title: Evidence that Cerambycid Beetles Mimic Vespid Wasps in Odor as well as Appearance.
abstract: We present evidence that cerambycid species that are supposed mimics of vespid wasps also mimic their model's odor by producing spiroacetals, common constituents of vespid alarm pheromones. Adults of the North American cerambycids Megacyllene caryae (Gahan) and Megacyllene robiniae (Forster) are conspicuously patterned yellow and black, and are believed to be mimics of aculeate Hymenoptera, such as species of Vespula and Polistes. Adult males of M. caryae produce an aggregation-sex pheromone, but both sexes produce a pungent odor when handled, which has been assumed to be a defensive response. Headspace aerations of agitated females of M. caryae contained 16 compounds with mass spectra characteristic of spiroacetals of eight distinct chemical structures, with the dominant compound being (7E,2E)-7-ethyl-2-methyl-1,6-dioxaspiro[4.5]decane. Headspace samples of agitated males of M. caryae contained five of the same components, with the same dominant compound. Females of M. robiniae produced six different spiroacetals, one of which was not produced by M. caryae, (2E,7E)-2-ethyl-7-methyl-1,6-dioxaspiro[4.5]decane, and five that were shared with M. caryae, including the dominant (2E,8E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane. The latter compound is the sole spiroacetal produced by both males and females of a South American cerambycid species, Callisphyris apicicornis (Fairmaire & Germain), which is also thought to be a wasp mimic. Preliminary work also identified spiroacetals of similar or identical structure released by vespid wasps that co-occur with the Megacyllene species.
authors.affiliation: Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA. mitchellr@uwosh.edu.|Department of Biology, University of Wisconsin Oshkosh, 142 Halsey Science Center, 800 Algoma Blvd., Oshkosh, WI, 54901, USA. mitchellr@uwosh.edu.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Mitchell
authors.affiliation: Departamento de Sanidad Vegetal, Universidad de Chile, PO Box 1004, Santiago, Chile.
authors.forename: Tomislav
authors.initials: T
authors.lastname: Curkovic
authors.affiliation: Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Judith A
authors.initials: JA
authors.lastname: Mongold-Diers
authors.affiliation: Institut für Organische Chemie, Universität Hamburg, 20146, Hamburg, Germany.
authors.forename: Lara
authors.initials: L
authors.lastname: Neuteboom
authors.affiliation: Institut für Organische Chemie, Universität Hamburg, 20146, Hamburg, Germany.
authors.forename: Hans-Martin
authors.initials: HM
authors.lastname: Galbrecht
authors.affiliation: Institut für Organische Chemie, Universität Hamburg, 20146, Hamburg, Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Tröger
authors.affiliation: Instituto de Química, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile.
authors.forename: Jan
authors.initials: J
authors.lastname: Bergmann
authors.affiliation: Institut für Organische Chemie, Universität Hamburg, 20146, Hamburg, Germany.
authors.forename: Wittko
authors.initials: W
authors.lastname: Francke
authors.affiliation: Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Hanks
mesh_terms: D000080:Acetals / Q000032:analysis / Q000378:metabolism; D000818:Animals; D000067558:Biological Mimicry; D001517:Coleoptera / Q000378:metabolism*; D005260:Female; D008297:Male; D009812:Odorants / Q000032:analysis*; D010675:Pheromones / Q000032:analysis / Q000378:metabolism; D013141:Spiro Compounds / Q000032:analysis / Q000378:metabolism; D014863:Wasps / Q000378:metabolism*
chemical_list: D000080:Acetals; D010675:Pheromones; D013141:Spiro Compounds
keywords: Callisphyris apicicornis; Cerambycidae; Megacyllene caryae; Megacyllene robiniae; Spiroacetal; chemical defense; chemical mimicry