Structure, distribution and number of surface sensilla and their receptor cells on the olfactory appendage of the male moth Manduca sexta

摘要: Distribution and neuronal organization of sensilla on the surface annulate flagellar segment antenna maleManduca sexta were studied by scanning transmission electron microscopy. Nine types identified their bipolar neurons ascribed to specific sensory modalities basis cuticular dendritic morphology. Cuticle morphology identifies two trichodea, basiconica one type sensillum coeloconicum. Certain these olfactory are further subdivided structures. One chaeticum was interpreted as a contact chemoreceptor. A second coeloconicum styliform complex bimodal hygro- thermosensilla. species serves mechanosensation. Counts from annuli situated about midway along flagellum revealed total 2200 supplied approximately 5160 neurons. conservative estimate suggests that male with 85–90 provides nerve at least 3.6 × 105 receptor axons, number exceeds previous estimates almost 50% Each has characteristic location annulus. Of 2100 or so dorsal, ventral leading edge surfaces, 800 consist male-specific type-I trichoids containing pheromone-sensitive receptors. Arciform arrays upper lower surfaces each annulus presumably optimize capture absorbtion odour molecules. The trailing flagellum, which is thickly covered scales assumed until now lack receptors, contains both mechanosensitive chemoreceptors. modality non-olfactory receptors considered respect similar elements have been functionally in other species. coexistence discussed current knowledge centres brain.