Key B: Species of the Sphex nigrohirtus group

1. Propodeal setae golden or silvery-golden, obscuring sculpture completely .................................... .................................................................................................................. S. ahasverus Kohl, 1890

– Propodeal setae black or silvery-white, leaving sculpture partially visible.................................2

2. Female: body length> 28 mm; mandible black with only small dark ferruginous stripe centrally; conspicuous clypeal indentation. Male: flagellomeres IV–VII with broad placoids covering their entire length; apical part of penis valvae dorsolaterally with concave emargination (Figs 79–80) .............................................................................................................. S. camerunicus Strand, 1916

– Female: body length <28 mm; basal half of mandible bright ferruginous; smaller clypeal indentation. Male: flagellomere V or VI with narrow placoid; apical part of penis valvae dorsolaterally flat or convex (Figs 81–82)...........................................................................................3

3. Significant portion of erect setae on inner part of propodeal enclosure silvery (Fig. 85). Male: cellular wing area partially hyaline, with pale violet iridescence ..................................................... ........................................................................................................... S. incomptus Gerstaecker, 1871

– Erect setae on propodeal enclosure black, silvery near posterior margin at most (Fig. 86). Male: cellular wing area uniformly slightly fuscous, with conspicuous purple (Fig. 87) or cyan-violet iridescence..........................................................................................................................................4

4. Wings with cyan iridescence. Female: appressed setae posterolaterally on collar and propodeum and erect setae on posterior propodeal margin uniformly black (Fig. 84) .......................................... .................................................................................................................... S. nigrohirtus Kohl, 1895

– Wings without any cyan iridescence. Female: appressed setae posterolaterally on collar and propodeum and erect setae on posterior propodeal margin silvery (Fig. 86). Male: iridescence on forewing Byzantium-colored (Fig. 87) .................................................... S. pulawskii sp. nov.