Key to the New World Camponotus species complexes

Preliminary key to the New World species complexes of the subgenus Camponotus based on the majors (unless otherwise indicated), as prepared by Mackay (2019). Note that the species complexes are not been defined by Mackay (2019), but this key should be of use in separating them.

1

Anterior part of head, including most or all of clypeus, obliquely or perpendicularly truncated (Fig. 45, 47 and 48) => 2

Fig. 45.
Fig. 45.
Fig. 47.
Fig. 47.
Fig. 48.
Fig. 48.

Anterior part of head broadly rounded, not truncated (Fig. 46) although clypeus may be flattened => 7

Fig. 46.

2

return to couplet #1

Posterior edge of clypeus not part of truncated region, in same plane as remainder of head (Fig. 47); North America south to Nicaragua => Colobopsis

Fig. 47.
Fig. 47.

Posterior edge of clypeus in same plane as remainder of clypeus (Fig. 48) => 3

Fig. 48.
Fig. 48.

3

return to couplet #2

Shoulder of pronotum with carina, or at least noticeably swollen (Fig. 49) => 4

Fig. 49.
Fig. 49.

Shoulder of pronotum rounded, not swollen (Fig. 54) => 5

Fig. 54.

4

return to couplet #3

Cheeks indented, with concave surfaces laterally surrounded with carinae (Fig. 50, left); Caribbean and Perú => sphaericus species complex

Fig. 50 (left).

Surface of cheeks not concave, in same plane as remainder of anterior half of head (Fig. 50, right); Latin America => linnaei species complex

Fig. 50 (right).

5

return to couplet #3

Sides of clypeus strongly diverging anteriorly, making clypeus look somewhat bell-shaped (Fig 51); continental Americas => paradoxus species complex

Fig. 51.
Fig. 51.

Sides of clypeus diverging anteriorly (Fig. 52), nearly parallel, or slightly converging anteriorly, not bell-shaped => 6

Fig. 52.
Fig. 52.

6

return to couplet #5

Propodeum armed with sharp, unpaired, often double-toothed processes (Fig. 53); northern South America => heathi species complex

Fig. 53.
Fig. 53.

Propodeum without sharp processes (Fig. 54); Latin America and Caribbean => macilentus species complex

Fig. 54.

7

return to couplet #1

Mesosoma deeply constricted at notopropodeal suture (Fig. 55); promesonotum and propodeum rounded and scapes and tibiae with numerous erect and suberect setae (Fig. 58); clypeal carina usually absent (Fig. 51) => 8

Fig. 51.
Fig. 51.
Fig. 55.
Fig. 55.
Fig. 58.

Mesosoma not deeply constricted (Fig. 56), or if constricted, propodeum angulate between faces (Fig. 92), possibly with spines (Fig. 94); or scapes (Fig. 65) and tibiae without erect and suberect setae; or clypeal carina nearly always present (Fig. 67) => 9

Fig. 56.
Fig. 56.
Fig. 65.
Fig. 65.
Fig. 67.
Fig. 67.
Fig. 92.
Fig. 94.
Fig. 94.

8

return to couplet #7

Posterior part of head formed into slender neck (Fig. 57); clypeus with longitudinal carina; Ecuador (Orellana), Perú (Madre de Dios) and Brasil (Rondônia) => branneri species complex

Fig. 57.
Fig. 57.

Posterior part of head not formed into slender neck (Fig. 58); clypeus without longitudinal carina; USA (Florida), Latin America => sexguttatus species complex

Fig. 58.

9

return to couplet #7

Clypeus nearly always with well defined, longitudinal carina (Fig. 59), which is at least slightly raised from surface, which is not rounded like shield => 10

Fig. 59.
Fig. 59.

Clypeus without well-defined, longitudinal carina, medial longitudinal area may be raised, clypeus usually flat medially and shield-like (Fig. 60) => 32

Fig. 60.

10

return to couplet #9

Posterior tibia strongly flattened (Fig. 61), blade-like => 11

Fig. 61.
Fig. 61.

Posterior tibia round (Fig. 58) or only slightly flattened => 12

Fig. 58.

11

return to couplet #10

Pronotum with spines or sharp angles (Fig. 62); widely distributed and commonly collected => sericeiventris species complex

Fig. 62.
Fig. 62.

