1. Metasomal segment four, five or six the largest, when viewed laterally (a & b), with two to four small segments preceding largest segment. Rarely collected …2

- Metasomal segment two or three the largest, when viewed laterally (A), or fused into a syntergum (B), with at most only one small segment preceding the largest. Commonly collected …3

2. Metasoma, when viewed dorsally, extremely thin, blade-like (a); radial cell of forewing at least nine times as long as broad, closed on front margin (b). Large wasps, exceeding 2 cm in overall length (extra-limital family – one introduced species Ibalia leucospoides in South Africa) …IBALIIDAE

- Metasoma, when viewed dorsally, evenly rounded on both sides, often rather stout (A); radial cell of forewing less than nine times as long as broad (B). Small to large wasps, ranging from 2 mm to 1.75 cm ...LIOPTERIDAE

3. Pronotal plate present, often projecting forward, with distinct ventro-lateral margins (a, b). Mesoscutum usually smooth (at least dorsally) (b), occasionally microcoriaceous; may be longitudinal carinate (c). Mesopleuron usually smooth (d), often with a single longitudinal carina (d). Scutellum frequently with distinct central plate (a, d), and/or posteriorly directed spine (c, d) ...FIGITIDAE

- Pronotal plate absent or reduced, ventro-lateral margins not visible (A). Mesoscutum horizontally striate (A) or coriaceous (B). Mesopleuron distinctly striate to rugose, lacking a distinct longitudinal groove (B). Scutellum never with a cnetral plate or an apical spine (A) …CYNIPIDAE