Key to Micronesian Ants

AntWiki: The Ants --- Online

This worker key is based on: Clouse, R. M. 2007. The Ants (Hymenoptera: Formicidae) of Micronesia. Micronesica. 39(2): 171–296.

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List of Micronesia Ant species

1

  • Body with two isolated segments (the petiole and postpetiole) between mesosoma and gaster (Fig. 1C) . . . . . 2
  • Body with one isolated segment between mesosoma and gaster (the petiole), its separation from the gaster being a narrow constriction (Fig. 1A–B) . . . . . 3
  • Body with one isolated segment between mesosoma and gaster that is broadly attached to the first segment of the gaster (Fig. 9B) (Amblyoponinae) . . . . . 66

2

return to couplet #1

  • Frontal carinae close and vertical, such that antennal insertions are completely visible from above; pygydium flattened and bordered by tiny denticles (Fig. 3B–C) (Cerapachyinae) . . . . . 4
  • Frontal carinae usually covering antennal insertions such that they are at most only partly visible from above; pygydium simple (Myrmicinae) . . . . . 5

3

return to couplet #1

4

return to couplet #2

  • With prominent eyes (Fig. 3B) . . . . . Cerapachys sp. 91952

5

return to couplet #2

6

return to couplet #5

7

return to couplet #6

  • Mandibles compact and triangular; labial shield without extended lateral margins (never T-shaped); inner margins of mandibles lined with teeth (Fig. 11B) . . . . . 8
  • Mandibles long and thin; labial shield with extended lateral margins, making the whole sclerite T-shaped; teeth only at ends of the mandibles (Fig. 11C) . . . . . 9

8

return to couplet #7

  • Eyes present; head with a single, long hair projecting laterally from each side, immediately above end of the antennal scrobe (Fig. 11A) . . . . . Strumigenys karawajewi
  • Eyes tiny, almost completely missing; head without single, distinct hair projecting laterally from each side . . . . . Strumigenys membranifera

9

return to couplet #7

10

return to couplet #9

  • When view from above, mandibles with 3 apical teeth, the middle one shorter than other two (Fig. 11C) . . . . . Strumigenys rogeri

11

return to couplet #10

  • Posterior propodeum to anterior gaster covered with a light-colored,

spongy substance (Fig. 11D) . . . . . 12

12

return to couplet #11

  • Combining the following: Mesosoma with little or no sponge, most sponge concentrated on the ventral side of the petiolar node and postpetiole; conspicuous standing hairs on the mesonotum consisting of a short pair on the pronotum and mesonotum . . . . . Strumigenys mayri

13

return to couplet #12

  • HL around 0.7 mm; curved, erect hairs on head long and spaced about as far apart as their length; spongiform bodies on propodeum forming two distinct ridges from the propodeal spines down to the petiolar insertion; the inner margin of the mandibles straight, base of subapical tooth joining base of end tooth, with no straight section of mandible separating the two (Fig. 11E) . . . . . Strumigenys godeffroyi
  • HL usually less than 0.5 mm; curved, erect hairs on head spaced closer together than their length; two pairs of extremely long hairs often missing; spongiform bodies on propodeum disorganized and not covering propodeal spines; inner margin of mandibles continuously curved, the subapical tooth separated from the base of the end tooth by a section of mandible longer than the subapical tooth’s length . . . . . Strumigenys frivaldszkyi

14

return to couplet #5

  • Postpetiole attached to dorsal surface of the gaster; small yellow ants . . . . . 15
  • Postpetiole attached to anterior end of the gaster, the gaster not noticeably suspended below the postpetiole; size and color variable . . . . . 16

15

return to couplet #14

  • Dorsal edge of each propodeal spine with a stout hair (Fig. 3D) . . . . . Crematogaster biroi cf.

