title: Conservation of Olfactory Avoidance in Drosophila Species and Identification of Repellents for Drosophila suzukii.
abstract: Flying insects use olfaction to navigate towards fruits in complex odor environments with remarkable accuracy. Some fruits change odor profiles substantially during ripening and related species can prefer different stages. In Drosophila species attractive odorants have been studied extensively, but little is understood about the role of avoidance pathways. In order to examine the role of the avoidance cue CO2 emitted from fruit on behavior of two species with different ripening stage preferences, we investigated the CO2-detection pathway in Drosophila melanogaster and Drosophila suzukii, a harmful pest of fruits. Avoidance to CO2 is not conserved in D. suzukii suggesting a behavioral adaptation that could facilitate attraction to younger fruit with higher CO2 emission levels. We investigated known innate avoidance pathways from five species at different evolutionary distances: D. melanogaster, D. yakuba, D. suzukii, D. pseudoobscura and D. virilis. Surprisingly, only DEET shows strong repellency across all species, whereas CO2, citronellal and ethyl 3-hydroxybutyrate show only limited conservation. These findings guide us to test recently discovered safe DEET substitutes, and we identify one that protects fruits from D. suzukii thus providing a new behavioral strategy for controlling agricultural pests.
authors.affiliation: Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521.
authors.forename: Christine
authors.initials: C
authors.lastname: Krause Pham
authors.affiliation: 1] Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521. [2] Entomology Department, University of California, Riverside, CA 92521.
authors.forename: Anandasankar
authors.initials: A
authors.lastname: Ray
mesh_terms: D000383:Agriculture; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects; D002245:Carbon Dioxide / Q000494:pharmacology; D003671:DEET / Q000494:pharmacology; D004330:Drosophila / Q000187:drug effects* / Q000502:physiology*; D007302:Insect Repellents / Q000494:pharmacology*; D010571:Pest Control; D012903:Smell / Q000187:drug effects*; D013045:Species Specificity
chemical_list: D007302:Insect Repellents; D003671:DEET; D002245:Carbon Dioxide