Ruizantheda gaullei ( Vachal, 1903 ) Coelho & Engel, 2018

Coelho, Beatriz W. T. & Engel, Michael S., 2018, A new group of species within the bee genus Ruizantheda, with a revised key to the males of the genus (Hymenoptera: Halictidae: Caenohalictini), Zootaxa 4415 (3), pp. 513-532 : 526-529

Ruizantheda gaullei ( Vachal, 1903) , comb. n.

( Figures 8 , 22, 25 , 29, 32, 36–37, 48–50)

Halictus (Paragapostemon) gaullei Vachal, 1903: 97 . Type locality: Argentina, Tucumán (MNHP) (examined). Caenohalictus gaullei (Vachal) ; Schrottky, 1913: 240.

Diagnosis. Apical margin of S4 with a small medial projection ( Fig. 22 ) is a distinct autapomorphy for this species. Other diagnostic characters include: small body size, mesobasitarsus with a thin keel on the inner surface, moderate size and rounded U-shaped gradulus of S5, with a patch of setae more conspicuous in profile ( Fig. 25 ). Regarding the male genitalia, no marked differences between R. gaullei and that of R. baeri were found.

Redescription. Male: Size. Length approximately 7.0 mm. Forewing length 6.4 mm. Intertegular distance about 1.3 mm.

Colour. Head and mesosoma blackish with dark blue highlights, green reflections on clypeus, lower paraocular area, and sometimes along inner orbit. About distal half of clypeus with yellow transverse band. Mandible blackish with reddish apex. Labral basal area yellow, brown elsewhere. Antenna blackish, flagellum lighter (yellow) below than above. Legs blackish to dark brown, sometimes protibia with small yellowish spot. Metasoma blackish to dark brown, discs of T1–5 with weak green tint; posterior marginal zones with yellowish-white translucent edges. Pygidial plate brown.

Pubescence. Compound eyes with brownish setae, approximately as long as ocellar diameter. Face with long, plumose, whitish setae, less-branched setae on frons and vertex; lower paraocular area with broad strip of short, plumose, white setae along inner margin of compound eye. Mesosoma and legs with whitish setae except metatarsus with yellowish setae. Discs of T2–5 with whitish setae of variable size. Posterior marginal zones of T3–5 with short, simple, decumbent setae. Apicolateral lobes of S4 with tuft of branched setae and about 5 stout, simple, recurved setae on margin, a few plumose setae near tuft. S5 with patch of short, decumbent setae, more conspicuous in profile, arising from inside U-shaped gradulus and extending toward apical margin.

Structure. Head wider than longer, ratio about 1.2 ( Fig. 8 ). Ratio of upper to lower interocular distances about 1.3. Malar area linear. Mandible simple. Labral distal process in form of a minute inverted triangle. Epistomal sulcus forming obtuse angle. Clypeus projecting approximately one-half of its total length below lower orbital tangent. Ocellocular area slightly concave. Vertex slightly expanded behind ocelli. Frons slightly depressed. Preoccipital ridge rounded. Antenna unmodified, F2 1.7× length of F1. Profemur swollen. Outer surface of mesotrochanter with ventral margin convex, forming a very weak keel; mesofemur greatly swollen, ventrally flattened; mesotibia slightly swollen with flat, minutely ridged ventral area and minute distal tooth on outer surface; mesobasitarsus nearly one-half length of mesotibia, with thin keel restricted to one margin of inner surface. Hind legs unmodified. S4 shortened medially, largely hidden under S3, with transverse median depression and apical margin shallowly emarginate, with small medial projection ( Fig. 22 ). Apical margin of S5 very shallowly emarginate, moderate size and rounded U-shaped gradulus ( Fig. 25 ). Gradulus of S6 interrupted medially (Fig. 29). S7 with median apical process angulate, short and without setae. S8 with median apical process broad and trapezoidal shaped, apical margin bearing lateral membranous lobes, separated by a transverse, very thin surface, a round lobe medially (Fig. 32). Pygidial plate ovoid.