16

return to couplet #14

  • Pronotum, mesonotum, and propodeum each bearing a pair of long spines; workers distinctly dimorphic . . . . . Pheidole sexspinosa
  • Lacking spines on the mesosoma as described above; workers monomorphic, polymorphic, or dimorphic . . . . . 17

17

return to couplet #16

  • Body surfaces, except for tarsi, funiculi, and mandibles covered with evenly spaced paddle-like hairs; antennae 12-segmented . . . . . Calyptomyrmex
  • Paddle-shaped hairs usually absent, or, if present, not covering all body surfaces as described above; antennal segment number variable . . . . . 18

18

return to couplet #17

  • Large, plate-like keel on the ventral surface of petiole; propodeum without spines (Fig. 15D) . . . . . 19
  • Ventral petiole without a large, plate-like keel; propodeum often with spines or blunt projections . . . . . 24

19

return to couplet #18

20

return to couplet #19

  • Head and mesosoma covered with thick, smooth, wavy, striate sculpture, giving a wrinkled appearance; HW 0.68 mm; HL 0.76 mm (Fig. 15A) . . . . . Vollenhovia mwereka
  • Head and mesosoma not sculptured as above (not wrinkled in appearance and with smooth patches on dorsum); head square in front view, both HW and HL about 0.8 mm . . . . . Vollenhovia oblonga

21

return to couplet #19

  • Area behind eyes distincly striate (Fig. 14C); middle part of frons punctate; HW 0.42–0.45 mm; HL 0.52–0.55 mm, CI = 81–86 (Fig. 14D) . . . . . 22
  • Area behind eyes smooth (Fig. 15C); middle part of fronts striate or smooth; head either smaller (and usually narrower) or larger and more square . . . . . 23

22

return to couplet #22

  • Central propodeal dorsum and anterior pronotum with smooth patches; body orangish brown . . . . . Vollenhovia sp. 6041940

23

return to couplet #21

  • Antennae 11-segmented; HW 0.37–0.41 mm (Fig. 15B); mesosoma mostly punctate, except for smooth patch on central anterior pronotum . . . . . Vollenhovia pwidikidika
  • Antennae 12-segmented; HW 0.55 mm (Fig. 14B); Mesosoma with smooth areas on dorsal and lateral propodeum and promesonotum . . . . . Vollenhovia sp. 23031948

24

return to couplet #18

  • Head with a prominent carina on each side that runs below eye from base of the mandibles to posterior corner of the head (Fig. 5C–D) . . . . . Myrmecina sp. 7121952

25

return to couplet #24

  • Antennae with 10 segments, with the last 2 forming a conspicuous club . . . . . 26

26

return to couplet #25

  • Eyes tiny; area around propodeal spiracle shining; workers monomorphic . . . . . Solenopsis papuana
  • Maximum eye diameter about equal to antennal club width; area around propodeal spiracle dull in larger workers; workers polymorphic . . . . . Solenopsis geminata

27

return to couplet #25

  • Clypeus forming a flange or shelf above the mandibles . . . . . 28
  • Clypeus completing the overall curve of the head to the mouth . . . . . 33

28

return to couplet #27

  • Mesosoma sculptured but lacking teeth, corners, or spines; anterior clypeal border extended forward as a distinctive, narrow, rectangular lobe; antennal scrobes large and deep, partly concealed by broad, downwardly-curving frontal carinae . . . . . Metapone truki
  • Mesosoma glossy and with teeth, corners, or spines; clypeus projecting outward to form an acutely cornered shelf above the mandibles; antennal scrobes shallow, not concealed by carinae (Fig. 10A–C) . . . . . 29

29

return to couplet #28

  • Head and mesosoma with strong, coarse, reticulate sculpture; propodeal spines as long as the petiole . . . . . Pristomyrmex punctatus
  • Reticulate sculpture absent and propodeal spines shorter than the petiole . . . . . 30

30

return to couplet #29

31

return to couplet #30

  • Pronotal spines nearly as large as the propodeal spines and clearly projecting upwards above the dorsal surface in side view (Fig. 10C) . . . . . Pristomyrmex quadridens
  • Pronotal spines notably shorter than the propodeal spines and projecting laterally, often not altering the outline of dorsal pronotum in side view . . . . . Pristomyrmex minusculus

