Ruizantheda pilosa

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: 523-526

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Ruizantheda pilosa

n. sp.

Ruizantheda pilosa  n. sp.

( Figures 7View FIGURES3–8, 9–10View FIGURES 9–10. 9, 14–16View FIGURES 14–19, 24View FIGURES 20–25, 33, 38–41)

Diagnosis. This species is very similar to R. baeri  , differentiated in both sexes mainly by the blue head and mesosoma and metapostnotum usually lacking rugosity. Male: mesobasitarsus with thin keel on inner surface ( Figs. 15–16View FIGURES 14–19); S5 with well-defined triangular patch of setae inside small and slightly angulate U-shaped gradulus ( Fig. 24View FIGURES 20–25); apex of rvl moderately expanded with many rows of setae that do not overlap those of opposing gonostylus ( Fig 38–41View FIGURES 38–41)

Description. Male: Size. Length approximately 10.0 mm. Forewing length 7.5–7.6 mm. Intertegular distance about 1.6 mm.

Colour. Head and mesosoma blue, except lower head and along inner orbit with green reflections and sometimes faint blue-green highlights on dorsal and posterior surface of mesosoma. 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 (yellow brownish) below than above. Legs blackish to dark brown, except apical tarsomeres yellowish brown. Metasoma blackish to dark brown; discs of T1–5 with bluegreen tint, posterior marginal zones with yellowish-white translucent edges. Pygidial plate dark brown to brown.

Pubescence. Compound eyes with brownish setae, longer than 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 and yellowish setae. Discs of T2–5 with many long-branched, whitish setae, some short setae intermixed. Posterior marginal zones of T3–5 with short, simple, decumbent setae not reaching apical margin. Apicolateral lobes of S4 with tuft of branched setae and about 10 stout, simple, recurved setae on margin; plumose setae similar to those of S2–3 elsewhere. S5 with broad and well-defined triangular patch of short, branched, decumbent, erect setae arising from inside U-shaped gradulus and extending toward apical margin.

Structure. Head slightly wider than long, ratio about 1.2 ( Fig. 7View FIGURES3–8). 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 approximately 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 1.7× 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.14View FIGURES 14–19); 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 thin keel restricted to one margin of inner surface ( Figs. 14–16View FIGURES 14–19). Hind legs unmodified. S4 shortened medially, largely hidden under S3, with transverse median depression and apical margin shallowly emarginate. Apical margin of S5 very shallowly emarginate, with small and slightly angulate U-shaped gradulus ( Fig. 24View FIGURES 20–25). 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. 33). Pygidial plate ovoid.

Genitalia ( Figs 38–41View FIGURES 38–41). 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. Gonostylus with basal region with rvl sclerotized, long, more than one-half length of gonocoxite and moderately expanded apically, with many rows of simple setae at extremity not overlapping those of opposing gonostylus; with middle and broad projection formed by a sclerotized area that partially borders a translucent and inflated region. 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 size at base of ogp, most of them 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 irregularly punctate. Clypeus with punctures separated by 1–3 PD laterally, becoming sparser medially. Face with surface between punctures microreticulate, slightly weaker on clypeus. 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 (1–3 PD). Pre-episternum with setal bases separated by 2–3 PD. Mesepisternum with setal bases separated by 2–4 PD. Metapostnotum with triangular area defined by microareolate sculpture and usually without rugosity. 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, surface reticulate.

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

Colour. Blackish, with green to dark green reflections on lower paraocular area, supraclypeal area, and basal half of clypeus; blue reflections on gena, narrow stripe on lateral and posterior margins of mesoscutum and stronger blue tint on pleura and propodeum; legs sometimes dark brownish; posterior marginal zones of T1–4 with yellowish-white translucent edges.

Pubescence. Compound eyes with dark setae about as long as ocellar diameter. Face with whitish setae, except on frons and vertex with some blackish setae. Mesosoma and legs with brownish to light brownish setae, except inner surface of tarsi yellowish white. Discs of T2–4 with semi-erect setae and many short, semi-decumbent setae intermixed, posterior marginal zones with short, decumbent setae.

Structure. Head slightly wider than longer, ratio about 1.2 ( Fig. 9View FIGURES 9–10. 9). Lower to upper interocular distances ratio about 1.0. Mandible bidentate. Labral elevation apical, with apex orbicular and protuberant, distal process long with narrow keel. Inner metatibial spur pectinate with four branches.

Sculpture. Labrum with verrucose basal elevation. Punctures on face similar to those of male, except: lower paraocular area with coarse punctures separated by 1–4 PD and frons slightly roughened. Mesoscutum with setal bases separated by 4–6 PD medially, finely roughened laterally. Pre-episternum with setal bases separated by 3–4 PD. Mesepisternum with setal bases separated by 2–6 PD. 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 about 2–3 PD, surface between punctures reticulate.

Distribution. Ruizantheda pilosa  n. sp. is found in Argentina: provinces of Catamarca and Salta.

Type material. Holotype male (AMNH), “ARG.— SALTA \ El Aybal \ Fritz—2. 91” and “ HOLOTYPE \ Ruizantheda pilosa  \Coelho & Engel” [red label]  . Paratypes. ARGENTINA, Catamarca: one female and one male ( PCYU), “ ARGENTINA, Catamarca \ 33km N of Andalgala ,\S27.27.460 W066.23887 \ 2530m 15.ii.03 L. Packer "GoogleMaps  . Salta: one female with same data of Holotype;  one female ( AMNH), “ ARG.— SALTA \ Cuesta Obispo \ Fritz—2.85 \2.500mts”;  one female ( AMNH) with same data except, "2.86 \ 2400 mts.";  one male ( AMNH), “ ARG.— SALTA \ El Maray \ Fritz—2. 92”. 

Etymology. The specific epithet is take from the Latin pilosus, meaning, “hairy”, in reference to the numerous setae on its retrorse ventral lobe compared with that of R. baeri  .

FIGURES 28–33. Male. 28–29, S6; 30–33, S 7–8. 28, 31, Ruizantheda nigra  n. sp.; 29, 32, R. gaullei (Vachal)  ; 30, R. baeri (Vachal)  ; 33, R. pilosa  n. sp.


The Packer Collection at York University


American Museum of Natural History


Argotti Botanic Garden