Key to Afrotropical Leptogenys workers

Key to Leptogenys Workers. Based on Bolton (1975)

1

 * With petiole in profile the posterodorsal angle projecting as a spine or tooth ..... 2
 * With petiole in profile the posterodorsal angle not projecting as a spine or tooth ..... 3

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return to couplet ..... 1


 * Rugosity of head and alitrunk overlaid by a dense puncturation. Scapes, legs, and at least the first gastral tergite reticulate and dull. (Guinea, Gabon, Cameroun, Zaire, Sudan) ….. Leptogenys crustosa
 * Rugosity of head and alitrunk not overlaid by puncturation. Scapes and legs usually shiny, not reticulate; first gastral tergite highly polished. (Ivory Coast, Ghana, Cameroun) …..Leptogenys conradti

3
return to couplet ..... 1


 * Entirety of head, alitrunk and gaster densely shagreened and opaque, with scattered larger punctures and short, dense, greyish, pruinose pubescence ..... 4
 * Not entirely shagreened, usually not opaque, at least the gaster usually shining. If finely and densely reticulate-punctate everywhere then scattered larger punctures absent and dense pruinose pubescence lacking ..... 7

4
return to couplet ..... 3


 * Dorsum of head, alitrunk and first two gastral tergites with numerous standing hairs. Larger species, HL > 1.75. (Tanzania) ….. Leptogenys jeanneli
 * Dorsum of head, alitrunk and first two gastrat tergites without standing hairs. Smaller species, HL < 1.75 ..... 5

5
return to couplet ..... 4


 * Fringing lamella of clypeus broad and broadly rounded. Outer margin of mandible straight or concave in its distal half. Sides of head not strongly divergent anteriorly in full-face view. (Somalia, Sudan, Cameroun, Kenya, Tanzania; tramp species in Old World tropics) ….. Leptogenys pavesii
 * Fringing lamella of clypeus narrow, either narrowly rounded or obtusely angulate medially. Outer margin of mandible convex throughout its length. Sides of head divergent anteriorly in full-face view ..... 6

6
return to couplet ..... 5


 * Node of petiole in dorsal view distinctly broader than long, DPI > 105. (Zaire, Rhodesia, S.W. Africa; pantropical tramp species) ..... Leptogenys maxillosa
 * Node of petiole in dorsal view at least as long as broad. usually distinctly longer than broad, DPI 100 or less (pantropical tramp species) ….. Leptogenys falcigera

7
return to couplet ..... 3


 * First and second gastral tergites without hairs, with sparse, strongly adpressed pubescence. Eyes minute, their maximum diameter less than the maximum width of the scape. Gaster very weakly or not constricted between the first and second segments ..... 8
 * First and second gastral tergites with hairs, often also with pubescence. If gastral hairs sparse then either eyes larger, their maximum diameter greater than the maximum width of the scape, or garter strongly constricted between first and second segments, or both ..... 11

8
return to couplet ..... 7


 * Pronotal dorsum with a pair of long, erect hairs anteriorly, much longer than the remaining pilosity. Minute species, HL < 0.70, PW < 0.42, with minute eyes, diameter < 0.05. (Ivory Coast) .....Leptogenys microps
 * Pronotal dorsum without a pair of long, erect hairs anteriorly, pilosity absent or hairs of approximately equal length. Larger species, HL > 0. 75. PW > 0.45 with larger eyes, diameter > 0.07 ..... 9

9
return to couplet ..... 8


 * Pronotal dorsum without short, standing hairs. Petiole in profile a thick scale, tapering dorsally. Larger species with relatively longer antennal scapes, HL > 1.25. SI > 140. (Ghana) ….. Leptogenys spandax
 * Pronotal dorsum with numerous short, standing hairs. Petiole in profile not a thick scale but a high, narrow node. Smaller species with relatively shorter scapes, HL<1.10 Sl<130 ..... 10

10
return to couplet ..... 9


 * Apex of mandible with three teeth, apical plus two preapical. (Ghana) ….. Leptogenys testacea
 * Apex of mandible with two teeth, apical plus one preapical. (Guinea, Ghana) ….. Leptogenys guineensis

11
return to couplet ..... 7
 * Petiole in profile or in dorsal view with the upper halves of the sides longitudinally rugose or sulcate ..... 12
 * Petiole in profile or in dorsal view with the upper halves of the sides not longitudinally rugose or sulcate ..... 15

