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Key to New World Leptogenys
This key to North and South American species of Leptogenys is based on Lattke (2011) as modified by Lopez-Munoz et al. (2018) and Tozetto et al. (2022).
See also:
- Leptogenys species groups (New World species)
- Key to US Leptogenys species
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
 1a. Head of Leptogenys montuosa worker |
 1b. Head of Leptogenys elongata worker |
2
return to couplet #1
- With head in full-face view hypostomal teeth distinctly visible, either wholly or partially (Fig. 2a, 2b) . . . . . 3
- With head in full-face view hypostomal teeth not visible at all . . . . . 14
 2a. Leptogenys bohlsi worker |
 2b. Leptogenys unistimulosa worker |
3
return to couplet #2
- Petiole with an apical tooth or crest that overhangs at least part of posterior margin of node in lateral view (Fig. 3a) . . . . . 4
- Posterior margin of node without overhanging tooth or crest (Fig. 3b) . . . . . 9
 3a. Leptogenys amazonica worker |
 3b. Leptogenys sonora worker |
4
return to couplet #3
- Petiolar node with acutely pointed apical tooth in lateral view (see images in couplets 5 and 6) . . . . . 5
- Petiolar node with apical crest or blunt tooth (see images in couplet 8) . . . . . 7
5
return to couplet #4
- Head in full-face view broad (CI > 0.90) with lateral margins distinctly diverging anteriorly . . . . . 6
- Head narrower (CI < 0.90) with lateral margins sub-parallel or slightly diverging anteriorly . . . . . 5a
5a
return to couplet #5
- Clypeal median lobe with 3–4 apical chaetae; mandible arched . . . . . Leptogenys bohlsi
 Head of Leptogenys bohlsi worker |
 Profile of Leptogenys bohlsi worker |
- Clypeal median lobe with 12 apical chaetae; mandible straight . . . . . Leptogenys elzasoares
6
return to couplet #5
- Mandible gradually increasing in width towards apex . . . . . Leptogenys paraensis
 Head of Leptogenys paraensis worker |
 Profile of Leptogenys paraensis worker |
- Mandible of equal width throughout length . . . . . Leptogenys unistimulosa
 Head of Leptogenys unistimulosa worker |
 Profile of Leptogenys unistimulosa worker |
7
return to couplet #4
- Mandible with parallel basal and external margins, not expanding apicad . . . . . Leptogenys pubiceps (in part - also #25)
- Mandible distinctly expanding apicad . . . . . 8
8
return to couplet #7
- With head in full-face view mandible mostly straight except for strong basal arch; hypostomal tooth large, frequently extending behind mandible; petiolar node in dorsal view subquadrate . . . . . Leptogenys gatu
 Head of Leptogenys gatu worker |
 Profile of Leptogenys gatu worker |
- Mandible evenly arched, without strong basal arch; hypostomal tooth small, barely projecting anterad of clypeus; petiolar node in dorsal view elongate . . . . . Leptogenys punctaticeps (in part - also #28)
 Head of Leptogenys punctaticeps worker |
 Profile of Leptogenys punctaticeps worker |
9
return to couplet #3
- Body and head without standing pilosity . . . . . 10
- Body and head with standing pilosity . . . . . 11
10
return to couplet #9
- Mandible with parallel basal and external margins, not widening apicad; mandibular dorsum smooth and shining . . . . . Leptogenys maxillosa
 Head of Leptogenys maxillosa worker |
 Profile of Leptogenys maxillosa worker |
- Mandible gradually widening apicad; mandibular dorsum finely striolate . . . . . Leptogenys maya
 Head of Leptogenys maya worker |
 Profile of Leptogenys maya worker |
11
return to couplet #9
- 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
return to couplet #11
- Head in full-face view with evenly arched mandible, with subparallel external and basal margins; body black . . . . . Leptogenys chamela
 Head of Leptogenys chamela worker |
 Profile of Leptogenys chamela worker |
- Mandible with an approximately straight external margin and convex basal margin, apically widening; body ferruginous . . . . . Leptogenys sonora
