title: (6Z,9Z-3R,4S)-Epoxy-heptadecadiene: major sex pheromone component of the larch looper,Semiothisa sexmaculata (Packard) (Lepidoptera: Geometridae).
abstract: Gas chromatographic-electroantennographic analysis (GC-EAD) of female larch looper,Semiothisa sexmaculata (Packard), gland extracts revealed two EAD-active compounds. Retention index calculations, GC-mass spectroscopy in selected ion monitoring mode, and GC-EAD analysis of authentic standards identified the compounds as (3Z,6Z,9Z)-heptadecatriene (3Z,6Z,9Z-17∶H) and (6Z,9Z)-cis-3,4-epoxy-heptadecadiene (6Z,9Z-cis-3,4-epoxy-17∶H). Chirality determination of the monoepoxydiene in gland extracts was impeded by small quantities, but field experiments indicated that maleS. sexmaculata were most strongly attracted to enantiomerically enriched 6Z,9Z-3R,4S-epoxy-17∶H (69% ee), while maleS. neptaria (Guenée) responded well to various blends of theR,S- and S,R-epoxide enantiomers. Binary combinations of theR,S-epoxide enantiomer with 3Z,6Z,9Z-17∶H significantly inhibited response by maleS. sexmaculata, but strongly enhanced attraction of sympatric maleS. marmorata Ferguson. Enantiomerically enriched 6Z,9Z-3R,4S-epoxy-17∶H can be used as a trap bait to monitor populations of the larch-defoliatingS. sexmaculata. Whether 6Z,9Z-3R,4S-epoxy-17∶H serves as single component sex pheromone inS. sexmaculata or small amounts of 6Z,9Z-3S,4R-epoxy-17∶H synergize or suppress optimal attraction, will be tested as chirally pure monoepoxydienes become available.
authors.affiliation: Centre for Pest Management Department of Biological Sciences, Simon Fraser University, V5A 1S6, Burnaby, British Columbia, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Gries
authors.forename: R
authors.initials: R
authors.lastname: Gries
authors.forename: E W
authors.initials: EW
authors.lastname: Underhill
authors.forename: L
authors.initials: L
authors.lastname: Humble