Systropha (Austrosystropha) macronasuta Strand, 1911

Bossert, Silas & Patiny, Sébastien, 2017, Description of the previously unknown male of Systropha (Austrosystropha) macronasuta (Hymenoptera: Halictidae: Rophitinae) from Kenya, Journal of Melittology 2017 (67), pp. 1-9 : 3-6

Systropha (Austrosystropha) macronasuta Strand, 1911

( Figs. 1–12 )

MATERIAL EXAMINED: 6♂♂, 13♀♀, Kenya: Great Rift Valley , Marigat, 0°27’22”N, 35°52’49”E, 1300 m, 12 October, 2012, leg. B.N. Danforth, T . Griswold, L. Packer, D. Martins, C. Njoki, M. Nzisa Mutiso, W. Tiren ( CUIC) .

DIAGNOSIS: ♂: The specimens match the subgeneric morphology of Austrosystropha ( Patiny & Michez, 2006): F7 and following flagellomeres well-differentiated and forming part of the spiral, femur 1 dorsoventrally and laterally enlarged, femur 2 enlarged but less prominent than femur 1, coxa 3 elongate, T7 laterally toothed .

Systropha macronasuta is the largest species of Austrosystropha (12.0– 15.5 mm) known to date. The first six terga lack teeth, S1 is unmodified, and S2–S4 bear blade-like projections. S6 has two small apicolateral teeth, and the apex of S8 is enlarged with a well-developed ventral groove ( Figs. 8–9 ). S6 bears a protruding bilobed projection ( Fig. 9 ). The inner hind tibial spurs show two ventral rows of teeth but these are less prominent than in the female. The proboscis is conspicuously elongate and up to 5.6 mm in length.

♀: As all females of the subgenus, the female of S. macronasuta possess two conspicuous and well-developed rows of ventral teeth on the inner hind tibial spurs of tibia 3. The overall body size is large (11.5–13.0 mm in length). The integument is dark brown, with creamy white setae on the thorax, the first tergum, and the anterior parts of T2 . The pilosity of the following terga is increasingly brownish, and the setae on T5 and T6 are entirely brown. The second submarginal cell has a pentagonal shape .

DESCRIPTION: ♂: Head ( Fig. 4 ) slightly shorter than broad (length: 2.25–2.63 mm; width: 2.36–2.83 mm). Integument darkish brown to black with creamy white setae. Setae highly branched, most densely plumose around antennal sockets, sparse and thin around ocelli and denser along posterior part of vertex. Setae which originate from genal area noticeably long and plumose ( Fig. 2 ). Clypeus distinctly protruding, clearly shorter than broad (length: 0.39–0.46 mm; width: 0.94–1.08 mm), entirely shagreened with sparse, shallow but coarse punctation. Clypeal distal margin without projections but setae extending below margin. Mandible dark, bearded, 1.11–1.22 mm long, bidentate with preapical tooth shorter than apical tooth. Proboscis long, comparable with morphology of female mouthparts drawn in Ebmer (1994). Genal area slightly broader than compound eye ( Fig. 2 ), with coarse punctation and shiny interspaces. Malar distance linear. Supraclypeal area shagreened, upper half with punctation. Supra-antennal area without punctation but with coarse structuring and dull surface. Antennal foramen located in lower third of face, in close proximity to epistomal sulcus. Scape enlarged, cone-shaped in frontal view. F1 conspicuously long and slender (length: 0.96–1.01 mm; width: 0.20–0.21), longer than two following segments combined. Apical flagellomeres (F7–F11) strongly recurved, forming apical hook. F11 short. Dorsal surfaces of F1–F6 dark brown, F7–F11 light to reddish brown. Ventral surfaces of F3–F11 lighter colored. Diameter of lateral ocellus 0.18–0.19 mm, median ocellus 0.25–0.26 mm. Ocular-ocellar line 0.44–0.45 mm in length.