 Head of Leptogenys sonora worker |
 Profile of Leptogenys sonora worker |
13
return to couplet #11
- 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 . . . . . Leptogenys montuosa
 Head of Leptogenys montuosa worker |
 Profile of Leptogenys montuosa worker |
- Third antennal segment < 2 × as long as wide; clypeus with modest median lobe of thick cuticle, not anterolaterally thin and lamellate . . . . . Leptogenys arcuata (in part - also #22)
 Head of Leptogenys arcuata worker |
 Profile of Leptogenys arcuata worker |
14
return to couplet #2
- Petiole in lateral view without dorsoposterior tooth or point (Fig. 14a) . . . . . 15
| 14a. Leptogenys sonora worker |
14b. Leptogenys amazonica worker |
- Petiole with a dorsoposterior tooth, blunt point or crest that usually overhangs the posterior petiolar margin (Figs. 14b ) . . . . . 25
15
return to couplet #14
- Petiolar node triangular in lateral view . . . . . Leptogenys panops
 Head of Leptogenys panops worker |
 Profile of Leptogenys panops worker |
- Petiolar node subquadrate in lateral view (compare petiolar node in profile view of panops above to profile view of workers in couplets below) . . . . . 16
16
return to couplet #15
- Cephalic dorsum between and posterad of eyes mostly densely sculptured (Fig 16a) . . . . . 17
 |
- Cephalic dorsum between and posterad of eyes mostly smooth and shining, at most with sparse piligerous punctulae (Fig 16b) . . . . . 21
17
return to couplet #16
- 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
return to couplet #17
- Mandible with subparallel basal and external margins; head broad in full-face view; ocular diameter > 1/3 the length of lateral cephalic margin . . . . . Leptogenys wheeleri
 Head of Leptogenys wheeleri worker |
 Profile of Leptogenys wheeleri worker |
- Mandible widens apically; head elongate in full-face view; ocular diameter 1/4 of lateral cephalic margin . . . . . Leptogenys ixta
 Head of Leptogenys ixta worker |
 Profile of Leptogenys ixta worker |
19
return to couplet #17
- Head in full-face view wider than long; mandible of even width from base to apex . . . . . Leptogenys donisthorpei
 Head of Leptogenys donisthorpei worker |
 Profile of Leptogenys donisthorpei worker |
- Head longer than wide, mandible wider apically than basally . . . . . 20
20
return to couplet #19
- Median clypeal lobe with a single apical point . . . . . Leptogenys peninsularis
 Head of Leptogenys peninsularis worker |
 Profile of Leptogenys peninsularis worker |
- Median clypeal lobe bifurcate . . . . . Leptogenys bifida
 Head of Leptogenys bifida worker |
 Profile of Leptogenys bifida worker |
21
return to couplet #16
- Head in full-face view with brief anteromedian clypeal lobe, not longer than basal width (Fig. 21a) . . . . . 22
 |
- Head with clypeal lobe longer than basal width (Fig. 21b) . . . . . 23
22
return to couplet #21
- Petiolar node in lateral view with continuously convex anterodorsal margin; node posterior margin weakly convex . . . . . Leptogenys santacruzi
 Head of Leptogenys santacruzi worker |
 Profile of Leptogenys santacruzi worker |
- Petiolar node in lateral view with vertical anterior margin and convex dorsal margin; posterior margin vertical . . . . . Leptogenys arcuata (in part - also #13)
| Head of Leptogenys arcuata worker |
Profile of Leptogenys arcuata worker |
23
return to couplet #21
- 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 . . . . . Leptogenys toxeres
 Head of Leptogenys toxeres worker |
 Profile of Leptogenys toxeres worker |
- 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 . . . . . 24
24
return to couplet #23
- 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 . . . . . Leptogenys gagates
 Head of Leptogenys gagates worker |
 Profile of Leptogenys gagates worker |
- 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 . . . . . Leptogenys langi (in part - also #70)
 Head of Leptogenys langi worker |
 Profile of Leptogenys langi worker |
25
