The wild species Rhodnius brethesi (Matta, 1919) (Hemiptera: Reduviidae) is found in areas of piassabais in microregion of Rio Negro, Amazonas, Brazil. Its geographical distribution overlaps the areas of Leopoldinia piassaba palm. In areas where palm trees are found, transmission cycle of Trypanosoma cruzi is related to the extractive activity of the palm fiber, exposing workers to wild vector transmission of this parasite. The close association with the palm tree L. piassaba suggests that this wild triatomine has special features in its sensory system allowing specificity of ecotope. The objective of the study is to identify the antennal sensilla phenotype and morphologically characterize the size and shape of the wings of wild R. brethesi, and to compare with the phenotype present in individuals reared in the laboratory. From the samples taken in the field, the presence of the species R. brethesi was found on both banks of the Rio Negro. The techniques used to verify the morphological patterns are important resources for observations of the triatomine populations, be they in an artificial or natural habitat.