Bembecinus rhopalocerus (Handlirsch)

Gess, Friedrich W., Pulawski, Wojciech J. & Gess, Sarah K., 2015, A Revision of the rhopalocerus Species Group of Bembecinus Costa (Hymenoptera: Crabronidae: Bembicinae), Proceedings of the California Academy of Sciences 62 (7), pp. 207-256 : 240-242

Bembecinus rhopalocerus (Handlirsch)

Figures 5c , 20 a-c, 21.

Stizus rhopalocerus Handlirsch, 1895:986 , Pl. 11, Figs 4 and 7 , ♀. Holotype: ♀, South Africa: Cape Colony = Cape Province: no specific locality ( MHNG), examined by W. Pulawski.— Dalla Torre, 1897:529 (in catalog of world Sphecidae ); Brauns, 1911:92 (sleeping aggregations on Datura ); Arnold, 1929:293, Figs 46, 46 a-d, ♀, ♂, Cape Province [Eastern Cape], Willowmore (in revision of southern African Sphecidae ).— As Bembecinus rhopalocerus (Handlirsch) : Evans, 1966:135 (new combination, observations by Brauns, 1911); R. Bohart and Menke, 1976:532 (new combination, in checklist of world Sphecidae ); S. Gess, 1996:281 (floral records); S. Gess and F. Gess 2003:117 (floral records), 2014:210 (nest situation),214 (prey); Pulawski, 2014:33 (in catalog of world Sphecidae sensu lato).

RECOGNITION.— Bembecinus rhopalocerus has the clypeus roundly angulate basally (best seen in profile ( Fig. 20a ), whereas it is evenly arcuate in the other species except the female of B. hyperocrus . The female has the forefemur unusually broadened ventrally, whereas the dorsal margin is straight or nearly so ( Fig. 20b ). The female of B. damarensis is similar, but has the clypeus evenly arcuate in profile, the ventral broadening of the forefemur less prominent, and the dorsal margin slightly concave ( Fig. 6a ). The male of B. rhopalocerus has the apical flagellomere straight (neither curved nor emarginate), the setae appressed on tergum II, and the gastral terga yellow and black (except for some ferruginous on tergum I). Unlike gilvus , it has a row of erect setae between the mandibular base and the occipital carina. It is similar to B. quadristrigatus and B. somalicus , but differs, in addition to the shape of the clypeus, in having tergum VII broadly rounded apically (less so in the other two species) and the scutum all black mesally (with a pair of admedian yellow stripes in the other two).

MATERIAL EXAMINED.— NAMIBIA:! Karas Region: Aus, 8–30.xi.1929, R.E. Turner (3 ♀, 2 ♂, SAMC ex NMZB, 6 ♀, 6 ♂, BMNH); Aus, xii.1929, R.E. Turner (1 ♂, BMNH); Keetmanshoop , 15.xii.1974, H. Empey (1 ♀, AMGS); 30 miles [48.28 km] SE Keetmanshoop, 23.x.1968, J.G. Rozen and E. Martinez (1 ♀, AMNH). No specific locality: no date, as S.W. Africa, R.E. Turner (1 ♂, UCDC). SOUTH AFRICA: North West Province : Constable, xii.1962, SAM [staff] (1 ♀, SAMC) . Northern Cape Province: Namaqualand, Hester Malan [now Goegap] Nature Reserve, 4.xi.1986, M. Struck (1 ♂, AMGS); Upington, 10–12.x.1966 , SAM [F.W. and W.H.R. Gess] (33 ♂, SAMC) ; Doorn River Falls, xi.1931, A. Mackie (1 ♂, BMNH); Doringbos at 31°59′S 19°14′E, 17.xi.1984 , C.D. Eardley (1 ♀, PPRI); Britstown, 28.xii.1970 , H. and M. Townes (1 ♀, AEI). Western Cape Province : 17.5 km from Clanwilliam on road 363 to Klawer, 9.x.1990, F.W. and S.K. Gess, on flowers of Athanasia trifurcata (Linnaeus) Linnaeus , Asteraceae (1 ♂, AMGS); 31.5 km from Clanwilliam on road to Klawer, 9–10.x.1990, F.W. and S.K. Gess, on flowers of Athanasia trifurcata (Linnaeus) (2 ♂, AMGS); 24 km NE Clanwilliam, 14.xi.1996, M.A.Metz (1 ♀, CAS); 38 km NE Clanwilliam , 12.xi.1996, M.A. Metz (1 ♀, CAS); Olifants River between Citrusdal and Clanwilliam, x-xi.1931, Museum Staff (2 ♀, 9 ♂, SAMC); 19 km S Clanwilliam on old road to Citrusdal, 14.xi.1992, D.W. Gess (1 ♀, AMGS); Leipoltville, xi.1956, SAM [staff] (6 ♀, SAMC); 43 km ENE of Ceres on road to Sutherland, 2–3.xii.1989, F.W. and S.K. Gess (1 ♀, AMGS); Hex River , i.1884, no collector, det. Arnold (2 ♀, SAMC) ; Matijesfontein , 1–18.xii.1928, R.E. Turner (1 ♀, UCDC, det. Bembecinus mutabilis by R. Bohart) ; Whitehill, 26.xi, T.D.A. Cockerell (1 ♀, BMNH) ; Tankwa Karoo , i.1949, Zinn-Hesse Museum Expedition [ SAMC] (1 ♀, SAMC) ; 18 miles [28.97 km] E of Touws River to Hondewater , xii.1962, SAM [staff] (I ♂, SAMC) ; Oudtshoorn, Onverwacht , 9–12.xii.1986, F.W., S.K., H.W. and R.W. Gess (1 ♀; from nests Homoptera prey in dry collection and larvae in wet collection; Gess and Gess fieldnotes 86/87/18 and 86/87/23) (13 ♀, 2 ♂, AMGS) ; Rietbron , 11.i.1965, H. Empey (1 ♀, 1 ♂, AMGS) . Eastern Cape Province: Willowmore , 25.ii.1905, H. Brauns (1 ♂, SAMC ex NMZR), same locality, 4.xii.1917, H. Brauns (1 ♀, SAMC ex NMZR), same locality, 21.i.1965, H. Empey (1 ♀, 1 ♂, AMGS) ; 9 km E Willowmore at 33°15′S 23°34′E, 28.i.1996, W.J. Pulawski (1 ♀, CAS) ; near Fullarton , 30.x.1967, C. Jacot Guillarmod (1 ♂, AMGS) .