return to couplet #14
- Mandible parallel-sided in cephalic full-face view; cephalic dorsum usually smooth and shining with scattered punctulae . . . . . Leptogenys pubiceps (in part - also #7)
- 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
return to couplet #25
- 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 . . . . . Leptogenys ingens
 Head of Leptogenys ingens worker |
 Profile of Leptogenys ingens worker |
27
return to couplet #26
- In cephalic full-face view lateral clypeal lobe prominent, appearing as distinct lobe or blunt tooth next to median clypeal lobe posterior margin of the petiolar node broadly concave in lateral view (Figs. ) . . . . . Leptogenys carbonaria (in part - also #44)
 Head of Leptogenys carbonaria worker |
 Profile of Leptogenys carbonaria worker |
- 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
return to couplet #27
- Cephalic dorsum mostly smooth and shining; apex of petiolar node with distinct short, slender tooth . . . . . Leptogenys amazonica
 Head of Leptogenys amazonica worker |
 Profile of Leptogenys amazonica worker |
- Cephalic dorsum mostly punctate; apex of petiolar node with blunt crest, not shaped as a distinct tooth . . . . . Leptogenys punctaticeps (in part - also #8)
| Head of Leptogenys punctaticeps worker |
Profile of Leptogenys punctaticeps worker |
29
return to couplet #1
- 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
return to couplet #29
- Propodeal dorsum mostly sculpted, either striate or punctulate (Fig. 30a) . . . . . 31
 |
- Propodeal dorsum mostly smooth and shining (Fig. 30b) . . . . . 34
31
return to couplet #30
- Petiole in lateral view with a distinct dorso-apical tooth (Fig. ); anteromedian clypeal process flanked by lateral lobes near apex . . . . . Leptogenys tiobil
 Head of Leptogenys tiobil worker |
 Profile of Leptogenys tiobil worker |
- Petiole never dentate, dorso-apically rounded or with a sharp angle at most (Figs. ); clypeal process regularly triangular at apex (Figs. ) . . . . . 32
32
return to couplet #31
- Pronotal disc rugose; body black without blue opalescence . . . . . Leptogenys socorda
 Head of Leptogenys socorda worker |
 Profile of Leptogenys socorda worker |
- Pronotal disc punctulate, or smooth and shining; body frequently with blue opalescence . . . . . 33
33
return to couplet #32
- Pronotal disc mostly smooth and shining with sparse punctulae; propodeal dorsum transversely striate; mandible widening apicad with low jagged denticles on chewing margin . . . . . Leptogenys famelica
 Head of Leptogenys famelica worker |
 Dorsal view of Leptogenys famelica mesosoma |
- Pronotal disc densely punctulate; propodeal dorsum densely punctulate, striae mostly limited to declivity; mandible of equal width apicad, chewing margin edentate . . . . . Leptogenys imperatrix
 Head of Leptogenys imperatrix worker |
 Dorsal view of Leptogenys imperatrix mesosoma |
34
return to couplet #30
- 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
35
return to couplet #34
- 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 . . . . . Leptogenys pucuna
36
return to couplet #35
- 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 . . . . . Leptogenys gaigei
 Head of Leptogenys gaigei worker |
 Profile of Leptogenys gaigei worker |
- 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 . . . . . Leptogenys vogeli
 Head of Leptogenys vogeli worker |
 Profile of Leptogenys vogeli worker |
37
- Propodeal declivity in lateral view ending in an abrupt overhang formed by propodeal lobes (Fig. 40B); mandible expanding apicad of mid-length; body with blue iridescence (southeastern Brazil) . . . . . . Leptogenys luederwaldti
 Head of Leptogenys luederwaldti worker |
 Profile of Leptogenys luederwaldti worker |
- Propodeal lobes in lateral view absent or low and weakly developed (Fig. 71B), shaped either rounded or bluntly triangular, never forming an overhang; mandible not expanding apicad of mid-length; body lacking any iridescence . . . . . 38