Pronotum rounded (Fig. 63); widely distributed, but rarely collected; Colombia, Ecuador, Perú and Brasil => mocsaryi species complex

Fig. 63.

12

return to couplet #10

Anterior border of clypeus concave, nearly always with rounded angles on each side (Fig. 64); scapes and tibiae usually with erect, coarse setae (Fig. 64); scapes usually flattened near base and not reaching or barely surpassing posterior border of head (Fig. 65) => 13

Fig. 64.
Fig. 64.
Fig. 65 (right).
Fig. 65 (right).

Anterior edge of clypeus straight, or convex (Fig. 67), if concave, usually forming rounded, lateral corners; scapes and tibiae rarely with erect, coarse setae; scape round near base and usually extending well past posterior border of head (Fig. 70) => 14

Fig. 67.
Fig. 67.
Fig. 70.
Fig. 70.

13

return to couplet #12

Clypeal carina very sharp (Fig. 65, left); sides of head somewhat parallel (Fig. 65, left); not commonly collected; South America => coruscus species complex

Fig. 65 (left).
Fig. 65 (left).

Clypeal carina defined, but not especially sharp; head narrowed anteriorly (Fig. 65, right); very common, New World => atriceps species complex

Fig. 65 (right).
Fig. 65 (right).

14

return to couplet #12

Often with abundant appressed, silver or gold setae on most surfaces (Fig. 66); mesosoma robust, approximately as long as length of head (excluding mandibles), generally dorsopropodeum broadly rounded into posteropropodeum (Fig. 66); clypeal carina nearly always sharp, well raised from surface of clypeus (Fig. 67) => 15

Fig. 66.
Fig. 66.
Fig. 67.
Fig. 67.

Rarely with abundant, appressed setae (Fig. 68); mesosoma generally elongated (Fig. 68), longer than length of head (excluding mandibles); mesosoma often slightly angulate posteriorly (Fig. 68), to sharply angulate between faces of propodeum (Fig. 76); clypeal carina may be sharp, but rarely greatly raised from surface of clypeus (Fig. 70)=> 20

Fig. 68.
Fig. 68.
Fig. 70.
Fig. 70.
Fig. 76.
Fig. 76.

15

return to couplet #14

Shoulder of pronotum often swollen, sometimes nearly forming carina (Fig. 69), shoulder of minor worker definitely swollen, region posterior to eye of minor usually swollen (Fig. 69); Latin America => 16

Fig. 69.
Fig. 69.

Shoulder (Fig. 58) and region posterior to eye of major and minor not noticeably swollen => 17

Fig. 58.

16

return to couplet #15

Commonly collected; majors large with well-developed clypeal carina (Fig. 67); Latin America => cressoni species complex

Fig. 67.
Fig. 67.

Rarely collected; majors unknown; Mexico (and undescribed species in SW USA) => declivus species complex

17

return to couplet #15

Scape with abundant, erect and suberect setae (Fig. 70); South America => 18

Fig. 70.
Fig. 70.

Scape without erect and suberect setae (except at apex), or with few scattered setae (Fig. 72); Latin America => 19

Fig. 72.
Fig. 72.
Fig. 72.
Fig. 72.

18

return to couplet #17

Head wider posterior to eyes (Fig. 70); common and widely distributed in South America => femoratus species complex

Fig. 70.
Fig. 70.

Head as wide anterior to eye as posteriorly (Fig. 71); known only from type series from southern Brasil => sericatus species complex

Fig. 71.
Fig. 71.

19

return to couplet #17

Sides of head nearly parallel (Fig. 72, left) => novogranadensis species complex

Fig. 72 (left).
Fig. 72 (left).

Sides of head narrowed anteriorly (Fig. 72, right) => blandus species complex

Fig. 72 (right).
Fig. 72 (right).

20

return to couplet #14

Anterior half of head very roughly sculptured and with blunt-tipped, golden setae (Fig. 73); surface of clypeus strongly convex (Fig. 73, right); southern Texas to Latin America => alboannulatus species complex

Fig. 73.
Fig. 73 (right).