12
return to couplet ..... 11


 * Pronotal dorsum unsculptured apart from pits from which hairs arise ..... 13
 * Pronotal dorsum sculptured, at least anteriorly ..... 14

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return to couplet ..... 12


 * In full-face view the occipital margin of the head feebly convex. Petiole node in profile longer, LPI<140. (Gabon) ….. Leptogenys sulcinoda
 * In full-face view the occipital margin of the head broadly concave. Petiole node in profile shorter, LPI > 145. (Guinea) ….. Leptogenys occidentalis

14
return to couplet ..... 12


 * Larger species, HL > 1.00 PW > 0.58. with relatively longer head and scapes. CI < 65, SI > 140. (Ivory Coast, Ghana) ….. Leptogenys mastax
 * Smaller species, HL < 1.00 PW <0.58, with relatively shorter head and stapes. CI > 65, SI <135. (Ivory Coast. Ghana) ….. Leptogenys nuserra

15
return to couplet ..... 11


 * Mandibles extended into elongate, narrow, linear or sublinear blades, the inner margins of which are often concave. Mandibles not capable of closing tightly against the median lobe of the clypeus, which is often reduced, enclosing a space (sometimes large) between themselves and the clypeus ..... 16
 * Mandibles short and usually quite stout, their inner margins usually distinctly convex. Mandibles capable of closing tightly against the median lobe of the clypeus never enclosing a space between themselves and the clypeus (Text-figs 13-1£1)..... 35

16
return to couplet ..... 15
 * Antennal scapes with SL>1.90. Gaster very weakly or not constricted between the first and second segments. Metanotal groove not cross-ribbed or sculptured ..... 17
 * Antennal scapes with SL < 1.70. Gaster distinctly constricted between first and second segments. Metanotal groove distinctly cross-ribbed or otherwise sculptured ..... 27

17
return to couplet ..... 11
 * With head in full-face view eyes not breaking the outline of the sides of the head. Antennal scapes with dense pubescence but without erect hairs which are as long as the maximum width of the scape. Large species with relatively short scapes. HL > 2.10, SI < 170 ..... 18
 * With head in full-face view eyes breaking the outline of the sides of the head. Antennal scapes with numerous erect hairs which are as long as or longer than the maximum width of the scape; pubescence on scapes usually sparse. Smaller species with relatively long scapes. HL < 2.10, SI > 180 ..... 19

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return to couplet ..... 17
 * Dorsum of pronotum and propodeum unsculptured apart from pits from which hairs arise. Maximum diameter of eye about 0.66. (Cameroun) ….. Leptogenys titan
 * Dorsum of pronotum and propodeum, especially the latter, sculptured. Maximum diameter of eye about 0.50. (Kenya, Tanzania) ….. Leptogenys regis

19
return to couplet ..... 17
 * Entire dorsum of alitrunk completely unsculptured. Sides of alitrunk unsculptured apart from cross-ribbing at meso-metapleural suture and a few rugae around the bulks of the metapleural gland. Full adult colour brown or deep red-brown, with bluish or violet opalescence, which may be patchy ..... 20
 * Propodeal dorsum at least weakly, usually strongly sculptured; pronotum sometimes sculptured, often not. Sides of alitrunk with pleurae and propodeum striate or rugose. Full adult colour black or brown but without opalescence ..... 21

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return to couplet ..... 19
 * Larger species with antennal scapes both absolutely and relatively longer, SL > 2.75, SI > 230. (Cameroun, Zaire) ….. Leptogenys camerunensis
 * Smaller species with antennal scripts both absolutely and relatively shorter, SL < 2.60, SI < 220. (Mozambique) ….. Leptogenys leiothorax

21
return to couplet ..... 19


 * Inner margin of mandible with a convex, semi-translucent lamella. (Ghana) ….. Leptogenys zapyxis
 * Inner margin of mandible without a convex, semi-translucent lamella ..... 22

22
return to couplet ..... 21


 * Antennal scapes relatively shorter, SI < 200 ..... 23
 * Antennal scenes relatively longer, SI > 200 ..... 24

