Scaptotrigona ederi 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 : 6-12

Scaptotrigona ederi Engel , new species

ZooBank: urn:lsid:zoobank.org:act:3004F475-B4C8-48ED-8C9A-350A4EAA18D2

( Figs. 1–11 )

DIAGNOSIS: This is a comparatively abundant and distinctive species in the western Andean region of Colombia around Cali and currently known to range in elevation from 740–1500 m, making it one of the highest occurrences for Scaptotrigona (second only to S. magdalenae , vide infra). Reports of S. ederi (as a nomen nudum) from the East of Colombia and elsewhere have generally been based on misidentifications. Among species in this subgroup, S. ederi is most superficially similar to those species of subgroup B in relation to its generally dark coloration, although it still falls within subgroup A at the darker end of the spectrum. The species is one of a few that lacks a defined genal tooth projecting upward from the lower margin of the lateral concavity in the preoccipital carina. Among those without such a defined genal tooth, the dark coloration, black or at least dark fuscous bristles of the vertex and mesoscutal anterolateral corners, and nearly entirely black bristles of the metabasitarsus (and frequently the metatibia), serve to distinguish this species most readily. In addition, the prominent bristles of metasomal terga III – V are yellow to fulvous in color.

DESCRIPTION: ⚲: Total body length approximately 5.8–6.2 mm, forewing length (to base of humeral sclerite) 5.8–6.2 mm. Head wider than long, width 2.30–2.42 mm, length 1.91–2.06 mm; compound eye length 1.36–1.39 mm; upper interorbital distance 1.55–1.61 mm, lower interorbital distance 1.45–1.52 mm. Scape length 0.88–0.91 mm, about as long as torulocellar distance, torulocellar distance 0.88–0.91 mm; flagellomere I longer than wide, longer than flagellomere II, remaining flagellomeres about as long as wide to slightly longer than wide except apical flagellomere longer than wide. Clypeus broader than long, approximately 1.7–1.75× as wide as long, length 0.61–0.64 mm, width 1.06–1.09 mm. Malar area long, length approximately 1.55–1.7× flagellar diameter or 0.75–0.82× basal mandibular width. Preoccipital ridge carinate, weakly lamellate dorsally, with bordering medial indentation shallower than lateral indentations, laterally concavity interrupting carina comparatively shallow, lower margin of concavity with carina forming rounded angle, sometimes slightly acute, without sharply acute lamellate projection (genal tooth) extending upward.

Integument of labiomaxillary complex yellow orange except prementum typically brown; labrum yellow orange to dark orange; mandible yellow orange to ferruginous; clypeus largely yellow orange to orange except typically with dark brown mark at medioapical margin and apicolateral corners from apical margin to epistomal sulcus (sometimes absent or faint, and sometimes these all merged medioapically), often with mediolongitudinal brown mark from base to about midlength, epistomal sulcus well delineated by brown to black; supraclypeal area brown to dark brown; malar space often dark brown, sometimes light brown to orange; face below tangent of antennal toruli orange to light yellow brown, typically slightly darker toward lateral borders of antennal toruli and often extending along inner orbit as narrow strip to point slightly above upper tangent of antennal toruli; scape yellow orange except typically brown dorsoapically, sometimes brown extending along entire dorsal surface; pedicel and flagellum typically dark brown above, with narrow underside of flagellum orange to light brown; remainder of face dark brown to black, sometimes with small areas of light brown immediately above antennal toruli; posterior of head dark brown; upper gena dark brown, remainder of gena orange, although if malar space dark brown, then such dark brown extends onto gena ventroapically; postgena orange to yellow orange. Mesosoma typically dark brown to black, with ferruginous apex to mesoscutellum, except sometimes with areas of reddish orange to reddish brown on mesepisternum, typically as small areas posteriorly and ventrally, and sometimes ventrally on propodeum, and mesoscutellum ranging from wholly orange to wholly black, with degrees of intermixing of colors between, V-shaped incision in mesoscutellum typically black; tegula wholly yellow orange and semi-translucent, sometimes with slight brownish darkening anteriorly; legs typically yellow orange on coxae, trochanters, basal portions of tibiae, distitarsomeres, and inferior and superior areas of metabasitarsus, with remainder of tibiae, femora, and tarsi dark brown to black, except sometimes mesoand metacoxae light brown. Wing membranes hyaline clear to lightly parchment colored; veins yellow orange. Metasoma generally dark brown to black except anterior-facing surface of tergum I typically reddish brown to light yellow brown, dorsal-facing disc of tergum I often medially lighter reddish brown to yellowish brown and with exceptionally narrow apical marginal zone of reddish brown to yellow and terga II– IV with variably developed apical marginal zones of light brown to more frequently yellow, sometimes quite broad on terga II and III; tergum II sometimes with light reddish brown laterally and on disc and blending gradually to yellow apical marginal zone; yellow apical marginal zones of terga III and IV typically obscured by dense tomentum; sterna reddish brown to dark brown.

