The chemical ecology of the fly.

Not only is the sense of smell of pivotal importance to most animals but also serves as a significant model system in biological research. In recent years, great strides in our understanding of how the olfactory system is organized and operates have been made. Instrumental in these efforts has been work performed in Drosophila melanogaster. In spite of the wealth of information gathered, it remains unclear how the fly's olfactory system is used to decode the chemical environment. Here we describe recent findings on the chemical ecology of the fly and speculate on possible functions of the volatile chemicals that flies detect. We argue that for many of the fly's olfactory chemoreceptors, distinct and ecologically relevant functions can be identified.