Key to Malagasy Euponera sikorae species-group

This worker key is based on: Rakotonirina, J.C. & Fisher, B.L. 2013. Revision of the Pachycondyla sikorae species-group (Hymenoptera: Formicidae) in Madagascar. Zootaxa 3683, 447-485.

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Euponera

The function of the key is primarily to identify workers, but can also identify ergatoid and winged queens to species as long as the shape of the mesosoma is not considered.

1

 * With head in full-face view, anterior margin of clypeus widely transverse and more or less straight, with weak median notch (Fig. 2) (sikorae complex) . . . . . 2


 * With head in full-face view, anterior margin of clypeus generally convex or medially bluntly angulate; slight median notch may be present (Fig. 3) (vohitravo complex) . . . . . 8

2
return to couplet #1
 * Posterior surface of petiole node covered with numerous slender hairs and abundant pubescence; anterior surface of third abdominal segment concave, forming a shallow cavity to lodge the posterior surface of the petiole (Fig. 4) . . . . . 3


 * Posterior surface of petiole node convex and not covered with numerous slender hairs and abundant pubescence; anterior sur¬face of the third abdominal segment straight, without shallow cavity to lodge the posterior surface of the petiole (Fig. 5) . . . . . 4

3
return to couplet #2
 * Lateral surface of head and petiole node smooth and shiny, with scattered piligerous punctures (Fig. 6) [known from queen specimen] . . . . . Euponera ivolo


 * Lateral portion of head densely and finely reticulate-rugulose, sides of petiolar node densely and finely punctate (Fig. 7) . . . . . Euponera haratsingy

4
return to couplet #2
 * With mesosoma in dorsal view, metanotal groove deeply impressed (Fig. 8); in lateral view the dorsal outline of mesosoma complex, at least with distinct convex mesonotum (Figs 37, 46) . . . . . 5


 * With mesosoma in dorsal view, metanotal groove not impressed or absent (Fig. 9); in lateral view, the dorsal outline of meso¬soma almost straight or slightly evenly convex, without breaks (Figs 49, 51) . . . . . 7

5
return to couplet #4
 * Petiole node anteroposteriorly flattened in profile (Fig. 10), in dorsal view its posterior margin medially notched; posterior margin of head slightly concave; antennal scape not surpassing the concave posterior cephalic margin (Figs 38, 47); mandible smooth between small punctures; tegument densely and finely reticulate-punctate (Figs 37, 46) . . . . . 6


 * Petiole node thick in profile (Fig. 11); in dorsal view, the posterior margin broadly convex; antennal scape surpassing the broadly convex posterior cephalic margin (Fig. 59); mandible striate-punctate; black species with mostly smooth and shiny tegument (Fig. 58) . . . . . Euponera sikorae

6
return to couplet #5
 * Posterolateral margin of propodeum bordered with broad lamellae which project as tubercles at about the level of propodeal spiracle; antennal scape and outer surface of each tibia covered with erect, slender hairs (Fig. 12); dorsum of head near the posterior margin and rest of body covered with numerous slender long hairs; posterior cephalic margin more or less straight . . . . . Euponera gorogota


 * Posterolateral margin of propodeum bordered with narrow lamellae which form an obtuse angle at about the level of propodeal spiracle; antennal scape and outer surface of each tibia lacking erect, slender hairs (Fig. 13); dorsum of head and rest of body covered with few erect, slender hairs; posterior cephalic margin concave . . . . . Euponera maeva

7
return to couplet #4
 * Smaller species (HW: 1.15, HL< 1.5, WL: 1.78); eyes smaller, with seven to eight ommatidia; metanotal groove absent (Fig. 14); mesopleural suture lacking . . . . . Euponera mialy


 * Larger species (HW: 1.44, HL: 1.62, WL: 2.34); eyes larger, with 13 ommatidia; metanotal groove present as a dotted line (Fig. 15); mesopleural suture present . . . . . Euponera nosy

8
return to couplet #1
 * Anterior surface of the third abdominal segment concave (Fig. 16), forming a shallow cavity to lodge the median portion of the posterior surface of petiole node . . . . . Euponera agnivo


 * Anterior surface of the third abdominal segment straight, not forming a shallow cavity to lodge the posterior surface of petiole node (Fig. 17) . . . . . 9

9
return to couplet #8
 * Posterolateral margins of petiole node without a series of sharp teeth or tubercles (Fig. 18); dorsum of node not tubercuate . . . . . 10


 * Posterolateral margins of petiole node armed with a series of sharp teeth or tubercles (Fig. 19); dorsum of node tuberculate . . . . . 12

10
return to couplet #9
 * In dorsal view, petiole node almost twice as broad as long (Fig. 20); in lateral view, subpetiolar process simple with only an anterior triangular lobe (Fig. 18) . . . . . Euponera daraina


 * In dorsal view, petiole nodenearly as broad as long (Fig. 21); in lateral view subpetiolar process with an anterior hook-like pro¬cess and a posterior subtriangular process separated by a concavity (Fig. 55) . . . . . 11

11
return to couplet #10
 * Larger ant (HW: 1.22–1.32, WL: 1.85–2.05); mesopleuron and lower half of the side of propodeum mostly smooth and shiny with scattered small punctures in the center and fine rugulae at the junction of anepisternum and katepisternum and the lower portion of the metapleuron near the opening of the metapleural gland (Fig. 22) . . . . . Euponera zoro


 * Smaller species (HW: 1.01–1.14, WL: 1.58–1.77); mesopleuron and lower half of the side of propodeum densely rugulose and superimposed with punctures or foveolae (Fig. 23) . . . . . Euponera rovana

12
return to couplet #9
 * Second gastral (fourth abdominal) tergite punctate to sparsely punctuate; pubescence absent or reduced in abundance on first and second gastral segments, distance between two adjacent pubescences generally equal to or greater than the length of the pubescence itself (Fig. 24) . . . . . 13


 * Second gastral (fourth abdominal) tergite densely punctate, with small punctures between larger ones; first and second gastral segments with abundant pubescence, distance between two adjacent pubescences always less than the length of the pubescence itself (Fig. 25) . . . . . Euponera vohitravo

13
return to couplet #12
 * Mesopleural suture distinctly continuous and narrowly impressed (Fig. 26); head densely and finely reticulate-rugulose or reticulate-punctate behind the level of eye; with head in full-face view, the lateral borders at the level of anterior margin of eye not strongly curving towards the base of mandibles (Fig. 32); in profile, distance between eyes and base of mandibles roughly three times or more than the maximum diameter of eye . . . . . Euponera antsiraka


 * Mesopleural suture indistinct, with broad and discontinuous concavities or impressions in this region, but no obvious suture (Fig. 27); head mostly smooth and shiny with faintly effaced reticulate-punctate sculpture behind the level of eyes; with head in full-face view, the lateral margins from the level of anterior margin of eye abruptly curving toward the base of mandibles (Fig. 62); in lateral view, distance between eye and base of mandible slightly less than twice the maximum diameter of eye . . . . . Euponera tahary