Lacking at least 1 of the above mentioned characteristics => 21

21

return to couplet #20

Eyes strongly convex, bulging past sides of head (Fig. 74); head usually widest at point of eye; posterior face of petiole with fine, transverse horizontal striae (Fig. 75); Latin America => chartifex species complex

Fig. 74.
Fig. 74.
Fig. 75.
Fig. 75.

Lacking above listed characteristics => 22

22

return to couplet #21

Minor worker (major unknown or may not exist) dull black with orange or brown legs; petiole thick when viewed in profile (Fig. 76); gaster black with lighter, transverse bands at ends of each gastral tergum (Fig. 76); mostly island species (Galapagos, Caribbean, but also South America) => planus species complex

Fig. 76.
Fig. 76.

Minor not as described above => 23

Note: An undescribed species from Colombia would key here, but differs in that the mesosoma is elongated and rounded between the faces of the propodeum, and the dorsopropodeum is much longer than the posteropropodeum. The erect hairs on the mesosoma and petiole are coarse and thickened, not fine as in members of the planus species complex. It is apparently a member of the mocsaryi species complex.

23

return to couplet #22

Head of major only moderately narrowed anteriorly (Fig. 77, left) or wider anteriorly (Fig. 78) => 24

Fig. 77 (left).
Fig. 77 (left).
Fig. 78.
Fig. 78.

Head strongly narrowed anteriorly (Fig. 77, right) => 27

Fig. 77.
Fig. 77.

24

return to couplet #23

Clypeus elongate (Fig. 78), usually more than 1.5 times as long as wide at level of tentorial pits (Fig. 90) => 25

Fig. 78.
Fig. 78.
Fig. 90.
Fig. 90.

Clypeus not notably elongate, usually about as long as wide (Fig. 81) => 26

Fig. 81.

25

return to couplet #24

Head of female (Fig. 78), major and minor 1.6 - 2 times as long as broad; frontal carinae closely spaced; South America => mirabilis species complex

Fig. 78.
Fig. 78.

Head of female and major less than 1.6 times as long as broad (Fig. 79); frontal carinae widely spaced (Fig. 79); Latin America => improprius species complex

Fig. 79.
Fig. 79.

26

return to couplet #24

Much of major (especially head) smooth and glossy (Fig. 80); Latin America and Caribbean => balzani species complex

Fig. 80.

Entire major worker (especially head) punctate and dull (Fig. 81); southern USA to Latin America => egregius species complex

Fig. 81.

27

return to couplet #23

Head usually coarsely punctate; cheek usually without erect and suberect setae (Fig. 82); scape may be flattened or even widened at base (Fig. 82) => 28

Fig. 82.

Head usually finely punctate or coriaceous; cheek often with at least 6 erect and suberect setae (Fig. 83); base of scape never noticeably flattened => 29

Fig. 83.
Fig. 83.

28

return to couplet #27

South America; cheek occasionally with several (> 10) erect and suberect setae (Fig. 84); scape not flattened at base (Fig. 84); South America => distinguendus species complex

Fig. 84.
Fig. 84.

North America; cheek usually without erect and suberect setae (up to 5 may be present); scape flattened at base and may form lobe (Fig. 85); North America => sansabeanus species complex

Fig. 85.

29

return to couplet #27

Clypeus usually about as long as broad (Figs. 86) or longer than broad; frontal carinae widely spaced (Fig. 85); anterior femur swollen and shortened (Fig. 87, left); Latin America => improprius species complex

Fig. 85.
Fig. 86.
Fig. 87.

Clypeus often broader than long (Fig. 88, right); frontal carinae closely spaced (Fig. 88); anterior femur not swollen (Fig. 87, right) => 30

Fig. 87.
Fig. 88.
Fig. 88 (right).

30

return to couplet #29

Anterior border of clypeus slightly concave (Fig. 88); cheek usually without (or with very few) erect or suberect setae (Fig. 88) => maculatus species complex

Fig. 88.
Fig. 88.

Anterior border of clypeus nearly straight (Fig. 70), slightly convex, if slightly concave (Fig. 89), cheek nearly always with erect and suberect setae (Fig. 89) => 31

Fig. 70.
Fig. 70.
Fig. 89.
Fig. 89.

31

return to couplet #30

Abundantly hairy, cheeks and malar area nearly always with more than 15 erect and suberect setae (Fig. 89); generally larger (Total Length > 9 mm); New World => picipes species complex

Fig. 89.
Fig. 89.