32

return to couplet #30

  • Propodeal spines only about half length of postpetiole; deep, well-defined pits on head, especially laterally between eyes and mandibles; dark brown species (Fig. 10B) . . . . . Pristomyrmex levigatus
  • Propodeal spines about as long as length of postpetiole; head with shallow pits only; orange species (Fig. 10A) . . . . . Pristomyrmex largus

33

return to couplet #27

  • Antennal insertions in deep pit, the walls of which are formed by the fused rear clypeus and frontal lobes (Figs. 12B, 12D, 13B, 14A) . . . . . 34

34

return to couplet #33

35

return to couplet #34

  • Head and mesosoma with distinct, widely spaced, longitudinal and loosely reticulate sculpturing; frons and most of head with longitudinal sculpturing only; petiolar node smooth, shiny, and nearly square in profile

(Fig. 12B) . . . . . Tetramorium sp. 14121952

  • Mesosoma with deep reticulate sculpturing, head with reticulate sculpturing at vertex; petiolar node sculptured and rounded in profile (Fig. 13E, 14A) . . . . . Tetramorium smithi

36

return to couplet #34

  • Anterior edge or the dorsal pronotum with four evenly-spaced, stout hairs that are shorter than the spaces between them (Fig. 13C) . . . . . Tetramorium simillimum
  • Anterior dorsal pronotal hairs numbering more than four and longer than the spaces between them . . . . . 37

37

return to couplet #36

38

return to couplet #37

39

return to couplet #38

  • Petiolar node quadrate; sculptured middle ridge of the frons distinct and cleanly split into two ridges that run parallel to each other at a point even with eyes, then rejoining before clypeus (Fig. 12C); dorsal propodeal spines longer than the height of the median peduncle by about half this height, about twice as long as ventral propodeal spines . . . . . Tetramorium bicarinatum
  • Petiolar node rounded in profile; middle ridge of frons indistinct, mixed with dense reticulate sculpturing, not temporarily split at level of eyes; dorsal propodeal spines equal to height of median peduncle and only slightly longer than ventral propodeal spines (Fig. 13F) . . . . . Tetramorium tonganum

40

return to couplet #38

41

return to couplet #33

  • Combining the following: Clypeus with two longitudinal carinae; propodeum smoothly rounded lacking teeth or spines; last 3 segments of the antennae forming a distinct club . . . . . 42

42

return to couplet #41

  • Maximum diameter of the eyes more than half the width of the antennal club . . . . . 43
  • Maximum diameter of the eyes less than half the width of the antennal club . . . . . 46

43

return to couplet #42

44

return to couplet #43

  • Terminal antennal segment about as long as preceding two combined; gaster dark brown to black, other parts of body yellow-brown . . . . . Trichomyrmex destructor
  • Terminal antennal segment distinctly longer than the combined length of previous two; coloration variable . . . . . 45

45

return to couplet #44

  • Petiole, including peduncle, longer than tall (Fig. 4F); dorsal pronotum distinctly lighter than the vertex of head . . . . . Monomorium floricola
  • Petiole, including peduncle, only about as long as tall (Fig. 4E); concolorous dark . . . . . Monomorium chinense-group

46

return to couplet #42

  • Mesepisternum smooth and shiny; propodeal angles broad, about 140 degrees (Fig. 5A) . . . . . Syllophopsis australica
  • Mesepisternum with coarse, reticulate sculpturing that gives it a dull appearance; propodeal angles steep, about 100 degrees (Fig 5B) . . . . . Syllophopsis sechellensis

47

return to couplet #41

48

return to couplet #47

  • Mesosoma in profile with distinct dorsal furrow separating propodeum from promesonotum; propodeal spines long and thin, about as long as the height of petiolar node peduncle (Fig. 3A); head and mesosoma yellow-orange, gaster dark brown . . . . . Cardiocondyla obscurior
  • Mesosoma smooth and continuous or with only a hint of a metanotal groove; propodeal spines not as long; head and gaster dark brown . . . . . 49

49

return to couplet #48

  • Postpetiolar sternite convex; maximum height of petiole about equal to maximum height of postpetiole . . . . . Cardiocondyla nuda
  • Postpetiolar sternite nearly flat; maximum height of petiole greater than maximum height of postpetiole . . . . . 50

