Chemical signals sexual identity

Ferrets, Mustek furo, distinguish between anal sac secretions of males and females. Males did not discriminate between the anal gland odors of estrous and anestrous females. Chemical sex differences were found, but no seasonal differences. Males had high concentrations of 2,3-dimethylthietane and/or 3,4-dimethyl-l,2-dithiolane (Fig. 7.6). Most individuals had 2-propylthietane. Clapperton etal. (1988) concluded that the odor of the anal gland provides sexual and territorial signals and cues to individual identity. 

This model has come to dominate our understanding of chemical communication in Diptera, in particular those signals involved in courtship and mating. In fact, most dipteran species do not fit the Musca model. Although some species, like houseflies, show a marked qualitative sexual dimorphism, many species express only quantitative variation for compounds shared by both sexes (Bartelt et al., 1986 Jallon and David, 1987 Toolson and Kuper-Simbron, 1989 Byrne et al., 1995), while in other species adults of both sexes appear to be virtually identical (Stoffolano et al., 1997 Howard et al., 2003). Furthermore, there are relatively few examples of the kind of rigorous demonstration of a pheromonal role for CHCs that was established in Musca (e.g. Carlson et al., 1984 Adams and Holt, 1987 Ferveur and Sureau, 1996 Lacaille et al., 2007). 

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