title: A male-predominant cuticular hydrocarbon, 7-methyltricosane, is used as a contact pheromone in the western flower thrips Frankliniella occidentalis.
abstract: In a laboratory bioassay, adult female Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) spent more time near filter paper disks that had been exposed to adult males than near unexposed disks; this effect was not observed on disks exposed to adult females. The response could only partly be explained by the known male-produced aggregation pheromone, neryl (S)-2-methylbutanoate, suggesting the presence of an unknown male-produced compound. In gas chromatography/mass spectrometry analyses, 7-methyltricosane was detected on disks exposed to males, but not on disks exposed to females. Extracts of cuticular lipids also showed relatively large amounts of 7-methyltricosane on males, whereas only trace amounts were found on females and none on larvae. Bioassays of synthetic 7-methyltricosane showed that adults responded only after contact. The response to this compound was clearly different from that to n-tricosane or hexane-only controls. Females that contacted 7-methyltricosane on glass beads stayed in the vicinity and frequently raised the abdomen, a behavior that rejects mating attempts by males. Males stayed in the vicinity and wagged the abdomen sideways, a behavior used in fighting between males. This is the first identification of a contact pheromone in the order Thysanoptera.
authors.affiliation: Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, ST5 5BG, UK.
authors.forename: Oladele A
authors.initials: OA
authors.lastname: Olaniran
authors.forename: Akella V S
authors.initials: AV
authors.lastname: Sudhakar
authors.forename: Falko P
authors.initials: FP
authors.lastname: Drijfhout
authors.forename: Ian A N
authors.initials: IA
authors.lastname: Dublon
authors.forename: David R
authors.initials: DR
authors.lastname: Hall
authors.forename: James G C
authors.initials: JG
authors.lastname: Hamilton
authors.forename: William D J
authors.initials: WD
authors.lastname: Kirk
mesh_terms: D000473:Alkanes / Q000737:chemistry* / Q000494:pharmacology; D000818:Animals; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006838:Hydrocarbons / Q000737:chemistry*; D007814:Larva / Q000378:metabolism; D008297:Male; D012724:Sex Attractants / Q000737:chemistry* / Q000494:pharmacology; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology; D061149:Thysanoptera / Q000254:growth & development / Q000378:metabolism*
chemical_list: C583615:7-methyltricosane; D000473:Alkanes; D006838:Hydrocarbons; D012724:Sex Attractants