Mesosoma: Integument predominantly black, darkish brown along ventral parts of mesepisternum. Pilosity creamy white, most dense on scutellum and on metepisternum behind base of hind wing, less dense on mesoscutum and metanotum. Sparse but erect setae on mesepisternum. Propodeal triangle completely hairless. Intertegular distance 2.57–2.87 mm. Mesoscutum with punctation, generally dense but with greater distances between punctures around median and parapsidal lines. Interspaces up to three times puncture diameter. Integument between punctation shiny, slightly shagreened. Distal part of mesepisternum with shallow and scattered punctation, interspaces usually more than three times puncture diameter, mostly shiny. Basal area of propodeum without punctation but slightly shagreened and less shiny than posterior surface. Posterior surface of propodeum almost completely impunctate and distinctly shiny. Tegula brown, slightly darker anteriorly. Wings not strongly pigmented, yellowish-brown with brown venation. Three submarginal cells, stigma yellow-brown. First recurrent vein intersecting at second submarginal cell. Basal vein strongly arcuate.

Metasoma: Surfaces of T 1– T 7 with fine reticulate sculpture on tergal discs and marginal zones, most prominent on T 1– T 5. Surfaces of T 1– T 4 evenly and acutely punctured, interspaces sometimes greater than 3 times diameter. Punctation on T 5– T 7 slightly more dense but less acute. Marginal zones of T 1– T 5 notably less densely punctured, with sparse and very shallow punctures. Only T 7 with distinct lateral spines and a blunt median process, comparable with S. krigei Brauns ( Brauns, 1926: his fig. 2a). T 1 with erect white setae, all other terga except T 7 with sparse, more or less appressed, setae and without tergal bands. Coloration of setae mostly whitish, becoming darker on T 6 and T 7. Setae on T 7 mostly yellowish-brown, erect. Sternal structures without bands of setae, but with a patch of sparse, erect and branched setae on S1. Following sterna more or less hairless, except for small sparse lateral patches. S1 unmodified. S2–S4 with distinct, paired blade-like ventral projecting lobes, those on S3 most prominent. S5 unmodified. S6 with two lateral spines and a conspicuous median posterior process ( Fig. 9 ). S7 and S8 highly modified ( Figs. 7–9 ); S8 elongate, with enlarged, bilobed apex visible in unprepared specimens. Genital capsule morphology illustrated in figures 10–12.

Modified Couplets of the Species Identification Key of Systropha by Patiny et al. (2013)

2. T 6– T 7 lacking lateral teeth; S2–S3 with compressed tubercles, forming an apical lamella; S6 with two teeth (a medio-proximal and a medio-terminal ventral tooth) [ Morocco] ............................................... S. (Systropha) pici Pérez

—. T 6 and/or T 7 with strong lateral teeth; S2–S3 with differently shaped tubercles or blade-like projections; S6 lacking teeth as described above but may have a ventral projection and small apicolateral teeth ..................................... 3

6. T 1– T 5 lacking teeth ................................................................................................. 6a

—. T 1– T 5 with small lateral spines or blades ............................................................ 7

6a. Small species (ca. 8–9 mm); vertex and/or mesoscutum at least partly covered with reddish setae; S6 distally without protruding projection [ South Africa] .............................................................. S. (Austrosystropha) krigei Brauns

—. Large species (ca. 12–15 mm); all setae of vertex and mesosoma whitish, without red; S6 distally with protruding projection ( Fig. 9 ) [Eastern Africa ( Zanzibar, Kenya)] ........................................... S. (Austrosystropha) macronasuta Strand

Figures

Figures 1–6. The male of Systropha (Austrosystropha) macronasuta Strand. 1. Habitus. 2. Head, lateral view. 3. Habitus, dorsal view. 4. Head, frontal view. 5. Habitus, lateral view. 6. Metasomal terga, dorsal view.

Figures 7–9. Details of male metasomal sterna 6–8 of Systropha (Austrosystropha) macronasuta Strand. 7. Sternum 7. 8. Sternum 8. 9. Metasomal sterna in natural position, lateral view.

Figures 10–12. Genital capsule of Systropha (Austrosystropha) macronasuta Strand. 10. Dorsal view. 11. Oblique dorsal view. 12. Ventral view.