Genitalia ( Figs. 36–37 ). Basal region of gonobase with W-shaped in ventral view. Gonocoxae with outer margins divergent and convex near apex; inner dorsal margins progressively divergent, at about midpoint becoming slightly curved and more divergent. Gonostylus with basal region with rvl sclerotized, long, more than one-half length of gonocoxite and rounded apically, with rows of simple setae at extremity, overlapping those of opposing gonostylus; with middle and broad projection formed by a sclerotized area that partially borders a translucent and inflated region, inner lobe present. Mgl an crescent-shaped, with outer surface expanded medially, and with scattered short setae. Ogp large, terminating before apex of mgl, with many long, plumose setae arising at juncture of ogp with mgl, outer margin less sclerotized, extending to ventral region and laterally forming an inflated area with cuticular wrinkles; clump of setae of different lengths at base of ogp, most setae semi decumbent and turning toward dorsal surface. Penis valve strongly arched in lateral view; strong, main, central dorsal ridge; apex pointed; outer lateral expansion strongly bilobed, nearly right-angled between two sections and with posterior projection; prong very narrow, extending past volsella posteriorly. Volsella medio-apical margin strongly emarginate; basal region slightly rounded.

Sculpture. Upper paraocular area and frons densely punctate, with fine, contiguous punctures and some scattered setal bases intermixed. Lower paraocular area with coarse punctures separated by 1–3 PD. Supraclypeal area with punctures separated by 1–4 PD. Clypeus with punctures separated by 1–3 PD laterally, becoming sparser medially. Face with surface between punctures microreticulate. Mesoscutum with setal bases separated by 4–8 PD centrally. Mesoscutellum with a few coarse setal bases centrally, becoming more densely punctured posteriorly and laterally (1–4 PD). Pre-episternum with setal bases separated by 2–4 PD. Mesepisternum with setal bases separated by 2–4 PD. Metapostnotum with triangular area defined by microareolate sculpture, usually without rugosity.

Surface between setal bases reticulate throughout mesosoma. Discs of T2–3 with strong punctures separated by about 4 PD and finer punctures intermixed, posterior marginal zones with fine punctures separated by 2–3 PD.

Distribution. Ruizantheda gaullei is found in Argentina: provinces of Salta and Tucuman. Type material. Holotype female ( MNHP), Tucumán, Argentina. Specimen in good condition ( Figs. 48–50 ). Material examined. ARGENTINA, Salta: one male ( AMNH), " ARG.— SALTA \ Cuesta Obispo\ 2500 m aprox.\ Fritzb- 2.84". Tucuman: one male ( AMNH), " ARGENTINA, Tucumán \ Tafi del. Valle,\ December 6, 1971 \ Charles Porter ".

Figures

FIGURES3–8. Male heads. 3, Ruizantheda nigra n. sp; 4, R.colombianan. sp.; 5, R.venezuelana n. sp.; 6, R. baeri (Vachal); 7, R. pilosa n. sp.; 8, R. gaullei (Vachal).

FIGURES 20–25. Male metasomal sterna. 20–21, S4–5: 20, Ruizantheda nigra n. sp.; 21, R. venezuelana n. sp. 22, S2–4, R. gaullei (Vachal). 23–24, S3–6: 23, R.baeri (Vachal); 24, R. pilosa n. sp. 25, S5, R. gaullei.

FIGURES 34–37. Male genital capsule. 34, 36 ventral view; 35, 37 dorsal view. 34–35, R. colombiana n. sp.; 36–37, R. gaullei (Vachal).

FIGURES 45–50. Female holotype. 45, 48, dorsal view; 46, 49, head; 47, 50, mesosoma, dorsal view. 45–47, R. baeri (Vachal); 48–50, R. gaullei (Vachal).