title: Neural coding merges sex and habitat chemosensory signals in an insect herbivore.
abstract: Understanding the processing of odour mixtures is a focus in olfaction research. Through a neuroethological approach, we demonstrate that different odour types, sex and habitat cues are coded together in an insect herbivore. Stronger flight attraction of codling moth males, Cydia pomonella, to blends of female sex pheromone and plant odour, compared with single compounds, was corroborated by functional imaging of the olfactory centres in the insect brain, the antennal lobes (ALs). The macroglomerular complex (MGC) in the AL, which is dedicated to pheromone perception, showed an enhanced response to blends of pheromone and plant signals, whereas the response in glomeruli surrounding the MGC was suppressed. Intracellular recordings from AL projection neurons that transmit odour information to higher brain centres, confirmed this synergistic interaction in the MGC. These findings underscore that, in nature, sex pheromone and plant odours are perceived as an ensemble. That mating and habitat cues are coded as blends in the MGC of the AL highlights the dual role of plant signals in habitat selection and in premating sexual communication. It suggests that the MGC is a common target for sexual and natural selection in moths, facilitating ecological speciation.
authors.affiliation: Division of Chemical Ecology, Department of Plant Protection Biology, SLU, PO Box 102, 23053 Alnarp, Sweden. federica.trona@slu.se
authors.forename: Federica
authors.initials: F
authors.lastname: Trona
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Anfora
authors.forename: Anna
authors.initials: A
authors.lastname: Balkenius
authors.forename: Marie
authors.initials: M
authors.lastname: Bengtsson
authors.forename: Marco
authors.initials: M
authors.lastname: Tasin
authors.forename: Alan
authors.initials: A
authors.lastname: Knight
authors.forename: Niklas
authors.initials: N
authors.lastname: Janz
authors.forename: Peter
authors.initials: P
authors.lastname: Witzgall
authors.forename: Rickard
authors.initials: R
authors.lastname: Ignell
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001921:Brain / Q000502:physiology*; D003463:Cues; D017753:Ecosystem; D005260:Female; D008297:Male; D018613:Microscopy, Confocal; D009036:Moths / Q000502:physiology*; D012737:Sex Factors; D012726:Sexual Behavior, Animal / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D012903:Smell / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology