Bembecinus damarensis F. Gess and Pulawski, 2015

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 : 217-219

Bembecinus damarensis F. Gess and Pulawski , sp. nov.

Figures 3a , 6 a-d.

Bembecinus sp. nov. A ( rhopalocerus species group): S. Gess and F. Gess, 2003:117 (floral records).

NAME DERIVATION.— The name, a newly coined Neolatin adjective, is derived from the geographical name, Damaraland, a historic province of Namibia, and refers to the provenance of the holotype .

RECOGNITION.— Bembecinus damarensis has the scutum black mesally, the mesopleuron largely yellow, and the terga largely yellow (at least terga I-III black basally), without ferruginous color. In the female, the length of the hindtibial arolium is about 0.5 × of the inner claw. The females of pakhuisae and zebratus are similar, but damarensis differs in having the dorsal surface of tergum I yellow except for the median, black, nearly rectangular marking ( Fig. 6b ) that does not attain posterior margin and the scape without erect setae. Also, the dorsal margin of the forefemur is somewhat concave basally and the ventral margin slightly expanded basally. In the other two species, tergum I is black except for narrow, yellow apical fascia, the scape apically has several erect setae (setal length at least 0.5 × midocellar width), and the dorsal margin of the forefemur is practically straight and the ventral margin is not expanded basally. The shape of the forefemur is similar in the female of rhopalocerus , in which, however, the clypeus is roundly angulate basally (best seen in profile), whereas evenly convex in damarensis .

The male of damarensis shares with that of mutabilis a conspicuously curved and excavated apical flagellomere ( Fig. 6c ), markedly more so than in pakhuisae and zebratus . It differs from that of mutabilis in having the scutal punctures averaging about one diameter apart, the mesopleuron yellow, the gastral terga mostly yellow (partly black), tergum VII elongate, roundly triangular ( Fig. 6d ), and the length of 12.7–14.7 mm. In mutabilis , the scutal punctures, near center, average about two diameters apart, the mesopleuron is all or predominantly black, the gaster is ferruginous (with some parts black), tergum VII is short, trapezoid, with apical margin nearly straight ( Fig. 13d ), and the length is of 10.5–11.5 mm.

DESCRIPTION.— Head black, with the following yellow: mandible except apex, labrum, clypeus, face below antennae and narrowly up to midheight along orbit, streak on frons in midline below anterior ocellus, occasionally small spot touching posterior ocellus anteromedially, gena narrowly above and widely below, cardo, stipes, galea, both pairs of palps, scape except for dorsal black streak, underside of pedicel and of flagellomere I. Rest of antennae ferruginous except for black dorsal surface of pedicel and of flagellomeres VI–IX. Thorax black with the following yellow: entire pronotum except for black streptaulus, a C-shaped marking apically on each propleuron, lateral streak on scutum, tegula, triangular area on each side of scutellum, metanotum except narrowly black basally, and mesopleuron largely. Propodeum black, with the following yellow: anterior third of lateral surface, posterolateral margin, and a pair of spots on preapical part of enclosure. Gaster yellow with the following black: anterior declivity of tergum I, extending posteriorly into subrectangular, median marking on disk, basal transverse band expanded posteriorly in the middle on tergum II, and similar but often less developed markings on terga III and IV. Female legs yellow with the following light ferruginous: outer and inner surface of fore- and midtrochanters and fore- and midfemora and almost entire hindtrochanter and hindfemur, streaks on lower surface of all tibiae, tarsomeres to a variable degree. Male legs predominantly yellow with only the inner surface of hindfemur light ferruginous, inner surface of fore- and midfemora marked with black, and inner surface of hindfemur with ferruginous area marked with black. Wings hyaline, Sc + R black, other veins brown.

Clypeus, face below antennae and halfway up along sides densely covered with decumbent silvery pubescence, rest of face more sparsely so.

♀: Length 12.2–14. 7 mm (average of 13: 13.3 mm; holotype: 12.3 mm). Ocular index 1.9–2.0 (average of 13 = 1.9). Minimum interocular distance equal to 2.9–3.2 × that between antennal scrobe and base of clypeus (average of 8 = 3.0); distance between posterior ocelli 1.4 × ocellocular distance. Clypeus impunctate, markedly convex, fairly evenly curved from base to free margin, its high point near center of disk, its width at insertion of mandibles 1.8–1.9 × its median length (average of 13 = 1.85). Labrum triangular, markedly shiny, with small, widely separated punctures, sparsely microsculptured unlike clypeus which is densely microsculptured; its width at base subequal to median length. Dorsal margin of forefemur somewhat concave basally, ventral margin slightly expanded basally ( Fig. 6a )

♂: Length 12.7–14. 7 mm (average of 6 = 13.9 mm). Ocular index 1.9–2.1 (average of 6 = 2.0). Minimum interocular distance equal to 2.1–2.6 × that between margin of antennal scrobe and base of clypeus (average of 6 = 2.26); distance between posterior ocelli 1.4 × ocellocular distance; width of clypeus at insertion of mandibles 1.5–1.7 × its median length (average of 6 = 1.6). Flagellomere XI curved, excavate below, hook-like ( Fig. 6c ). TergumVII triangular, rounded apically ( Fig. 6d ).

