Key to Afrotropical Leptogenys workers

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to navigation Jump to search


Key to Leptogenys Workers. Based on Bolton (1975) [1]

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

2

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
Leptogenys crustosa casent0281916 p 1 high.jpg
  • 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
Leptogenys conradti sam-hym-c002505a profile 1.jpg

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
Leptogenys jeanneli casent0915234 p 1 high.jpg
  • 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
Leptogenys pavesii casent0132269 profile 1.jpg
  • 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
Leptogenys maxillosa casent0101496 profile 1.jpg
  • 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
Leptogenys falcigera casent0003814 profile 1.jpg

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
Leptogenys microps casent0902576 p 1 high.jpg
  • 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 antenna) scapes, HL > 1.25. SI > 140. (Ghana) ….. Leptogenys spandax
Leptogenys spandax casent0902577 p 1 high.jpg
  • 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
Leptogenys testacea casent0902575 p 1 high.jpg
Leptogenys guineensis casent0281915 p 1 high.jpg

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

13

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
L sulcinoda casent0915466 p 1 high.jpg
  • In full-face view the occipital margin of the head broadly concave. Petiole node in profile shorter, LPI > 145. (Guinea) ….. Leptogenys occidentalis
Leptogenys occidentalis casent0317007 p 1 high.jpg

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
Leptogenys mastax casent0902605 p 1 high.jpg
  • Smaller species, HL < 1.00 PW <0.58, with relatively shorter head and stapes. CI > 65, SI <135. (Ivory Coast. Ghana) ….. Leptogenys nuserra
Leptogenys nuserra casent0270563 p 1 high.jpg

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

18

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
Leptogenys titan casent0902599 p 1 high.jpg
  • Dorsum of pronotum and propodeum, especially the latter, sculptured. Maximum diameter of eye about 0.50. (Kenya, Tanzania) ….. Leptogenys regis
Leptogenys regis casent0217120 p 1 high.jpg

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

20

return to couplet ..... 19

  • Larger species with antennal scapes both absolutely and relatively longer, SL > 2.75, SI > 230. (Cameroun, Zaire) ….. Leptogenys camerunensis
Leptogenys camerunensis casent0003147 profile 1.jpg
  • Smaller species with antennal scripts both absolutely and relatively shorter, SL < 2.60, SI < 220. (Mozambique) ….. Leptogenys leiothorax
Leptogenys leiothorax sam-ent-0011536 profile 1.jpg

21

return to couplet ..... 19

  • Inner margin of mandible with a convex, semi-translucent lamella. (Ghana) ….. Leptogenys zapyxis
Leptogenys zapyxis casent0902595 p 1 high.jpg
  • 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

23

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
Leptogenys stuhlmanni sam-hym-c008614 profile 1.jpg
  • 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
Leptogenys sterops casent0902594 p 1 high.jpg

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
Leptogenys vindicis casent0902598 p 1 high.jpg

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
Leptogenys erythraea casent0281917 p 1 high.jpg
  • 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
L schwabi casent0822196 p 1 high.jpg
  • 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
Leptogenys nebra casent0902597 p 1 high.jpg

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
Leptogenys terroni casent0270580 p 1 high.jpg
  • 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
Leptogenys trilobata rmcaent000017736 p 1 high.jpg

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
Leptogenys excellens casent0902601 p 1 high.jpg
  • 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
Leptogenys princeps casent0902606 p 1 high.jpg
  • 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

31

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
Leptogenys longiceps casent0281919 p 1 high.jpg
  • 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
Leptogenys bellii casent0903973 p 1 high.jpg
  • 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
Leptogenys elegans casent0902602 p 1 high.jpg
  • Smaller species, HL < 0.90, SL < 0.85. with shorter petiole, LPI>140. Full adult colour brown. (Zaire, Rhodesia) ….. Leptogenys ferrarii
Leptogenys ferrarii sam-hym-c002453 profile 1.jpg

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
Leptogenys ergatogyna casent0003152 profile 1.jpg
  • 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

Leptogenys khaura casent0401863 p 1 high.jpg
  • 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
Leptogenys stygia casent0270579 p 1 high.jpg
  • Antennal scapes shorter, SI 115 or less. Eyes smaller, with less than 10 facets. Full adult colour yellow-brown. (Ghana) ….. Leptogenys cryptica
Leptogenys cryptica casent0317006 p 1 high.jpg

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
Leptogenys furtiva sam-ent-0011533 profile 1.jpg
  • 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
Leptogenys peringueyi casent0317008 p 1 high.jpg
  • 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
Leptogenys arnoldi sam-ent-0011530 profile 1.jpg
  • 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
Leptogenys havilandi sam-hym-c000891a profile 1.jpg

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
Leptogenys strator casent0902583 p 1 high.jpg
  • 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
Leptogenys honoria casent0902584 p 1 high.jpg
  • Pronotal dorsum smooth, without foveolate impressions. Larger species, SL > 1.10, with relatively longer antennal scapes, SI > 135. (Zaire) ….. Leptogenys ankhesa
Leptogenys ankhesa casent0902582 p 1 high.jpg

46

return to couplet ..... 43

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
Leptogenys buyssoni casent0907353 p 1 high.jpg
  • 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
MCZ ENT Leptogenys-attenuata hal.jpg
  • 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
Leptogenys crassinoda sam-ent-0011532 profile 1.jpg
  • 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
Leptogenys bubastis casent0270541 p 1 high.jpg

50

return to couplet ..... 46

Leptogenys mactans casent0902588 p 1 high.jpg
  • 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
Leptogenys striatidens casent0902587 p 1 high.jpg
  • 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
Leptogenys amon casent0317004 p 1 high.jpg
  • 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
Leptogenys castanea sam-hym-c006309a profile 1.jpg
  • 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
Leptogenys diatra casent0902585 p 1 high.jpg
  • 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)
Leptogenys intermedia sam-hym-c002646b profile 1.jpg
  • 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
Leptogenys piroskae casent0907362 p 1 high.jpg

References