Oxytrigona Cockerell, 1917

Lepeco, Anderson, 2024, Contribution to the taxonomy of Oxytrigona Cockerell, 1917 (Apidae, Meliponini), Zootaxa 5506 (3), pp. 369-395 : 390-392

Key to the species of Oxytrigona Cockerell , based on workers

1. Forewing with distal portion of radial cell and entire marginal cell distinctly darkened; veins and pterostigma dark brown ( Figure 8A )......................................................................................... 2

- Forewing with membrane completely or mostly hyaline, distal portion of radial and marginal cells not strongly darkened, sometimes yellowish or brownish infumate (as in Figures 3E, F ); veins and pterostigma yellow to brown............... 3

2. Body predominantly yellow to orange; pubescence of head and mesosoma ferruginous; antennal scape with erect black setae (between 0.5 and 0.8 MOD in length) restricted to its distal portion ( Figure 8B ).... Oxytrigona mulfordi ( Schwarz, 1948)

- Body predominantly dark brown to black, only lower half of head pale; pubescence of head and mesosoma black; antennal scape usually with erect black setae (between 0.8 and 1.5 MOD in length) scattered throughout............................................................................................... Oxytrigona obscura (Friese, 1900)

3. Head mostly dark brown to black, often becoming lighter ventral to antennal socket level; mesoscutum entirely black; scutellum dark brown to black; pubescence mostly black.............................................................. 4

- Head mostly orange or yellow, at most with dark spot near ocelli; mesoscutum usually yellowish to brown, at least medially and on surface adjacent to tegula (except for O. cagafogo , in which it sometimes is entirely black, but the head is orange); scutellum yellow to brown; color of pubescence variable ............................................................. 7

4. Mesoscutum with long erect setae becoming virtually absent posterior to mid-level of tegula; scutellum with erect setae becoming distinctly shorter or absent on anterior half; scape mostly without erect black setae, only with very short erect setae near distal end; distal angle of dorsal margin of hind basitarsus sharply angled ( Figure 6D ); distal corner of dorsal margin of hind tibia with dense tuft of densely branched brown setae ( Figure 6D ).................. Oxytrigona sauronica sp. nov.

- Mesoscutum with long erect setae evenly distributed throughout sclerite; scutellum with erect setae evenly long, distributed throughout sclerite; scape with black erect setae with at least 0.5 MOD in length, often restricted to distal end; distal portion of dorsal margin of hind basitarsus widely angled or rounded; distal corner of dorsal margin of hind tibia with relatively sparse black setae with few apical ramifications.................................................................. 5

5. Hind basitarsus conspicuously narrower proximally, distal corner of dorsal margin rounded (as in Figure 8C ); smaller size, head width below 2.3 mm; scape with erect black setae (0.5–1.2 × F2 width) scattered throughout (as in Figure 8E ); pubescence on posterior surface of T3–T5 relatively sparse; short setae on posterior margin of T3 and T4 scarce, shorter than 0.2 MOD; F2 with distinctly long setae (longer than 0.7 F2 width, these setae can be absent in some specimens); surface between mid and lateral ocelli with short branched setae.................................................................... 6

- Hind basitarsus almost as wide proximally as on its distal portion, distal corner of dorsal margin widely angled ( Figure 8D ); larger size, head as wide as 2.5 mm or more; scape with erect black setae (0.5–1.2 × F2 width) restricted to its distal end ( Figure 8F ); T3–T5 with dense pubescence on posterior surface; short setae on posterior margin of T3 and T4 relatively abundant, longer than 0.2 MOD; F2 never with distinctly long setae; surface between mid and lateral ocelli with simple setae................................................................................ Oxytrigona ignis Camargo, 1984

6. Metasomal terga yellow to light ferruginous; scape light to dark brown; ventral half of face with orange hue................................................................................ Oxytrigona daemoniaca Camargo, 1984

- Metasomal terga dark brown; scape usually dark brown to black; ventral half of face with yellowish to light brown hue............................................................... Oxytrigona chocoana Gonzalez and Roubik, 2008

7. Surface between ocellar triangle and antennal sockets with dense coverage of short setae, punctation relatively dense, especially near ocellar triangle level (as in Figures 4B , 5B )............................................................ 8

