Key to Simopelta species

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This worker key is based on: MacKay, W.P., MacKay, E.E. 2008. Revision of the ants of the genus Simopelta Mann (pp. 285-328). In Jíminez, E., Fernández, F., Arias, T.M. & Lozano-Zambrano, F.H. (eds). Sistematica, biogeografia y conservación de las hormigas cazadoras de Colombia: 609 pp. Instituto Alexander von Humboldt, Bogota. PDF

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Simopelta

1

  • Mandible with 6 or more teeth (Figure 4); bright ferruginous red, appendages, petiole, and gaster yellow; Brasil (Espírito Santo) . . . . . Simopelta bicolor
Mackay and Mackay 2008. Figure 4.
  • Mandible with 3 - 5 teeth (Figure 5 and 6); usually dark, nearly black; widely distributed . . . . . 2
Mackay and Mackay 2008. Figure 5. Scale bar = 1 mm.
Mackay and Mackay 2008. Figure 6.

2

return to couplet #1

  • Mandible with 5 teeth (Figure 5), two apicalmost teeth well developed, remaining 3 teeth smaller (some may be broken or missing); Costa Rica . . . . . Simopelta pentadentata
  • Mandible with 3 or 4 teeth (Figure 6), all approximately equal in size, if additional tooth is present, it is much smaller than others; widely distributed . . . . . 3

3

return to couplet #2

  • Mandible with 3 teeth, approximately equal sized (Figure 6, left); relatively common . . . . . 4
  • Mandible with 4 teeth, approximately equal sized (Figure 6, right); rarely collected . . . . . 17
Mackay and Mackay 2008. Figure 6.

4

return to couplet #3

  • Pronotum mostly smooth and shining, as are large part of anterior dorsum of head and various other parts of mesosoma (Figure 7); background may be punctated (Figure 8) or otherwise sculptured; black . . . . . 5
Mackay and Mackay 2008. Figure 7.
  • Head and mesosoma, including pronotum, mostly roughly sculptured and more or less opaque (Figure 9); usually dark reddish-brown . . . . . 6
Mackay and Mackay 2008. Figure 9.

5

return to couplet #4

  • At least posterior 1/4 of head punctated, pronotum with weak punctures; northern Ecuador . . . . . Simopelta manni
  • Head glossy and shiny from frontal lobes to posterior border of head (Figure 8); pronotum glossy; Colombia . . . . . Simopelta laevigata
Mackay and Mackay 2008. Figure 8. Scale bar = 1 mm.

6

return to couplet #4

  • Eye (single ommatidium, maximum diameter ~ 0.1 mm) relatively large and conspicuous (Figure 9), greatest diameter greater than or equal to antennomere 4; dark brown; head densely and evenly punctate; dorsum of postpetiole (first segment of gaster) smooth and glossy; Costa Rica . . . . . Simopelta oculata
Mackay and Mackay 2008. Figure 9.
Simopelta oculata casent0249243 p 1 high.jpg
  • Eyes smaller (Figure 10), greatest diameter (usually less than 0.08 mm) distinctly less than greatest width of antennomere 4, if eyes larger, dorsum of postpetiole punctate, or head with transverse costulae or granulated . . . . . 7
Mackay and Mackay 2008. Figure 10.

7

return to couplet #6

  • Posterior part of head, front of pronotum, mesonotum and propodeum more or less distinctly transversely striate or rugulose (Figure 5); median clypeal lobe without slender tooth or process (Figure 10); blackish brown . . . . . 8
Mackay and Mackay 2008. Figure 5. Scale bar = 1 mm.
  • Head and mesosoma as seen from above uniformly and densely punctate or granulose, if striae are present, they are mostly longitudinal; tooth or process may be present on clypeus; color varies but often reddish . . . . . 14

8

return to couplet #7

  • Suberect hairs on outer surface of posterior tibia (Figure 11) of two distinct lengths: shorter hairs 0,07 mm, longer hairs 0.13 mm; petiolar node wider than long (seen from above - Figure 13); western Colombia . . . . . Simopelta transversa
Mackay and Mackay 2008. Figure 11. Scale bar = 1 mm.
Mackay and Mackay 2008. Figure 13.
Simopelta transversa casent0915306 p 1 high.jpg
  • Suberect hairs on outer surface of tibia (Figure 12) all approximately same length (usually shorter than 0.07 mm), or absent . . . . . 9
Mackay and Mackay 2008. Figure 12. Scale bar = 1 mm.

9

return to couplet #8

  • Third tooth (basalmost) nearly always bluntly truncated (Figure 10); petiolar node usually square-shaped or circular (as seen from above); mesonotum approximately as long as dorsal face of propodeum (Figure 7) . . . . . 10
Mackay and Mackay 2008. Figure 10.
Mackay and Mackay 2008. Figure 7.
  • Third tooth (basalmost tooth) nearly always sharply pointed (Figure 14); petiolar node usually longer than broad (Figure 17) and narrowed anteriorly (seen from above); mesonotum shorter than propodeum (as seen from side - Figure 17) . . . . . 12
Mackay and Mackay 2008. Figure 14.
Mackay and Mackay 2008. Figure 17.

10

return to couplet #9

  • Clypeal lobe elongated, projecting above clypeal apron (Figure 14); extreme southwestern Colombia and north central Ecuador . . . . . Simopelta longirostris
  • Clypeal lobe not elongated, rounded or slightly angulate (Figure 15), not greatly extending over clypeal apron . . . . . 11
Mackay and Mackay 2008. Figure 15. Scale bar = 1 mm.

