Identification of volatile compounds from fungus‐infected date fruit that stimulate upwind flight in female Ectomyelois ceratoniae

Four volatile compounds emitted from fungus‐infected date fruit, Phoenix dactylifera L., were identified using coupled gas chromatographic‐electroantennographic recordings, coupled gas chromatographic‐mass spectrometric analysis, electroantennographic assays of synthetic standards, and wind tunnel bioassays. These compounds were ethyl hexanoate, ethanol, acetaldehyde, and 2‐phenylethanol. Wind tunnel bioassays showed that ethyl hexanoate was capable of stimulating upwind flight and landing on the source by mated female carob moths, Ectomyelois ceratoniae (Zeller). Addition of both ethanol and acetaldehyde to ethyl hexanoate resulted in an increase in attraction to a level similar to that found for date fruits. No such effect was noted for additions of 2‐phenylethanol at the dosages tested. In this study, it appears that ethyl hexanoate is a dominant olfactory stimulant and attractant for mated female carob moths, and represents a novel compound with regard to previously identified lepidopteran host odor attractants. 1994 The Netherlands Entomological Society