Key to minor workers of the Malagasy Camponotus, subgenus Myrmosaga

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This key to the minor workers of the Malagasy Camponotus, subgenus Myrmosaga, is based on Rakotonirina & Fisher (2022).

1

  • With head in full-face view, eyes not breaking lateral cephalic margins (Fig. 2A) => 2
  • With head in full-face view, eyes breaking lateral cephalic margins (Fig. 2B), if not then lateral cephalic margin diverging posteriorly (Fig. 2C) => 5
Figure 2. Head in full-face view A C. joany (CASENT0408908) B C. radamae (CASENT0066777) C C. immaculatus (CASENT0179441).

2

  • Dorsal margin of propodeum entirely straight (Fig. 3A) => 3
  • Dorsal margin of propodeum with blunt angle at ca. posterior 1/2 (Fig. 3B) => 4
Figure 3. Mesosoma in lateral view A C. aina (CASENT0217291) B C. harenarum (CASENT0499207).

3

  • Propodeal dorsum 3 × as long as the declivity; petiolar node with dorsal margin as long as posterior margin (Fig. 4A) => Camponotus aina
  • Propodeal dorsum 2 × as long as the declivity; petiolar node with dorsal margin shorter than posterior margin (Fig. 4B) => Camponotus joany
Figure 4. Mesosoma and petiolar node in lateral view A C. aina (CASENT0217291) B C. joany (CASENT0408908).

4

  • With mesosoma in lateral view, junction of mesonotum and anterior 1/2 of propodeum continuously straight, sloping down to make noticeable angle with posterior 1/2 of propodeum; petiolar node low and long (Fig. 5A) => Camponotus karsti
  • With mesosoma in lateral view, mesonotum and anterior 1/2 of propodeum forming separate convexities; petiolar node ca. as high as long (Fig. 5B) => Camponotus harenarum
Figure 5. Mesosoma and petiolar node in lateral view A C. karsti (CASENT0217292) B C. harenarum (CASENT0499207).

5

  • With head in full-face view, lateral cephalic margins converging posteriorly towards eye level (Fig. 6A) => 6
  • With head in full-face view, lateral cephalic margin either approximately parallel or diverging posteriorly towards eye level (Fig. 6B, C) => 14
Figure 6. Head in full-face view A C. sambiranoensis (CASENT0231845) B C. radamae (CASENT0066777) C C. immaculatus (CASENT0179441).

6

  • Two apical teeth of mandible normally spaced (Fig. 7A); clypeus with anterolateral corner => 7
  • Two apical teeth of mandible closely spaced (Fig. 7B); clypeus without anterolateral corner, lateral and anteromedian margin continuously forming broad convexity => 12
Figure 7. Mandibles in frontal view A C. niavo (CASENT0300086) B C. bemaheva (CASENT0153778).

7

  • With head in full-face view, anteromedian margin of clypeus broadly convex (Fig. 8A) => 8
  • With head in full-face view, anteromedian margin of clypeus either generally straight (Fig. 8B) or medially excised (Fig. 8C) => 10
Figure 8. Head in full-face view A C. cervicalis (CASENT0217303) B C. dufouri (CASENT0487727) C C. lokobe (CASENT0436584).

8

  • With head in full-face view, lateral cephalic margin anterior to eye level without erect hairs (Fig. 9A) => Camponotus sambiranoensis
  • With head in full-face view, lateral cephalic margin anterior to eye level covered with erect hairs (Fig. 9B) => 9
Figure 9. Head in full-face view A C. sambiranoensis (CASENT0231845) B C. cervicalis (CASENT0217303).

9

  • With head in full-face view, level of posterior ocular margin located approximately at posterior 1/4 of the length of head; antennal scape with appressed hairs (Fig. 10A) => Camponotus niavo
  • With head in full-face view, level of posterior ocular margin located at posterior 1/3 of the length of head; antennal scape with suberect hairs (Fig. 10B) => Camponotus cervicalis
Figure 10. Head in full-face view A C. niavo (CASENT0134004) B C. cervicalis (CASENT0217303).

