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), Tozetto et al. (2022) and Cavalcanti & Lattke (2024).

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)

Leptogenys pubiceps

• 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

16a Head of Leptogenys wheeleri and 16b. Head of Leptogenys toxeres

• 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

21a Leptogenys santacruzi and 21b Leptogenys toxeres

• 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)

Leptogenys pubiceps

• 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

30a Leptogenys socorda and 30b Leptogenys gaigei

• 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

• Propodeal dorsum and pronotal disc densely punctate; petiole, in lateral view, with anterodorsal margin convex (Fig. 3B); clypeus, in frontal view, truncate anteromedially, sometimes with median denticle (Fig. 3A) . . . . . Leptogenys imperatrix

Head of Leptogenys imperatrix worker

Dorsal view of Leptogenys imperatrix mesosoma

• Propodeal dorsum transversely striate and pronotal disc mostly smooth and shining with scattered punctulae; petiole anteriorly narrow in lateral view (Fig. 3D); in frontal view, clypeus anteromedially pointed (Fig. 3C) . . . . . 33a

• 

  Cavalcanti & Lattke (2024), Figure 3. Head in full-face view presenting shape of clypeus, and body in lateral view presenting shape of petiole. A and B: L. imperatrix (Antweb specimen code: INBIOC-RI001283938). C and D: L. famelica (DZUP549346).

33a

• Head with a longitudinal sulcus between the carinae that surpasses the posterior ocular margin in full-face view (Fig. 4A); mesosoma with a distinct mesometanotal suture, in dorsal view; anterodorsal margin of petiolar node with abrupt angle anteriorly to petiolar spiracle in lateral view; (Fig.4B) . . . . . Leptogenys famelica

Head of Leptogenys famelica worker

Dorsal view of Leptogenys famelica mesosoma

• Head with a longitudinal sulcus not surpassing ocular posterior margin in full-face view (Fig.4C); mesosoma without a distinct mesometanotal suture, in dorsal view; anterodorsal margin of petiolar node mostly straight anterior to spiracle in lateral view (Fig. D) . . . . . Leptogenys pujoli

• 

  Cavalcanti & Lattke (2024), Figure 4 Head in full-face view indicating longitudinal sulcus and shape of petiole in profile. A and B: L. famelica (DZUP549346). C and D: L. pujoli, holotype (DZUP549564).

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

Cavalcanti, J.P., Lattke, J.E. 2024. Leptogenys pujoli, a new amazonian species, and the redescription of Leptogenys famelica Emery, 1896 (Formicidae: Ponerinae). Revista Brasileira de Entomologia 68(2), e20240012 (doi:10.1590/1806-9665-rbent-2024-0012).

• 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).