Scaptotrigona (Gymnotrigona) aurantipes, 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 : 13-17

Scaptotrigona (Gymnotrigona) aurantipes Engel, new species

ZooBank: urn:lsid:zoobank.org:act:533E0BA4-0AFE-458A-8E96-869B3087A5CA

( Figs. 20–29 )

DIAGNOSIS: This species is superficially similar to S. hellwegeri (Friese) owing to the extensive yellow to orange markings, rather than the other species of the subgenus in which the integument is almost wholly dark brown to black. Scaptotrigona aurantipes can be most readily distinguished from S. hellwegeri ( Fig. 19 ) by the reversal of coloration: in S. aurantipes the mesoscutum black (versus orange in S. hellwegeri ), the mesoscutellum is orange (versus black in S. hellwegeri ), the tegula is orange (versus dark brown in S. hellwegeri ), and the metasoma lacks orange markings. Like most species of Gymnotrigona , metasomal terga II–V have minute fimbriae (absent in three of the species: vide Key, supra).

DESCRIPTION: As described for S. totobi (vide supra) except as follows: ⚲: Total body length approximately 5.6–6.0, forewing length (to base of humeral sclerite) 5.6–5.9 mm. Head wider than long, width 2.42–2.55 mm, length 1.94–1.97 mm; compound eye length 1.39–1.42 mm; upper interorbital distance 1.58–1.67 mm, lower interorbital distance 1.45–1.52 mm. Scape length 0.91–0.94 mm, slightly longer than torulocellar distance, torulocellar distance 0.85–0.88 mm. Clypeus approximately 1.7–1.8× as wide as long, length 0.61–0.64 mm, width 1.15–1.21 mm. Malar area 1.6× flagellar diameter. Preoccipital carina strong, lamellate dorsally and bordered by deep medial and lateral indentations, carina interrupted laterally by shallow concavity, preoccipital lamella scarcely extending into concavity, lower margin of concavity rounded, not projecting upward as tooth.

Integument generally dark brown to black except with extensive areas of orange as follows: clypeus and supraclypeal area yellow orange to orange except typically fading to brown in apicolateral corners of clypeus; face below tangent of antennal toruli and malar space yellow orange to orange; scape yellow orange to orange, typically with some brown dorsoapically; flagellum brown except orange beneath; face of antennal toruli largely dark brown to black except with triangular area of yellow orange to orange beneath sloping to inner orbit of compound eye and fading to reddish brown or brown before dark brown to black on frons; majority of gena and postgena yellow orange to orange, yellow bordering hypostomal fossa; pronotum yellow orange; mesoscutellum reddish orange to orange; tegula orange and semi-translucent; posterior half of mesepisternum orange except sometimes with reddish brown spot medially in posterior section; propodeum sometimes with patch of orange on lateral surface; legs largely yellow brown to orange, with areas of brown to dark brown on femora and prolateral surface of metatibia; metasomal terga largely dark brown except reddish brown on anterior-facing surface of tergum I and sometimes brown to reddish brown apically on apical margins of terga II–V; sterna dark brown with lighter, semi-translucent apical margins.

Integument smooth and shining amid punctures; clypeus with small shallow punctures separated by a puncture width or less; supraclypeal area as on clypeus; lower face with small shallow punctures as on clypeus along inner orbit blending to sparse toward epistomal sulcus and antennal torulus; punctures on frons separated by less than a puncture width, punctures more minute and separated by 1–2× a puncture width in ocellocular area; punctures of vertex ill-defined and blending to coarsely imbricate integument; posterior of head coarsely imbricate; gena with punctures similar to frons; postgena nearly impunctate. Mesoscutum and mesoscutellum with small contiguous punctures; pleura with coarse, irregular, contiguous punctures, punctures slightly weaker ventrally; punctures of metepisternum smaller and more distinct than those of mesepisternum; propodeum with small contiguous punctures on lateral surface; basal area of propodeum tessellate. Metasomal terga coarsely imbricate, except anterior-facing surface of tergum I smooth, apical marginal zones virtually absent; tergum VI finely imbricate, largely impunctate, shining; sterna finely imbricate.

Fine pubescence generally consisting of sparse, minute, appressed or decumbent yellow to off white setae, such minute setae often simple but sometimes plumose. Pronotal lobe with dense, yellow, plumose setae; mesoscutum and mesoscutellum with scatered, minute, simple, yellow to slightly fulvous setae; metanotum with abundant, yellow to off-white, plumose setae; mesepisternum with similar setae to that of mesoscutum, such setae blending ventrally to longer setae ventrally; metepisternum with dense, off-white, plumose setae; propodeum lateral surface with similar setae to that of metepisternum. Legs with largely yellow to light fulvous setae. Metasomal terga with scatered, minute, simple, decumbent, fulvous setae, 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, light fulvous setae; sterna with elongate, erect, simple, yellow scopal setae, such setae with wavy apices. Bristles in distinct areas of body: Labrum with some erect, simple, yellow to fulvous bristles; upper frons and vertex with fulvous bristles, those of vertex longest, particularly medially posterior to ocelli; fulvous bristles along anterior margin of pronotal lobe; mesoscutum anterior and lateral margins with abundant fulvous bristles; tegula with suberect yellow to fulvous bristles anteriorly; mesoscutellum with fulvous bristles, particularly long and abundant along posterior margin; yellow bristles scatered over mesepisternum and a distinct line of fulvous bristles along rounded margin with preëpisternum; legs with largely yellow to light fulvous bristles; corbicular bristles dark fuscous to dark fulvous, metatibial fringe bristles fulvous; metabasitarsus with some fulvous to dark fulvous bristles on margins and a few finer such bristles on prolateral surface. Metasoma terga I–V without bristles on discs; terga I and II without bristles laterally; terga II–V with minute to short, subdecumbent to suberect, fulvous bristles laterally; tergum VI with such bristles sparse on disc, but more numerous long, erect, fulvous bristles laterally and along margin.

