title: Anatomical localization and stereoisomeric composition of Tribolium castaneum aggregation pheromones.
abstract: We report that the abdominal epidermis and associated tissues are the predominant sources of male-produced pheromones in the red flour beetle, Tribolium castaneum and, for the first time, describe the stereoisomeric composition of the natural blend of isomers of the aggregation pheromone 4,8-dimethyldecanal (DMD) in this important pest species. Quantitative analyses via gas chromatography-mass spectrometry showed that the average amount of DMD released daily by single feeding males of T. castaneum was 878 ± 72 ng (SE). Analysis of different body parts identified the abdominal epidermis as the major source of aggregation pheromone; the thorax was a minor source, while no DMD was detectable in the head. No internal organs or obvious male-specific glands were associated with pheromone deposition. Complete separation of all four stereoisomers of DMD was achieved following oxidation to the corresponding acid, derivatization with (1R, 2R)- and (1S, 2S)-2-(anthracene-2,3-dicarboximido)cyclohexanol to diastereomeric esters, and their separation on reversed-phase high-performance liquid chromatography at -54°C. Analysis of the hexane eluate from Porapak-Q-collected volatiles from feeding males revealed the presence of all four isomers (4R,8R)/(4R,8S)/(4S,8R)/(4S,8S) at a ratio of approximately 4:4:1:1. A walking orientation bioassay in a wind tunnel with various blends of the four synthetic isomers further indicated that the attractive potency of the reconstituted natural blend of 4:4:1:1 was equivalent to that of the natural pheromone and greater than that of the 1:1 blend of (4R,8R)/(4R,8S) used in commercial lures.
authors.affiliation: Department of Entomology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Lu
authors.forename: Richard W
authors.initials: RW
authors.lastname: Beeman
authors.forename: James F
authors.initials: JF
authors.lastname: Campbell
authors.forename: Yoonseong
authors.initials: Y
authors.lastname: Park
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Aikins
authors.forename: Kenji
authors.initials: K
authors.lastname: Mori
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Akasaka
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Tamogami
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Phillips
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004817:Epidermis / Q000378:metabolism; D008297:Male; D010675:Pheromones / Q000737:chemistry*; D013237:Stereoisomerism; D014231:Tribolium / Q000033:anatomy & histology* / Q000737:chemistry* / Q000378:metabolism
chemical_list: C466020:4,8-dimethyldecanal; D000447:Aldehydes; D010675:Pheromones