38
return to couplet #37
- Petiolar node in lateral view shaped as elongate triangle, with brief vertical anterior margin; masticatory margin of mandible meeting internal angle at an abrupt, almost perpendicular angle; foretibial apex with a transparent cuticular lobe next to strigil (Panama—eastern Peru) . . . . . . Leptogenys cuneata
 Head of Leptogenys cuneata worker |
 Profile of Leptogenys cuneata worker |
- Petiolar node in lateral view not elongate, anterior and dorsal margins form a continuous convexity; masticatory and internal mandibular margins meeting through blunt angle or convexity; foretibial apex without a transparent cuticular lobe next to strigil . . . . . 38a
38a
return to couplet #38
- Head subquadrate (CI 0.76–0.78), median clypeal process shaped as short rounded lobe with 3–4 seta on apex; mandible wid-est at mid length; propodeum rounded and unarmed (eastern Peru) . . . . . . Leptogenys peruana
 Head of Leptogenys peruana worker |
 Profile of Leptogenys peruana worker |
- Head in dorsal view elongate (CI 0.56–0.61), median clypeal process triangular, evenly tapering anterad, apex lacking setae; mandible in dorsal view of uniform width; propodeal declivity with low, but distinct, lateral lobes or teeth (southeastern Brazil). . . . . 38b
38b
return to couplet #38a
- Size larger (WL 2.91–2.94 mm); propodeal dorsum smooth and shining with sparse piligerous punctulae; propodeal lobe in lat-eral view triangular with jagged dorsal margin . . . . . . Leptogenys academica
 Head of Leptogenys peruana worker |
 Profile of Leptogenys peruana worker |
- Size smaller (WL 2.47–2.72 mm); propodeal dorsum mostly smooth and shining with scattered patches of shallow transverse rugulae and scattered shallow punctae; propodeal lobe shaped as low rounded lobe without jagged margins . . . . . . Leptogenys carioca
| Head of Leptogenys carioca worker |
Profile of Leptogenys carioca worker |
39
return to couplet #29
- 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 . . . . . 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 . . . . . 43
40
return to couplet #39
- Mandible triangular; head, mesosoma, and petiole with extensive sculpturing . . . . . Leptogenys honduriana
 Head of Leptogenys honduriana worker |
 Profile of Leptogenys honduriana worker |
- Mandible slender and semi-falcate; head, mesosoma, and petiole mostly smooth and shining . . . . . 41
41
return to couplet #40
- Small species: HW < 0.80 mm; WL < 1.76 mm . . . . . Leptogenys reggae
 Head of Leptogenys reggae worker |
 Profile of Leptogenys reggae worker |
- Larger species: HW > 0.80 mm; WL > 1.76 mm . . . . . 42
42
return to couplet #41
- Head in full-face view with eyes at mid-cephalic length; basal and masticatory mandibular margins separated by blunt angle . . . . . Leptogenys linda
| Head of Leptogenys toxeres worker |
Profile of Leptogenys toxeres worker |
- Eyes closer to mandibular insertion than to mid-cephalic length; basal and masticatory mandibular margins joined through broad curve . . . . . Leptogenys tama
 Head of Leptogenys tama worker |
 Profile of Leptogenys tama worker |
43
return to couplet #39
- Dorsum of head and mesosoma with extensive sculpturing . . . . . 44
- Dorsum of head and mesosoma mostly smooth and shining with sparse punctulae . . . . . 52
44
return to couplet #43
- Petiolar node in lateral view with posterodorsal blunt point that overhangs posterior petiolar margin . . . . . Leptogenys carbonaria (in part - also #27)
| Head of Leptogenys carbonaria worker |
Profile of Leptogenys carbonaria worker |
- Petiolar node without posterodorsal point or denticle . . . . . 45
45
return to couplet #44
- 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
return to couplet #45
- Mesosoma in lateral view with no standing hairs on dorsum . . . . . Leptogenys quirozi
 Head of Leptogenys quirozi worker |
 Profile of Leptogenys quirozi worker |