MATERIAL EXAMINED.— HOLOTYPE: ♀, NAMIBIA: Otjozondjupa Region: Osire, 24.xii.1974, H.N. Empey ( AMGS). PARATYPES: NAMIBIA: Otjozondjupa Region: 44 km SW Otjiwarongo at 20°37′S 16°22′E, 4.iii.1990, W.J. Pulawski (1 ♀, CAS); Osire, 24.xii.1974, H.N. Empey (8 ♀, 6 ♂, AMGS); 70 km N Okahandja, 16.iii.1990, W.J. Pulawski (2 ♀, 1 ♂, CAS); Okahandja, 2–4.ii. 1972, BMNH Southern African Expedition (2 ♀, 8 ♂, BMNH). Kunene Region: Kamanyab (sic, = Kamanjab), iii.1925, Mus. Exped. (2 ♀, 1 ♂, SAMC, det. Arnold as Stizus rhopalocerus Handl. ), same label data (1 ♀, SAMC ex NMB). Erongo Region: 17–19 km E Usakos, 18.iii.1976, J.G. and B.L. Rozen (1 ♀, AMNH); 11 km N Karibib, 27.ii.1990, W.J. Pulawski (1 ♀, CAS); 26 km N Karibib, 6.ii.1993, J. Gusenleitner (2 ♀, OÖLM). Khomas Region: between Rehoboth and Gamsberg Pass at 23°09.43′S 16°41.97′E, 11.iii.1999, F.W. and S.K. Gess (1 ♀, 1 ♂, AMGS), visiting flowers of Hermstaedtia odorata (Burch.) T. Cooke , Amaranthaceae ; 18 km W junction 1237 and C26 at 23°09′S 16°42′E, 11.iii.1999, F.W. and S.K. Gess (1 ♀, 1 ♂, AMGS), visiting flowers of Hermbstaetia sp., Amaranthaceae ; Narebis (sic = Naribis?), iii.1921, K.H. Barnard (1 ♀, SAMC, det. Arnold as Stizus rhopalocerus Handl. ). Omaheke Region: Gobasis [= Gobabis], 17.xii.1933, J. Ogilvie (1 ♀, BMNH); Gobabis District, 40 km W Witvlei, 16.ii.1990, W.J. Pulawski (1 ♀, 2 ♂, CAS) and M. Schwarz (2 ♂, CAS; 3 ♂, MS). Hardap Region: SW Gibeon at 25°19.76′S 17°28.85′E, 8.iii.1999, F.W. and S.K. Gess (2 ♂, AMGS), one visiting flowers of Limeum sulcatum (Klotsch) Hutch. , Molluginaceae ; SW Gibeon at 25°19.76′S 17°28.85′E, 10.iii.1999, F.W. and S.K. Gess(4 ♂, AMGS), visiting flowers of Limeum sulcatum (Klotsch) Hutch. , Molluginaceae ; SW Gibeon 41 km on 1089 at 25°20′S 17°29′E, F.W. and S.K. Gess, 8.iii.1999 (2 ♂, AMGS), one visiting flowers of Limeum sp. , Molluginaceae , 10.III.1999 (5 ♂, AMGS), four visiting flowers of Limeum sp. , Molluginaceae , 24.iii.1999 (1 ♀, AMGS). SOUTH AFRICA: Northern Cape: 11 km from Twee Rivieren on Nossob road at 26°24′S 20°41′E, 8–11.iii.1990, F.W. and S.K. Gess (5 ♂, AMGS), visiting flowers of Limeum aethiopicum Burm. , Molluginaceae .

GEOGRAPHICAL DISTRIBUTION.— Known from the Nama-Karoo/Savanna fringe in Northern Namibia to the Nama-Karoo in southern Namibia and the southern Kalahari to the north of Twee Rivieren ( Fig. 24a )

FLORAL ASSOCIATIONS.— Visiting flowers of two families: Molluginaceae ( Limeum sulcatum (Klotsch) Hutch. and Limeum aethiopicum Burm. ) and Amaranthaceae ( Hermbstaedtia odorata Burch. ) (label data, see Material Examined; S. Gess and F. Gess 2003).

NESTING.— Unknown.

PREY.— Unknown.

Figures

FIGURE 3. Bembecinus spp.: a – damarensis, female, male, b – gariepensis, female, male, c – gilvus, female, male, d – helicicola, female; e – hyperocrus, female, male, f – inexpectatus, female, male. (approximate lengths of females: a. 12 mm, b. 11.5 mm, 9 mm, d. 10 mm, e. 10 mm, f. 9.2 mm).

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

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 24. Collecting records of Bembecinus spp.: a – damarensis, b – gariepensis, c – gilvus, d – helicicola, e – hyperocrus, f – inexpectatus.