title: Disentangling visual and olfactory signals in mushroom-mimicking Dracula orchids using realistic three-dimensional printed flowers.
abstract: Flowers use olfactory and visual signals to communicate with pollinators. Disentangling the relative contributions and potential synergies between signals remains a challenge. Understanding the perceptual biases exploited by floral mimicry illuminates the evolution of these signals. Here, we disentangle the olfactory and visual components of Dracula lafleurii, which mimics mushrooms in size, shape, color and scent, and is pollinated by mushroom-associated flies. To decouple signals, we used three-dimensional printing to produce realistic artificial flower molds that were color matched and cast using scent-free surgical silicone, to which we could add scent. We used GC-MS to measure scents in co-occurring mushrooms, and related orchids, and used these scents in field experiments. By combining silicone flower parts with real floral organs, we created chimeras that identified the mushroom-like labellum as a source of volatile attraction. In addition, we showed remarkable overlap in the volatile chemistry between D. lafleurii and co-occurring mushrooms. The characters defining the genus Dracula - a mushroom-like, 'gilled' labellum and a showy, patterned calyx - enhance pollinator attraction by exploiting the visual and chemosensory perceptual biases of drosophilid flies. Our techniques for the manipulation of complex traits in a nonmodel system not conducive to gene silencing or selective breeding are useful for other systems.
authors.affiliation: Institute of Ecology & Evolution, 5289 University of Oregon, Eugene, OR, 97403, USA.
authors.forename: Tobias
authors.initials: T
authors.lastname: Policha
authors.affiliation: Institute of Ecology & Evolution, 5289 University of Oregon, Eugene, OR, 97403, USA.
authors.forename: Aleah
authors.initials: A
authors.lastname: Davis
authors.affiliation: Department of Visual Arts, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA.|Magpie Studio: Fabrication for Art and Science, La Jolla, CA, 92092, USA.
authors.forename: Melinda
authors.initials: M
authors.lastname: Barnadas
authors.affiliation: Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, UK.|Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Cledwyn Building, Penglais, Aberystwyth, Ceredigion, SY23 3DD, UK.
authors.forename: Bryn T M
authors.initials: BT
authors.lastname: Dentinger
authors.affiliation: Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Raguso
authors.affiliation: Institute of Ecology & Evolution, 5289 University of Oregon, Eugene, OR, 97403, USA.
authors.forename: Bitty A
authors.initials: BA
authors.lastname: Roy
mesh_terms: D000363:Agaricales / Q000502:physiology*; D000818:Animals; D003116:Color; D035264:Flowers / Q000033:anatomy & histology*; D055696:Olfactory Perception / Q000502:physiology*; D029595:Orchidaceae / Q000502:physiology*; D010858:Pigmentation; D012903:Smell; D014796:Visual Perception / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D055549:Volatile Organic Compounds
keywords: Dracula lafleurii; Drosophilidae; GC-MS; Orchidaceae; cloud forest; mimicry; neotropical; pollination