10

  • Anteromedian margin of clypeus noticeably excised medially (Fig. 11A) => Camponotus lokobe
  • Anteromedian margin of clypeus straight (Fig. 11B) => 11
Figure 11. Head in full-face view A C. lokobe (CASENT0436584) B C. tendryi (CASENT0145284).

11

  • Lateral cephalic margin posterior to eye level covered with erect hairs (Fig. 12A); larger size (CS: 1.97±0.19; 1.66–2.26; ML: 4.23±0.39; 3.56–4.81) => Camponotus dufouri
    • Lateral cephalic margin posterior to eye level without erect hairs (Fig. 12B); smaller size (CS: 1.57±0.01; 1.56–1.58; ML: 3.26±0.01; 3.21–3.31) => Camponotus tendryi
Figure 12. Head in full-face view A C. dufouri (CASENT0274127) B C. tendryi (CASENT0145284).

12

  • Lateral cephalic margin posterior to eye level without erect hairs (Fig. 13A) => Camponotus bemaheva
  • Lateral cephalic margin posterior to eye level covered with erect hairs (Fig. 13B) => 13
Figure 13. Head in full-face view A C. bemaheva (CASENT0154158) B C. roeseli (CASENT0492473).

13

  • Integument of entire body yellowish orange to reddish orange (Fig. 14A) => Camponotus daraina
  • Head and gaster reddish black and mesosoma reddish orange or integument entirely reddish black (Fig. 14B) => Camponotus roeseli
Figure 14. Body in lateral view A C. daraina (CASENT0077433) B C. roeseli (CASENT0492473).

14

  • In full-face view, lateral margin of head anterior to eye level approximately parallel and covered with erect hairs (Fig. 15A) => 15
  • In full-face view, lateral margin of head anterior to eye level diverging posteriorly (Fig. 15C), if parallel then lacking erect hairs (Fig. 15B) => 23
Figure 15. Head in full-face view A C. mahafaly (CASENT0115287) B C. tapia (CASENT0493939) C C. quadrimaculatus (CASENT0096044).

15

  • With mesosoma in lateral view, mesonotum elongate and constricted at midlength, propodeum broadly convex (Fig. 16A) => Camponotus imitator
  • With mesosoma in lateral view, mesonotum short and lacking constriction at midlength; promesonotum an even convexity; propodeal dorsum almost straight (Fig. 16B) => 12
Figure 16. Mesosoma in lateral view A C. imitator (CASENT0452849) B C. mahafaly (CASENT0115287).

16

  • Two apical teeth of mandible closely spaced (Fig. 17A) => 17
  • Two apical teeth of mandible normally spaced from each other (Fig. 17B) => 19
Figure 17. Mandibles in frontal view A C. radamae (CASENT0228250) B C. boivini (CASENT0477264).

17

  • Antennal scape covered with erect hairs; lateral cephalic margin posterior to eye level with erect hairs (Fig. 18A); larger in size => Camponotus hova
  • Antennal scape covered with appressed hairs (Fig. 18B); lateral cephalic margin posterior to eye level without erect hairs; smaller in size => 18
Figure 18. Head in full-face view A C. hova (CASENT0055710) B C. radamae (CASENT0217307).

18

  • In lateral view, mesosoma much higher and short (MPH/ML: 0.34±0.01; 0.31–0.36), propodeal dorsum at most 3 × as long as declivity; petiolar node more or less flattened anteroposteriorly and tapering dorsally (Fig. 19A) => Camponotus radamae
  • In lateral view, mesosoma very low and long (MPH/ML: 0.29±0.02; 0.28–0.31), propodeal dorsum at least four times as long as declivity; petiole much nodelike (Fig. 19B) => Camponotus vano
Figure 19. Mesosoma and petiolar node in lateral view A C. radamae (CASENT066777) B C. vano (CASENT0217316).

19

  • Antennal scape covered with appressed hairs (Fig. 20A) => Camponotus mahafaly
  • Antennal scape covered with erect to suberect hairs (Fig. 20B) => 20
Figure 20. Head in full-face view A C. mahafaly (CASENT0115287) B C. hovahovoides (CASENT0487242).

