Scaptotrigona yungasensis Engel, 2022

Engel, Michael S., 2022, Notes on South American stingless bees of the genus Scaptotrigona (Hymenoptera: Apidae), Part II: Subgroup A of the postica species group, Journal of Melittology 2022 (110), pp. 1-51 : 43-45

Scaptotrigona yungasensis Engel , new species

ZooBank: urn:lsid:zoobank.org:act:77DD467E-37B2-4CB3-B659-85CA7549EFA6

( Figs. 59–61 )

DIAGNOSIS: In many respects this species is much like the Venezuelan S. ochrotricha (vide infra), as both are comparatively large species with a generally similar coloration. However, in the new species the corbicular bristles differ in color between the inferior and superior margins and the fringes are typically yellow to light fulvous, while in S. ochrotricha they are dark fuscous to black on the corbicula while the marginal fringes range from fulvous to more typically black. Additionally, S. yungasensis lacks the conspicuous mesoscutal stripes present in the former species (cf. Figs. 60 , 67 ), as well as the dark fulvous to black bristles otherwise present on the mesotibia and mesepisternum of S. ochrotricha (cf. Figs. 59 , 64 ).

DESCRIPTION: As described for S. ederi (vide supra), with the following modifications: ⚲: Total body length approximately 6.4–7.0 mm, forewing length (to base of humeral sclerite) 6.6–6.9 mm. Head wider than long, width 2.61–2.67 mm, length 2.21–2.27 mm; compound eye length 1.52–1.55 mm; upper interorbital distance 1.73–1.76 mm, lower interorbital distance 1.64–1.67 mm. Scape length 0.97–1.03 mm, about as long as torulocellar distance, torulocellar distance 0.91–0.94 mm. Clypeus approximately 1.7–1.8× as wide as long, length 0.70–0.73 mm, width 1.24–1.27 mm. Malar area approximately 1.8× flagellar diameter or 0.70–0.73× basal mandibular width. Preoccipital ridge carinate, lamellate dorsally, with bordering medial and lateral indentations deep, carina interrupted laterally by deep concavity, lower margin of concavity with carina forming acute angle projecting upward as sharp tooth.

Integument of labiomaxillary complex yellow orange except prementum typically brown; labrum yellow orange to orange; mandible orange basally and reddish orange apically; clypeus largely yellow orange to orange, epistomal sulcus well delineated by brownish orange to black; supraclypeal area yellow orange to orange; malar space yellow orange to orange; face below tangent of antennal toruli yellow orange to orange; scape yellow except brown dorosapically; pedicel and flagellum brown to dark brown, flagellum orange underneath; face above antennal toruli reddish brown to dark brown, even black in some specimens, sometimes with areas of orange immediately above antennal toruli; vertex and posterior of head dark brown to black; uppermost portion of gena dark brown to black, remainder of gena orange to yellow orange; postgena yellow orange to yellow. Mesosoma largely yellow orange to orange except mesoscutum black; propodeum orange to black, often reddish brown; mes- and metepisternum reddish brown to dark brown ventrally, mesepisternum also often with black above between pronotal lobe and hypoepimeral area; lateral surface of propodeum reddish brown to black except upper third to quarter typically orange; tegula yellow to yellow orange and semi-translucent; legs largely yellow orange to orange except reddish brown to dark brown medially on corbicula and sometimes on prolateral surface of metabasitarsus. Wing membranes hyaline clear to lightly parchment colored; veins orange. Metasoma generally dark brown to black except anterior-facing surface of tergum I yellow orange to orange, dorsal-facing surface of tergum I and terga II– V posteriorly brownish orange blending to yellow apical marginal zones; sterna yellow brown to orange.

Areas of short, white, plumose setae in S. ederi instead yellow. Vertex with numerous erect, simple, yellow to light fulvous bristles; pronotal dorsolateral margin near and anterior to pronotal lobe with yellow to light fulvous bristles; mesoscutum anterior and lateral borders with largely yellow to sometimes light fulvous bristles; tegula with suberect yellow bristles anteriorly; mesoscutellum with abundant, elongate, erect yellow to sometimes light fulvous bristles; mesepisternum with scatered, erect to subdecumbent yellow to light fulvous bristles, longer ventrally, along rounded anterior border with preëpisternum a line of abundant, suberect yellow to light fulvous bristles extending ventrally from pronotal lobe; lateral surface of propodeum with scatered, long, erect, yellow bristles. Legs with abundant yellow to sometimes light fulvous bristles except metatibial marginal fringes yellow to fulvous, inferior corbicular bristles light fulvous to fulvous, superior corbicular bristles dark fulvous to nearly black. Metasoma with numerous, prominent, suberect to subdecumbent, light fulvous to yellow bristles on terga III – V arising amid tomentum.

♀: Latet.

♂: Latet.

HOLOTYPE: ⚲, Bolivia: Yungas del Palmar , 1000m, Oct. 1950, Zischka ( SEMC).

PARATYPES: 116⚲⚲, Bolivia: Yungas del Palmar , 1000m, Oct. 1950, Zischka ( SEMC) ; 1⚲, Bolivia: Depto. La Paz, Alto Marani , N of Rurrenbeque, 10 Nov 1966, L. Peña ( SEMC) ; 2⚲⚲, Bolivia: Pto. Fon Beni, Beni, 12 Nov. 1956, L. Peña ( SEMC) ; 2⚲⚲, Bolivia: Reyes Chitihuara , 14/ 30 Nov 1956 ( SEMC) .

ETYMOLOGY: The specific epithet is taken from the type locality, Yungas del Palmar. The name is formed from Yungas and the Latin suffix – ēnsis, which is added to a toponym to indicate “from” or “of”.

Figures

Figures 59–61. Worker of Scaptotrigona yungasensis, new species. 59. Lateral habitus. 60. Dorsal habitus. 61. Facial view.

Figures 67–68. Worker of Scaptotrigona ochrotricha (Buysson). 67. Dorsal view of head and me- sosoma. 68. Dorsal view of metasoma.

Figures 64–66. Worker of Scaptotrigona ochrotricha (Buysson). 64. Lateral habitus. 65. Dorsal habitus. 66. Facial view.