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return to couplet ..... 22


 * Larger species, HL > 1.80, with maximum diameter of eye 0.50 or more. Pronotal dorsum weakly sculptured. With mandibular apices overlapping the basal portion of each blade passing through a curve before its junction with the clypeus. (Sudan, Kenya, Mozambique. Comoro Islands)….. Leptogenys stuhlmanni
 * Smaller species, HL. < 1.60, with maximum diameter of eye <0.45 (ca 0.40). Pronotal dorsum unsculptured apart from minute hair-pits. With mandibular apices overlapping the basal portion of each blade not passing through a curve before its junction with the clypeus. (Ivory Coast) ….. Leptogenys sterops

24
return to couplet ..... 22
 * Dorsum of head unsculptured apart from minute hair-pits: pronotal dorsum usually the same but rarely with some faint sculpturation ..... 25
 * Dorsum of head and pronotum distinctly sculptured everywhere. (Cameroun) ….. Leptogenys vindicis

25
return to couplet ..... 24
 * Larger species with very large eyes. HL > 1.90, maximum diameter of eye 0.54 or more. Full adult colour brown. (Ethiopia) ….. Leptogenys erythraea
 * Smaller species with smaller eyes, HL < 1.85. maximum diameter of eye 0.48 or less. Full adult colour black ..... 26

26
return to couplet ..... 25


 * Eyes larger, maximum diameter in the range 0.44-0.48 (in HW rangeof 1.08-1.22). Width of head across eyes the same as or only slightly less than the width across the clypeus from corner to corner. (Rhodesia, South Africa) ….. Leptogenys schwabi
 * Eyes smaller, maximum diameter about 0.36 (with HW ca 1.22). Width of head across eyes much less than width across the clypeus from corner to corner. (Cameroun) ….. Leptogenys nebra

27
return to couplet ..... 16


 * Dorsum of head finely rugose or reticulate-rugose, the interrugal spaces with numerous fine punctures ..... 28
 * Dorsum of head not rugose nor reticulate-rugose; either punctate, reticulate-punctate or smooth and shining ..... 29

28
return to couplet ..... 27
 * Pronotom with a fine and very dense reticulation which  the entire dorsum, also with scattered hair-pits. larger species, HL > 1.30 SL. > 1.40. SI > 125. (Cameroun) ….. Leptogenys terroni
 * Pronotum without a fine reticulation, at most with a few weak, rounded rugulae. Smaller species. HI. < 1.20. SI, < 1.20. St < 120. (Cameroun. Zaire) ….. Leptogenys trilobata

29
return to couplet ..... 27
 * Sides of head below and behind eyes and lateral portions of ventral surface of head strongly sculptured. (Zaire) ….. Leptogenys excellens
 * Sides of head below and behind eyes and lateral portions of ventral surface of head unsculptured except for hair pits and very rarely some weak, superficial reticulation ..... 30

30
return to couplet ..... 29
 * Dorsum of head coarsely and closely reticulate-punctate the punctures not separated by smooth areas. Larger species, HL > 1.20, PW > 0.75. Node of petiole massive. PL > 0.60. PH > 0.75 ….. Leptogenys princeps
 * Dorsum of head with scattered punctures which are separated by smooth areas. Smaller species, HL < 1.15, PW < 0.70. Node of petiole smaller, PL < 0.55 PH <0.70 ..... 31

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return to couplet ..... 30
 * Mesopleuron completely reticulate-punctate, with numerous transverse rugulae. Petiole dorsum and upper halves of sides reticulate-punctate superimposed upon a coarser regulation. (Senegal, Ghana) ….. Leptogenys longiceps
 * Mesopleuron not reticulate-punctate: a few punctures and transverse rugulae may be present but there are extensive unsculptured areas. Petiole dorsum and sides not reticulate punctate ..... 32

32
return to couplet ..... 31
 * Middle of posterodorsal margin of petiole slightly projecting as an obtuse tubercle. (Ethiopia) ….. Leptogenys bellii
 * Middle of posterodorsal margin of petiole not projecting as a tubercle ..... 33

33
return to couplet ..... 32
 * Eyes smaller, their maximum diameter approximately equal to the length of the third funicular segment. Head black, very polished, with only few scattered, minute punctures. (Zaire) ….. Leptogenys ravida


 * Eyes larger, their maximum diameter markedly greater than the length of the third funicular segment. Head brown or black, if black then with numerous quite distinct punctures ..... 34

