Key to New World Leptogenys

Based on Lattke (2011).

1

 * Basal internal mandibular margin well separated from anterior clypeal margin with head in full-face view and mandibles closed, leaving distinct gap wider than mid-mandibular width (Fig. 1a) . . . . . 2


 * Basal internal margin of each mandible shuts tightly against clypeus, if gap is present it is narrow and not wider than mid-mandibular width (Fig. 1b) . . . . . 29

2
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 * With head in full-face view hypostomal teeth distinctly visible, either wholly or partially (Fig. ) . . . . . 3


 * With head in full-face view hypostomal teeth not visible at all (Fig. ) . . . . . 14

3
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 * Petiole with an apical tooth or crest that overhangs at least part of posterior margin of node in lateral view (Fig. ) . . . . . 4


 * Posterior margin of node without overhanging tooth or crest (Fig. ) #|. . . . . 9

4
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 * Petiolar node with acutely pointed apical tooth in lateral view (Fig. ) . . . . . 5


 * Petiolar node with apical crest or blunt tooth (Fig. ) . . . . . 7

5
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 * Head in full-face view broad (CI < 0.90) with lateral margins distinctly diverging anteriorly (Fig. ) . . . . . 6


 * Head narrower (CI > 0.90) with lateral margins sub-parallel or slightly diverging anteriorly (Figs. 5a, b) . . . . . Leptogenys bohlsi

6
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 * Mandible gradually increasing in width towards apex . . . . . Leptogenys paraense


 * Mandible of equal width throughout length (Figs. 6a, b) . . . . . Leptogenys unistimulosa

7
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 * Mandible with parallel basal and external margins, not expanding apicad . . . . . Leptogenys pubiceps (in part)


 * Mandible distinctly expanding apicad . . . . . 8

8
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 * With head in full-face view mandible mostly straight except for strong basal arch; hypostomal tooth large, frequently extending behind mandible (Fig. ); petiolar node in dorsal view subquadrate (Figs. ) . . . . . Leptogenys gatu


 * Mandible evenly arched, without strong basal arch; hypostomal tooth small, barely projecting anterad of clypeus (Fig. ); petiolar node in dorsal view elongate (Figs. 8a, b) . . . . . Leptogenys punctaticeps(in part)

9
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 * Body and head without standing pilosity . . . . . 10


 * Body and head with standing pilosity . . . . . 11

10
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 * Mandible with parallel basal and external margins, not widening apicad Fig. ; mandibular dorsum smooth and shining (Figs. 10a, b) . . . . . Leptogenys maxillosa


 * Mandible gradually widening apicad (Fig. ); mandibular dorsum finely striolate . . . . . Leptogenys maya

11
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 * WL > 2.5 mm; HW > 1.3 mm; body covered with abundant decumbent golden pilosity that partially obscures the underlying integument . . . . . 12


 * WL < 2.5 mm; HW < 1.3 mm; body with sparse erect pilosity never obscuring the underlying integument . . . . . 13

12
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 * Head in full-face view with evenly arched mandible, with subparallel external and basal margins; body black . . . . . Leptogenys chamela


 * Mandible with an approximately straight external margin and convex basal margin, apically widening; body ferruginous . . . . . Leptogenys sonora

13
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 * Third antennal segment > 2 × as long as wide; clypeus in cephalic full-face view with a prominent median laminate lobe, anterolaterally bordered by narrow lamella (Figs. ) . . . . . Leptogenys montuosa


 * Third antennal segment < 2 × as long as wide; clypeus with modest median lobe of thick cuticle, not anterolaterally thin and lamellate (Figs. 13a, b) . . . . . Leptogenys arcuata (in part)

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 * Petiole in lateral view without dorsoposterior tooth or point (Fig. ) . . . . . 15


 * Petiole with a dorsoposterior tooth, blunt point or crest that usually overhangs the posterior petiolar margin (Figs. ) . . . . . 25

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 * Petiolar node triangular in lateral view (Figs. ) . . . . . Leptogenys panops


 * Petiolar node subquadrate in lateral view (Figs. ) . . . . . 16

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 * Cephalic dorsum between and posterad of eyes mostly densely sculptured . . . . . 17


 * Cephalic dorsum between and posterad of eyes mostly smooth and shining, at most with sparse piligerous punctulae . . . . . 21

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 * Dorsum of head and mesosoma opaque; dorsum of mesosoma in lateral view with no standing hairs . . . . . 18


 * Dorsum of head and mesosoma with shining cuticle; dorsum of mesosoma with abundant standing hairs . . . . . 19

18
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 * Mandible with subparallel basal and external margins; head broad in full-face view; ocular diameter > 1/3 the length of lateral cephalic margin (Figs. 18a, b) . . . . . Leptogenys wheeleri


 * Mandible widens apically; head elongate in full-face view; ocular diameter 1/4 of lateral cephalic margin . . . . . Leptogenys ixta

19
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 * Head in full-face view wider than long; mandible of even width from base to apex (Figs. ). . . . . Leptogenys donisthorpei