Cheeks and malar area often with erect and suberect setae, but usually fewer than 15 present (Fig. 90); generally smaller (TL less than 9 mm); New World, but more common in Latin America => bonariensis species complex

Fig. 90.
Fig. 90.

32

return to couplet #9

Clypeus elongated (Fig. 91), at least slightly longer than broad at level of tentorial pits (Fig. 91) propodeum without process => 33

Fig. 91.
Fig. 91.

Clypeus not elongated, usually wider than long (at level of tentorial pits) (Fig. 92, left), if elongated, propodeum with transverse bend or bilobed flattened process or spines (Figs. 92, 94, 96 & 97) => 34

Fig. 92 (left).
Fig. 92.
Fig. 94.
Fig. 94.
Fig. 96.
Fig. 97.

33

return to couplet #32

Head of major and especially female greatly elongated (Fig. 91), occasionally twice as long as wide (Fig. 91); frontal carina of major worker closely spaced (Fig. 91); anterior femur not swollen => mirabilis species complex

Fig. 91.
Fig. 91.

Head of female and worker less than twice as long as wide (Fig. 93, excluding mandibles); frontal carina of major worker more widely spaced (Fig. 93) and anterior femur swollen (Fig. 87, left); Latin America => improprius species complex

Fig. 87.
Fig. 93.
Fig. 93.

34

return to couplet #32

Propodeum with single angle between faces (Fig. 100), or with pair of spines (Fig. 94), or with an abrupt transverse bend or shelf between faces of propodeum (Fig. 96) => 35

Fig. 94.
Fig. 94.
Fig. 96.
Fig. 100.
Fig. 100.

Propodeum without spines or shelf (Fig. 95) => 37

Fig. 95.

35

return to couplet #34

Dorsopropodeum not forming shelf (Fig. 95) or if so, armed with pair of small relatively narrow spines (Fig. 99) => 36

Fig. 95.
Fig. 99.

Dorsopropodeum forming transverse shelf with sharp bend into posteropropodeum (Fig. 96), or forming pair of flattened broad processes (Fig. 97); SW USA and Latin America => rectangularis species complex

Fig. 96.
Fig. 97.

36

return to couplet #35

Pronotum with longitudinal carina (Fig. 98); propodeum without pair of spines (Fig. 95); Latin America, Caribbean => gilviventris species complex

Fig. 95.
Fig. 98.

Pronotum without carina, but may be swollen; propodeum with pair of small spines (Fig. 99); Latin America, Caribbean => bidens species complex

Fig. 99.

37

return to couplet #34

Propodeum angulate between two faces (as single point, Fig. 100); mostly islands (Caribbean, Galapagos) => planus species complex

Fig. 100.
Fig. 100.

Propodeum rounded between two faces (Figs. 101), if somewhat angulate, found in continental Latin America => 38

Fig. 101.

38

return to couplet #37

Pronotal shoulder of minor and often major forming longitudinal carina or shelf (Fig. 101) => 39

Fig. 101.

Pronotal shoulder rounded (Fig. 100) => 42

Fig. 100.
Fig. 100.

39

return to couplet #38

Anterior edge of gaster with upturned lip (Fig. 101); Caribbean, South America => gilviventris species complex

Fig. 101.

Anterior edge of gaster not forming lip, although abrupt change in the amount of pubescence may be found there => 40

40

return to couplet #39

Anterior half of mesosoma humpbacked (Fig. 102) and/or gaster covered with thickened appressed white setae; mostly found in Caribbean area and rarely Latin America => sphaericus species complex

Fig. 102.
Fig. 102.

Mesosoma convex throughout length, not appearing hump-backed (Fig. 103); gaster rarely with thick appressed white setae; mostly from continental Latin America => 41

Fig. 103.

41

return to couplet #40

Dorsopropodeum of minor worker (Fig. 103) somewhat flattened (side view) and rounded or angulate into posteropropodeum, not laterally flattened (Fig. 103); Latin America => conulus species complex

Fig. 103.

Mesonotum and dorsopropodeum of minor worker laterally flattened, forming blunt ridge dorsally (Fig. 104, top); rarely collected; SW USA and Mexico => undescribed species complex

Fig. 104.

