Characterization of the antennal ultrastructure of Neoeuantha aucta (Wiedmann, 1830) (Diptera, Tachinidae)

Tachinidae is a large family of flies, but studies on its antennal morphology and ultrastructure are still scarce. Thus, the male and female antennae of Neoeuantha aucta (Wiedmann) were studied using scanning electron microscopy. The three antennal segments are densely covered with microtrichia, with postpedicel being the one that carries the greatest diversity of sensilla. In total, eight types of sensillar structures were observed: trichoid, basiconic (three subtypes), coeloconic, chaetic, setiferous plaques, and pedicellar button. The s. trichoid and s. basiconic have a porous wall, indicating a chemoreceptor function. A central pore was found in the pedicellar button, possibly with mechanoreceptor and chemoreceptor function. Another highlight is the numerous sensory pits covered by microtrichia in the postpedicel, housing only one type of sensilla each. Our results were compared with those available for Tachinidae and other families of dipterans, mainly those of Calyptratae, and provide the basis for future investigations in sensory functions related to the behavior of parasitoid flies, as well as for studies of comparative morphology.