50

return to couplet #49

  • Propodeal spines short and blunt; head, mesosoma, and gaster overall dark brown, the gaster only slightly darker . . . . . Cardiocondyla kagutsuchi
  • Propodeal spines distinct and pointed; mesosoma clearly lighter than gaster and head . . . . . 51

51

return to couplet #50

  • Metanotal groove absent but suggested by a slight impression in the mesosomal profile; mesosoma orange to warm yellow, and gaster black to dark brown . . . . . Cardiocondyla tjibodana
  • Metanotal groove completely absent, dorsal mesosoma flat or convex in profile; mesosoma yellow to brown, but without an orange or warm hue, and gaster black to dark brown . . . . . Cardiocondyla minutior

52

return to couplet #47

  • Combining the following: Petiole lacking anterior peduncle; frontal carinae elongate; antennal scrobes present; propodeum with thick, long (0.3 mm or longer) spines . . . . . 53
  • Petiole with anterior peduncle; frontal carinae indistinct and shorter than half the length of antennal scape; antennal scrobes weak or absent; propodeum with or without spines, but if with spines, less than 0.3 mm . . . . . 56

53

return to couplet #52

  • Propodeal spines approximately 0.5 mm long; pronotum flattened and marginate anteriorly and laterally . . . . . Romblonella palauensis
  • Propodeal spines 0.3 mm long; pronotum not marginate as described above . . . . . 54

54

return to couplet #53

  • Mesosomal dorsum with fine, reticulate sculpturing . . . . . 55
  • Mesosomal dorsum sculpturing predominately shallow longitudinal rugulae and coarse reticulations . . . . . Romblonella yapensis

55

return to couplet #54

  • Propodeal spines straight or very slightly curved at most; head dark brown, remainder of body light brown . . . . . Romblonella townesi
  • Propodeal spines distinctly curved; coloration of head, mesosoma, petiole, postpetiole, and gaster black . . . . . Romblonella sp. 6051940

56

return to couplet #52

  • Antennae nine-segmented and with a two-segmented club . . . . . Carebara atoma

57

return to couplet #56

  • Antennae lacking apical club or appearing to have an indistinct four-segmented club; mesosoma generally smooth and shiny except for strongly punctate mesopleuron . . . . . Aphaenogaster osimenseis
  • Antennae with three-segmented apical club, indistinctly only in Rogeria sp. 25111995; mesosomal sculpturing variable . . . . . 58

58

return to couplet #57

  • Mesosomal profile smooth and more or less evenly convex, interrupted only by a small, notch-like metanotal groove . . . . . 59
  • Mesosomal profile concave in profile, dropping between pronotum and propodeum . . . . . 60

59

return to couplet #58

  • Dorsal propodeum between and anterior to propodeal spines coarsely punctate . . . . . Rogeria stigmatica
  • Dorsal propodeum between and anterior to propodeal spines smooth and shining . . . . . Rogeria sp. 25111995

60

return to couplet #58

  • Pronotal dorsum sculptured, not smooth and shining . . . . . 61

61

return to couplet #60

  • Entire mesosoma of minors with deep, reticulate sculpturing (Fig 7A, B); (majors unknown) . . . . . Pheidole sp. 24041958
  • Entire mesosoma of minors with punctate sculpturing (Fig. 8B); majors with mostly punctate sculpturing, except for small smooth areas . . . . . 62

62

return to couplet #61

  • Majors: Frontal carinae short: punctate sculpturing near eyes blending with linear sculpturing between antennae; entire mesosoma mostly punctured, even under reticulate sculpturing, except for small patches under the pronotal protuberances; Majors and minors: entire body reddish brown to orange. Minors: dorsal propodeum fairly flat in profile . . . . . Pheidole nindi
  • Majors: Frontal carinae long, clearly separating punctate sculpturing near eyes from linear sculpturing between antennae; mesosoma mostly covered in punctate sculpturing, although reticulate sculpturing on pronotum and smooth patches on lateral pronotum and mesosoma distinct; Majors and minors: entire body blackish orange to ashy brown. Minors: dorsal propodeum convex in profile . . . . . Pheidole recondita