42

return to couplet #38

Anterior edge of clypeus notched or depressed medially (Fig. 105); major relatively small (total length < 8 mm); North America => caryae species complex

Fig. 105.
Fig. 105.

Anterior edge of clypeus not notched (Fig. 109), rarely depressed medially, or if so, major worker larger => 43

Fig. 109.
Fig. 109.

43

return to couplet #42

Major large (total length > 8 mm); North America (including northern Mexico) => (subgenus Camponotus) herculeanus species complex
Major smaller (total length < 8 mm); widely distributed, but not common in North America => 44

44

return to couplet #43

Erect and suberect setae sparse or absent on dorsum of mesosoma (Fig. 106); Latin America, Caribbean => macilentus species complex

Fig. 106.
Fig. 106.

Erect and suberect setae relatively abundant on dorsum of mesosoma (Fig. 107 & 108) => 45

Fig. 107.
Fig. 107.
Fig. 108.
Fig. 108.

45

return to couplet #44

Dorsum of mesosoma impressed at notopropodeal suture (may be only weakly depressed in major) (Figs. 107 & 108); Latin America => 46

Fig. 107.
Fig. 107.
Fig. 108.
Fig. 108.

Dorsum of mesosoma not impressed at notopropodeal suture (Fig. 106); entire New World => 47

Fig. 106.
Fig. 106.

46

return to couplet #45

Mesopleuron covered primarily with parallel striae (Fig. 107), some of which may form concentric circles dorsally on mesosoma, especially dorsopronotum => striatus species complex

Fig. 107.
Fig. 107.

Mesopleuron covered primarily by punctures (Fig. 108), which may form rows, but never form concentric circles on dorsum of mesosoma (Fig. 108) => abscisus species complex

Fig. 108.
Fig. 108.

47

return to couplet #45

Cheek lacking erect and suberect setae (Fig. 109, left); Latin America => canescens species complex

Fig. 109 (left).

Cheek with numerous, erect and suberect setae (Fig. 109, right); entire New World => 48

Fig. 109 (right).

48

return to couplet #47

Mesosoma broadly convex from promesonotal suture to near attachment of petiole (Fig. 110); North America, (southwestern United States and northwestern Mexico); often in arid ecosystems => mina species complex

Fig. 110.
Fig. 110.

Dorsum of mesosoma moderately convex (Fig. 113) to nearly straight (Fig. 111) to completely flattened (Fig. 112) from pronotum to posteropropodeum, where outline bends and forms straight or slightly concave posteropropodeum (Figs. 111 & 112); widely distributed, but most common in South American tropical habitats => 49

Fig. 111.
Fig. 112.
Fig. 112.
Fig. 113.
Fig. 113.

49

return to couplet #48

Dorsum of mesosoma flattened (at least mesonotum and dorsopropodeum) and slender dorsoventrally (Fig. 112); dorsopropodeum greatly elongated => depressus species complex

Fig. 112.
Fig. 112.

Dorsum of mesosoma not completely flattened (Figs. 113 & 114); dorsopropodeum about as long as posteropropodeum (Fig. 113); head of normal shape; Latin America => 50

Fig. 113.
Fig. 113.
Fig. 114.

50

return to couplet #49

Dorsum of mesosoma weakly convex (Fig. 113), occasionally nearly flat; lateral edges of dorsopropodeum usually rounded into lateropropodeum; head length (measured from side, from anterior edge of clypeus to posterior most point of head) shorter than Weber’s length (WL) (Fig. 113); usually larger (total length of major > 5 mm total length) => arboreus species complex

Fig. 113.
Fig. 113.

Dorsum of mesosoma convex (Fig. 114); lateral edges of dorsopropodeum nearly forming carina with lateropropodeum; head length (measured from side, from anterior edge of clypeus to posterior-most point of head) longer than Weber’s length; usually smaller (total length of major < 5 mm total length) => excisus species complex

Fig. 114.

References

Mackay, W.P. 2019. New World Carpenter Ants of the Hyperdiverse genus Camponotus. Volume 1. Introduction, keys to the subgenera and species complexes and the subgenus Camponotus: 412 pp. Lambert Academic Publishing.