Plectoplebeia nigrifacies ( Friese, 1900 ), 2016

Melo, Gabriel A. R., 2016, Plectoplebeia, a new Neotropical genus of stingless bees (Hymenoptera: Apidae), Zoologia (e 20150153) 33 (1), pp. 1-8 : 5-6

Plectoplebeia nigrifacies ( Friese, 1900) comb. nov.

Trigona nigrifacies Friese, 1900: 387 . Holotype worker, Peru: Cusco, “Callanga” (ZMB, examined).

Trigona (Plebeia) intermedia Wille, 1960: 219 . Holotype worker, Bolivia: Cochabamba, Chapare, Yungas del Palmar (SEMK, not examined). Syn. nov.

Diagnosis and Comments. For species diagnosis, see above “Diagnosis and Comments” for the genus. The species is known from only five workers collected in three different localities: Callanga , Cusco, in Peru ( FRIESE 1900), Yungas del Palmar , Chapare and Mapiri , Larecaja , in Bolivia ( WILLE 1960, CAMARGO 1988). Based on information provided by GADE (1999), RASMUSSEN & VIVALLO (2014) have recently pointed out that Callanga , in Peru, refers to the zone in Cusco covering the watersheds of a river under the same name and tributary of the river Madre de Dios. All three localities are within the domain of the Bolivian Yungas , an ecoregion extending from west-central Bolivia to southeastern Peru.

