Ruizantheda baeri ( Vachal, 1904 ) 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 : 521-522

Ruizantheda baeri ( Vachal, 1904) , comb. n.

( Figures 1–2 , 6 , 17–18 , 23 , 30, 45–47)

Halictus (Paragapostemon) baeri Vachal, 1904: 25 . Holotype female from Argentina (MNHP), (examined). Caenohalictus baeri (Vachal) ; Schrottky, 1913: 240.

Diagnosis. In both sexes: dorsal surface of mesosoma bright green with golden reflections ( Figs. 45, 47 ), lateral surface of mesosoma with blue highlights; metapostnotum microareolate with surface roughened; metasomal terga with apical marginal zones translucent so that underlying structures usually result in a yellowish-white coloration ( Fig. 45 ). Male: mesofemur with small ventro-lateral, proximal projection ( Fig. 17 ); mesobasitarsus with thick keel on inner surface ( Fig. 18 ); S5 with patch of short, simple, semi-decumbent setae, more conspicuous in profile, inside rounded U-shaped gradulus of moderate size ( Fig. 23 ); apex of rvl narrow with a few rows of simple setae overlapping those of opposing gonostylus ( Fig. 1 ).

Description. Male: Size. Length 9.0–11.0 mm. Forewing length 7.2–7.5 mm. Intertegular distance about 1.5 mm.

Colour. Head and dorsal surface of mesosoma bright green with golden reflections, blue highlights on genal area and lateral surface of mesosoma, sometimes on frons. About distal half of clypeus with yellow transverse band. Mandible blackish with reddish apex. Labral basal area yellow, brown elsewhere. Antenna blackish to dark brown, flagellum lighter (brownish yellow) below than above. Legs blackish to dark brown, except apical tarsomeres yellowish brown, sometimes inner surface of protibia yellowish brown. Metasoma dark brown to brown; discs of T1–5 with strong bluish green tint, apical marginal zones translucent. Pygidial plate dark brown to brown.

Pubescence. Compound eyes with whitish, yellowish, to light brownish setae, longer than ocellar diameter (about 1.2×). 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 with whitish setae, sometimes dorsal surface of mesoscutum and mesoscutellum with yellowish setae. Legs with whitish setae. Discs of T2–5 with many long, branched, whitish setae, some short setae intermixed. Posterior marginal zones of T2–4 with many short, simple, decumbent setae not reaching apical margin. Apicolateral lobes of S4 with tuft of branched setae and about 6 stout, simple, recurved setae on margin, a few plumose setae elsewhere. S5 with patch of short, decumbent setae, more conspicuous in profile, arising from inside U-shaped gradulus and extending toward apical margin, setae becoming slightly longer near margin.

Structure. Head slightly wider than long, ratio 1.2 ( Fig. 6 ). Ratio of upper to lower interocular distances about 1.2. Malar area linear. Mandible simple. Labral distal process in form of a minute inverted triangle. Epistomal sulcus forming obtuse angle. Clypeus projecting more than one-third of its total length below lower orbital tangent. Ocellocular area concave. Vertex slightly expanded behind ocelli. Frons slightly depressed. Preoccipital ridge rounded. Antenna unmodified, F2 about 1.6× length of F1. Profemur swollen. Outer surface of mesotrochanter with ventral margin convex forming a weak keel; mesofemur greatly swollen, ventrally flattened and with small ventro-lateral, proximal projection ( Fig. 17 ); mesotibia slightly swollen with flat, minutely ridged ventral area and minute distal tooth on outer surface; mesobasitarsus less than one-half length of mesotibia, with thick keel occupying entire inner surface, lateral sides of keel with setae, apical surface smooth and projecting to next tarsomere with widely rounded apex ( Fig. 17–18 ). Hind legs unmodified. S4 shortened medially, largely hidden under S3, with transverse median depression and apical margin shallowly emarginate. Apical margin of S5 shallowly emarginate, with U-shaped gradulus of moderate size medially ( Fig. 23 ). Gradulus of S6 interrupted medially. S7 with median apical process angulate, short, without setae. S8 with median apical process broad and trapezoidal shaped, apical margin bearing weak lateral membranous lobes, separated by a transverse, sclerotized surface (Fig. 30). Pygidial plate ovoid.