Integument mostly smooth and shining between punctures, punctures of head difficult to see, those of mesosoma and metasoma clear; clypeus with small, shallow, nearly contiguous punctures, in some small areas punctures separated by up to 0.75× a puncture width, punctures somewhat faint; supraclypeal area with small, shallow, nearly contiguous punctures; lower face with small punctures separated less than a puncture width, slightly fainter and more spaced than on clypeus, and slightly sparser along orbital border and in malar space; upper face with small punctures nearly contiguous to contiguous medially, such punctures becoming shallower toward ocelli and giving surface a roughened appearance, laterally punctures smaller and more distinct, separated by a puncture width or less; ocellocular area with punctures of upper lateral face becoming denser and blending posteriorly to slightly larger punctures like those of medial face; vertex and posterior of head punctures with shallow, coarse, contiguous punctures giving surface a roughened appearance, such punctures blending to minute, shallow, punctures separated by less than a puncture width on gena; postgena nearly impunctate and smooth. Mesoscutum and mesoscutellum with small contiguous punctures, punctures coarser and more irregular in shape along borders; pleura with punctures as on mesoscutum, those punctures ventrally a bit more separated, posteriorly punctures more irregularly shaped and elongate; metepisternum with small, nearly contiguous punctures; lateral surface of propodeum as on metepisternum; basal area of propodeum tessellate to microalveolate. Metasomal terga with minute contiguous punctures blending to imbricate integument in apical marginal zones, except anterior-facing surface of tergum I impunctate and smooth; punctures laterally blending to imbricate integument, punctures weaker on tergum V, tergum VI largely impunctate and faintly imbricate; sterna finely and faintly imbricate.

Fine pubescence generally consisting of sparse to scatered, minute to short, appressed or decumbent yellow setae, such setae often simple but sometimes with minute branches or plumose, as well as areas of short, white, plumose setae such as dense on pronotal lobe, largely obscuring integument on metepisternum and lateral surface of propodeum; fine setae sparse on clypeus, more numerous on face and progressively longer on upper face and vertex; scape with sparse, minute, appressed setae and two erect to suberect, simple bristles at base (frequently obscured or even sometimes broken off); terga I– VI with plumose yellow tomentum, on tergum I such setae are diffuse, more suberect, and not obscuring integument, frequently worn such that in some specimens they are completely absent to only scatered in irregular places (most easily seen in profile), tergum II with such setae diffuse to sometimes lacking laterally (most easily seen in profile), but dense in apical marginal zone, terga III – V with such tomentum dense and obscuring integument, tomentum paler and sparser on tergum VI; sterna II– V with scopa composed of elongate, erect, simple setae with characteristically wavy apices, such scopal setae yellowish. Bristles (thick, typically erect, often simple or with minute pectinate branches apically) typically sparse on body except in certain areas as noted. Labrum with sparse, erect, simple, yellow to fulvous bristles, those medially longest; vertex with numerous erect, simple, fulvous to sometimes fuscous bristles, longest medially and extending across vertex to just posterior to upper orbit; pronotal dorsolateral margin near and anterior to pronotal lobe with bristles, sometimes arched apically, yellow to fulvous; mesoscutum anterior and lateral borders with erect bristles, those on lateral border short, bristles largely fulvous to sometimes fuscous along anterior margin, typically fuscous bristles intermixed with fulvous bristles in anterolateral corner but sometimes intermixed along entire anterior margin, bristles on lateral border typically fuscous to black; tegula with short, suberect bristles anteriorly, such bristles typically yellow or fulvous, more uncommonly fuscous; mesoscutellum with abundant, elongate, erect bristles posteriorly, such bristles minutely pectinate apically, mesoscutellar bristles typically light fulvous, sometimes more darkly fulvous; mesepisternum with scatered, subdecumbent fulvous bristles, longer ventrally, along rounded anterior border with preëpisternum a line of abundant, suberect to subdecumbent bristles extending ventrally from pronotal lobe, such bristles fulvous to dark fulvous; lateral surface of propodeum with scatered, long, erect, yellow to fulvous bristles emerging amid dense, appressed, white, plumose setae. Legs with abundant bristles, those on basal podites typically yellow to fulvous, those apically on tibiae and tarsi typically black, sometimes with black bristles apically on femora, particularly metafemur, distitarsi typically with fulvous bristles dominant; metatibia with elongate simple black corbicular bristles and margins with long, arched, largely simple, black bristles; penicillum black; rastellum fulvous to fuscous; metabasitarsus with scatered erect black bristles on prolateral surface and numerous black bristles on margins intermixed with fulvous bristles, those of inferior margin most numerous; a few black bristles on distitarsomeres. Metasoma with numerous, prominent, suberect to subdecumbent, yellow to fulvous bristles on terga III – V arising amid tomentum, such bristles sparse to absent on tergum II, and more scatered on tergum VI except longer and more numerous laterally and on margin.