- Mesosoma with 10 or more standing hairs on dorsum . . . . . 47
47
return to couplet #46
- Clypeal anterior margin in cephalic full-face view with strongly developed lateral clypeal lobes at each side of median lobe . . . . . Leptogenys foraminosa
- Clypeus with anterior margin converging evenly to median lobe, lateral clypeal lobes indistinct . . . . . Leptogenys sianka
 Head of Leptogenys sianka worker |
 Profile of Leptogenys sianka worker |
48
return to couplet #45
- Mandible not widening apicad; basal and external margins mostly semi-parallel . . . . . 49
- Mandible usually widening apicad, becoming triangular, or unusually shaped . . . . . 50
49
return to couplet #48
- 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 . . . . . Leptogenys volcanica
- Scape surpasses posterior cephalic margin by ≤ 1/4 its length; second funicular segment slightly longer than third segment; mandibular dorsum mostly striate . . . . . Leptogenys linearis (in part - also #61)
 Head of Leptogenys linearis worker |
 Profile of Leptogenys linearis worker |
50
return to couplet #48
- Mandible triangular; median clypeal lobe ending in a blunt point . . . . . 51
- Mandible with large preapical rounded notch; median clypeal lobe apically truncate . . . . . Leptogenys oaxaca
 Head of Leptogenys oaxaca worker |
 Profile of Leptogenys oaxaca worker |
51
return to couplet #50
- Mesosoma wider than long in dorsal view . . . . . Leptogenys elongata
 Head of Leptogenys elongata worker |
 Profile of Leptogenys elongata worker |
- Mesosoma longer than wide in dorsal view . . . . . Leptogenys manni
 Head of Leptogenys manni worker |
 Profile of Leptogenys manni worker |
52
return to couplet #43
- Apical half of mandible increasing in width giving mandible a triangular or semi-triangular aspect (Fig. ) . . . . . 53
- Apical half of mandibular dorsal surface of uniform width; masticatory margin not expanded into semi-triangular shape (Fig. ) . . . . . 60
53
return to couplet #52
- Propodeum with lateral tooth or lobe; mandibular masticatory margin edentate . . . . . 54
- Propodeum without a trace of lobe or tooth, laterally rounded; mandible with preapical tooth or denticles along masticatory margin . . . . . 57
54
return to couplet #53
- Mandible elongate, basal margin > 2 × longer than masticatory margin . . . . . 55
- Mandible triangular, lengths of basal and masticatory margin approximately equal . . . . . 56
55
return to couplet #54
- Large ant, WL > 2.3 mm; mandible does not shut tight against clypeus (Fig. ), meso- and metapleura with variable amounts of striae . . . . . Leptogenys ciliata
- Small ant, WL < 2.3 mm; mandible shuts tight against clypeus (Fig. ); meso- and metapleura smooth and shining . . . . . Leptogenys consanguinea
 Head of Leptogenys consanguinea worker |
 Profile of Leptogenys consanguinea worker |
56
return to couplet #54
- Compound eye covers almost 1/3 the length of lateral cephalic margin; eye dorsolaterally placed on head . . . . . Leptogenys nigricans
 Head of Leptogenys nigricans worker |
 Profile of Leptogenys nigricans worker |
- Compound eye covering ≤ 1/4 lateral cephalic margin; eye placed laterally on head . . . . . Leptogenys deborae
 Head of Leptogenys deborae worker |
 Profile of Leptogenys deborae worker |
57
return to couplet #53
- Length of second antennal segment 1/2 of segment III; petiolar node elongate in dorsal view, width < 85% of length . . . . . 58
- Length of second antennal segment > 1/2 of segment III; petiolar node subquadrate, width > 85% of length . . . . . 59
58
return to couplet #57
- Mesonotum wider than long; mesopleural lobe shaped low and convex . . . . . Leptogenys phylloba
 Head of Leptogenys phylloba worker |
 Profile of Leptogenys phylloba worker |
- Mesonotum longer than wide; mesopleural lobe projects laterally as small fin or wing . . . . . Leptogenys pinna
 Head of Leptogenys pinna worker |
 Profile of Leptogenys pinna worker |
59
return to couplet #57
