Identification of female-produced sex pheromone of the honey locust gall midge, Dasineura gleditchiae.
The honey locust gall midge, Dasineura gleditchiae Osten Sacken 1866 (Diptera: Cecidomyiidae) is the main pest of ornamental varieties of the honey locust tree, Gleditsia triacanthos L., in North America, and is now becoming a pest of concern in Europe. Female midges were observed to emerge in the early morning with their ovipositor extended until they mated. Volatiles were collected from virgin females in a closed-loop stripping apparatus and analyzed by gas chromatography (GC) coupled to electroantennographic (EAG) recording from the antenna of a male midge. A single EAG response was observed, which was assumed to be to the major component of the female sex pheromone. This was identified as (Z)-2-acetoxy-8-heptadecene by comparison of its mass spectrum and GC retention times on different columns with those of synthetic standards and by micro-analytical reactions. This compound was synthesized, and the individual enantiomers were produced by kinetic resolution with lipase from Candida antarctica. Analysis of the naturally-produced compound on a cyclodextrin GC column indicated it was the (R)-enantiomer. In EAG dose-response measurements, the (R)-enantiomer alone or in the racemic mixture evoked significant responses from the antennae of male D. gleditchiae, whereas the (S)-enantiomer did not. In field trapping tests, the (R)-enantiomer attracted male D. gleditchiae. The racemic compound was equally attractive, but the (S)-enantiomer was not attractive. Both the pure (R)-enantiomer or racemic (Z)-2-acetoxy-8-heptadecene, applied to red rubber septa in a dose range of 3-30 microg, constitute a strongly attractive bait in sticky traps for monitoring the flight of D. gleditchiae.
Molnár
Béla
B
Plant Protection Institute, Hungarian Academy of Sciences, H-1525, Budapest, P.O. Box 102, Hungary.
Kárpáti
Zsolt
Z
Szocs
Gábor
G
Hall
David R
DR
D000475:Alkenes / Q000032:analysis; D000818:Animals; D004175:Diptera / Q000502:physiology*; D004594:Electrophysiology; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D008297:Male; D012724:Sex Attractants / Q000737:chemistry*; D012726:Sexual Behavior, Animal; D013237:Stereoisomerism
C473093:8-heptadecene; D000475:Alkenes; D012724:Sex Attractants