63

return to couplet #60

  • Pronotum and mesonotum fused to form the promesonotum; in minor workers, promesonotum shiny dorsally . . . . . 64
  • Pronotum and mesonotum separated by an impression that causes the mesonotum to look distinctly humped in side view, forming a separate section from pronotum and propodeum; mesonotum dull and sculptured dorsally . . . . . 65

64

return to couplet #63

  • Majors with a large, often blunt median hypostomal tooth, flanked closely by two teeth, one on each side (two lateral teeth, one each near the mandibular insertions, are also present but difficult to see); propodeal teeth of minors reduced to minute denticles . . . . . Pheidole umbonata
  • Major with two lateral hypostomal teeth (one each next to the mandibular insertions) only; minors with short but distinct propodeal teeth (Fig. 8A) . . . . . Pheidole megacephala

65

return to couplet #63

  • Majors: Area between eye and the antennal insertion with at least some reticulate sculpturing (Fig. 7C); dorsum of postpetiole mostly smooth and shining; majors and minors: propodeal spine horter than maximum width of propodeal spiracle (Fig. 7D) . . . . . Pheidole fervens
  • Majors: Area between eye and antennal insertion with longitudinal sculpturing only (Fig. 7E); dorsum of postpetiole mostly punctate, weakly shining; majors and minors: propodeal spine longer than maximum width of propodeal spiracle (Fig. 7F) . . . . . Pheidole oceanica

66

return to couplet #1

67

return to couplet #3

  • Mandibles long, falcate, and without teeth; pretarsal claws pectinate . . . . . Leptogenys falcigera

68

return to couplet #67

  • Mandibles long, slender, straight, bent sharply at apex (Fig. 1A) . . . . . 69

69

return to couplet #68

  • Apex of petiolar node rounded or acute, but no spine present . . . . . 70

70

return to couplet #69

  • Dorsal surface of head and pronotum largely smooth and shining; petiolar apex acute in profile; head notably darker than remainder of body . . . . . Anochetus splendidulus
  • Median dorsal surface of head and usually rest of pronotal dorsum with conspicuous sculpture; petiolar apex rounded in profile; body and head concolorous, usually dark brown, although many specimens orange . . . . . Anochetus graeffei

71

return to couplet #68

  • Pretarsal claws with a single median tooth (Fig. 8C); petiolar node longer than wide when viewed from above; body nearly devoid of erect hairs; antennal insertions widely separated by broad clypeus; hind legs with 2 pectinate spurs at apex of tibia . . . . . Platythyrea parallela
  • Pretarsal claws simple; petiolar node usually broader or nearly as broad as long when viewed from above; body with erect hairs; antennal insertions closely approximated; tibial spurs not as above . . . . . 72

72

return to couplet #71

  • Apex of hind tibia with two spurs: a large pectinate spur behind a much smaller, simple spur . . . . . 73
  • Apex of hind tibia with one large pectinate spur . . . . . 75

73

return to couplet #72

74

return to couplet #73

  • In profile, mesosoma flat or weakly convex, propodeum continuous with promesonotum; mesopleuron rough and dull with various degrees of pilosity . . . . . Pseudoponera stigma
  • Mesosoma when viewed in profile with a distinct drop from mesonotum down to propodeum; mesopleuron smooth and shining, without hairs or sculpturing . . . . . Brachyponera luteipes

75

return to couplet #72

76

return to couplet #75

  • In profile, anterior face of petiole strongly concave while posterior face lightly convex (Figs. 1B, 4A); head and gaster with blackish-orange coloration . . . . . Cryptopone butteli
  • In profile, petiole with anterior and posterior faces sloping upward at nearly equal angles (Fig. 4B); body concolorous orange or head and gaster slightly darker . . . . . Cryptopone testacea

77

return to couplet #75

  • Ventral keel of petiole with a small translucent “window” and with two small teeth projecting posteriorly (Fig. 9A) . . . . . 78
  • Ventral keel of petiole simple, lobe-like, completely opaque . . . . . 82