 * Head longer than wide, mandible wider apically than basally . . . . . 20

20
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 * Median clypeal lobe with a single apical point (Figs. 20a, b) . . . . . Leptogenys peninsularis


 * Median clypeal lobe bifurcate . . . . . Leptogenys bifida

21
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 * Head in full-face view with brief anteromedian clypeal lobe, not longer than basal width (Figs. ) . . . . . 22


 * Head with clypeal lobe longer than basal width (Figs. ) . . . . . 23

22
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 * Petiolar node in lateral view with continuously convex anterodorsal margin; node posterior margin weakly convex (Figs. ) . . . . . Leptogenys santacruzi


 * Petiolar node in lateral view with vertical anterior margin and convex dorsal margin; posterior margin vertical (Figs. 22a, 22b) . . . . . Leptogenys arcuata (in part)

23
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 * Petiolar node wider than long in dorsal view with sub-parallel anterior and posterior margins; head, mesosoma and petiole with numerous punctae; clypeal lobe broadly triangular (Figs. ) . . . . . Leptogenys toxeres


 * Petiolar node longer than wide with a convex anterior margin and a transverse, straight posterior margin; body mostly smooth and shining with sparse minute punctulae; clypeal lobe slender (Figs. ) . . . . . 24

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 * Width of third antennal segment < 1/2 its length; length of clypeal median lobe less than width of third antennal segment; WL > 1.3 mm (Figs. ) . . . . . Leptogenys gagates


 * Width of third antennal segment > 1/2 its length; length of clypeal median lobe more than width of third antennal segment; WL < 1.3 mm (Figs. 24a, b) . . . . . Leptogenys langi (in part)

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 * Mandible parallel-sided in cephalic full-face view; cephalic dorsum usually smooth and shining with scattered punctulae . . . . . Leptogenys pubiceps (in part)


 * Mandible widening apicad; cephalic dorsum variable, usually punctate with striae at least on anterior region close to antennal insertions, or mostly smooth and shining . . . . . 26

26
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 * Head longer than wide in full-face view; body lacking iridescence; petiolar node with crest or modest apical tooth (Fig. ) . . . . . 27


 * Head wider than long; body with purple-blue iridescence; petiolar node with large apical tooth (Figs. 26a, b) . . . . . Leptogenys ingens

27
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 * In cephalic full-face view lateral clypeal lobe prominent, appearing as distinct lobe or blunt tooth next to median clypeal lobe (Fig. 29A) posterior margin of the petiolar node broadly concave in lateral view (Figs. ) . . . . . Leptogenys carbonaria (in part)


 * Lateral clypeal lobe inconspicuous, not appearing as distinct lobe or blunt tooth next to median clypeal lobe (Fig. ); posterior margin of the petiolar node sinuate . . . . . 28

28
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 * Cephalic dorsum mostly smooth and shining; apex of petiolar node with distinct short, slender tooth (Figs. 28a, b) . . . . . Leptogenys amazonica


 * Cephalic dorsum mostly punctate; apex of petiolar node with blunt crest, not shaped as a distinct tooth (Figs. 28c, ) . . . . . Leptogenys punctaticeps (in part)

29
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 * Petiolar node mostly triangular and elongate in lateral view, with a sloping, and fairly straight, anterior margin and a vertical posterior margin; if distinct vertical anterior margin is present, it is < 1/4 the height of posterior margin (Fig. ) . . . . . 30


 * Node not triangular, generally semi-quadrate with vertical, subparallel, anterior and posterior margins, and a more or less horizontal dorsal margin (rarely angular), the anterior margin is > 1/4 the length of the posterior margin (Fig. ); less commonly the node may be dome-shaped or with a continuously convex anterodorsal margin and more or less vertical posterior margin. (Fig. ) . . . . . 39

30
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 * Propodeal dorsum mostly sculpted, either striate or punctulate . . . . . 31


 * Propodeal dorsum mostly smooth and shining . . . . . 34

31
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 * Petiole in lateral view with a distinct dorso-apical tooth (Fig. ); anteromedian clypeal process flanked by lateral lobes near apex (Fig. ) . . . . . Leptogenys tiobil


 * Petiole never dentate, dorso-apically rounded or with a sharp angle at most (Figs. ); clypeal process regularly triangular at apex (Figs. ) . . . . . 32

32
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 * Pronotal disc rugose; body black without blue opalescence . . . . . Leptogenys socorda


 * Pronotal disc punctulate, or smooth and shining; body frequently with blue opalescence . . . . . 33

33
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 * Pronotal disc mostly smooth and shining with sparse punctulae; propodeal dorsum transversely striate; mandible widening apicad with low jagged denticles on chewing margin (Figs. 33a, b) . . . . . Leptogenys famelica


 * Pronotal disc densely punctulate; propodeal dorsum densely punctulate, striae mostly limited to declivity; mandible of equal width apicad, chewing margin edentate (Figs. 33c, d) . . . . . Leptogenys imperatrix

