Fore wing with submarginal vein (SMV) with 3 or more setae dorsally. Postmarginal vein (PMV) present: at most 1.25 times longer than stigmal vein, often equal or shorter.
Scape slender and not exceeding apex of vertex. Club 3-segmented. Funicle 2-segmented in both sexes with usually 1-2 anelli.
Fronto-facial suture adjacent anterior ocellus; usually also a transverse short groove from eye margin to scrobal cavity about halfway between ocellus and torulus. Malar sulcus present and straight. In species of Cirrospilus " sensu strictu" the vertex is not vaulted: i.e. extends less than 1/3 of eye length above the eye. However, in the Cirrospilus "variegatus group" the vertex is vaulted: i.e. extends more than 1/3 of eye length above the eye.
Notauli almost always complete to posterior margin of mesoscutum (however, the one Southeast Asian species included in this key, C. ambiguus, is the only species with notauli not reaching posterior margin of mesoscutum, but curving and extending to anterior margin of axilla).Propleura separated posteriorly and not covering prosternum. Scutellum with 2 pair of setae and with 1 pair of longitudinal grooves, although these may be sometimes faint and difficult to see. Propodeum usually with median carina, with or without plicae (plc). Petiole not distinct. Gaster with cercal setae short and subequal in length.
Coloration variable, from dark to metallic to non-metallic and yellow.