78

return to couplet #77

  • Mesometanotal suture distinctly visible on dorsal mesonotum; antennae with a weak, five-segmented club; HW 0.36–0.40 mm . . . . . Ponera incerta
  • Mesometanotal suture absent from dorsal mesonotum; antennal club variable; HW usually larger or smaller . . . . . 79

79

return to couplet #78

  • Large species (HW 0.51–0.58); mesosoma dorsum with numerous erect hairs; antennal club indistinctly four- or five-segmented . . . . . Ponera loi
  • HW smaller; dorsal mesosoma lacking standing hairs; antennal club distinctly four-segmented . . . . . 80

80

return to couplet #79

  • Tiny species (HW 0.325 mm in single specimen); antennae with four-segmented club; anterior gaster with distinct corners when viewed from above (Fig 8E); overall color light orange-brown . . . . . Ponera sp. 10091995
  • HW 0.39–0.48 mm; gaster and antennal club not as above (Fig 8F); color orangish brown to dark brown . . . . . 81

81

return to couplet #80

  • Petiolar node narrow (PNI 66–78), HW 0.39–0.45 . . . . . Ponera tenuis

82

return to couplet #77

  • Petiolar node tapering dorsally, and its height (not counting the ventral process) distinctly greater than length; mesepisternum usually smooth and outlined by a carina . . . . . 83
  • Anterior and posterior faces of petiolar node parallel, or if tapering slightly, then the height (not counting ventral process) nearly the same as the length; mesepisternum usually sculptured and fused with mesonotum . . . . . 84

83

return to couplet #82

  • Eyes with 6 or fewer ommatidia (average of 4) (Fig. 4C); petiolar node tapering, but not severely, its dorsal tip flattened; often orange-brown, although some specimens dark brown . . . . . Hypoponera confinis
  • Eyes with 7 to 20 ommatidia (average of 12); petiolar node tapering significantly, often creating a narrow, rounded dorsal point in profile; color dark brown to black . . . . . Hypoponera pruinosa

84

return to couplet #82

  • Petiole quadrate, its length at base about the same as petiole height, not counting ventral process (Fig. 4D) . . . . . Hypoponera punctatissima

85

return to couplet #3

86

return to couplet #85

  • Dorsal mesosoma bordered by a flange that starts behind the head and continues to the propodeal spines; flange forming distinct corners on anterior-lateral pronotum (Fig 8D) . . . . . Polyrhachis sp. 91952
  • Dorsal mesosoma missing a flange; anterior-lateral pronotum with sharp spines . . . . . Polyrhachis dives

87

return to couplet #85

88

return to couplet #87

  • Antennal sockets set back from rear border of clypeus; antennae 12- segmented; workers polymorphic . . . . . 89
  • Antennal sockets located at rear border of clypeus; antennae 11- or 12-segmented; workers monomorphic . . . . . 98

89

return to couplet #88

  • Petiolar node a raised projection or point (Fig. 2A–C, E–F) . . . . . 91

90

return to couplet #89

  • Clypeus wider than tall; head tapering toward mandibles in front view; head and mesosoma reddish orange . . . . . Camponotus erythrocephalus
  • Clypeus width and height nearly the same or slightly taller than wide; head nearly square in front view; body overall matte black . . . . . Camponotus peleliuensis

91

return to couplet #89

  • Propodeum with distinct dorsal and posterior faces, mesosoma almost squarish in profile (Fig. 2E) . . . . . 92
  • Propodeum lacking distinct dorsal and posterior faces, sloping with varying degrees of smoothness . . . . . 93

92

return to couplet #90

  • Dorsum of gaster with a shiny coat of gold hairs; mesosoma and petiole with silver hairs of various lengths covering both dorsum and sides; body color uniformly black . . . . . Camponotus flavicomans
  • Dorsum of gaster lacking coat of gold hairs: body overall mahogany to black and hairs silver and scattered . . . . . Camponotus marianensis

93

return to couplet #91

  • Gastral tergites with orange-brown posterior margins and yellow coloration anteriorly, creating a gaster with distinct transverse stripes . . . . . Camponotus variegatus

