Key to species groups and ungrouped species of Sphex Linnaeus, 1758

1. Erect setae medially on propodeal enclosure extremely short (≤ 0.2 mm); fore- and hindwing yellow with fuscous margin, scutellum and propodeal enclosure ferruginous (Fig. 39). Body length greater than 25 mm ......... S. paulinierii Guérin-Méneville, 1843 (subgenus Menkeella subgen. nov.)

– Length of most erect setae medially on propodeal enclosure at least 0.5 mm; color combination different..............................................................................................................................................2

2. Metanotum markedly raised, usually with distinct median impression (Fig. 7). Area between metapleural sulcus and upper spiracular groove concave, with bulge anterior to the spiracular groove (Fig. 9) ........................................................................................ argentatus group (Key A)

– Metanotum not strongly raised, with indistinct impression or not impressed (Fig. 8), or area between metapleural sulcus and upper spiracular groove convex or plane and not bulging (Fig. 10) 1 ......................................................................................................................................................3

1 In several species groups, the metanotum is raised but has very indistinct tubercles and no bulging near the spiracle is present. On the other hand, in the satanas group the bulging is present, but the metanotum is always flat.

3. Erect propodeal setae oriented posteriorly (Fig. 1)........................................................................4

– Erect propodeal setae oriented anteriorly or perpendicularly (Figs 2–4)......................................5

4. Female: appressed setae on face uniformly silvery (Fig. 13) or rich golden. Male: cellular wing area without yellow tinge; sternum VIII posterolaterally concavely emarginate .............................. .................................................................................................................. nigrohirtus group (Key B)

– Female: appressed setae on clypeus at least medially dark brown (Figs 14–18). Male: apical part of sternum VIII semicircular (Fig. 20) or rectangular (Fig. 25), if concavely emarginate then cellular wing area with conspicuous yellow tinge (Fig. 93) ................................ bohemanni group (Key C)

5. Petiole length more than 3 × its medial width; basal half of forewing with yellow tinge and yellowish veins (Fig. 38)....................................................................................................................6

– Petiole much shorter, its length at most 2.8 × its medial width. If longer, then wings without yellow tinge and wing veins dark brown (Fig. 100)........................................................................7

6. Free clypeal margin in both sexes medially with distinct tooth-like process. Male: placoids on flagellomeres IV–VI, covering their entire length. Western Africa ...... S. cinerascens Dahlbom, 1843

– Process at free clypeal margin broad and very short or absent. Male: placoids on flagellomeres V and VI, covering only their basal third. South and central Asia, Arabian Peninsula ...... ................................................................................................................ S. obscurus Fabricius, 1804

7. Erect propodeal setae oriented anteriorly, especially laterally on propodeal enclosure (Fig. 2)....8

– Erect propodeal setae oriented perpendicularly (Figs 3–4)..............................................................9

8. Female: scutellum and metanotum markedly flat (Fig. 5). Male: clypeus uniformly black or at most free margin ferruginous; erect clypeal setae silvery; petiole length less than 3× its medial width ............................................................................................................... satanas group (Key D)

– Female: scutellum and metanotum convex (Fig. 6). Male: clypeus uniformly black or lower third or half ferruginous (Fig. 28); erect clypeal setae silvery, golden or black; petiole length in one species more than 3× its medial width (Fig. 100) ............................... gaullei group (Key E)

9. Metanotum not raised medially, with silvery-golden vestiture (Figs 119–120). Longest erect setae in anterior center of propodeal enclosure at least 0.75 mm. Madagascar and surrounding islands .................................................................................................... malagassus group (Key F)

– Metanotum raised medially, with black vestiture (Figs 3–4). Longest erect setae in anterior half of propodeal enclosure no more than 0.65 mm. Continental Africa............................................10

10. Female: scutellar vestiture coarse and dense (Figs 3–4); usually some erect setae (similar length as the long erect metanotal setae) present near scutellar center; propodeal sculpture discontinuously rugose; outer side of midtibial apex with distinctly curved spine. Male: free clypeal margin medially with distinct tooth-like process (Fig. 27) ..................................... umtalicus group (Key G)

– Female: scutellar vestiture fine and less dense (Fig. 8); scutellar center without any long erect setae like the ones on the metanotum (with long erect setae only being present near posterolateral scutellar margin); propodeal sculpture with fine transverse continuous carinae; spines on outer side of midtibial apex straight. Male: free clypeal margin without tooth-like process (Fig. 28)......11

11. Female: clypeus black except for ferruginous free margin (Fig. 101). Male: appressed facial setae silvery; free clypeal margin largely black, lower clypeal center sometims ferruginous; basal half of mandible black with only a ferruginous stripe medially on mandible (Fig. 28) ............................ ....................................................................................................................... S. decipiens Kohl, 1895

– Female: clypeus completely ferruginous (Figs 36–37). Male: appressed facial setae brassy or golden; free clypeal margin and basal half of mandible largely ferruginous ..... meridionalis group (Key H)