Genitalia ( Figs. 1–2 ). 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 much more divergent. Basal region of gonotylus 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 broad and middle projection formed by a sclerotized area that partially borders a translucent and inflated region; inner lobe present. Mgl 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 variable length 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 projection posteriorly; 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 irregularly spaced. Disc of clypeus with coarse punctures separated by usually 1–3 PD. Face with surface between punctures microreticulate. Mesoscutum with setal bases separated by 3–6 PD centrally. Mesoscutellum with few coarse setal bases centrally, becoming more densely punctured posteriorly and laterally (1–3 PD). Pre-episternum with setal bases separated by 1–3 PD. Mesepisternum with setal bases separated by 2–4 PD. Metapostnotum with triangular area defined by microareolate sculpture and usually with fine rugae not reaching posterior margin medially. Surface between setal bases reticulate throughout mesosoma. Discs of T2–4 with strong punctures separated by 3–6 PD and some finer punctures intermixed, posterior marginal zones with fine punctures separated by 2–3 PD.

Female: Size. Length, 9.0–10.0 mm. Forewing length about 7.5 mm. Intertegular distance 1.8 mm.

Colour. Head and mesosoma as in male, sometimes dorsal surface of mesosoma with coppery reflections, but following parts blackish: less than apical half of clypeus ( Fig. 46 ), labrum, antenna, and T1–5, but with faint green highlights on T1–3. Posterior marginal zones of T1–4 with yellowish white translucent margins.

Pubescence. Compound eyes with brownish setae approximately as long as ocellar diameter. Most setae whitish, few yellowish setae. T2–4 with semi-erect setae more concentrated laterally and many short, semidecumbent setae intermixed, posterior marginal zones with short, decumbent setae.

Structure. Head slightly wider than long, ratio 1.1–1.2. Ratio of upper to lower interocular distances about 1.0. Mandible bidentate. Labral basal area with median elevation, its apex orbicular and protuberant; distal process long with narrow keel. Inner metatibial spur pectinate, with four branches ( sensu Engel, 2009 ).

Sculpture. Labral basal area with elevation verrucose. Punctures on face similar to those of male, except frons slightly roughened. Mesoscutum with setal bases separated by 2–4 PD in small medial area, rugose-punctate elsewhere. Punctures on mesoscutellum and pleura similar to those of male. Metapostnotum usually finely roughened with posterior margin finely microareolate. T2–4 with fine punctures separated by 2–4 PD, T4 with coarser setal bases separated by 4–6 PD, but irregularly spaced on discs of T2–3; posterior marginal zones with fine punctures separated by 2–3 PD, surface between punctures reticulate.

Distribution. Ruizantheda baeri is found in Argentina: provinces of Catamarca, Jujuy, Salta, and Tucuman.

Type material. Holotype female ( MNHP), Tucumán, Argentina, “ La Criolla ”, 1500m. Specimen in good condition except for the lack of left antenna and posterior surface of propodeum damaged ( Figs. 45–47 ).

Material examined. ARGENTINA, Catamarca: one female and two males ( AMNH), “ ARG.— CATAMARCA \ Capillitas—1.86\ Fritz— 2650m ”; one female ( AMNH), with same data except, "2.200 mts" . Jujuy: three males ( AMNH), “ ARG.— JUJUY \ Tilcara \ Peña—2.92"; one female ( AMNH), “ ARG.— JUJUY \ Humahuaca\ Fritz—1.97" . Salta: one female ( AMNH), “ ARG.— SALTA \ Alt. Amblayo\ Fritz—4.97 ”; one male (AMNH), “ARG.— SALTA \ Alturas Amblayo \ Fritz—3.86\ 3.200 mts”; one female ( AMNH), with same data except, "3.87—3.200 mts"; one female ( AMNH), with same data except, "3000 mts approx.\ 15-4-85 "; one female and male ( AMNH), “ ARG.— SALTA \ Cuesta Obispo \ 3.600 mts.\ Fritz— 15.3.85 ”; one male ( AMNH), with same data except, "2.86" one female ( AMNH), “ ARG.— SALTA \ Cuesta Obispo \ 3.200m—4.92”; three males ( AMNH), “ ARG.— SALTA \ Cuesta Obispo \ Piedra Molino \ Fritz—1.92”; one male ( AMNH), with same data except, "3.92" . Tucuman: one male ( AMNH), “ ARGENTINA, Tucuman \ Los Cardones \ 19km SE of Amaicha \ S26.40.301 W065.49.062\ 2765m 18.ii.03 L. Packer ”; one male ( AMNH), “ ARG.— TUCUMAN \ Tafi del Valle\ Fritz- 2400m- 1.05”.

Figures

FIGURES 1–2. Male genital capsule of Ruizantheda baeri (Vachal). 1, ventral view; 2, caudal view. Ogp, outer gonostylar plate; mgl, main gonostylar lobe; rvl, retrorse ventral lobe.

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 14–19. Male legs. 14, 17 mid leg.15, inner surface—16, outer surface, 18–19 mesobasitarsus. 14–16, Ruizantheda pilosa n. sp.; 17–18, R.baeri (Vachal); 19, R. nigra n. sp.

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 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).