- Surface between ocellar triangle and antennal sockets glabrous or with scattered tiny setae, punctation sparse (as in Figure 3B )............................................................................................... 11

8. Frons with evenly dense punctation between compound eye and frontal line, interspaces about as long as puncture diameter; long setae on frons absent ventrad ocellar triangle level; antennal sockets separated by nearly one socket diameter ( Figure 4B ); postero-dorsal surface of propodeum striate; ventral margin of fore femur carinate; mid basitarsus relatively short, as long as 2 × its maximum width.................................................. Oxytrigona mellicolor ( Packard, 1869)

- Frons with denser punctation near ocellar triangle level, becoming sparser near antennal sockets, interspaces far longer than puncture diameter; long setae usually present ventrad ocellar triangle level; antennal sockets separated by 0.8 × socket diameter or less; postero-dorsal surface of propodeum smooth; ventral margin of fore femur not carinate, rounded; mid basitarsus relatively long, longer than 2.3 × its maximum width........................................................ 9

9. Fore femur less than 3.7 times longer than its maximum width; smaller size, head width equal 2.4 mm or less; short setae on posterior margin of T3 relatively longer (0.5 × MOD) and densely branched................................................................................................... Oxytrigona isthmina Gonzalez & Roubik, 2008

- Fore femur longer than 4 × its maximum width; larger size, head width over 2.5 mm; short setae on posterior margin of T3 shorter than 0.4 × MOD and mostly simple............................................................... 10

10. Longest setae on vertex about 1.7 × MOD; mesoscutum yellow to orange between notauli and dark brown to black laterad; legs brown; posterior margin of S6 widely rounded (see fig. 9 in Gonzalez & Roubik 2008); setae on distal end of scape longer than 0.7 × MOD......................................................... Oxytrigona mediorufa (Cockerell, 1913)

- Longest setae on vertex about 1.3 × MOD or shorter; mesoscutum entirely light brown or caramel yellow; legs yellow; posterior margin of S6 truncate (see fig. 21 in Gonzalez & Roubik 2008); setae on distal end of scape shorter than 0.5 × MOD.................................................................................... Oxytrigona pallida sp. nov.

11. Erect setae on vertex yellowish; hind basitarsus relatively slender, with a slightly curved dorsal margin, with the posterior distal corner somewhat angled towards a straight distal margin ( Figure 3D ); distal half of wing membrane hyaline, at most slightly yellowish dorsally ( Figure 3F ); posterior margin of S6 somewhat pointed (see figure 65 of Gonzalez & Roubik 2008); S4–S6 with relatively denser coverage of setae, which are mostly yellowish; posterior margin of T4 mostly with sparse simple setae....................................................................... Oxytrigona flaveola (Friese, 1900)

- Erect setae on vertex light brown to black; hind basitarsus relatively broad, with a strongly curved dorsal margin, with the posterior distal corner somewhat rounded towards a curved distal margin (as in Figures 1D , 3C ); color of wing membrane variable, often with light or dark brown spots (as in Figures 1A , 3E ); posterior margin of S6 widely rounded (see figure 62 of Gonzalez & Roubik 2008); S4–S6 with sparser coverage of setae, which are entirely or mostly dark; posterior margin of T4 with relatively denser coverage of branched setae.......................................................... 12

12. Mesoscutum entirely black, sometimes with a lighter stripe adjacent to tegula ( Figure 3A ); forewing with distal portion of radial cell and entire marginal cell brownish infumate ( Figure 3E ); labrum and mandible mostly dark brown to black.................................................................................. Oxytrigona cagafogo ( Müller, 1874)

- Mesoscutum usually yellow to light brown between notauli and darker laterad, sometimes entirely light brown (as in Figures 1B , 7A ); forewing with distal portion of radial cell and entire marginal cell hyaline or yellowish (as in Figure 3F ); labrum yellowish to light brown; medial third of mandible usually yellowish to light brown (as in Figure 1C )................. 13

13. Mesoscutum with short branched setae reaching posterior level of tegula, coverage of branched setae relatively denser ( Figure 7B ); mesepisternum with dense coverage of branched setae ( Figures 7C, D )........... Oxytrigona tataira (Smith, 1863)

- Mesoscutum with short branched setae restricted to anterior portion of sclerite, not reaching posterior level of tegula, coverage of branched setae sparse ( Figure 1B ); branched setae on mesepisternum relatively sparse...... Oxytrigona banana sp. nov.

