Bembecinus mutabilis (Arnold)

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 : 228-231

Bembecinus mutabilis (Arnold)

Figures 4b , 13a–d .

Stizus mutabilis Arnold, 1929:295 , Figs 48, 48a and b, ♀, ♂. Lectotype: ♂, South Africa: Western Cape Province: Montagu (BMNH), designated by W. Pulawski: present designation.— Arnold, 1930:20 (in checklist of Afrotropical Sphecidae ).— As Bembecinus mutabilis : R. Bohart and Menke, 1976:531 (new combination, in checklist of world Sphecidae ); S. Gess, 1996:277, 280 (floral records); S. Gess and F. Gess, 2003:116 (floral records); Pulawski, 2014:24 (in catalog of world Sphecidae sensu lato).

Bembecinus ruficaudus R. Bohart, 1997:170 , Fig. 6 , ♀, ♂. Holotype: ♂, South Africa: Western Cape Province: Doorn River at Moedverloor, now Moedverloren Nature Reserve ( UCDC), examined by W. Pulawski. New synonymy by W. Pulawski.— Pulawski, 2014:33 (in catalog of world Sphecidae sensu lato).

RECOGNITION.— Bembecinus mutabilis has a gaster either largely ferruginous (tergum I black basally, several or all following terga all ferruginous or narrowly black basally) or (one female from Montague) with ferruginous apical fascia, but without yellow apical fasciae on terga, and with setae appressed on gastral tergum II. B. hyperocrus is similar, but mutabilis has the following: the face below the antenna and the clypeus are all yellow in most specimens (the clypeus is black basally in the single female from Upington), male flagellomere XI is markedly curved and excavated ( Fig. 13b ), male tergum VII is trapezoidal, with apical margin truncate, widely, shallowly emarginate mesally ( Fig. 13d ), and the ocular index is 2.68– 2.92 in the female and 2.67– 2.90 in the male. In hyperocrus , the setae of tergum II are erect (only laterally so in the female), the face below the antenna and the clypeus basally are black (the entire clypeus and labrum are black in some males), male flagellomere XI is simple (not curved and not excavated), male tergum VII is rounded with the apical margin convex and narrowly emarginate mesally ( Fig. 10d ), and the ocular index is 2.13– 2.26 in the female and 2.08– 2.27 in the male. Also similar is inexspectatus , which has pale yellow apical fasciae on gastral terga and the apical flagellomere of the male simple (not curved and not emarginate); the apical flagellomere is also simple in the male of namaquensis (the female is unknown).

LECTOTYPE SELECTION.— Arnold described mutabilis from one female and three males. He labeled the female and one male as Types, and the remaining two males as paratypes.W. Pulawski has designated the male labeled Type as a lectotype, and the female as a paralectotype. JUSTIFICATION OF NEW SYNONYMY.— Both the holotype male and the female paratypes of Bembecinus ruficaudus are identical to mutabilis , and the former name is clearly a junior synonym of the later. It should be noted that Bohart’s (1979) illustration 6c of the apical flagellomere of the male ruficaudus is misleading, as it does not show its curvature. In reality, this flagellomere is markedly more curved and excavated in the holotype than represented, just as in the other males of mutabilis .

