Argentinean Species of Chalarus Walker (Diptera: Pipunculidae): New Records and Description of Chalarus tani n. sp.

The Argentinean species of Chalarus Walker were studied. Pipunculidae adults belonging to four species, C halarus chilensis Collin, Chalarus triramosus Rafael, Chalarus absonus Rafael and Chalarus tani n. sp. were described based on two male specimens collected in the La Rioja and Tucuman Provinces, northwestern region of Argentina. Chalarus absonus is recorded for the first time in Argentina. New distributional data and an identification key to the adult males of the Argentinean representatives are provided including figures.