The wings are equal in length to the body or slightly longer. Wings have the lower calypter much reduced or absent. The chaetotaxy is well developed, especially on the head. The postvertical orbital bristles on the head are always present and divergent, inner and outer vertical bristles on the head are well developed. They have ocellar bristles, frontal bristles (two to eight pairs of frontal bristles, the lower one to three pairs curve inward, the other pairs backward), vibrissae (in some cases weakly developed), and oral bristles are always present. Interfrontal bristles are absent, but interfrontal setulae are sometimes present. The basal segment of the antennae is very short; the second antennal segment is not grooved. The third antennal segment is always large, usually round (not elongated but sometimes with a sharp point) and usually with swollen, and the almost bare or pubescent arista never is plumose. The face in lateral view is not deeply excavated between the antennae and the edge of the mouth. The ptilinal suture is clearly defined. The mouthparts are functional. The proboscis is usually short and thick, rarely elongated and geniculated ("Ophiomyia"). The maxillary palps are single-segmented and porrect. The thorax is without a continuous dorsal suture and without well-defined posterior calli. The thorax has well-developed dorsocentral bristles, posterior bristles, supra-alar bristles, and acrostichal and intra-alar bristles. The scutellum has two to four bristles. On each side of the thorax is a humeral bristle and one or two notopleural bristles.