MATERIAL EXAMINED.— SOUTH AFRICA: Northern Cape Province: Naib or Boesmanland, between Springbok and Pella, Mus. Staff, x.1939 (1 ♀, SAMC); Namaqualand , 67 km E Port Nolloth , 17.x.1972, J.G. Rozen and C. Thompson (2 ♀, AMNH); Namaqualand, Anenous, 11–13.x.1988 , F.W. and S.K. Gess (26 ♀, 2 ♂, AMGS), same locality and dates, D.W. Gess (22 ♀, 1 ♂, AMGS), same locality, 12.x.1989, F.W. and S.K. Gess (2 ♀, AMGS); 10 km W Steinkopf [Anenous], 10.xi.19960, R. Miler (1 ♀, UCDC, paratype of Bembecinus ruficaudus ); Namaqualand, Eksteenfontein, 2817CD, 9.x.1980, V. Whitehead (1 ♂, SAMC); Namaqualand, 42 km S Eksteenfontein at 29°06.8′S 17°26.6′E, 9.x.2008, B.N. Danforth (1 ♀, CAS), on flowers of Grielum , Neuradaceae ; 53 km S Vioolsdrift at 29°10′S 17°50′E, 12.x.2000, F.W. and S.K. Gess (1 ♀, AMGS); Namaqualand, Springbok , Hester Malan [now Goegap] Nature Reserve, 15–21.x.1987, F.W. and S.K. Gess (1 ♀, AMGS) , same locality, 10–12.x.1988, D.W. Gess (2 ♂, AMGS), same locality, 10–11.x.1989, D.W. Gess (7 ♀, AMGS); Springbok, Voelklip, 2 and 7.x.1994, F.W. and S.K. Gess (3 ♀, AMGS); Kamieskroon , Bakleikraal, 9–11.x.1994, F.W. and S.K. Gess (1 ♂, AMGS); Moedverloren Nature Reserve, Knersvlakte, 8.x.1975, R.M. Bohart (1 ♂, UCDC, holotype of Bembecinus ruficaudus ); Augustfontein (Calvinia), ix.1947, Museum Expedition [ SAMC] (1 ♀, SAMC); Niewoudtville, 18–22.xi.1931, J. Ogilvie (2 ♀, BMNH); Van Rhyn’s Pass, 11–21.xi.1931, J. Ogilvie (1 ♀, BMNH). Western Cape Province: Doringboos NE Clanwilliam, 11.x.1999, M. Halada (10 ♀, OÖLM); Bulshoek, Klaver-Clanwilliam, x.1950, Museum Expedition (8 ♀, 3 ♂, SAMC); Pakhuis Pass , 7.x.1975 (2 ♀, UCDC, paratypes of Bembecinus ruficaudus ); 12 miles [19.31 km] N Clanwilliam, 4.xi.1966, J.G. Rozen (1 ♂, AMNH); Clanwilliam, 20.x.1968, J.G. Rozen and E. Martinez (1 ♂, AMNH); 5 km W Clanwilliam on road to Graafwater, 12.x.1987, F.W. and S.K. Gess (5 ♂, AMGS), same locality, 5–6.x.1988, F.W. and S.K. Gess (1 ♀, AMGS), same locality and dates, D.W. Gess (4 ♂, AMGS); 11 km W Clanwilliam on road to Graafwater, 2–8.x.1990, F.W. and S.K. Gess (1 ♀, 3 ♂, AMGS), 1 ♂ on flowers of Helichrysum hebelepis DC. , Asteraceae ; Clanwilliam Dam, 3–7.x.1988, F.W. and S.K. Gess (6 ♀, 6 ♂, AMGS), 1 ♂ on flowers of Limeum africanum , Aizoaceae ; same locality and dates, D.W. Gess (3 ♀, 5 ♂, AMGS); E Clanwilliam, 10.x.1999, M. Halada (6 ♀, 1 ♂, OÖLM); Clanwilliam Dam, Caleta Cove, 19–20.x.1989, F.W. and S.K. Gess (1 ♀, AMGS), same locality and dates, D.W. Gess (1 ♀, AMGS); 4 miles [6.44 km] S Clanwilliam on old road to Citrusdal, 6.x.1991, D.W. Gess (1 ♂, AMGS); 10 km S Clanwilliam at 32°13’39″S 18°50′50″E, 5–25.x.2004, M.E. Irwin, F.D. Parker, M. Hauser (3 ♀, 2 ♂, ZMB; 16.5 km S Clanwilliam on old road to Citrusdal, 13.x.1990, F.W. and S.K. Gess (9 ♀, 11 ♂, AMGS), 2 ♀ and 1 ♂ on flowers of Athanasia trifurcata (Linnaeus) Linnaeus , Asteraceae ; 15 km S Clanwilliam on old road to Citrusdal, 14.xi.1992, D.W. Gess (1 ♀, AMGS); 19 km S Clanwilliam on old road to Citrusdal, 14.xi.1992, D.W. Gess (3 ♀, AMGS); 20 km S Clanwilliam on old road to Citrusdal, 15.x.1994, F.W. and S.K. Gess (1 ♀, AMGS); Olifants River between Citrusdal and Clanwilliam, x-xi.1931, Museum Staff [ SAMC] (16 ♀, 16 ♂, SAMC); 20 km N Citrusdal, 27.x.1999, M. Halada (1 ♀, CAS) (4 ♀, 1 ♂, OÖLM); 8 miles [12.88 km] N Citrusdal, ix.1961, SAM (1 ♂, SAMC); Citrusdal District, xi.1948, Museum Expedition [ SAMC] (3 ♂, SAMC); Groenkloof, between Clanwilliam and Algeria, 19.x.1989, D.W. Gess (1 ♂, AMGS); Paleisheuwel, xi.1948, Museum Expedition [ SAMC] (4 ♀, SAMC), 6.x.1990, F.W. and S.K. Gess (2 ♂, AMGS); Het Kruis, x.1947, Museum Expedition [ SAMC] (2 ♂, SAMC); 25 km E Velddrif, 23.x.1972, J.G. Rozen et al. (1 ♂, AMNH); Upper Sources, Olifants River, Ceres, xii.1949, Museum Expedition [ SAMC] (1 ♀, SAMC); 43 km ENE of Ceres on road to Sutherland, 2–3.xii.1989, F.W. and S.K. Gess (1 ♀, AMGS); Montagu, 1–21.x.1924, R.E. Turner (2 ♀, 6 ♂, BMNH, including lectotype, paralectotype, and 2 paratypes), same locality and dates, R.E. Turner (labeled Stizus mutabilis Arn. , det. R.H.R. Stevenson and clearly the same material from which the types were drawn) (2 ♀, SAMC ex ZMHB); 18 miles [28.97 km] E Touws River [on road] to Hondewater, xii.1962, SAM [staff] (2 ♀, SAMC); Laingsburg at 33°12′S 20°51′E, 25.xii.1996, W.J. Pulawski (1 ♀, CAS); Koup Siding, Laingsburg, xi.1939, Museum Staff [ SAMC] (2 ♀, SAMC); Moordenaars Karoo, Swanepoel, x.1952, Museum Expedition [ SAMC] (2 ♂, SAMC); Prince Albert District, Tierberg, 26.xi.-5.xii.1987, F.W., S.K. and R.W. Gess (1 ♀, AMGS); 60 km N Cape Town, 9.xi. 1999, M. Halada (2 ♀, 1 ♂, OÖLM). Eastern Cape Province: Willowmore, 12.i.1965, H. Empey (1 ♀, AMGS), 18.x.1970, H. and M. Townes (1 ♀, AEI), 5.x.1971, C. Jacot-Guillarmod (1 ♀, AMGS), same locality, 7.x.1971, F.W. Gess (1 ♂, AMGS); Waterford, 29.x.1967, C. Jacot-Guillarmod (1 ♀, AMGS); Rietbron, 11.i.1965, H. Empey (1 ♀, AMGS).