20

  • Mesosoma generally short and high, its dorsal outline strongly convex, propodeal dorsum < 2 × height of declivity surface (Fig. 21A) => Camponotus cemeryi
  • Mesosoma low and long, its dorsal outline more or less straight or not strongly convex, propodeal dorsum 2 × or more as long as height of declivity surface (Fig. 21B) => 21
Figure 21. Mesosoma and petiolar node in lateral view A C. cemeryi (CASENT0217306) B C. hovahovoides (CASENT0496908).

21

  • In lateral view, dorsum of mesosoma from mid-mesonotum to posterodorsal corner of propodeum approximately straight, propodeal dorsum ca. 3 × as long as height of declivity surface (Fig. 22A) => Camponotus hovahovoides
  • In lateral view, posterior 1/2 of mesonotum to posterodorsal corner of propodeum slightly convex, propodeal dorsum ca. 2 × as long as height of declivity surface (Fig. 22B) => 22
Figure 22. Mesosoma in lateral view A C. hovahovoides (CASENT0496908) B C. mixtellus (CASENT0132606).

22

  • Antennal scape covered with suberect hairs inclined at ca. 30° (Fig. 23A); larger species (CS: 1.59±0.10; 1.36–1.75; ML: 3.10±0.16; 2.76–3.45) => Camponotus mixtellus
  • Antennal scape covered with suberect hairs inclined at ca. 45° (Fig. 23B); smaller species (CS: 1.15±0.06; 1.00–1.27; ML: 2.11±0.10; 1.87–2.28) => Camponotus boivini
Figure 23. Head in full-face view A C. mixtellus (CASENT0076675) B C. boivini (CASENT0168345).

23

  • With head in full-face view, lateral margins of head anterior to eye level parallel to each other (Fig. 24A) => 24
  • With head in full-face view, lateral margins of head anterior to eye level diverging posteriorly (Fig. 24B) => 31
Figure 24. Head in full-face view A C. atimo (CASENT0454042) B C. quadrimaculatus (CASENT0096044).

24

  • In full-face view, clypeus with distinctly visible anterolateral corner (Fig. 25A) => 25
  • In full-face view, clypeus without visible anterolateral corner, lateral and anteromedian clypeal margin continuously forming broad convexity (Fig. 25B) => 30
Figure 25. Head in full-face view A C. tapia (CASENT0217310) B C. aro (CASENT0489917).

25

  • Dark body color, or posterior portion of mesosoma pale brown; in lateral view, petiolar node scalelike or more or less compressed anteroposteriorly (Fig. 26A) => 26
  • Pale yellow to orange body color; in lateral view, petiole nodelike and not compressed anteroposteriorly (Fig. 26B) => 28
Figure 26. Posterior portion of mesosoma, petiolar node, and gaster in lateral view A C. bozaka (CASENT0217309) B C. atimo (CASENT0454042).

26

  • With head in full-face view, anteromedian clypeal margin truncate; erect hairs present on lateral cephalic margin behind level of posterior ocular margin (Fig. 27A) => Camponotus becki
  • With head in full-face view, anteromedian clypeal margin broadly convex or triangular; erect hairs absent on lateral cephalic margin behind level of posterior ocular margin (Fig. 27B) => 27
Figure 27. Head in full-face view A C. becki (CASENT0071380) B C. asara (CASENT0493252).

27

  • In lateral view, mesosoma low and long, propodeal dorsum ca. 3 × as long as declivity, their junction rounded; petiolar node with dorsal margin inclined posteriorly; integument matte (Fig. 28A) => Camponotus asara
  • In lateral view, mesosoma short and high, length of propodeal dorsum < 2 × height of declivity, their junction angulate; petiolar node scalelike; integument shining (Fig. 28B) => Camponotus bozaka
Figure 28. Mesosoma and petiolar node in lateral view A C. asara (CASENT0493252) B C. bozaka (CASENT0217309).

28

  • With head in oblique profile, three pairs of erect hairs arranged successively from level of anterior ocular margin towards posterior cephalic margin (Fig. 30A) => Camponotus strangulatus
  • With head in oblique profile, four or more pairs of erect hairs arranged successively from level of anterior ocular margin towards posterior cephalic margin (Fig. 30B) => 29
Figure 29. Head in lateral view A C. strangulatus (CASENT0136581) B C. tapia (CASENT0493939).