- Eye length > oculomalar distance; masticatory margin of mandible denticulate to crenulate . . . . . Leptogenys serrata
 Head of Leptogenys serrata worker |
 Profile of Leptogenys serrata worker |
- Eye length < oculomalar distance; masticatory margin of mandible edentate except for single preapical tooth . . . . . Leptogenys pittieri
 Head of Leptogenys pittieri worker |
 Profile of Leptogenys pittieri worker |
60
return to couplet #52
- Compound eyes situated dorsolaterally with head in full-face view; not only is whole dorsal ocular perimeter observable, but also part of ventral ocular perimeter, or only a small part or none of the dorsal ocular margin extends beyond the lateral cephalic margin (Fig. ) . . . . . 61
- Compound eyes extended more laterally in full-face view of head; the ventral ocular perimeter is not visible, and all or most of the dorsal ocular margin extends beyond the lateral cephalic margin (Fig. ) . . . . . 65
61
return to couplet #60
- Dorsal mandibular surface mostly striate; dorsal mesosomal margin continuously curved in lateral view; clypeal apex with at least two stout setae . . . . . Leptogenys linearis (in part - also #48)
| Head of Leptogenys linearis worker |
Profile of Leptogenys linearis worker |
- Mandibles mostly smooth and shining with sparse punctures; dorsal mesosomal margin divided by deep or shallow metanotal groove into convex promesonotal margin, and convex or flat propodeal margin; clypeal apex lacking stout setae . . . . . 62
62
return to couplet #61
- Width of anterior petiolar margin ≤ 1/2 width of posterior margin in dorsal view . . . . . 63
- Anterior margin of petiole > 1/2 width of posterior margin in dorsal view . . . . . 64
63
return to couplet #62
- Mesonotum 3 × wider than long in dorsal view; node with anterior margin 1/2 width of posterior margin in dorsal view . . . . . Leptogenys rasila
 Head of Leptogenys rasila worker |
 Profile of Leptogenys rasila worker |
- Width of mesonotum ≤ 2 × its length; anterior margin of node < 1/2 width of posterior margin . . . . . Leptogenys iheringi (in part - also #75)
 Head of Leptogenys iheringi worker |
 Profile of Leptogenys iheringi worker |
64
return to couplet #62
- HL < 1.10 mm, WL < 1.70 mm; width of third antennal segment > 1/2 its length . . . . . Leptogenys amu
 Head of Leptogenys amu worker |
 Profile of Leptogenys amu worker |
- HL > 1.10 mm, WL > 1.70 mm; width of third antennal segment approximately 1/4 its length . . . . . Leptogenys crudelis
 Head of Leptogenys crudelis worker |
 Profile of Leptogenys crudelis worker |
65
return to couplet #60
- With head in full-face view, the midpoint of compound eye closer to mandibular insertion than to mid-length of lateral cephalic margin (Fig. ) . . . . . 66
- With head in full-face view, the midpoint of compound eye exactly at, or closer to mid-length of lateral cephalic margin than to mandibular insertion (Fig. ) . . . . . 68
66
return to couplet #65
- Head in full-face view with semiparallel lateral margins; abdominal tergites III and IV mostly smooth and shining with sparse punctulae . . . . . 67
- Head with anteriorly diverging lateral margins; abdominal tergites III and IV punctate to varying degree . . . . . Leptogenys foveonates
 Head of Leptogenys foveonates worker |
 Profile of Leptogenys foveonates worker |
67
return to couplet #66
- Clypeal anterior margin in cephalic full-face view with gradually tapering median lobe; in lateral view propodeum edentate, with low triangular lobes at most . . . . . Leptogenys ritae
 Head of Leptogenys ritae worker |
 Profile of Leptogenys ritae worker |
- Clypeal anterior margin with abruptly projecting slender median lobe; propodeum with 2 distinct teeth . . . . . Leptogenys corniculans
 Head of Leptogenys corniculans worker |
 Profile of Leptogenys corniculans worker |
68
return to couplet #65
- Median clypeal lobe elongate and slender in cephalic full-face view (Fig. ) . . . . . 69
- Median clypeal lobe broader, triangular with a pointed, blunt or truncate apex (Figs. ) . . . . . 71
