Syrphidae

Small to large, very slender to robust flies, 4-25 mm long. Body usually black, very often with yellow or orange markings on head and thorax and particularly on abdomen, more rarely predominantly brown, yellow, metallic green, or blue, or with various combinations of these or other colors. Integument usually smooth but sometimes partly or totally punctate, sculptured, or rugose, usually nearly covered with dense short hairs, rarely with long hairs or nearly bare; some hairs sometimes flattened or scale-like and forming dense tomentum, or on thorax strong and bristle-like; both haired and bare portions shining, slightly to densely pruinose or with very short dense pile. Wing with C ending at apex or R4+5; an unattached longitudinal vein (spurious vein) present, running most of length of cells br and r4+5; apex of M bent strongly forward near wing margin to end in R4+5 and forming apical crossvein; cell cup closed near wing margin. Many species excellent mimics of aculeate Hymenoptera. (Vockeroth & Thompson 1987, Thompson & Rotheray 1998)