Redescription. Holotype worker. Approximate body length: 5.5 mm; maximum head width: 2.33 mm; length of forewing: 6.0 mm; maximum width of T2: 2.0 mm. Color: head and mesosoma predominantly dark brown to black, with the following yellow maculae: a narrow band on each side of the pronotal collar and a small spot on anterior portion of pronotal lobe; a narrow stripe along each side of the mesoscutum; entire dorsal portion of axilla; a broad band along posterior margin of scutellum; a small spot on the apex of the fore femur; a small spot on the basis of all three tibia, more conspicuous on the fore tibia and almost entirely obscured on the hind tibia. Reddish brown are the entire mandible, except for dark brown basis and apical margin, most of the labrum, a broad band along the midline of the clypeus and on the lower parocular area, the entire supraclypeal area, most of the pronotal lobe, the fore tarsus and the last tarsomeres of the mid and hind legs, the inner surface of the hind tibia and of the hind basitarsus. Wing veins and pterostigma brown; wing membrane very lightly brown infumated. Metasoma mostly dark brown; most of T1, a broad semicircular band on the basis of the T2, a smaller band on T3 and most of the sterna reddish brown. Pubescence : predominantly pale-yellow to light brown; tarsi with brown setae; erect pilosity well developed on head and mesosoma, mostly simple, except on pronotal lobe, tegula, anterior margin of mesoscutum and along anterior portion of mesepisternum. Clypeus densely covered with short pubescence, mostly simple on upper two-thirds and plumose on lower one-third; longer erect simple setae abundant, about 2-3x longer than short hairs. Entire frons with a dense pile of short plumose pubescence and sparser intermingled simple and longer hairs, longest setae on upper frons and vertex about 0.24-0.28 mm in length; erect setae on scape short, longest ones on upper surface about as long as diameter of scape (0.12:0.12); upper two-thirds of gena with a dense pile of short decumbent plumose pilosity. Mesoscutum with a dense pile of short simple pubescence and sparser intermingled longer hairs; setae along anterior margin mostly plumose, longest ones about 0.36-0.40 mm in length, those on remainder of sclerite simple and shorter (0.18-0.22 mm); longest setae on scutellum about 0.40-0.44 mm in length. Lateral portion of mesepisternum with conspicuously long erect setae, those near wing and along omaular region mostly plumose and those on remainder of sclerite simple; also with a stratum of finely plumose hairs, which are relatively short and not very dense, leaving the integument clearly visible; metepisternum and lateral portion of propodeum with similar vestiture, shorter plumose pilosity denser compared to mesepisternum. Metapostnotum entirely glabrous. Tergum 1 mostly glabrous, with only sparse minute hairs around basal depression and on lateral portion near the spiracle; T2 with only sparse minute hairs along marginal zone, pubescence becoming denser on lateral portion of sclerite; T3-T5 with pubescence restricted to marginal zone, forming a band of relatively short, mostly erect, simple setae, longest setae with 0.12-0.14 mm in length; pubescence of T6 mostly similar to that of T3-T5, its posterior margin, when seen from above, with a fringe of dense and short plumose hairs. Sterna with erect simple hairs, most of them with a gently curved apex; longest setae on S2 with 0.34-0.38 mm in length. Integumental surface: clypeus and supraclypeal area finely reticulate-rugulose and somewhat dull, piligerous punctures not evident. Lower parocular area smooth and shiny, except for fine piligerous punctures. Frons with relatively coarse punctures; puncture density about 1-3 pd on mid portion and upper frons; mid portion of frons, above antennal alveoli, upper frons around ocelli and vertex finely rugulose and somewhat dull; integument around basis of longer setae on upper frons and vertex distinctly raised in relation to remainder of surface; punctures on gena about as coarse as those on frons, but denser (about 0.5-1 pd). Punctures on mesoscutum with size and density similar to those on frons, interspace between them mostly smooth and shiny, except for conspicuous reticulation along anterior margin and along lateral yellow stripe; punctures on scutellum slightly larger and sparser than those on mesoscutum, interspace smooth and shiny, except for finely rugulose and somewhat dull integument along posterior margin of sclerite. Mesepisternum laterally mostly shiny, surface sparsely punctate and with some irregular and weak reticulation, integument around basis of longer setae distinctly raised in relation to remainder of surface; metepisternum finely rugulose-reticulate, somewhat dull. Punctures on lateral portion of propodeum with size and density similar to those on gena, interspace between smooth to finely reticulated; surface of posterior portion mostly shiny and finely reticulated. Metapostnotum finely rugulose-striate and mostly dull along anterior margin, remainder finely reticulate and mostly shiny. Outer surface of hind tibia finely reticulated and somewhat dull on basal one-third, reticulation gradually becoming weaker on remainder of surface, apical one-third entirely smooth and shiny. Terga mostly shiny, with fine reticulation visible along marginal zone of T1, on posterior half of T2 and on visible portions of T3-T6. Structure (measurements in mm): head about 1.2x wider than long (2.33:1.90); inner orbits slightly converging below (upper to lower interorbital distance, 1.55:1.27); clypeus 2.0x wider than long (1.13:0.57); F2 wider than long (0.15:0.125), and F3 as long as wide (0.15:0.15); minimum distance between clypeus and eye about 0.83x the width of F2 (0.125:0.15); malar space about 0.67x as long as F2 width (0.10:0.15); eye about 2.8x longer than its maximum width (1.48:0.53), in side view about as wide as gena (0.43:0.43). Intertegular distance subequal to mesoscutum length (1.50:1.43); scutellum about 1.9x wider than long (0.97:0.50), relatively short and not completely hiding the mid portion of metanotum in dorsal view, basal fovea lacking, but with a shallow emargination on the center of the slanted anterior margin. Hind wings with 6 hamuli. Corbicular depression occupying about distal half of hind tibia; anterior border of apex of tibia not raised in relation to remainder of surface; anterior margin of hind tibia following a gentle curve in side view.

Type material examined. Holotype worker of Trigona nigrifacies ( ZMB), “ Peru \ Callanga \98” “ Trigona [worker symbol]\ nigrifacies\1900 Friese det.\Fr.”, “Type” (plus additional labels, as shown in Fig. 1 ). The specimen is in good condition, except for lacking the right hind leg; the left mid leg is also broken between the femur and trochanter and has been glued back. Paratype worker of Trigona (Plebeia) intermedia (DZUP) , “Yungas del Pal-\mar Boliva [sic] VI\10-1950 Zischka” “KU” “ Paratype \ Trigona intermedia \ A. Wille ”.

Distribution. Northern portion of the Yungas, in Bolivia (Chapare, Larecaja) and Peru (Cusco).

Figures

Figures 1-2. Plectoplebeia nigrifacies: (1) labels of the holotype of Trigona nigrifacies Friese, 1900; (2) place under which the holotype of T. nigrifacies was found in the ZMB collection.