♀: Latet.

♂: Latet.

HOLOTYPE: ⚲, Colombia: Prov. Valle, 5 km SE of Dagua , 4 Feb 1977, M.D. Breed & C.D. Michener ( SEMC).

PARATYPES: 14⚲⚲, Colombia: Prov. Valle , 5 km SE of Dagua, 4 Feb 1977, M.D. Breed & C.D. Michener ( SEMC) ; 2⚲⚲, Colombia: Valle , near Loboguerrera, 6 Oct 1976, Michael Breed ( SEMC) ; 14⚲⚲, Colombia: Prov. Valle , Loboguerrera, 740 m, 4 Feb 1977, M.D. Breed & C.D. Michener ( SEMC) ; 7⚲⚲, Colombia: Prov. Valle , Cali, 1000 m, 16 Feb 1977, M.D. Breed & C.D. Michener ( SEMC) ; 2⚲⚲, Colombia: Valle , Lago Calima, 1500 m, IX-23-76 [23 September 1976], Bell, Breed, & Michener ( SEMC) ; 1⚲, Colombia: Valle , km 33, old Buenaventura Rd., 1300 m, IX-27-76 [27 September 1976], Bell, Breed, & Michener ( SEMC) ; 21⚲⚲, Colombia: Valle, El Carmen, 1370 m, IX-22-76 [22 September 1976], Bell, Breed, & Michener ( SEMC) ; 20⚲⚲, Colombia: Prov. Valle , 10 km SW Jamundi, 14 Feb 1977, 1200 m, M.D. Breed & C.D. Michener ( SEMC) ; 5⚲⚲, Colombia: Prov. Valle , 7 km SW Jamundi, 14 Feb 1977, 1100 m, M.D. Breed & C.D. Michener ( SEMC) .

ETYMOLOGY: This species has been frequently referenced in the literature but has never been described formally. In order to maintain some continuity the original name is maintained. The specific epithet was first proposed by Herbert F. Schwarz (1883– 1960) for an unnamed member of the Eder family. Henry J. (1870–1949) and Walter Eder (floruit 1927), son and grandson of the pioneering sugar industrialist James Martin Eder (1838–1921), provided logistical assistance to Schwarz during his 1935 collecting visit to Cali ( Schwarz, 1948). Herein, I take the presumption of proposing that the specific epithet honors the patriarch of the family in Colombia, J.M. Eder.

Figures

Figures 1–2. Workers of Scaptotrigona ederi, new species. 1. Lateral habitus of individual on the darker end of the color spectrum. 2. Lateral habitus of individual on the lighter end of the spectrum.

Figures 3–6. Workers of Scaptotrigona ederi, new species. 3. Facial view of individual on the lighter end of the color spectrum. 4. Facial view, darker worker. 5. Dorsal habitus, darker worker. 6. Dorsal habitus, lighter worker.

Figures 7–11. Workers of Scaptotrigona ederi, new species. 7. Dorsal view of mesosoma, lighter worker. 8. Dorsal view of mesosoma, darker worker. 9. Mesoscutellum. 10. Prolateral surface of metatibia, metatarsus, and metapretarsus. 11. Apical view of metasoma.