The olfactory system of the sphinx moth Manduca sexta bears many similarities to its vertebrate counterpart in functional organization, physiology and development. In the moth, the antenna (the olfactory organ) and the antennal lobe (the primary olfactory center) of the brain arise during postembryonic metamorphic development and are accessible, independently manipulable, and structurally relatively simple. In addition, they house a conspicuous, sexually dimorphic subsystem specialized for detection of a specific pheromonal odor. These features make this system experimentally favorable for studies of development of olfactory glomeruli. Such studies have demonstrated the importance of regulatory interactions among sensory axons, glial cells and antennal-lobe neurons.