94

return to couplet #93

  • Heads of smaller workers about as wide as long (excluding mandibles); propodeum in profile not sloping smoothly (Fig. 2F); mesosoma and gaster equally black or deep brown, although can fade to lighter shades at joints . . . . . 95
  • Heads of all workers, but especially small ones, much longer than wide (excluding mandibles); propodeum in lateral view sloping smoothly to petiolar insertion (Fig. 2A, B, C); mesosoma yellow-orange to reddish brown (at least posteriorly), head and gaster orange or dark brown to black . . . . . 96

95

return to couplet #94

  • Mesosoma with long, recumbent, silver hairs which are especially abundant on the dorsal surface . . . . . Camponotus sp. 121958
  • Mesosoma with some long standing hairs and more numerous small, fine, recurved hairs . . . . . Camponotus reticulatus

96

return to couplet #94

  • Maximum HW 2.3 mm and maximum HL 2.6 mm in major workers; maximum total body length 6.5 mm . . . . . 97
  • Maximum HW 2.8 mm and maximum HL 3.0 mm in major workers; maximum total body length exceeding 8.0 mm . . . . . Camponotus sp. 1945

97

return to couplet #96

  • Long, standing hairs lateral to eyes present in majors; head and gaster orange, mesosoma often more yellow . . . . . Camponotus chloroticus
  • Long, standing hairs absent in majors; head and gaster dark brown to black, mesosoma yellow to yellow-orange . . . . . Camponotus eperiamorum

98

return to couplet #88

  • HW < 0.4 mm and mesosoma without standing hairs . . . . . Tapinoma (all species)
  • HW > 0.5 mm, but if smaller (as in Paratrechina minutula, below), then mesosoma with standing hairs . . . . . 99

99

return to couplet #98

100

return to couplet #99

101

return to couplet #99

  • Anterior clypeal border evenly rounded, straight, or slightly concave; dorsal mesosoma with pubescence and coarse, standing hairs . . . . . 102
  • Anterior mid-clypeal border with distinct concavity that in some cases appears as an obvious notch (Technomyrmex), or clypeal border with a projection (Iridomyrmex) in the middle; dorsal mesosoma without coarse, standing hairs, although some fine standing hairs are visible . . . . . 105

102

return to couplet #101

  • HW < 0.4 mm; black, coarse, standing hairs on mesosoma; overall yellow (except for population on Guam, which is dusky orange-brown) . . . . . Paraparatrechina minutula

103

return to couplet #102

  • Upper sides of propodeum glossy (above the spiracle); katepisternum dark brown, bulbous and glossy, without pubescence or sculpturing (Fig. 6A–C) . . . . . Nylanderia clandestina
  • Sides of propodeum above the spiracle pubescent; katepisternum not as above . . . . . 104

104

return to couplet #103

  • Katepisternum pubescent; significant pubescence between propodeal spiracle and dorsum which continues ventrally anterior to propodeal spiracle (Fig. 5E) . . . . . Nylanderia bourbonica
  • Katepisternum glossy and without hairs (a few isolated hairs may be present along posterior and ventral borders of both katepisternum and pronotum, and a few isolated hairs may appear at central portion of katepisternum); pubescence between propodeal spiracle and dorsum slight and lacking pubescence around spiracle and often anteriorly to border with katepisternum (Fig 5F) . . . . . Nylanderia vaga

105

return to couplet #101

  • Anterior clypeal border with projection in middle; petiole with distinct node that rises steeply to height more than half that of propodeum; dorsal mesosoma without standing hairs . . . . . Iridomyrmex anceps
  • Anterior clypeal border with notch in middle; petiole a flattened scale, often covered by gaster; dorsal mesosoma with standing hairs . . . . . 106

106

return to couplet #105

  • Body length approximately 2 mm; antennal scapes barely extending beyond vertex; uniformly dark grey . . . . . Technomyrmex albipes
  • Body length > 2 mm; antennal scapes clearly reaching beyond vertex by more than one fourth their length; uniformly brown . . . . . Technomyrmex kraepelini