11

return to couplet #10

  • Side and top (Figure 13) of petiolar node with distinct striae or rugulae; Costa Rica south to Ecuador . . . . . Simopelta williamsi
  • Side and top (Figure 13) of petiolar node nearly smooth and glossy; Colombia and Ecuador . . . . . Simopelta vieirai
Mackay and Mackay 2008. Figure 13.

12

return to couplet #9

  • Antennal scape elongate (Figure 15), extending about 0.25 mm (more than length of first 2 funicular segments) past posterior lateral corner; southern Colombia . . . . . Simopelta fernandezi
Mackay and Mackay 2008. Figure 15. Scale bar = 1 mm.
  • Antennal scape less elongate (Figure 16), extending about 0.12 mm past posterior lateral corner (less than length of first funicular segment); Costa Rica and Panamá . . . . . 13
Mackay and Mackay 2008. Figure 16. Scale bar = 1 mm.

13

return to couplet #12

  • Node of petiole (seen from above) approximately as long as broad (Figure 13); lower third of pronotum and mesopleuron sculptured and moderately shining; dorsal surface of propodeum covered with transverse or longitudinal striolae; top of petiolar node coarsely sculptured; Panamá . . . . . Simopelta breviscapa
Mackay and Mackay 2008. Figure 13.
  • Node of petiole much longer than broad (Figure 17); lower third of pronotum and mesopleuron polished and shiny; dorsal surface of propodeum granulated; dorsum of petiole nearly smooth and glossy (Figure 17); Costa Rica . . . . . Simopelta longinoda
Mackay and Mackay 2008. Figure 17.
Simopelta longinoda casent0249245 p 1 high.jpg

14

return to couplet #7

  • Larger species (head width usually > 0.66 mm, total length > 4 mm); punctures of head, mesosoma and node of petiole coarse, separate punctures of head larger than eye (Figure 18); color ferruginous red to black, with contrasting yellow, red or brown gaster and appendages; anterior medial clypeal margin with sharp tooth; Ecuador (Orellana); Brasil (Rondônia) . . . . . Simopelta jeckylli
Mackay and Mackay 2008. Figure 18.
Simopelta jeckylli casent0902466 p 1 high.jpg
  • Usually smaller species (head width often < 0.66 mm; total length usually less than 4 mm); punctuation fine and shallow, separate punctures of head about 1/3 size of eye (Figure 19), or head granulose, or with predominantly longitudinal striae; color yellowish-brown to dark brown; clypeus with or without tooth; Central America south to Brasil . . . . . 15
Mackay and Mackay 2008. Figure 19.

15

return to couplet #14

  • Yellowish to reddish brown; head finely punctate; petiole narrow as seen from side (Figure 20); dorsum of postpetiole (first tergum of gaster) with tiny, sparse punctures . . . . . 16
Mackay and Mackay 2008. Figure 20.
  • Dark reddish black; head granulose, or with poorly defined, longitudinal striae or rugae; petiole thick as seen from side (Figure 21); Dorsum of postpetiole (first gastral tergite) punctate (Figure 21); Costa Rica and Panamá . . . . . Simopelta paeminosa
Mackay and Mackay 2008. Figure 21.
Simopelta paeminosa casent0217574 p 1 high.jpg

16

return to couplet #15

  • Small (total length less than 2.5 mm); head elongate (0.73 ≥ HW/HL ≥ 0.78); dorsal surface of mandibles smooth and glossy; Bahia, Brasi . . . . . Simopelta minima
  • Larger (TL > 3 mm); head less elongate (HW/HL > 0.8, excluding spine); dorsal surface of mandibles dull, covered with striolae; Guatemala south to Venezuela (Tachira) and Colombia (Magdalena) . . . . . Simopelta pergandei
Simopelta pergandei casent0178701 profile 1.jpg

17

return to couplet #3

  • Clypeus with well developed medial tooth (Figure 24); Perú and Brasil . . . . . 18
Mackay and Mackay 2008. Figure 24.
  • Clypeus without medial tooth, broadly rounded anteriorly (Figure 26); Costa Rica (Puntarenas) . . . . . 20
Mackay and Mackay 2008. Figure 26. Scale bar = 1 mm.

18

return to couplet #17

  • Posterior margin of head distinctly concave in middle, as seen in full-face view (Figure 23); southwestern Colombia and northern Perú . . . . . Simopelta laticeps
Mackay and Mackay 2008. Figure 23.
Simopelta laticeps castype09451 profile 1.jpg
  • Posterior margin of head nearly straight, as seen in full-face view (Figure 25); Colombia (Nariño), southern Brasil (Mato Grosso, Santa Catarina) . . . . . 19
Mackay and Mackay 2008. Figure 25. Scale bar = 1 mm.

19

return to couplet #18

  • Larger (Total length 5 mm); posterior dorsal region of head with distinct, transverse striolae; southern Colombia (Nariño) . . . . . Simopelta mayri
  • Smaller (TL < 3.5 mm); posterior dorsal region of head punctate, without evidence of striolae; southern Brasil (Mato Grosso, Santa Catarina) . . . . . Simopelta curvata

20

return to couplet #17

  • Eye (Figure 25) relatively large (maximum diameter ≥ 0.1 mm); hairs on scape slightly elevated from surface . . . . . Simopelta andersoni
Mackay and Mackay 2008. Figure 25. Scale bar = 1 mm.
Simopelta andersoni casent0249246 p 1 high.jpg
Mackay and Mackay 2008. Figure 26. Scale bar = 1 mm.