title: Conserved, highly specialized olfactory receptor neurons for food compounds in 2 congeneric scarab beetles, Pachnoda interrupta and Pachnoda marginata.
abstract: Few studies have systematically addressed evolutionary changes in olfactory neuron assemblies, either by genetic drift or as an adaptation to specific odor environments. We have studied the sense of olfaction in 2 congeneric scarab beetles, Pachnoda interrupta Olivier and Pachnoda marginata Drury (Coleoptera: Scarabaeidae: Cetoniinae), which are both opportunistic polyphages, feeding mainly on fruit and flowers. The 2 species occur in dissimilar habitats: P. interrupta is found in dry savannah, and P. marginata in tropical parts of equatorial Africa. To study how these species may have adapted their sense of olfaction to their odor environments, we utilized single-unit electrophysiology on olfactory sensilla with a wide selection of food-related compounds. Despite the differences in habitat, we found that the species shared most of the physiological types of olfactory receptor neurons (ORNs) encountered, although their proportions frequently varied between the species. The high degree of conservation in olfaction between the species implies that a similar sensory strategy is efficient for food search in both habitats. However, shifts in proportions of receptor neuron classes, and slight shifts in response profiles and/or presence of some ORN classes unique to either species, may reflect adaptation to a different set of hosts.
authors.affiliation: Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO Box 102, 230 53 Alnarp, Sweden. jonas.bengtsson@iasma.it
authors.forename: Jonas M
authors.initials: JM
authors.lastname: Bengtsson
authors.forename: Hamida
authors.initials: H
authors.lastname: Khbaish
authors.forename: Andreas
authors.initials: A
authors.lastname: Reinecke
authors.forename: Yitbarek
authors.initials: Y
authors.lastname: Wolde-Hawariat
authors.forename: Merid
authors.initials: M
authors.lastname: Negash
authors.forename: Emiru
authors.initials: E
authors.lastname: Seyoum
authors.forename: Bill S
authors.initials: BS
authors.lastname: Hansson
authors.forename: Ylva
authors.initials: Y
authors.lastname: Hillbur
authors.forename: Mattias C
authors.initials: MC
authors.lastname: Larsson
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000145:classification* / Q000648:ultrastructure*; D005502:Food; D008855:Microscopy, Electron, Scanning; D055696:Olfactory Perception / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000502:physiology / Q000648:ultrastructure; D010802:Phylogeny