BackgroundThe genus Evandromyia is widely found in Brazil, but occurs mainly in Brazilian savannah. To date 13 species have been described in the subgenus Aldamyia. Here we described a new species of Evandromyia (Aldamyia) collected in the State of Mato Grosso do Sul, Brazil.MethodsMeasurements were made using a micrometer eyepiece on an Olympus CH-2 binocular microscope and drawings were executed with the aid of a camera lucida.ResultsThe new species, Evandromyia orcyi sp. nov., is closely related to Evandromyia lenti, Evandromyia carmelinoi and Evandromyia evandroi, however, characteristics of the male terminalia and female spermathecae distinguish it from other species of the genus Evandromyia.ConclusionWith the description of Evandromyia orcyi sp. nov., six species of the subgenus Aldamyia have been reported from the State of Mato Grosso do Sul.