title: (7Z,9E)-2-methyl-7,9-octadecadiene: a sex pheromone component of Lymantria bantaizana.
abstract: Our objective was to identify the sex pheromone of Lymantria bantaizana (Lepidoptera: Lymantriidae) whose larvae feed exclusively on walnut, Juglans spp., in China, and Japan. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone gland extracts revealed a single EAD-active component. Retention index calculations of this compound on four GC columns suggested that it was a methyl-branched octadecadiene with conjugated double bonds. In GC-EAD analyses of 2-methyloctadecenes, (Z)-2-methyl-7-octadecene and (E)-2-methyl-7-octadecene elicited the strongest antennal responses, suggesting that the double bond positions were at C7 and C9. In comparative GC-EAD analyses of pheromone gland extract and stereoselectively synthesized isomers (E,E; E,Z; Z,E; Z,Z) of 2-methyl-7,9-octadecadiene, the (E,Z)- and (Z,E)-isomer had retention times identical to that of the candidate pheromone, but only the latter isomer elicited strong EAD activity. Results of field experiments in Japan substantiated that (7Z,9E)-2-methyl-7,9-octadecadiene is the L. bantaizana sex pheromone, a compound previously unknown in the Lepidoptera. Detection surveys in North America for exotic Eurasian forest defoliators could include traps baited with the L. bantaizana pheromone.
authors.affiliation: Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada. gries@sfu.ca
authors.forename: Regine
authors.initials: R
authors.lastname: Gries
authors.forename: Grigori
authors.initials: G
authors.lastname: Khaskin
authors.forename: Tadao
authors.initials: T
authors.lastname: Gotoh
authors.forename: Paul W
authors.initials: PW
authors.lastname: Schaefer
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gries
mesh_terms: D000466:Alkadienes / Q000737:chemistry* / Q000494:pharmacology; D000818:Animals; D002849:Chromatography, Gas; D005260:Female; D007536:Isomerism; D007915:Lepidoptera / Q000737:chemistry* / Q000502:physiology; D008297:Male; D010572:Pest Control, Biological; D012724:Sex Attractants / Q000737:chemistry*; D012726:Sexual Behavior, Animal / Q000502:physiology
chemical_list: C506588:(7Z,9E)-2-methyl-7,9-octadecadiene; D000466:Alkadienes; D012724:Sex Attractants