Identification of Female-produced Sex Pheromone of the Honey Locust Gall Midge, Dasineura gleditchiae

Abstract

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.

The Chemical Ecology of Cecidomyiid Midges (Diptera: Cecidomyiidae)

“…The effect of lure loading, and hence release rate, on the attractiveness of lures in the field varies with species. With D. gleditchiae (Table 1, entry 4), there was no difference in catches of male midges with lures loaded with 1-30 μg (Molnár et al, 2009). With several species, increasing pheromone loading increased catches of males over the range tested, as with D. mali over the range 300 ng-30 mg (Suckling et al, 2007) (Fig.…”

“…Specially designed Plexiglas holders have been used for the antennal preparation (Hillbur et al, 2001(Hillbur et al, , 2005Andersson et al, 2009a), while Gries et al (2002) used a severed head and antenna suspended between two glass electrodes. Male midges generally have long antennae relative to their bodies, and EAD preparations can be made by inserting a body into the glass reference electrode, after first removing wings and head, and then inserting one or both antennae into the recording electrode (Birkett et al, 2004;Amarawardana, 2009;Hall et al, 2009;Molnár et al, 2009).…”

“…These were separated by silica gel chromatography to give the S-butyrate with 99.8% ee and the alcohol, which, after acylation, gave the Rbutyrate, with 99.1% ee. The latter is the sex pheromone of the honey locust gall midge, D. gleditchiae (Molnár et al, 2009). Successive hydrolysis and acetylation with this enzyme also were used to produce all three diastereomers of 2,6-diacetoxyheptane, the major pheromone component of O. oryzae (Hall et al, unpublished).…”

(2S,8Z)-2-Butyroxy-8-heptadecene: Major Component of the Sex Pheromone of Chrysanthemum Gall Midge, Rhopalomyia longicauda

“…The backbone has an odd number of carbon atoms with an oxygenated functionality in the 2-position ). The opposite enantiomer of the corresponding acetate, (2R,8Z)-2-acetoxy-8-heptadecene, is the pheromone of the honey locust gall midge, Dasineura gleditchiae (Molnár et al 2009), and (Z)-13-acetoxy-8-heptadecen-2-one is the pheromone of the apple leaf curling midge, D. mali (Cross and Hall 2005;Suckling et al 2007;). The butyrate ester functionality has also been found in the sex pheromone component, (2S,7S)-2,7-dibutyroxynonane, of the orange wheat blossom midge, Sitodiplosis mosellana (Gries et al 2000).…”

Synthesis of (1R,7Z)-1-Methyl-7-hexadecenyl Acetate, the Female Sex Pheromone of the Honey Locust Gall Midge

“…In order to monitor the flight of the midge by means of pheromone-based trapping, Sz} o ocs and coworkers identified the female-emitted sex pheromone of D. gleditchiae as (1R,7Z)-1-methyl-7-hexadecenyl acetate (1) in 2009. 4) The R absolute configuration at C-1 of 1 was determined by synthesis and bioassay of the enantiomers of 1.…”