Scaptotrigona macarenensis 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 : 32-35

Scaptotrigona macarenensis Engel , new species

ZooBank: urn:lsid:zoobank.org:act:E26E55DA-844C-47C5-B518-F484DE092234

( Fig. 49 )

DIAGNOSIS: This is a larger species much like S. ochrotricha (Buysson) , S. nigrohirta Nogueira & Santos-Silva , and S. xanthotricha Moure , and, owing to the stripes of the mesoscutum most closely resembles the first of these. Unlike S. ochrotricha , however, the fore and mid-legs lack black bristles and the metatibia is dominated by yellow to fulvous bristles. There is the possibility that this is a much lighter form of S. ochrotricha (if this species exhibited color dimorphism), but until more sampling is made across the region and nests found it seems that they are quite distinct.

DESCRIPTION: As described for S. ederi (vide supra), with the following modifications: ⚲: Total body length approximately 6.3–6.8 mm, forewing length (to base of humeral sclerite) 6.3–6.5 mm. Head wider than long, width 2.61–2.73 mm, length 2.09–2.18 mm; compound eye length 1.45–1.52 mm; upper interorbital distance 1.67–1.71 mm, lower interorbital distance 1.55–1.64 mm. Scape length 0.97–1.00 mm, about as long as torulocellar distance, torulocellar distance 0.91–0.94 mm. Clypeus approximately 1.7–1.75× as wide as long, length 0.67–0.75 mm, width 1.18–1.27 mm. Malar area approximately 2.0× flagellar diameter or 0.83–0.85× 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 acutely rounded angle projecting upward as a large lamellate tooth.

Integument of labiomaxillary complex yellow; labrum yellow; mandible yellow, sometimes blending to slightly orange apically; clypeus yellow, epistomal sulcus nearly concolorous with clypeus, delineated by light brown to orange; supraclypeal area yellow; malar space yellow; face below upper tangent of antennal toruli yellow; lower frons yellow and blending to brown or dark brown on upper frons, with brown extending slightly ventrally along inner orbit; ocellocular area and vertex brown to dark brown; uppermost gena brown; remainder of gena and postgena yellow; scape yellow, sometimes with patch of brown dorsoapically; pedicel and flagellum brown, with flagellum lighter ventrally. Mesosoma largely yellow except mesoscutum black and with longitudinal strips of reddish orange laterally, along posterior border, and from notauli to posterior border; metanotum sometimes dark brown to black; propodeum sometimes dark brown to black, but always with lateral surface largely yellow; metepisternum sometimes with dark brown along posterior border; mesepisternum sometimes with dark brown patch ventrally; tegula yellow and semi-translucent; legs yellow except sometimes with brownish mark on metafemur dorsoapically. Metasoma generally dark brown except anterior-facing surface of tergum I yellow, dorsal-facing disc of tergum I largely yellow except brown to dark brown laterally; tergum II yellow to yellow brown on disc, with broad areas of brown laterally and yellow apical marginal zone; terga III – V dark brown with large yellow marginal zones obscured by tomentum; sterna largely yellow to yellow brown.

As for S. ederi except areas of short, plumose setae yellow to pale yellow instead of white; metepisternum and lateral surface of propodeum obscured by dense, plumose, yellow setae; dorsal-facing surface of tergum I with largely simple setae, minute, decumbent, yellow, plumose setae nearly absent. Bristles of vertex erect, simple, yellow to fulvous; pronotal dorsolateral margin near and anterior to pronotal lobe with long, arched, yellow bristles; mesoscutum anterior and lateral borders with erect bristles, those on lateral border short, anterior margin with yellow to fulvous bristles; tegula with short, suberect, yellow bristles anteriorly; mesoscutellum with abundant, elongate, erect bristles posteriorly, such bristles minutely pectinate apically, discal bristles shorter, mesoscutellar bristles yellow; mesepisternal bristles as in S. ederi except yellow. Legs with abundant bristles, bristles yellow to fulvous; corbicular bristles dark fulvous to fuscous, marginal bristles yellow to fulvous; prolateral surface of metabasitarsus with scatered fine, simple, yellow setae (noticeably thinner than marginal bristles), without black setae or bristles; penicillum dark fulvous; rastellum fulvous. Metasoma with numerous, prominent, suberect to subdecumbent, yellow to fulvous bristles on terga III – V arising from tomentum, as well as similar bristles scatered on tergum II.

♀: Latet.

♂: Latet.

HOLOTYPE: ⚲, Colombia: Meta, Reserva La Macarena , between Rio Duda and Rio Guayabero, 1 April 1988, F. Fernández ( SEMC).

PARATYPES: 2⚲⚲, Colombia: Meta, Reserva La Macarena , between Rio Duda and Rio Guayabero, 1 April 1988, F. Fernández ( SEMC); 3⚲⚲, Colombia: Macarena Mts. , I-11-1950 [11 January 1950], 500–650 m, L. Richter ( SEMC) .

ETYMOLOGY: The specific epithet refers to the Serranía de la Macarena and its associated national ecological reserve in Meta Department, Colombia. The name is formed from Macarena and the Latin suffix – ēnsis, which is added to a toponym to indicate “from” or “of”.

Figures

Figures 49–50. Workers of Scaptotrigona Moure. 49. Lateral habitus of Scaptotrigona macarenensis, new species. 50. Lateral habitus of S. caduceus, new species.