Identification of a female-specific, antennally active volatile compound of the currant stem girdler

We identified (Z)-9-octadecen-4-olide as a female-specific, antennally acti ve compound from the currant stem girdler Janus integer Norton. Female spec ificity was demonstrated by gas chromatographic comparison of liquid chroma tography fractions of male and female volatile emissions and whole body ext racts. The gamma -lactone was identified by coupled gas chromatographic-ele ctroantennographic detection (GC-EAD), coupled gas chromatographic-mass spe ctrometric (GC-MS) analysis, microchemical reactions, and GC and MS compari son with authentic standards, GC-EAD analysis of female volatile emissions and cuticular extracts showed a single peak of activity on male antennae, w hich was not present in male-derived materials. Female antennae did not res pond to any of the tested materials. The hydrogenation product of the natur al EAD-active material was a known saturated gamma -lactone. The mass spect rum of the dimethyl disulfide derivative of the natural gamma -lactone was consistent with a double bond present in the 9 position. Comparison of the natural gamma -lactone and a synthesized racemic mixture of (Z)-9-octadecen -4-olide on a chiral GC column showed the presence of a single enantiomer i n the natural material.