Figures

FIGURE 1. Holotype worker of Oxytrigona banana sp. nov. (RPSP 23.1802) from Ribeirão Preto (São Paulo, Brazil). A) habitus, lateral view, scale bar: 1 mm; B) dorsal view, scale bar: 1 mm; C) head, frontal view, scale bar: 1 mm; D) hind basitarsus, scale bar: 0.5 mm.

FIGURE 3. A) Oxytrigona cagafogo (Müller, 1874), worker from São João de Petrópolis (Espírio Santo, Brazil, RPSP), dorsal view of mesosoma, scale bar: 0.5 mm; B) Oxytrigona flaveola (Friese, 1900), worker from Costa Marques (Rondônia, Brazil, RPSP), anterior view of dorsal portion of the head, scale bar: 0.5 mm; C) O. cagafogo, worker from São Sebastião (São Paulo, Brazil, RPSP), anterior view of hind basitarsus, scale bar: 0.5 mm; D) O. flaveola, worker from Costa Marques (Rodônia, Brazil, RPSP), anterior view of hind basitarsus, scale bar: 0.5 mm; E) O. cagafogo, worker from Salvador (Bahia, Brazil, RPSP), forewing, scale bar: 1 mm;; F) O. flaveola, worker from Pimenteira (Rodônia, Brazil, RPSP), forewing, scale bar: 1 mm.

FIGURE 4. Holotype worker of Oxytrigona mellicolor (Packard, 1889) from Ecuador (MCZ 559). A) habitus, lateral view; B) head, frontal view; C) habitus, dorsal view; D) forewing; E) lateral view of mesosoma. Credits of the images: Museum of Comparative Zoology, Harvard University; © President and Fellows of Harvard College (http://creativecommons.org/licences/ by-nc-sa/4.0/legalcode). No editions made over the original images.

FIGURE 5. Oxytrigona pallida sp. nov. A) worker holotype (RPSP 11295) from San José (Costa Rica), lateral view, scale bar: 2 mm; B) worker holotype, frontal view of dorsal portion of head, scale bar: 0.5 mm; C) worker holotype, dorsal view of mesosoma, scale bar: 1 mm; D) worker holotype, lateral view of legs and mesosoma, scale bar: 1 mm; E) male from Quepos (Costa Rica, RPSP), frontal view of head, scale bar: 1 mm; F) male from Quepos (Costa Rica, RPSP), lateral view, scale bar: 2 mm.

FIGURE 6. Holotype worker of Oxytrigona sauronica sp. nov. (RPSP 09.0361) from Tamara (Casanare, Colombia).A) habitus, lateral view, scale bar: 2 mm; B) head and mesosoma, dorsal view, scale bar: 0.5 mm; C) head, frontal view, scale bar: 0.5 mm; D) hind leg, scale bar: 0.5 mm.

FIGURE 7. Worker of Oxytrigona tataira (Smith, 1863), from Viçosa (Ceará, Brazil, RPSP). A) dorsal view of mesosoma; B) detail of mesoscutum; C) lateral view of mesosoma; D) detail of mesepisternum. Scale bars: 0.5 mm.

FIGURE 8. A) forewing of Oxytrigona obscura (Friese, 1900) from Cuiabá (Mato Grosso, Brazil, RPSP), scale bar: 1 mm; B) scape of Oxytrigona mulfordi (Schwarz, 1948) from Porto Acre (Acre, Brazil, RPSP), scale bar: 0.5 mm; C) anterior view of hind basitarsus of Oxytrigona daemoniaca Camargo, 1984, from Puerto Pilon (Panama, RPSP), scale bar: 0.5 mm; D) anterior view of hind basitarsus of Oxytrigona ignis Camargo, 1984, from Belém (Pará, Brazil, RPSP), scale bar: 0.5 mm; E) scape of O. daemoniaca from Puerto Pilon (Panama, RPSP), scale bar: 0.5 mm; F) scape of O. ignis from Belém (Pará, Brazil, RPSP), scale bar: 0.5 mm.