The First Record of the Genus Dichaeta Meigen (Diptera: Ephydridae) from Korea

The genus Dichaeta Megen is a small group of acalyptratae flies belonging to the subfamily Notiphilinae in the family Ephydridae. Up to now, six species are recorded only in the Northern Hemisphere. Adults are small flies and typically found in the sedge and grass around lentic and lotic aquatic systems, and larvae feed on saprophytic microorganisms. Adults are readily recognized with the following peculiar morphology of the male abdomen: fourth abdominal tegite with some markedly long setae along its posterior margin, and these setae sometimes extend beyond the length of the posterior apex of the abdomen; modified fifth abdominal tergite produced posteriorly, either forming a slender and elongated tube with two to three larger and elongated terminal setae. This genus is recorded for the first time in the Korean fauna based on the discovery of a nominated species, Dichaeta caudata (Fallén, 1813). Diagnoses and figures about the firstly recorded species are provided herein.