© DIANNA SARTO/CORBIS
Following a trail of smell, a male fruit fly zeroes in on a banana peel. For the fly, the banana is not only a fantastic food source, but also fertile ground for finding mates. Sure enough, a virgin female is already feasting on the banana peel. He approaches her, taps her with his forelegs, and flutters his wings to sound a staccato love song, all in the hopes of securing her as a mate. But there is more to this scene than meets the eye or ear. The success of this courtship ritual critically depends on a single substance: an organic ester, 11-cis-vaccenyl acetate (cVA). CVA is found on the male’s cuticle, or exoskeleton, and in his ejaculatory bulb, a structure similar in anatomy and ...
