Morphology of the antenna of Dermatobia hominis (Diptera: Cuterebridae) based on scanning electron microscopy.

Sensilla of the antennae of male and female Dermatobia hominis were studied by scanning electron microscopy. The images obtained were interpreted according to the scientific literature referring to the sensory structures of insects. Sensilla of the "long bristle" type and smaller spines of the "microtrichia" type were found in different numbers and patterns of distribution on the scape and pedicel. Coeloconic sensilla with longitudinal cuticular furrows were observed on the female flagellum, as well as two varieties of basiconic sensilla: a large one surrounded by pointed foliaceous structures and a smaller form implanted on a raised cuticular process. The larger type of basiconic sensilla was also observed on the flagellum of the male antenna, as well as a variety of coeloconic sensilla with apical dilatations. Trichoid and chaetic sensilla were encountered in greater numbers on the arista of females, with the former type predominating. Coeloconic sensilla were observed on the arista of both sexes, as well as sensilla of the "long bristle" and styloconic types exclusively in males. Adult D. hominis were observed to possess sensory structures with chemoreceptory, thermo-hygroreceptory and mechanoreceptory functions on their antennae. These results could facilitate the identification of the chemoreceptors by electrophysiological techniques. The sexual dimorphism noted for the antennae constitutes a new criterion for distinguishing between the sexes of D. hominis