Exploring the Interactions Between Plants and Insects
Jan. 18, 2011
Angela Smilanich didn't start out to become a biologist.
DAVIS---As a child, Angela Smilanich never harbored a “fascination or obsession for insects.”
That came later.
“My love for insects actually came later in life after visiting a lowland tropical rainforest in Costa Rica, where I was given my first project as a young scientist,” said Smilanich, a biologist at the University of Nevada, Reno who will speak on "Self-Medication vs. Self-Toxicity in Generalist and Specialist Herbivores” from 12:10 to 1 p.m., Wednesday, Jan. 26 in 1022 Life Sciences Addition, University of California, Davis.
“In a tropical rainforest, the diversity of insects literally smacks you in the face, and one cannot come away from this experience without awe and respect for nature. And I was no exception.”
Since then, she’s dedicated her career to studying the intricate interactions between insects and their environment, mostly plants. “The research has never ceased to amaze or challenge me, and I cannot think of a life more fulfilling than discovering science and sharing it with others.”\
Smilanich, who received her doctorate in ecology and evolution from Tulane University, New Orleans, in 2008. is now an adjunct faculty member in biology at University of Nevada, Reno, and an affiliate associate research faculty at the Desert Research Institute, Reno.
Her talk is part of the weekly seminars being held through March 9 by the UC Davis Department of Entomology. It will be webcast live at http://uc-d.na4.acrobat.com/ucsn1/ and then archived on the department website.
“Specialist and generalist caterpillars are different in many aspects,” she says. “My research highlights these differences in a tritrophic context by focusing on plant chemistry and natural enemies. For example, quite often, specialist caterpillars are physiologically constrained to feed on plants with specific leaf chemistry. In addition, they have adapted to sequester plant compounds in their tissues thereby becoming toxic to predators.”
“In contrast, generalist caterpillars may encounter several different classes of plant chemistry over the course of a day,” she said. “Given these differences in host plant chemistry, one question that I am interested in addressing is: what are the differences in physiological differences between specialist and generalist caterpillars?
To answer that question, she has focused on the insect immune response, which she describe as “ one of the most important defenses caterpillars have against natural enemies.”
Natural enemies may be influencing the evolution of the insect immune response, she says. In her UC Davis talk, she will show how host plant chemistry differentially affects a specialist caterpillar (Junonia coenia, buckeye) and a generalist caterpillar (Grammia incorrupta, woolly bear). In the case of the buckeye, I will show how ingesting and sequestering high concentrations of plant compounds negatively affects the immune response. With the woolly bear, there is evidence that plant compounds help the immune response; however, this question is still under investigation. “
--Kathy Keatley Garvey
UC Davis Department of Entomology