69
return to couplet #68
- Compound eye large (CI > 0.30), covering almost 1/3 length of lateral cephalic margin . . . . . Leptogenys mavaca
 Head of Leptogenys mavaca worker |
 Profile of Leptogenys mavaca worker |
- Compound eye smaller (CI < 0.30), covering ≤ 1/4 length of lateral cephalic margin . . . . . 70
70
return to couplet #69
- Scape extending beyond the posterior cephalic margin by > 1/3 length; petiole with prominent anterior shelf in lateral view, almost 1/2 length of node . . . . . Leptogenys cracens
 Head of Leptogenys cracens worker |
 Profile of Leptogenys cracens worker |
- Scape extending beyond the posterior cephalic margin by about 1/4 length; petiole without prominent anterior shelf, < 1/4 length of the node . . . . . Leptogenys langi (in part - also #24)
| Head of Leptogenys langi worker |
Profile of Leptogenys langi worker |
71
return to couplet #68
- Median clypeal lobe with subquadrate or bluntly angular apex, sometimes with apical lamellate denticle (Fig. ) . . . . . 72
- Clypeus in cephalic full-face view with median lobe evenly tapering anterad to pointed or rounded apex (Fig. ) . . . . . 73
72
return to couplet #71
- Mesometapleural suture broad, scrobiculate, widening anterad; cross-section of petiolar node at mid-length convex; width of second funicular segment more than 1/2 its length . . . . . Leptogenys cordoba
 Head of Leptogenys cordoba worker |
 Profile of Leptogenys cordoba worker |
- Mesometapleural suture fine, smooth, not scrobiculate; cross-section of petiolar node at mid-length V- shaped; width of second funicular segment less than 1/3 its length . . . . . Leptogenys glabra
 Head of Leptogenys glabra worker |
 Profile of Leptogenys glabra worker |
73
return to couplet #71
- Petiolar node elongate in dorsal view, anterior margin at most half as wide as posterior margin . . . . . 74
- Petiolar node subquadrate in dorsal view, anterior margin more than half as wide as posterior margin . . . . . 78
74
return to couplet #73
- Propodeum with distinct lobes or denticles (Figs. 11B, 45B) . . . . . 75
- Propodeum without teeth or denticles, at the most a low lobe may be present posterad of each propodeal spiracle (Figs. ) . . . . . 77
75
return to couplet #74
- Petiolar node with anterior and dorsal margins forming continuous convexity in lateral view; postero-dorsal propodeal margin evenly convex until apex of propodeal lobe in lateral view; WL > 1.4 mm . . . . . Leptogenys iheringi (in part - also #63)
| Head of Leptogenys iheringi worker |
Profile of Leptogenys iheringi worker |
- Node with distinctly vertical anterior margin and convex dorsal in lateral view; posterodorsal propodeal margin convex until base of propodeal tooth, tooth abruptly projecting; WL < 1.4 mm . . . . . 76
76
return to couplet #75
- Scape surpasses posterior cephalic margin by one apical diameter; width of third antennal segment > 1/2 its length; body without iridescence . . . . . Leptogenys gorgona
 Head of Leptogenys gorgona worker |
 Profile of Leptogenys gorgona worker |
- Scape surpasses posterior cephalic margin by at least 3 apical widths; width of third antennal segment ≤ 1/2 its length; body usually with blue iridescence . . . . . Leptogenys melena
 Head of Leptogenys melena worker |
 Profile of Leptogenys melena worker |
77
return to couplet #74
- Compound eye situated in the middle of the lateral cephalic margin with head in full-face view; width of petiolar posterior margin > 3/4 length of petiole . . . . . Leptogenys antillana
 Head of Leptogenys antillana worker |
 Profile of Leptogenys antillana worker |
- Compound eye situated anterad of midpoint of lateral cephalic margin; width of petiolar posterior margin < 3/4 length of petiole . . . . . Leptogenys quadrata
 Head of Leptogenys quadrata worker |
 Profile of Leptogenys quadrata worker |
78
return to couplet #73
- Propodeum with distinct denticles or lobes (Fig. ) . . . . . 79