♀: Latet.

♂: As described for worker except as follows: Total body length approximately 6.1–6.4 mm, forewing length (to base of humeral sclerite) 5.5–5.6 mm. Head wider than long, width 2.27–2.30 mm, length 1.88–1.91 mm; compound eye length 1.52 mm; upper interorbital distance 1.36–1.39 mm, lower interorbital distance 1.00– 1.03 mm. Scape length 0.64–0.67 mm, much shorter than torulocellar distance, torulocellar distance 0.76 mm. Clypeus approximately 1.7× as wide as long, length 0.58 mm, width 0.97–1.00 mm. Malar area 0.6× flagellar diameter. Gena narrower than compound eye. Preoccipital ridge carinate dorsally, sharply angled at best laterally, without concavity or bordering indentations. Terminalia in figures 26–29.

Face below tangent of antennal toruli yellow to orange, remainder of face black; vertex, posterior of head, and majority of gena black, lower gena near malar space orange; postgena reddish orange anteriorly, black posteriorly; scape yellow to yellow orange; pedicel and flagellum orange beneath, narrowly light brown above. Mesosoma black except pronotum yellow orange to orange; tegula wholly orange and semi-translucent. Legs entirely yellow to yellow orange. Metasomal terga dark brown except ventral-facing lateral surfaces yellow to yellow brown, anterior-facing surface of tergum I yellow brown, tergum VII apically yellow; sterna largely yellow to yellow brown.

Appressed, simple, short setae of mesoscutum more abundant and longer than in worker, more fulvous; sterna without scopal setae as in worker but with dense, subdecumbent to decumbent, mesial-posteriorly directed, simple, elongate, yellow setae. Bristles as follow: bristles of drone generally more elongate than those of worker. Legs with abundant yellow to light fulvous bristles except numerous, thin, black bristles intermixed on prolateral surface of metatibia.

HOLOTYPE: ⚲, Venezuela: Aragua, Rancho Grande Biol. Stn., Portachuelo Pass , 10°21’0’’N, 67°41’0’’W, 1100 m, 4 Jun 1998, J. Ashe, R. Brooks, R. Hanley, ex: insects moving thru pass against wind-migration ( SEMC).

PARATYPES: 1⚲, 2♂♂, Venezuela: Aragua, Rancho Grande Biol. Stn., Portachuelo Pass, 10°21’0’’N, 67°41’0’’W, 1100 m, 4 Jun 1998, J. Ashe, R. Brooks, R. Hanley, ex: insects moving thru pass against wind-migration ( SEMC); 1⚲, Venezuela: Aragua, El Pao de Zarate Carreteria, Guacomayo, 900 m, May 1977; 1⚲, Venezuela: Estación Biol. de los Llanos, Calabozo Ed. Guárico, 25 July 1987, N. Ramirez, ex: flowers of Croton [ Euphorbiaceae : Crotonoideae: Croton L.] ( SEMC); 1⚲, Venezuela: Suroeste del Valle de Caracas, Edo. Miranda, Bosque deciduo secundario, 10°30’N, 66°53’W, 110 m. s.n.m., N. Ramirez, visita flores de Mimosa [ Fabaceae : Caesalpinioideae: Mimosa L.] ( SEMC); 1⚲, Venezuela: Suroeste del Valle de Caracas, Edo. Miranda, Bosque deciduo secundario, 10°30’N, 66°53’W, 110 m. s.n.m., N. Ramirez, visita flores de Croton scaber [ Euphorbiaceae : Crotonoideae: Croton scaber Willd. ] ( SEMC).

ETYMOLOGY: The specific epithet is a combination of the Latin adjective aurantius (meaning, “orange”) and noun pēs (meaning, “foot”).

Figures

Figure 19. Lateral habitus of worker of Scaptotrigona (Gymnotrigona) hellwegeri (Friese).

Figures 20–22. Worker of Scaptotrigona (Gymnotrigona) aurantipes, new species. 20. Lateral habitus. 21. Dorsal habitus. 22. Facial view.

Figures 23–25. Drone of Scaptotrigona (Gymnotrigona) aurantipes, new species. 23. Lateral habitus. 24. Facial view. 25. Dorsal habitus.

Figures 26–29. Male terminalia of Scaptotrigona (Gymnotrigona) aurantipes, new species. 26. Ster- num VI. 27. Sternum VII. 28. Sternum VIII. 29. Genital capsule, left side dorsal view, right side ventral view.