GEOGRAPHICAL DISTRIBUTION.— Known from the Succulent Karoo and Nama-Karoo of southern Namibia south through the Succulent Karoo of Namaqualand, the Olifant’s River valley, the Tankwa Karoo and east to Willowmore in the Nama-Karoo ( Fig. 26c ).

FLORAL ASSOCIATIONS.— Visiting flowers of Asteraceae ( Athanasia trifurcata (Linnaeus) Linnaeus ) (label data, see Material Examined; S. Gess and F. Gess 2003).

NESTING.— Nesting in friable soil on a vegetated flood plane in an area of karroid scrub, Onverwacht, Oudtshoorn ( Fig. 21 ). Three single-celled nests were investigated (S. Gess). Burrows sloping, diameter circa 5 mm, reaching a depth of 47–98 mm, ending in a cell circa 9 mm in diameter and circa 23 mm in length; temporary closure maintained within entrance, cells of nests 86/87/18 and 86/87/23 provisioned, provisioning progressive (Gess and Gess, field notes 86/87/15, 86/87/18 and 86/87/23, AMGS).

PREY.— Two species of Homoptera, Telmosias cf. crito Fennah ( Nogodinidae ) and Sajuba reversa (Melichar) ( Flatidae ), all adults, prey extracted from nests 86/87/18 and 86/87/23 ( AMGS).

Figures

FIGURE 5. Bembecinus spp.: a – quadristrigatus, female, male; b – rhopaloceroides, female, male; c – rhopalocerus, female, male; d – somalicus, female, male; e – zebratus, female, male (approximate lengths of females: a. 11.5 mm, b. 11.5 mm, c. 13 mm, d. 11.8 mm, f. 10.5 mm).

FIGURE 20 (left). Bembecinus rhopalocerus: a – ventral part of female head in profile (arrow indicates the roundly angular portion of clypeus), b – female forefemur, c – male tergum VII.

FIGURE 4. Bembecinus spp.: a – karasanus, female, male, b – mutabilis, female, male; c – namaquensis, male; d – namibius, female, male; e – omaruru, female, male; f – pakhuisae, female, male.(approximate lengths of females: a. 11 mm, b. 10.5 mm, c. male 11.8 mm, d. 9.7 mm, e. 11.3 mm, f. 15 mm).

FIGURE 7. Bembecinus gariepensis: a – male fore- tibia in profile, b – male foretibia dorsally.

FIGURE 6. Bembecinus damarensis: a – female forefemur, b – female tergum I showing color pattern, c – apical flagellomere of male, d – male tergum VII.

FIGURE 26. Collecting records of Bembecinus spp.: a – quadristrigatus, b – rhopaloceroides, c – rhopalocerus, d – somalicus, e – zebratus, f – all species combined.

FIGURE 21. Bembecinus rhopalocerus at nest entrance.