- Propodeum unarmed, without teeth or denticles, at most low swelling may be present next to each propodeal spiracle (Fig. ) . . . . . 85
79
return to couplet #78
- Length of third antennal segment equal to or more than twice its apical width . . . . . 80
- Length of third antennal segment less than twice its apical width . . . . . 82
80
return to couplet #79
- Compound eye large, occupying at least 1/3 lateral cephalic margin in cephalic full-face view . . . . . Leptogenys minima
 Head of Leptogenys minima worker |
 Profile of Leptogenys minima worker |
- Compound eye smaller, occupying ≤ 1/4 lateral cephalic margin (Fig. ) . . . . . 81
81
return to couplet #80
- Mesonotum transverse in dorsal view, at least 3 × wider than long; metanotal groove smooth . . . . . Leptogenys quiriguana
 Head of Leptogenys quiriguana worker |
 Profile of Leptogenys quiriguana worker |
- Mesonotum oval in dorsal view, 2 × as long as broad; metanotal groove scrobiculate . . . . . Leptogenys australis
 Head of Leptogenys australis worker |
 Profile of Leptogenys australis worker |
82
return to couplet #79
- Compound eye small, approximately 4 ommatidia across, OI < 0.15 . . . . . Leptogenys rufa
 Head of Leptogenys rufa worker |
 Profile of Leptogenys rufa worker |
- Compound eye larger, at least 8 ommatidia across, OI > 0.15 (Fig. ) . . . . . 83
83
return to couplet #82
- Basal mandibular margin with 3 – 2 stiff setae basad; compound eye mostly flat . . . . . Leptogenys guianensis
 Head of Leptogenys guianensis worker |
 Profile of Leptogenys guianensis worker |
- Basal mandibular margin with sparse pilosity, none standing out as setae or noticeably thick; compound eye weakly convex (Fig. ) . . . . . 84
84
return to couplet #83
- Mandible with basal and masticatory margin joined by continuously curved flange in dorsal view; propodeal spiracle elongate . . . . . Leptogenys yocota
 Head of Leptogenys yocota worker |
 Profile of Leptogenys yocota worker |
- Mandible with basal and masticatory margin separated by blunt angle; propodeal spiracle broadly oval . . . . . Leptogenys orchidioides
85
return to couplet #78
- Mesonotum narrow and parallel sided, with straight anterior and posterior margins in dorsal view; mandible with a sinuate basal margin in cephalic full-face view, with a basal convexity and apical concavity . . . . . 86
- Mesonotum not parallel sided, with at least one curved margin; basal mandibular margin not sinuate, either mostly convex, or basally convex and apically straight . . . . . 87
86
return to couplet #85
- Apical width of the third antennal segment ≥ 3/4 its length . . . . . Leptogenys pusilla
 Head of Leptogenys pusilla worker |
 Profile of Leptogenys pusilla worker |
- Apical width of third antennal segment ≤ 2/3 its length . . . . . Leptogenys josephi
 Head of Leptogenys josephi worker |
 Profile of Leptogenys josephi worker |
87
return to couplet #85
- Length of third antennal segment ≥ 2 × its apical width; compound eye larger (OI: 0.23 – 0.27) . . . . . Leptogenys erugata
 Head of Leptogenys erugata worker |
 Profile of Leptogenys erugata worker |
- Length of third antennal segment < 2 × its apical width; compound eye smaller (OI: 0.18 – 0.20) . . . . . Leptogenys kiche
 Head of Leptogenys kiche worker |
 Profile of Leptogenys kiche worker |
References
- Lattke, J.E. 2011. Revision of the New World species of the genus Leptogenys Roger (Insecta: Hymenoptera: Formicidae: Ponerinae). Arthropod Systematics & Phylogeny, 69, 127-264.
- Lopez-Munoz, R.A., Villarreal, E., Lattke, J.E. 2018. Two new species of Leptogenys from southern Brazil (Hymenoptera: Formicidae). Zootaxa 4410: 559–566 (doi:10.11646/zootaxa.4410.3.9).
- Tozetto, L., Chaul, J.C.M., Boudinot, B.E., Lattke, J.E. 2022. Review of the Leptogenys unistimulosa species group (Hymenoptera: Formicidae) with the description of a new Amazonian species. Revista Brasileira de Entomologia 66(3): e20220045 (doi:10.1590/1806-9665-rbent-2022-0045).