34
return to couplet ..... 33


 * Larger species. HL > 0.95, SL > 0.85. with longer petiole, LPI < 140. Full adult colour black. (Ivory Coast, Ghana, Nigeria. Cameroun) ….. Leptogenys elegans
 * Smaller species, HL < 0.90, SL < 0.85. with shorter petiole, LPI>140. Full adult colour brown. (Zaire, Rhodesia) ….. Leptogenys ferrarii

35
return to couplet ..... 15
 * Propodeal dorsum with a longitudinal groove medially, and anteriorly with a broad, transverse impression posterior to the metanotal groove. Mandibles very broad, massively developed. Antennal scapes relatively very long, SI > 220. (Ghana, Uganda. Cameroun, Zaire) ….. Leptogenys ergatogyna
 * Propodeal dorsum without a median groove and transverse impression anteriorly. Mandibles not as above. Antennal scapes shorter, SI < 200 ..... 36

36
return to couplet ..... 35
 * Dorsum of head coarsely reticulate-punctate or very densely punctulate over most or all of its surface ..... 37
 * Dorsum of head either smooth and shining, with only scattered punctures from which hairs arise, or rarely superficially finely reticulate ..... 43

37
return to couplet ..... 36
 * Minute species. HL < 0.85, PW < 0.50. Eyes small or minute, their maximum diameter much less than the maximum width of the scape. Second funicular segment at most as long as third, usually much shorter than third ..... 38
 * Larger species, HL > 1.10, PW > 0.65. Eyes large, their maximum diameter greater than the maximum width of the scape,. Second funicular segment distinctly longer than the third ..... 40

38
return to couplet ..... 37
 * Pronotal dorsum unsculptured, smooth and shining. (Nigeria) ….. Leptogenys khaura
 * Pronotal dorsum strongly sculptured ..... 39

39
return to couplet ..... 38
 * Antennal scapes longer. SI 119 or more. Eyes larger, with more than 10 facets Full adult colour black. (Nigeria, Cameroun) ….. Leptogenys stygia
 * Antennal scapes shorter, SI 115 or less. Eyes smaller, with less than 10 facets. Full adult colour yellow-brown. (Ghana) ….. Leptogenys cryptica

40
return to couplet ..... 37
 * First and second gastral tergites covered with a fine, dense, reticulate--punctuation or granulation, without smooth, shining areas. (Rhodesia) ….. Leptogenys furtiva
 * First and second gastral tergites unsculptured. smooth and shining apart from pits from which hairs arise ..... 41

41
return to couplet ..... 40
 * Pronotal dorsum with scattered small pits separated by smooth areas, without a fine blanketing sculpture on any part of the sclerite. (South Africa) ….. Leptogenys peringueyi
 * Pronotal dorsum with a fine, dense sculpturation, blanketing the sclerite at least in part ..... 42

42
return to couplet ..... 41
 * Fringing lamella of clypeus narrow and indistinct. Antennal scapes relatively short, SI < 140. Eyes large, maximum diameter 0.34 or more. (Rhodesia) ….. Leptogenys arnoldi
 * Fringing lamella of clypeus broad and distinct, usually opaque. Antennal scopes relatively long, SI > 140. Eyes smaller, maximum diameter 0.30 or less. (South Africa) ….. Leptogenys havilandi

43
return to couplet ..... 36
 * Ventral process of petiole complex, double, consisting of a large lobe or tooth antero-ventrally and a smaller lobe or tooth situated more posteriorly, the two separated by a distinct space or indentation ..... 44
 * Ventral process of petiole simple, single, consisting only of a lobe or tooth antero-ventrally, of varying configuration ..... 46

44
return to couplet ..... 43
 * Sides and ventral surface of head sculptured. Node of petiole in profile decreasing slightly in thickness from base to apex. (Zaire) ….. Leptogenys strator
 * Sides and ventral surface of head not sculptured. Node of petiole in profile increasing slightly in thickness from base to apex ..... 45

45
return to couplet ..... 44
 * Pronotal dorsum with numerous shallow, foveolate impressions separated by smooth areas. Smaller species, SL < 1.10, with relatively shorter antennal scapes, SI < 135. (Cameroun) ….. Leptogenys honoria
 * Pronotal dorsum smooth, without foveolate impressions. Larger species, SL > 1.10, with relatively longer antennal scapes, SI > 135. (Zaire) ….. Leptogenys ankhesa

