May 3, 2012

Sonia Altizer with monarch butterflies that she studies.

DAVIS--Sonia Altizer, an associate professor in the Odum School of Ecology at the University of Georgia, Athens, will discuss "Migratory Immunity: Parasite Infection, Host Defense and Fitness Costs in Monarch Butterflies" at the UC Davis Department of Entomology seminar on Wednesday, June 6 in 122 Briggs Hall.

Millions of North American monarch butterflies migrate from Canada and the United States to overwintering areas in Mexico and then return, fluttering some 2000 to 3000 miles in what’s been called “an incredible mass migration."

"Monarchs are globally distributed and best known for undertaking a spectacular annual migration in parts of North America," Altizer says. "In wild populations, monarchs are commonly infected with a specialist protozoan Ophryocystis elektroscirrha; this parasite can be transmitted both vertically and horizontally and causes debilitating infections."

"The monarch-parasite system has served as a model for understanding how long-distance migration affects host-pathogen ecology, and parasite prevalence and virulence is highest in non-migratory monarch populations. Past work showed a high degree of variation among individual monarchs in their susceptibility to infection, and negative effects of infection on monarch survival and flight performance. Here I discuss collaborative studies aimed at two interrelated questions:  (1) To what degree do infected monarchs have lower migratory success than healthy butterflies?  (2) Do monarchs experience fitness tradeoffs between immune defense, energy reserves and other traits?  Results are based on a combination of field monitoring studies to quantify monarch lipid reserves and immune measures during fall migration, stable isotope work to examine migratory distances travelled by healthy and infected butterflies, and laboratory experiments to examine costs and benefits of immune defense. Findings support negative effects of parasitism on monarch migratory success. Although innate immune defenses in larvae do not appear to be costly as measured here, we found support for tradeoffs between defense and lipid reserves among fall migrating adults. Given growing human impacts on the ecology of monarchs other species with imperiled migrations, it is important to understand how infectious diseases will respond to such changes.

Monarch butterfly on Mexican sunflower. (Photo by Kathy Keatley Garvey)

Altizer received her bachelor’s degree from Duke University (1992), doctorate from the University of Minnesota (1998), and did postdoctoral work at Princeton and Cornell University. Her research focuses on the interplay between animal behavior and the spread and evolution of infectious diseases.   For the past 15 years, Altizer has studied monarch butterfly migration, ecology, and interactions with a protozoan parasite, asking how seasonal migration of these butterflies affects parasite transmission. She also developed collaborative databases of mammalian infectious diseases to ask how host behavior, ecology, and life history interact with global-scale patterns of parasitism. Other work has focused on songbird-pathogen dynamics, including studies of house finch conjunctivitis, West Nile virus, and salmonellosis. 

Most recently, Altizer has collaborated with her students and other researchers to study the dynamics of rabies virus infections in Peruvian vampire bats, and the effects of contact behavior on ape sexually-transmitted diseases. Collectively, this work has practical significance for mitigating disease risks in animal populations in the face of anthropogenic pressures, and is also relevant for understanding human risks from zoonotic pathogens.

Coordinators of the spring seminars are Louie Yang and Joanna Chiu, assistant professors. All lectures will take place on Wednesdays from 12:10 to 1 p.m. in 122 Briggs Hall. The series, launched April 4, will continue through May 23.

In a webcast project coordinated by professor James R. Carey, the seminars will be videotaped and can be accessed at a later date on UCTV.

The complete list of speakers for the April 4-June 6 seminars:

April 4: Ian Pearse, who just finished his doctorate, working with major professor  Rick Karban lab, UC Davis, will speak on "The Use of Non-Native Plants by Native Herbivores." 
Host: Rick Karban, professor, UC Davis Department of Entomology

April 11: James Harwood, graduate student, James R. Carey lab, UC Davis,"Biodemography of Reproductive Senescence in Fruit Flies (Tephritidae): The Influence of External Conditions on Age Specific Reproduction and Lifespan"
Host: James R. Carey, professor, UC Davis Department of Entomology

April 18: Bryony C. Bonning, professor, Iowa State University, "Novel Toxin Delivery Strategies for Management of Pestiferous Aphids"
Host: Bruce Hammock, distinguished professor, UC Davis Department of Entomology

April 25: Vince Jones, professor, Washington State University. "How a 'Perfect Storm' of Technology, Legislation, and Applied Ecology Is Finally Leading to IPM in Western Orchards"
Host: Michael Parrella, professor and chair, UC Davis Department of Entomology

May 2: Susan Cobey, bee breeder-geneticist at UC Davis and Washington State University, "Importation of  Honey Bee Germplasm to Increase  Genetic Diversity in Domestic Breeding Stocks"
Host: Eric Mussen, Extension apiculturist, UC Davis Department of Entomology

May 9: Cancelled. Sonia Altizer's talk will now be June 6

May 16: James C. Nieh, professor of biology, University of California, San Diego, "Role of Negative Signaling in a Superorganism: the Honey Bee Stop Signal"
Host: Brian Johnson, assistant professor, UC Davis Department of Entomology

May 23: Tara Thiemann, postdoctoral Scholar at UC Davis, William Reisen lab, "Survey of Culex Bloodfeeding Patterns in California"
Host: William Reisen, research entomologist, Center for Vectorborne Diseases, and adjunct professor, Pathology, Microbiology and Immunology (PMI), School of Veterinary Medicine

June 6: Sonia Altizer, professor, University of Georgia, "Infection and Immunity in Migratory Species: Monarchs as a Global Case Study" (Rescheduled from May 9)
Host: Louie Yang, assistant professor, UC Davis Department of Entomology

Contact information:
Louie Yang: (530) 754-3261 or lhyang@ucdavis.edu
Joanna Chiu: (530) 752-1839 or jcchiu@ucdavis.edu

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--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894