A Revision of the rhopalocerus Species Group of Bembecinus Costa (Hymenoptera: Crabronidae: Bembicinae) Author Gess, Friedrich W. Albany Museum and Rhodes University, Grahamstown, 6139 South Africa Author Pulawski, Wojciech J. California Academy of Sciences, San Francisco, California 94118, USA, wpulawski @ calacademy. org Author Gess, Sarah K. Albany Museum and Rhodes University, Grahamstown, 6139 South Africa, s. gess @ ru. ac. za text Proceedings of the California Academy of Sciences 2015 2015-04-15 62 7 207 256 journal article 299711 10.5281/zenodo.11512316 b5962602-3138-42ad-8b1a-e0e483d0c267 0068-547X 11512316 Bembecinus namaquensis Pulawski , sp. nov. Figures 4c , 14a, b. NAME DERIVATION .— The name, namaquensis , a newly coined Neolatin adjective, is derived from the Nama people of South Africa, Namibia and Botswana , and also from Namaqualand of South Africa , where the holotype was collected. RECOGNITION .— Bembecinus namaquensis has a ferruginous gaster (basal terga black basally), without pale yellow apical fasciae, a character shared with mutabilis .The female is unknown, but the male differs from mutabilis in having the apical flagellomere simple (not curved and not emarginate), and from gariepensis and rhopaloceroides in lacking yellow, apical fasciae on the terga and in having the foretibia not incrassate (incrassate in the lateral view in the other two species). DESCRIPTION .— Head black, with the following yellow: mandible except apex, labrum, clypeus, face below antenna and narrowly up to level of midocellus along orbit, gena narrowly along orbit, both pairs of palpi, scape and pedicel ventrally (black dorsally), flagellum ventrally (almost black dorsally). Thorax black with the following yellow: pronotal collar, pronotal side and ventral part of right pronotal lobe, narrow adlateral streak on scutum, tegula, triangular lateral spot on scutellum, posterior half of metanotum, and small spot on mesopleuron (spot size less than midocellus). Propodeum black, with posterolateral margin yellow mesally. Gaster ferruginous, tergum I black in about basal half, black area widened mesally; terga II and III with narrow basal band. Legs yellow, with the following black: coxae posteriorly, foretrochanter dorsally and posteriorly, mid- and hindtrochanters dorsally, mid- and hindfemora dorsally. Wings hyaline, vein Sc+R black, other veins brown. FIGURE 14. Bembecinus namaquensis : a – male labrum, b – tergum VII of male. ♂ : Length 11.8 mm . Ocular index 2.1. Minimum interocular distance equal to 2.1 × that between antennal scrobe and base of clypeus. Distance between posterior ocelli 1.8 × distance between posterior ocellus and eye margin. Width of clypeus at insertion of mandibles 1.6 × its midline, its apical area flattened, asetose. Labrum roundly triangular ( Fig. 14a ), its greatest width 1.25 × its midlength. Apical flagellomere simple. Tergum VII rounded, shallowly emarginate apically ( Fig. 14b ). MATERIAL EXAMINED .— HOLOTYPE : ♂ , SOUTH AFRICA : Northern Cape Province : 23 km S Alexander Bay at 28°46′S 16°37′E , 11.x.2000 , F.W. and S.K. Gess ( AMGS ) . PARATYPES : SOUTH AFRICA : Northern Cape Province : Richtersveld W Brandkaros at 28°29′S 16°40′E , 15.ix.1996 , F.W. Gess , S.K. Gess , and R.W. Gess ( 1 ♂ , AMGS ; 1 ♂ , CAS ) . GEOGRAPHICAL DISTRIBUTION .— Known from two localities in the arid Succulent Karoo of northwestern South Africa ( Fig. 25c ). SNAIL SHELL ASSOCIATION .— The two specimens from Brandkaros were collected from empty shells of the snail Trigonephrus sp. , Dorcasiidae , in which they were found sheltering. In windswept desertic areas snail shells provide shelter for various species of aculeates. Furthermore, some species use shells, sand-filled or empty, as secure nesting sites (F. Gess and S. Gess 1999 ; S. Gess and F. Gess 2008 ). FLORAL ASSOCIATIONS .— Unknown. NESTING .— Unknown. PREY .— Unknown.