46
return to couplet ..... 43
 * Antennal scapes with SL > 1.40 ..... 47
 * Antennal scapes with SL < 1.30 ..... 50

47
return to couplet ..... 46
 * Maximum diameter of eye in full-face view less than maximum width of scape. Ventral process of petiole a broad lobe with a posteroventral tooth. Full adult colour red-brown. (Ethiopia) ….. Leptogenys buyssoni
 * Maximum diameter of eye in full-face view greater than maximum width of scape. Ventral process of petiole a simple or acute lobe. Full adult colour black ..... 48

48
return to couplet ..... 47
 * Larger species with relatively longer head and antenna! scapes and larger eyes; HL. 1.50 or more, CI < 65, SI > 170, ocular diameter 0.36 or more. Node of petiole in dorsal view very strongly narrowed anteriorly, much broader behind than in front, the sides feebly concave. Head and body usually with bluish opalescence. (South Africa) ….. Leptogenys attenuata
 * Smaller species with relatively shorter head and antennal scopes and smaller eyes; HL < 1.45. CI > 65, SI < 165, ocular diameter 0.32 or less. Node of petiole in dorsal view only slightly narrower in front than behind. Head and body shiny black, without bluish opalescence ..... 49

49
return to couplet ..... 48
 * Mesonotum and propodeum without scattered large pits or punctures. Propodeal dorsum shorter, about 1.10 in profile from metanotal groove to apex of prominence on declivity in workers with HW range 0.96-1.00. (South Africa) ….. Leptogenys crassinoda
 * Mesonotum and propodeum with numerous scattered large pits or punctures. Propodeal dorsum longer, about 1.30 in profile from metanotal groove to apex of prominence on declivity in workers with head range 0.96-1.00. (Cameroun) ….. Leptogenys bubastis

50
return to couplet ..... 46
 * Antennal scapes relatively very short, SI < 95. (South Africa) ….. Leptogenys mactans
 * Antenna) scapes relatively long, SI 100 or more ..... 51

51
return to couplet ..... 50
 * Mandibles covered with dense, fine, longitudinal striation. Dorsum of head and pronotuM with dense but superficial reticulation. (Cameroun) ….. Leptogenys striatidens
 * Mandibles smooth and shining, not striate. Dorsum of head and pronotum smooth, without superficial reticulation ..... 52

52
return to couplet ..... 51
 * Circumocular impression very broad and deep in front of, above and behind eye, so that the eye appears to be sunk in a concavity in the side of the head. Node of petiole in dorsal view much longer than broad, DPI < 70; head long and narrow. CI < 65. (Cameroun) ….. Leptogenys amon
 * Circumocular impression very weak or absent, the eye not sunk into a concavity in the side of the head. Node of petiole much broader, DPI 80 or more; head shorter and broader. CI 69 or more ..... 53

53
return to couplet ..... 52
 * Antennal scapes both relatively and absolutely shorter, SI < 0.75 (range 0.62- 0.70). SI < 120 (range 100-117). (Rhodesia. South Africa) ….. Leptogenys castanea
 * Antennal scapes both relatively and absolutely longer, SI > 0.75 (range 0.80-1.08), SI 120 or more (range 120-130) ..... 54

54
return to couplet ..... 53
 * Smaller species, HL ca 0.86, HW ca 0.62, SL ca 0.80. Ventral process of petiole an elongate, recurved tooth. (Cameroun) ….. Leptogenys diatra
 * Larger species, HL > 0.90, HW >0.65, SL> 0.85. Ventral process of petiole a lobe, the posteroventral angle of which may be dentiform, but not as above ..... 55

55
return to couplet ..... 54
 * Eyes larger, ocular diameter greater than 0.11. the eyes set well forwards on the sides of the head. The maximum diameter of the eye equal to or greater than the maximum width of the scape in full-face view. (Eastern and southern Africa) ….. Leptogenys intermedia (as nitida in Bolotn, 1975)
 * Eyes small, ocular diameter ca 0.09, the eyes set well back on the sides of the head. The maximum diameter of the eye much less than the maximum width of the scope in full-face view. (Ethiopia) ….. Leptogenys piroskae