Evidence for a compound in Comstock-Kellog glands modulating premating behavior in male desert locust, Schistocerca gregaria.

The Comstock-Kellog glands in adult females of certain acridid species, including the desert locust, Schistocerca gregaria have been implicated as a source of volatiles that play a role in mating behavior. A dichloromethane extract of the glands was analyzed for metabolites by gas chromatography, coupled gas chromatography-electroantennographic detection, and mass spectrometry. Coupled gas chromatography-electroantennographic detector (GC-EAD) analysis revealed a component that elicited an electroantennogram response from the antenna of adult male S. gregaria. The compound was identified by GC-MS as pentanoic acid. The levels of the compound in the gland extract varied with age of female locust; it was present in detectable amounts only in 14- to 16-day-old females. In bioassays, pentanoic acid significantly stimulated pre-mating behavior in male desert locust. These results are discussed in relation to the biology of the locust.