Ultrastructure of the Antennae and Sensilla of Nyssomyia intermedia (Diptera: Psychodidae), Vector of American Cutaneous Leishmaniasis

Abstract

The antennal sensilla and the antenna of females Nyssomyia intermedia, one of the main vectors of American cutaneous leishmaniasis, were studied by scanning electron microscopy. The main goal was to characterize the quantity, typology, and topography of the sensilla with particular attention to the olfactory types. The insects were captured in the city of Corte de Pedra, State of Bahia, Brazil, by CDC-type light traps and raised in a laboratory as a new colony. Fourteen well-differentiated sensilla were identified, among six cuticular types: trichoidea, campaniformia, squamiformia, basiconica, chaetica, and coeloconica. Of these, six sensilla were classified as olfactory sensilla due to their specific morphological features. Smaller noninnervated pilosities of microtrichiae type were also evidenced by covering all antennal segments. The antennal segments differ in shapes and sizes, and the amount and distribution of types and subtypes of sensilla. This study may foment future taxonomic and phylogenetic analysis for a better evolutionary understanding of the sand flies. Besides, it may assist the targeting of future electrophysiological studies by Single Sensillum Recording, and aim to develop alternative measures of monitoring and control of this vector.

Keywords: Phlebotominae; sand fly; scanning electron microscopy; sense organs; sensillary typology.