29

  • With mesosoma in profile, junction of propodeal dorsum and declivity surface rounded (Fig. 30A) => Camponotus atimo
  • With mesosoma in profile, junction of propodeal dorsum and declivity surface broadly angulate (Fig. 30B) => Camponotus tapia
Figure 30. Mesosoma in lateral view A C. atimo (CASENT0454042) B C. tapia (CASENT0217310).

30

  • In full-face view, posterior portion of head extending into broadly short neck (Fig. 31A); in profile, entire propodeal dorsum more or less straight and separated from declivity surface by broad angle => Camponotus gouldi
  • In full-face view, posterior portion of head normally rounded, not extending into a short neck (Fig. 31B); in profile, propodeal dorsum immediately posterior to metanotal groove convex, then concave medially and rounding to declivity surface => Camponotus aro
Figure 31. Head in full-face view A C. gouldi (CASENT0121617) B C. aro (CASENT0489917).

31

  • With head in full-face view, lateral margin of head anterior to eye level with erect hairs (Fig. 32A); head and gaster black, mesosoma reddish orange to brown => 32
  • With head in full-face view, lateral margin of head anterior to eye level without erect hairs (Fig. 32B); body color uniquely black, brown to yellowish orange => 33
Figure 32. Head in full-face view A C. aurosus (CASENT0064815) B C. gibber (CASENT0188619).

32

  • With head in full-face view, anterior clypeal margin broadly triangular (Fig. 33A); mesosoma in profile short and high; gastral tergites covered with abundant pubescence => Camponotus aurosus
  • With head in full-face view, anterior clypeal margin truncate (Fig. 33B); mesosoma in profile low and long; gastral tergites without abundant pubescence => Camponotus hagensii
Figure 33. Head in full-face view A C. aurosus (CASENT0064815) B C. hagensii (CASENT0191568).

33

  • With head in full-face view, anterior clypeal margin broadly triangular (Fig. 34A) => Camponotus liandia
  • With head in full-face view, anterior clypeal margin truncate (Fig. 34B) => 34
Figure 34. Head in full-face view A C. liandia (CASENT0491145) B C. kelimaso (CASENT0487718).

34

  • No white spot on dorsum of second and third abdominal tergites (Fig. 35A) => 35
  • One pair of white spots on third abdominal tergites (Fig. 35B)or two pairs of white spots present on second and third abdominal tergites (Fig. 35C) => 37
Figure 35. Second and third abdominal tergites in dorsal view A C. kelimaso (CASENT0487718) B C. quadrimaculatus (CASENT0096044) C C. gibber (CASENT0491497).

35

  • With mesosoma in lateral view, propodeal dorsum broadly concave (Fig. 36A) => Camponotus immaculatus
  • With mesosoma in lateral view, propodeal dorsum approximately straight (Fig. 36B) => 36
Figure 36. Head, mesosoma and petiolar node in lateral view A C. immaculatus (CASENT0179441) B C. lubbocki (CASENT0486998).

36

  • Eye small (EL/CL: 0.19±0.01; 0.16–0.21) (Fig. 37A); posterior margin of head approximately straight => Camponotus kelimaso
  • Eye large (EL/CL: 0.24±0.01; 0.23–0.27) (Fig. 37B); posterior margin of head broadly convex => Camponotus lubbocki
Figure 37. Head in full-face view A C. kelimaso (CASENT0487718) B C. lubbocki (CASENT0486998).

37

  • Pronotum, mesonotum, and propodeum forming separate convexities, metanotal groove depressed; propodeum at lower level than promesonotum; petiolar node with dorsal face rounding to anterior and posterior faces (Fig. 38A) => Camponotus gibber
  • Pronotum, mesonotum, and propodeum not forming separate convexities, metanotal groove not depressed; propodeum immediately in junction with promesonotum; petiolar node with dorsal face joining posterior face into an angle and rounding to anterior face (Fig. 38B) => 38
Figure 38. Mesosoma and petiolar node in lateral view A C. gibber (CASENT0188619) B C. quadrimaculatus (CASENT0096044).

38

Figure 39. Mesosoma in lateral view A C. rotrae (CASENT0485625) B C. quadrimaculatus (CASENT0121629).

References