title: Antennal fine morphology of the threatened beetle Osmoderma eremita (Coleoptera: Scarabaeidae), revealed by scanning electron microscopy.
abstract: The aim of this study was to characterize the antennal morphology of Osmoderma eremita, a threatened scarab beetle inhabiting tree hollows. O. eremita males produce a sex pheromone, (R)-(+)-γ-decalactone, responsible mainly for the attraction of females but also other males. Gross and fine morphology of microstructures including sensilla, microsculpture and pores were analyzed using Scanning Electron Microscopy. The antenna of O. eremita showed the typical lamellicorn shape of scarab beetles, with a basal scape, a pedicel, a funicle composed of five antennomeres and a club composed of three lamellae. Six different subtypes of sensilla chaetica (Ch.1 - 6), Böhm sensilla (Bo), one subtype of sensilla basiconica (Ba.1), two subtypes of sensilla coeloconica (Co.1 - 2), two subtypes of sensilla placodea (Pl.1 - 2), pores and peculiar folds were described. The two sexes did not show any significant differences in the occurrence and number of the sensilla placodea, known to be responsible for the pheromone reception. Instead, some sexual differences were found on the occurrence and topology of three different microstructures: (1) one subtype of sensillum chaeticum (Ch.2) occurring on the pedicel only in males; (2) a characteristic pore occurring on the funicle only in males; (3) a peculiar fold occurring on different antennomeres of the funicle in the two sexes, on the fourth in males and on the fifth in females. A comparison between sensilla of O. eremita and those of other Scarabaeoidea is provided.
authors.affiliation: Department of Science, Roma Tre University, Rome, 00146, Italy.
authors.forename: Agnese
authors.initials: A
authors.lastname: Zauli
authors.affiliation: Department of Science, Roma Tre University, Rome, 00146, Italy.|CREA-ABP Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria-Centro di Ricerca per l'Agrobiologia e la Pedologia, Florence, 50125, Italy.|CFS-CNBF Centro Nazionale per lo Studio della Conservazione della Biodiversità Forestale di Verona-Bosco Fontana, Marmirolo, I-46045, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Maurizi
authors.affiliation: Department of Science, Roma Tre University, Rome, 00146, Italy.
authors.forename: Giuseppe M
authors.initials: GM
authors.lastname: Carpaneto
authors.affiliation: Department of Science, Roma Tre University, Rome, 00146, Italy.|CREA-ABP Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria-Centro di Ricerca per l'Agrobiologia e la Pedologia, Florence, 50125, Italy.|CFS-CNBF Centro Nazionale per lo Studio della Conservazione della Biodiversità Forestale di Verona-Bosco Fontana, Marmirolo, I-46045, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Chiari
authors.affiliation: Department of Biology, Lund University, Lund, SE-223 62, Sweden.
authors.forename: Glenn P
authors.initials: GP
authors.lastname: Svensson
authors.affiliation: Department of Science, Roma Tre University, Rome, 00146, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Di Giulio
mesh_terms: D000818:Animals; D057506:Arthropod Antennae / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000648:ultrastructure; D001517:Coleoptera / Q000033:anatomy & histology* / Q000648:ultrastructure*; D005260:Female; D008297:Male; D008855:Microscopy, Electron, Scanning; D058618:Sensilla / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000648:ultrastructure
keywords: SEM; lamellate antenna; pheromone-sensitive sensilla; saproxylic beetle; sensilla placodea