34
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 * Mesosoma in lateral view with dorsal margin mostly straight, metanotal groove shallow (Fig. ) . . . . . 35


 * Mesosoma in lateral view with dorsal margin forming two distinct convexities separated by broad metanotal groove (Fig. ) . . . . . 37

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 * Anterior margin of petiolar node in dorsal view < 1/2 the width of posterior margin, node elongate=>36 . . . . . 36


 * Anterior margin of petiolar node ≥ 1/2 the width of posterior margin (Figs. ) . . . . . Leptogenys pucuna

36
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 * Foretibial apex with transparent cuticular lobe next to strigil; head subrectangular in full-face view; eye flattened, barely convex; constriction between abdominal segments III and IV weak (Figs. 36a, b) . . . . . Leptogenys gaigei


 * Foretibial apex without transparent lobe next to strigil; head elongate in full-face view; eye broadly convex; constriction between abdominal segments III and IV strong (Figs. ) . . . . . Leptogenys vogeli

37
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 * Propodeal declivity in lateral view ending in an abrupt overhang formed by propodeal lobes (Fig. 40B); mandible expanding apicad of mid-length . . . . . Leptogenys luederwaldti


 * Propodeum in lateral view forming a continuous convexity (Fig. 72B); mandible not expanding apicad of mid-length . . . . . 38

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 * Petiolar node shaped as elongate triangle with brief vertical anterior margin in lateral view; mandible of uniform width; mandibular masticatory margin meets basal angle at an abrupt, almost perpendicular angle; foretibial apex with a transparent cuticular lobe next to strigil . . . . . Leptogenys cuneata


 * Petiolar node not elongate in lateral view, anterior and dorsal margins form a continuous convexity; mandible widest at mid-length, then tapering apicad; masticatory and basal mandibular margins meet through convexity; foretibial apex without a transparent cuticular lobe next to strigil . . . . . Leptogenys peruana

39
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 * Petiolar node in lateral view approximately dome-shaped, with the highest part close to the mid-distance of the node; anterior margin convex or with a blunt angle between the anterior and dorsal margins (Figs. 17B, 39B, 86B) . . . . . 40


 * Petiolar node subquadrate, with vertical, subparallel, anterior and posterior margins, and horizontal or convex dorsal margin; or the anterodorsal margin is convex and posterior margin vertical (Figs. 16B, 57B, 60B) . . . . . 43

40
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 * Mandible triangular; head, mesosoma, and petiole with extensive sculpturing . . . . . Leptogenys honduriana


 * Mandible slender and semi-falcate; head, mesosoma, and petiole mostly smooth and shining . . . . . 41

41

 * Small species: HW < 0.80 mm; WL < 1.76 mm . . . . . Leptogenys reggae


 * Larger species: HW > 0.80 mm; WL > 1.76 mm . . . . . 42

42

 * Head in full-face view with eyes at mid-cephalic length; basal and masticatory mandibular margins separated by blunt angle (Fig. 39A) . . . . . Leptogenys linda


 * Eyes closer to mandibular insertion than to mid-cephalic length; basal and masticatory mandibular margins joined through broad curve (Fig. 86A) . . . . . Leptogenys tama

43

 * Dorsum of head and mesosoma with extensive sculpturing . . . . . 44


 * Dorsum of head and mesosoma mostly smooth and shining with sparse punctulae . . . . . 52

44

 * Petiolar node in lateral view with posterodorsal blunt point that overhangs posterior petiolar margin . . . . . Leptogenys carbonaria(in part)


 * Petiolar node without posterodorsal point or denticle . . . . . 45

45

 * Postpetiolar tergite opaque and densely punctate, the space surrounding each puncture equal to or less than the diameter of each puncture . . . . . 46


 * Postpetiolar tergite mostly smooth and shining with sparse punctulae, the space surrounding each puncture many times greater than the diameter of each puncture . . . . . 48

46

 * Mesosoma in lateral view with no standing hairs on dorsum . . . . . Leptogenys quirozi


 * Mesosoma with 10 or more standing hairs on dorsum . . . . . 47

47

 * Clypeal anterior margin in cephalic full-face view with strongly developed lateral clypeal lobes at each side of median lobe (Fig. 16A) . . . . . Leptogenys foraminosa


 * Clypeus with anterior margin converging evenly to median lobe, lateral clypeal lobes indistinct (Fig. 21A) . . . . . Leptogenys sianka

48

 * Mandible not widening apicad; basal and external margins mostly semi-parallel . . . . . 49


 * Mandible usually widening apicad, becoming triangular, or unusually shaped . . . . . 50

49

 * Scape surpasses posterior cephalic margin by ≥ 1/3 its length; second funicular segment almost 2 × as long as third segment; mandibular dorsum mostly smooth, with weak striolae at most (Fig. 23) . . . . . Leptogenys volcanica


 * Scape surpasses posterior cephalic margin by ≤ 1/4 its length; second funicular segment slightly longer than third segment; mandibular dorsum mostly striate (Fig. 84) . . . . . Leptogenys linearis(in part)