GELIFES Seminars - Robert Raguso

Robert Raguso (Cornell University)

How do flowers “play dead”?

Extended phenotypes, holobionts and deceptive pollination

In pollination biology, conventional interactions between flowering plants and their pollinators often require flowers to advertise the presence of nectar or pollen rewards using visual and olfactory signals. Brood site deception departs from this theme in that such flowers “play dead” by mimicking decomposing substances (fungi, fruit, feces, carrion) used by unconventional pollinators as nursery sites. Persistent questions are how such phenotypes evolve, whether and how pollinators are truly deceived by them. Here I discuss parallel studies of brood site deception using non-model systems (Dracula orchids and Asimina triloba pawpaws) to functionally dissect fungal and rotting fruit mimicry. I combine chemical, behavioral and microbial analyses to demonstrate that both systems are more nuanced than expected, providing mating opportunities and food resources without offering appropriate substrates for oviposition and larval development.

Biosketch:
Robert Raguso developed a childhood fascination with the natural history of butterflies and plants into a career as a research biologist and educator. As an undergraduate at Yale University, he studied butterfly population genetics, but his future research interests were shaped by a pair of summer internships in pollination ecology. His doctoral thesis at the University of Michigan pioneered the study of genetic, physiological and ecological aspects of floral scent production in plants. As a postdoctoral fellow at the University of Arizona, Raguso studied the olfactory and behavioral responses of insects to floral scent, along with phylogenetic patterns in the evolutionary gain, loss and modification of floral scent. In 1999, he organized and chaired the first Gordon Research Conference on this subject and has taught workshops worldwide to build capacity in his field. He served as a US Fulbright Fellow during a sabbatical in South Africa and as a National Geographic Explorer in research expeditions to boreal Alaska and Patagonian Chile. Prof. Raguso’s plant-pollinator research has expanded to include fungi and microbes, exploring such themes as multi-modal sensory communication and signal evolution, and the roles of floral chemistry across the spectrum of generalized to specialized plant-pollinator interactions.