title: Pollinator attraction of the wasp-flower Scrophularia umbrosa (Scrophulariaceae).
abstract: Certain species of Scrophularia (Scrophulariaceae), such as S. nodosa and S. umbrosa, are mainly pollinated by social wasps and are consequently described as wasp-flowers. Because plants attract their pollinators with the help of various floral cues, such as floral odour and/or optical cues, we have investigated the role of olfactory and visual floral signals responsible for wasp attraction in S. umbrosa. Using a combination of chemical (GC, GC-MS) and electrophysiological analyses (GC-EAD), we identified ten compounds in the complex floral odour bouquet that are detectable by the wasps' antennae. As in the wasp-flower Epipactis helleborine, we found so-called 'green leaf volatiles' (GLVs) in the floral odour; these GLVs are highly attractive to the wasps. GLVs, mostly six-carbon aldehydes, alcohols and acetates, and other volatile organic compounds (VOCs), are emitted by many plants infested with herbivores, e.g. caterpillars. In contrast to other investigated wasp-flowers, behavioural experiments have demonstrated that, in addition to the floral odour of S. umbrosa, visual cues are involved in pollinator attraction.
authors.affiliation: Institute of Experimental Ecology, University of Ulm, Ulm, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Brodmann
authors.forename: D
authors.initials: D
authors.lastname: Emer
authors.forename: M
authors.initials: M
authors.lastname: Ayasse
mesh_terms: D000818:Animals; D035264:Flowers / Q000737:chemistry* / Q000254:growth & development; D060434:Herbivory / Q000187:drug effects; D018515:Plant Leaves / Q000737:chemistry; D011058:Pollen / Q000737:chemistry; D054817:Pollination / Q000502:physiology; D032266:Scrophularia / Q000737:chemistry* / Q000254:growth & development; D055549:Volatile Organic Compounds / Q000032:analysis*; D014863:Wasps / Q000187:drug effects*
chemical_list: D055549:Volatile Organic Compounds