GEOGRAPHICAL DISTRIBUTION.— Known only from South Africa, widely distributed from the winter rainfall Succulent Karoo of Namaqualand, south through the Olifant’s River Valley and eastwards to Willowmore in the Nama-Karoo ( Fig.25b ).

FLORAL ASSOCIATIONS.— Visiting flowers of four plant families: Asteraceae ( Helichrysum hebelepis DC. and Athanasia trifurcata (Linnaeus) Linnaeus , Amaranthaceae ( Hermbstaedia glauca (Wendl.) Reichb. Ex Steud. ), Aizoaceae (non-Mesembryanthema, Limeum africanum Linnaeus ) (label data, see Material Examined; S. Gess and F. Gess 2003), and Neuradaceae ( Grielum ) (label data, see Material Examined).

NESTING.— Nesting in friable soil of a stabilized dune mole rat ‘hillock’ in an area of dry Fynbos to the west of Clanwilliam. One nest was investigated (S. Gess). Burrow entrance was in sloping side of ‘hillock’, burrow sloping downwards for 84 mm, shaft ending in sub-horizontal cell, diameter of entrance and shaft 5 mm, diameter of cell 7.5 mm, length of cell 25 mm, depth of cell 56 mm. Female opens and closes the burrow on entering and leaving the nest. Cell containing larva and prey (F. Gess and S. Gess, field notes 90/91/124, AMGS).

PREY.— Cicadellidae (Homoptera) nymphs and adults from nest 90/91/124 (8 specimens in gelatin capsule on same pin as female 90/91/124, AMGS) .

Figures

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 13. Bembecinus mutabilis: a – apical hind- tarsomere of female showing length of arolium, b – male apical flagellomeres, c – male foretibia in profile, d – male tergum VII.

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

FIGURE 10. Bembecinus hyperocrus: a – female clypeus in profile (arrow indicates the roundly angular portion), b – left side of female terga I and II, c – dorsal parts of male terga I and II in profile, d – male tergum VII.

FIGURE 25. Collecting records of Bembecinus spp.: a – karasanus, b – mutabilis, c – namaquensis, d – namibius, e – omaruru, f – pakhuisae.