypic plasticity, chemical ecology and coevolution.
His research projects have included work on local biodiversity, ecology of invasive plants, the biology of Monarch butterflies, and the evolution of plant-defense strategies.
Agrawal, a native of Allentown, Penn., completed his undergraduate work in biology and his master’s degree in conservation biology at the University of Pennsylvania, where he became intrigued with plant-animal interactions.
He then headed out to California in 1994 to study with Karban, a noted expert on plant-animal interactions.
While at UC Davis, Agrawal received the 1999 Young Investigator Award, sponsored by the American Society of Naturalists. He went on to win the National Science Foundation’s 2004 Early Career Award and the Ecological Society of America’s 2006 George Mercer Award.
After receiving his doctorate from UC Davis, Agrawal accepted a postdoctoral fellowship at the University of Amsterdam before becoming an assistant professor of botany at the University of Toronto. He joined the Cornell faculty in 2004.
Among his honors: he won the sixth David Starr Jordan Prize for his innovative research involving plant-animal interactions. The international award, given approximately every three years, comes with a $20,000 prize and a commemorative medal.
In singling him out for the honor, the awards committee described Agrawal as “one of the foremost authorizes on the community and evolutionary ecology of species interactions.”
And tomorrow, Anurag Agrawal will be back on his "home turf" to talk about those interactions.
Anurag Agrawal, professor of evolution and ecology at Cornell, returns to the UC Davis campus Jan. 18 to give a seminar.
If you enjoy climbing the cliffs of Bodega Head on the Sonoma coast, keep your eyes out for bears--woolly bear caterpillars, that is.
The so-called "woolly bear caterpillar" is reddish, black and woolly and has a voracious appetite much like that of Joey Chestnut. It is the Ranchman's Tiger Moth caterpillar, Platyprepia virginalis.
Richard "Rick" Karban, professor of entomology at the University of California, Davis, studies this critter. "It has a taste for most alkaloid containing plants, like fiddleneck, although it doesn't appear to sequester the alkaloids," he told us. "The alkaloids may help caterpillars survive their parasitoids, however."
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.
Several woolly bear caterpillars were munching on fiddleneck. Another rolled around near a patch of California poppies and we couldn't tell what its menu included. It looked good, though!
You can read Karban's research on "Diet Mixing Enhances the Performance of a Generalist Caterpillar, Platyprepia virginalis," published last February in the Ecological Entomology journal.
A woolly bear caterpillar munching on foliage at the Bodega Head. (Photo by Kathy Keatley Garvey)
A woolly bear caterpillar munching on fiddleneck. (Photo by Kathy Keatley Garvey)
Evolutionary ecologist Anurag Agrawal (right), who received his doctorate in population biology from the University of California, Davis in 1999 under major professor Richard “Rick” Karban, has just received the sixth David Starr Jordan Prize for his innovative research inolving plant-animal interactions.
The international award, given approximately every three years, comes with a $20,000 prize and a commemorative medal.
Agrawal, now an associate professor in the Department of Ecology and Evolutionary Biology, Cornell University, also serves as the associate director for the Cornell Center for a Sustainable Future and director of the Cornell Chemical Ecology Group.
Does the name "David Starr Jordan" ring a bell? It should. He was a leading American biologist (1851-1931) who was educated at Cornell; taught zoology at Indiana; and served as president of both Indiana and Stanford universities.
The three universities established the joint endowment in 1986 and have awarded the prize since 1987. “The intent of the David Starr Jordan Prize is to recognize scientists who are making research contributions likely to redirect the principal foci of their fields,” the awards committee said.
The coveted award is given to a young scientist, age 40 or under, who is making novel innovative contributions in one of Jordan’s fields of interest: evolution, ecology, population and organismal biology.
The awards committee, comprised of Cornell, Indiana and Stanford scientists, described Agrawal as “one of the foremost authorities on the community and evolutionary ecology of species interactions.”
“Dr. Agrawal has made highly influential contributions, including empirical and conceptual advances in our understanding of plant defense against herbivory, impacts of genetic diversity on community processes, co evolutionary interactions between monarch butterflies and milkweeds and deciphering the success of invasive plants,” the committee announced.
As the recipient of the David Starr Jordan Prize, he will lecture at the sponsoring institutions, beginning Feb. 18 at Cornell.
Born in 1972 in Allentown, Penn., Agrawal completed his undergraduate work in biology and his master’s degree in conservation biology at the University of Pennsylvania, where he became intrigued with plant-animal interactions. He then headed out to California in 1994 to study with Karban, a noted expert on plant-animal interactions. Karban, now a newly elected Fellow of the American Association for the Advancement of Science, teaches field ecology and community ecology.
“It was an amazing time being a graduate student at UC Davis and working with Rick Karban… a great foundation and nothing but great memories!” Agrawal said.
When you visit the Peter J. Shields Oak Grove in the UC Davis Arboretum, you'll see one of the most diverse mature oak collections in the United States. More than 80 kinds of oaks, including scientifically documented trees native to the United States,Central America, Europe and Asia are planted there.
The dominant native oak is the Valley oak, Quercus lobata Née.
What Ian Pearse, a UC Davis researcher in the Department of Entomology, wanted to know was this: "Why do insects interact with some non-native plant species but not others?"
In a study encompassing three summers and 57 species of introduced (non-native) oaks in the grove, he found that many insects that target California’s native oak trees will also feed on non-native oaks planted near them, but with one distinct difference: the insects tend to do more damage to the non-native oaks that are closely related to the natives, than they do to the distant relatives.
“This is a confirmation of the ideas dating back to Darwin,” said Pearse, a doctoral candidate in the Department of Entomology who studies with major professor and noted insect ecologist Rick Karban.
Pearse and co-author Andrew Hipp of the Illinois-based Morton Arboretum and Field Museum of Natural History, Chicago, published their results in a recent edition of the journal, Proceedings of the National Academy of Sciences (PNAS).
“The insects were mostly small moths, fairly inconspicuous,” Pearse said. “They don’t cause a lot of damage. This was more of a theoretical study, of how insects on native oaks also tend to interact with non-native oaks that are similar.”
“Ian's study is important for several reasons,” said Karban. “Our collective intuition about what makes some introduced plants, including crop species, more susceptible to herbivores than others is poorly developed. By using a large number of oak species planted in a common environment, and accounting for the relatedness of the species, Ian can answer that question with a great deal of elegance and power. His finding that relatedness of the various oaks to the native species explains a lot of the picture and provides considerable insight.”
The journal cover features an image of the mural “Oak Family Tree,” from the UC Davis Arboretum oak collection. The mural, created through the UC Davis Art/Science Fusion Program, taught by entomology professor and artist Diane Ullman and artist Donna Billick, depicts the evolutionary relationships of 29 oak species and the animals associated with each species.
“The project was a collaboration with the arboretum,” Ullman said, noting that Emily Griswold, a national leader in oak conservation and the Arboretum’s assistant director of horticulture, “provided the leadership and knowledge base from the arboretum.”
The PNAS article is drawing widespread interest from ecologists, taxonomists and oak enthusiasts. Pearse is the first person to create a phylogeny of the oaks in Shields Oak Grove. Internationally recognized oak expert John Tucker (1916-2008), former UC Davis botany professor and a former director of the Arboretum, helped plant the trees nearly half a century ago.
And now we know more about the insects that interact with those oaks.