Volatile neutral compounds emanating from laboratory-reared colonies of the desert locust, Schistocerca gregaria

Abstract

An air-entrainment apparatus for the isolation of volatile compounds emanating from an insect colony is described. A simple technique for the identification of neutral volatiles dissolved in a relatively large amount of water has been developed: in a conventional headspace analysis of the aqueous solution, support-coated open tubular columns are used in coupled gas-liquid chromatography-mass spectrometry to separate the minor volatile constituents from the water vapour which would otherwise mask their identification in the mass spectrometer. Acetone, methyl acetate and ethyl acetate were found to be associated with colonies of mature male and female Schistocerca gregaria reared in a normal laboratory environment. No volatiles, other than respiratory water and carbon dioxide, were produced by freshly ecdysed immature S. gregaria, or by mature laboratory-reared males in which the anus and genital aperture had been sealed. No neutral organic volatiles were produced by colonies of mature males reared in a controlled environment.