|James, David - WA STATE UNIV,PROSSER, WA|
Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 12, 2001
Publication Date: September 1, 2001
Citation: COSSE, A.A., BARTELT, R.J., JAMES, D.G., PETROSKI, R.J. IDENTIFICATION OF A FEMALE-SPECIFIC, ANTENNALLY ACTIVE VOLATILE COMPOUND OF THE CURRANT STEM GIRDLER. JOURNAL OF CHEMICAL ECOLOGY. 2001. v. 27(9). p. 1841-1853. Interpretive Summary: Research was conducted to identify the pheromone of the North American red currant stem girdler, Janus integer. A pheromone is a species-specific natural chemical or blends of natural chemicals that insects emit to attract others of their own species. In the spring, egg laying female sawflies can make numerous punctures in canes of the red currant resulting in drooping and wilting of new shoots. Further damage occurs as emerging larvae tunnel within the canes. This insect also attacks poplar and willow trees, and damage to currants usually is more severe near stands of these trees. In this research, we were able to demonstrate that female sawflies communicate with males by releasing a female specific chemical, and additional chemical analyses yielded the chemical structure of this unique compound. This study has defined a chemical that is important in the sexual communication of J. integer sawfly, and this information is expected to facilitate the development of an environmentally friendly method to control this agricultural pest.
Technical Abstract: We have identified (Z)-9-octadecen-4-olide as a female-specific, antennally active compound from the sawfly Janus integer Norton. Female specificity was demonstrated by gas chromatographic comparison of liquid chromatography fractions of male and female volatile emissions and cuticular extracts. The gamma-lactone was identified by coupled gas chromatographic-electroantennographic detection (GC-EAD), coupled gas chromatographic-mass spectrometric (GC-MS) analysis, microchemical reactions, and GC and MS comparison with authentic standards. GC-EAD analysis of female volatile emissions and cuticular extracts showed a single peak of activity on male antennae, which was not present in male- derived materials. Female antennae did not respond to any of the tested materials. The hydrogenation product of the natural EAD- active material was a known saturated gamma-lactone. The mass spectrum 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 in the natural material.