The antennae are three-segmented and aristate; vein Rs is two-branched, a frontal suture is present, and the calypters are well developed. The arista is often plumose for the entire length. The hypopleuron is usually without bristles; generally, more than one sternopleural bristle is present. The R5 cell is either parallel-sided or narrowed distally. Vein 2A is short and does not reach the wing margin.
