title: (2R,7S)-diacetoxytridecane: sex pheromone of the aphidophagous gall midge, Aphidoletes aphidimyza.
abstract: In a recent study, evidence was presented that females of the aphidophagous midge Aphidoletes aphidimyza (Rondi) (Diptera: Cecidomyiidae) release a sex pheromone to attract mates. Our objectives were to identify and bioassay the pheromone. Coupled gas chromatographic-electroantennographic detection(GC-EAD) analyses of untreated and hydrogenated pheromone extract on three fused-silica columns (DB-5, DB-23, DB-210) revealed a single compound that elicited responses from male antennae. Retention index calculations of this candidate pheromone (CP) suggested that it was a di-acetate. Considering that most of the presently identified cecidomyiid pheromones consist of a 13-carbon chain with (at least) one acetate group in C2, we synthesized 2,6-, 2,7-, 2,8-, 2,9-, 2,10-, 2,11-, and 2,12-diacetoxytridecane. In GC analyses of these compounds, only 2,7-diacetoxytridecane cochomatographed with CP on all columns. In laboratory two-choice experiments with stereospecifically synthesized stereoisomers, only (2R,7S)-diacetoxytridecane elicited significant anemotatic responses by male A. aphidimyza. In trapping experiments in greenhouse compartments, only traps baited with (2R,7S)-diacetoxytridecane captured significant numbers of male A. aphidimyza, clearly revealing the absolute configuration of the pheromone. Failure of the stereoisomeric mixture (containing all four stereoisomers including the pheromone) to attract males is due to inhibitory characteristics of the (2R,7R)- and (2S,7R)-stereoisomers. The pheromone of zoophagous A. aphidimyza resembles those from phytophagous cecidomyiid midges, suggesting a common, diet-independent pathway for pheromone biosyntheses.
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6.
authors.forename: Man-Young
authors.initials: MY
authors.lastname: Choi
authors.forename: Grigori
authors.initials: G
authors.lastname: Khaskin
authors.forename: Regine
authors.initials: R
authors.lastname: Gries
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gries
authors.forename: Bernard D
authors.initials: BD
authors.lastname: Roitberg
authors.forename: David A
authors.initials: DA
authors.lastname: Raworth
authors.forename: Doo-Ho
authors.initials: DH
authors.lastname: Kim
authors.forename: Robb G
authors.initials: RG
authors.lastname: Bennett
mesh_terms: D000473:Alkanes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000825:Animal Structures / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002849:Chromatography, Gas; D004175:Diptera / Q000502:physiology*; D005260:Female; D008297:Male; D012724:Sex Attractants / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D012726:Sexual Behavior, Animal; D013237:Stereoisomerism
chemical_list: D000473:Alkanes; D012724:Sex Attractants