For terms see Morphology of Diptera The antennae have 2–6 segments. The first segment is well developed and the terminal segment annulated. The porrect maxillary palps have 1 or 2 segments. The wings have a discal cell, no sub-apical cell and the relatively long anal cell is closed.The fourth posterior cell is closed. The costa extends around the entire wing. Wing vein 3 is distally forked. The fork of wing vein 3 is narrow, and its lower branch reaches the wing margin near the apex.