Scaptotrigona (Gymnotrigona) stipula, Engel, 2022

Engel, Michael S., 2022, Notes on South American stingless bees of the genus Scaptotrigona (Hymenoptera: Apidae), Part III: A revised infrageneric classification and new species, Journal of Melittology 2022 (111), pp. 1-29 : 22-23

Scaptotrigona (Gymnotrigona) stipula Engel, new species

ZooBank: urn:lsid:zoobank.org:act:EA923AC6-8A8D-444B-B194-806EEF7F29F2

( Figs. 35, 36 )

DIAGNOSIS: This species is exceptionally similar to S. depilis (Moure) , and could represent a subspecific color variant. For now I have retained it as a full species, which can be distinguished from S. depilis most easily by the lighter mesoscutellum, which is brownish orange with yellow brown apically; and by the sparse, minute, decumbent bristles of terga III and IV black and tergum VI with minute, black bristles (absent in S. depilis ).

DESCRIPTION: As described for S. totobi (vide supra) except as follows: ⚲: Total body length approximately 6.0 mm, forewing length (to base of humeral sclerite) 5.8 mm. Head wider than long, width 2.58 mm, length 2.06 mm; compound eye length 1.48 mm; upper interorbital distance 1.67 mm, lower interorbital distance 1.52 mm. Scape length 0.97 mm, slightly longer than torulocellar distance, torulocellar distance 0.88 mm. Clypeus approximately 1.6× as wide as long, length 0.67 mm, width 1.09 mm. Malar area 1.6× flagellar diameter. Preoccipital carina strong, lamellate dorsally and bordered by deep medial and lateral indentations, carina interrupted laterally by deep concavity, preoccipital lamella extending slightly into concavity, lower margin of concavity projected upward as acute, lamellate tooth.

Integument generally dark reddish brown except as noted; labiomaxillary complex yellow brown; clypeus medially and apically yellow to yellow brown, laterally brown, mediobasally orange brown; supraclypeal area orange brown; face below tangent of antennal toruli orange brown, blending to reddish brown above, with circular spot of yellow bordering clypeus and lower outer margin of antennal torulus; malar space orange brown to yellow brown; scape dark brown above, narrowly yellow brown to orange ventrally; flagellum dark brown except light brown to orange below; face above antennal toruli reddish brown, lighter below and darker above; vertex, posterior of head, and majority of gena reddish brown, darker above than below; gena bordering malar space brownish yellow; hypostomal borders yellow. Pronotum reddish or orange brown; mesoscutum black; mesoscutellum reddish brown to brown with yellow brown medioapically; mesepisternum dark reddish brown except posteriorly becoming lighter; metepisternum and propodeum reddish brown. Legs largely dark reddish brown except yellow brown on coxae, trochanters, tibiae at apices, tarsi, and retrolateral surface of metatibia and metabasitarsus. Wing membranes hyaline clear to faintly parchment colored; veins orange. Metasoma largely reddish brown except lighter apically on tergum II and somewhat on tergum III; sterna yellow brown.

Sculpturing as described for S. psile (vide supra).

Fine pubescence generally consisting of sparse, minute, appressed to decumbent pale yellow to fulvous setae, such minute setae often simple but sometimes plumose; minute yellow setae sparse on lower face, more numerous on frons except upper frons such setae blending to more erect largely simple, fulvous setae and black bristles; gena with scatered yellow setae similar to that of face; postgena with erect, dark fulvous to fuscous setae. Pronotal lobe with dense, yellow, plumose setae; mesoscutum and mesoscutellum with scatered, minute, simple, subappressed to decumbent, fulvous setae; metanotum with abundant, yellow, plumose setae; mesepisternum with similar setae to that of mesoscutum, such setae blending ventrally to longer, more pale yellow or fulvous setae ventrally; metepisternum with dense, pale yellow, plumose setae; propodeum lateral surface with similar setae to that of metepisternum. Legs with largely pale yellow setae. Metasomal terga with minute, appressed fulvous setae sparse, such setae more abundant and noticeable on terga IV–VI, and longer on terga V and VI, except anterior-facing surface of tergum I glabrous; terga II–V with apical fimbriae of minute, fine, simple, yellow to golden setae; terga III–V with small, diffuse patches of appressed, plumose, pale yellow tomentum far laterally; sterna with elongate, erect, simple, pale yellow scopal setae, such setae with wavy apices. Bristles in distinct areas of body: Labrum with some erect, simple bristles; upper frons and vertex with dark fulvous to black bristles; fulvous to black bristles along anterior margin of pronotal lobe; mesoscutum anterior and lateral margins with abundant black bristles; tegula with suberect black bristles anteriorly; mesoscutellum with fulvous to black bristles, longest on posterior margin; black bristles scatered over mesepisternum, becoming fulvous ventrally, and a distinct line of black bristles along rounded margin with preëpisternum; legs with numerous black bristles, those of distitarsomeres typically fulvous; metatibial and metabasitarsal bristles black, sometimes with fulvous tips. Metasoma terga I and II without bristles on discs; tergum I without bristles laterally; tergum II with minute, subdecumbent, dark fuscous to black bristles laterally; terga III–V with sparsely scatered minute, subdecumbent dark fuscous to black bristles on discs and particularly laterally, those on terga IV and V progressively more fulvous; tergum VI with minute, subdecumbent to suberect, black bristles sparsely scatered on disc, and long, erect, pale yellow bristles laterally and along margin.

♀: Latet.

♂: Latet.

HOLOTYPE: ⚲, Brazil: S.P. [São Paulo], Barretos , II-15-66 [15 February 1966], Camargo & Weaver ( SEMC).

ETYMOLOGY: The specific epithet is the Latin noun stipula , meaning, “stubble”.

Figures

Figures 33–36. Workers of Scaptotrigona Moure. 33. Lateral habitus of Scaptotrigona (Gymnotrigona) nuda, new species. 34. Facial view of S. (G.) nuda. 35. Facial view of S. (G.) stipula, new species. 36. Lateral habitus of S. (G.) stipula.