Scaptotrigona baldwini 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 : 39-41

Scaptotrigona baldwini Engel , new species

ZooBank: urn:lsid:zoobank.org:act:875A20FC-7ECC-46CA-BA97-924EADF05EB5

( Fig. 57 )

DIAGNOSIS: This is a noticeably yellow species ( Fig. 57 ), and generally resembles species such as S. nigrohirta and S. xanthotricha , both of which are typically darker. From S. nigrohirta it is most easily distinguished by the presence of yellow bristles on metasomal terga III – V (rather than the dark fuscous bristles of S. nigrohirta ), and from S. xanthotricha by the presence of yellow bristles on the tegula and metasomal terga III – V (fuscous to black on the tegula, and fulvous to dark fulvous on the metasoma in S. xanthotricha ).

DESCRIPTION: As described for S. ederi (vide supra), with the following modifications: ⚲: Total body length approximately 6.0– 6.5 mm, forewing length (to base of humeral sclerite) 5.9–6.4 mm. Head wider than long, width 2.51–2.67 mm, length 2.15–2.24 mm; compound eye length 1.45–1.55 mm; upper interorbital distance 1.61–1.79 mm, lower interorbital distance 1.52–1.70 mm. Scape length 0.97–1.03 mm, about as long as torulocellar distance, torulocellar distance 0.91–1.03 mm. Clypeus approximately 1.7× as wide as long, length 0.67–0.73 mm, width 1.16–1.24 mm. Malar area approximately 2.2–2.4× flagellar diameter or 0.96–0.98× 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 a sharp lamellate tooth.

Integument of labiomaxillary complex yellow; labrum yellow; mandible yellow orange to orange; clypeus largely yellow to yellow orange, epistomal sulcus well delineated by yellow brown to dark brown; supraclypeal area yellow to yellow orange; malar space yellow to yellow orange; face below tangent of antennal toruli yellow orange; scape yellow to yellow orange except with patch of brown dorsoapically; pedicel and flagellum brown, with narrow underside of flagellum orange; lowermost frons as on face below antennal toruli, blending above to reddish brown and brown, vertex and ocellocular as on upper frons, except sometimes with small spot of orange in ocellocular area bordering upper orbit; posterior of as on upper frons; uppermost edge of gena as on vertex, remainder of gena orange; postgena orange to yellow orange. Mesosoma largely orange except mesoscutum black, mesepisternum with large patch of dark brown ventroanteriorly, and sometimes brown on lateral margins of basal area of propodeum; tegula wholly yellow orange and semi-translucent; legs yellow orange to orange. Wing membranes lightly parchment colored except with noticeable infumate patch at apex of marginal cell; veins orange. Metasoma generally dark brown except anterior-facing surface of tergum I orange, dorsal-facing disc of tergum I largely yellow medially and posteriorly, with lateral area dark brown; tergum II with large medial area of yellow and laterally with broad dark brown patches tapering mesally, apical marginal zone yellow; terga III – V dark brown with yellow apical marginal zones; tergum VI dark brown; sterna orange to light brown.

Vertex with numerous erect, simple, yellow to fulvous bristles; pronotal dorsolateral margin near and anterior to pronotal lobe with yellow to fulvous bristles; mesoscutum anterior and lateral borders with yellow to fulvous bristles; tegula with suberect yellow bristles anteriorly; mesoscutellum with abundant, elongate, erect yellow bristles posteriorly; mesepisternum with scatered, erect to subdecumbent yellow to fulvous bristles, longer ventrally, along rounded anterior border with preëpisternum a line of abundant, suberect to subdecumbent fulvous bristles extending ventrally from pronotal lobe; lateral surface of propodeum with scatered, long, erect, yellow bristles emerging amid dense, appressed, yellow, plumose setae. Legs with abundant yellow to fulvous bristles except corbicular bristles dark fuscous to black contrasting with yellow marginal bristles, sometimes with a few black bristles intermixed on margins; metabasitarsus with yellow bristles except sometimes with a few dark fulvous to black bristles intermixed on proventral margin, but prolateral surface uniformly with fine, erect, simple, yellow setae. Metasoma with numerous, prominent, suberect to subdecumbent, yellow to fulvous bristles on terga III – V arising amid tomentum.

♀: Latet.

♂: Latet.

HOLOTYPE: ⚲, Peru: Madre de Dios, Pakita Bio. Stn., Reserved Zone, Manu National Park , 317 m, 11°56’41’’S, 71°17’0’’W, 16 Oct. 2000, R. Brooks, ex: wet area near stream ( SEMC).

PARATYPES: 2⚲⚲, Peru: Madre de Dios, Pakita Bio. Stn., Reserved Zone, Manu National Park , 317 m, 11°56’41’’S, 71°17’0’’W, 16 Oct. 2000, R. Brooks , ex: wet area near stream ( SEMC) .

ETYMOLOGY: The specific epithet honors the inspiring writings and life of James A. Baldwin (1924–1987), whose energies and moral essays identified paths and placed crucial paving stones toward a more just, equitable, and healed world.

COMMENT: One of the paratypes exhibits an interesting aberration in the form of the right mesotibial spur. Rather than being a slender serrate spur it is instead formed like the protibial spur, complete with a velum and short malus.

Figures

Figures 57–58. Workers of Scaptotrigona Moure. 57. Lateral habitus of Scaptotrigona baldwini, new species. 58. Lateral habitus of S. santiago, new species.