Key to Pheidole sikorae species group

This worker key is based on: Salata, S. and B. L. Fisher. 2020b. Taxonomic revision of the Pheidole sikorae species group (Hymenoptera, Formicidae) from Madagascar. ZooKeys. 949:1–185. doi:10.3897/zookeys.949.51269

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1

Minute species. Major workers with HL < 1.1 mm and WL < 0.9 mm and minor workers with HL < 0.5 mm and WL < 0.6 mm. All four measurements must fit those requirements; if at least one is higher than stated limits then go to couplet 13 . . . . . 2

Moderately large species. Major workers with HL > 1.1 mm and WL > 0.9 mm and minor workers with HL > 0.55 mm and WL > 0.7 mm . . . . . 13

2

return to couplet #1

Figure 2. Major worker, head in full-face view. Pheidole andohahela (A). Pheidole beanka (B). Pheidole flavominuta (C). Pheidole havoana (D). Pheidole kely (E). Pheidole lavasoa (F). Pheidole midongy (G). Pheidole mikros (H). Pheidole nitidobruna (I). Pheidole parvula (J). Pheidole parvulogibba (K). Pheidole volontany (L). Major workers, hypostomal teeth. Pheidole andohahela (M). Pheidole lavasoa (N).

Figure 3. Major worker, profile. Pheidole andohahela (A). Pheidole beanka (B). Pheidole flavominuta (C). Pheidole havoana (D). Pheidole kely (E). Pheidole lavasoa (F). Pheidole midongy (G). Pheidole mikros (H). Pheidole nitidobruna (I). Pheidole parvula (J). Pheidole parvulogibba (K). Pheidole volontany (L).

Figure 4. Minor worker, head in full-face view. Pheidole andohahela (A). Pheidole beanka (B). Pheidole flavominuta (C). Pheidole havoana (D). Pheidole kely (E). Pheidole lavasoa (F). Pheidole midongy (G). Pheidole mikros (H). Pheidole nitidobruna (I). Pheidole parvula (J). Pheidole parvulogibba (K). Pheidole volontany (L).

Major workers. Head in full–face view sub–oval, body dark brown, and sides of head with very dense, relatively short to short, suberect pilosity (Fig. 2A, F). Minor workers. Scape, when laid back, surpassing the posterior head margin by two-fifths of its length, SI > 130.0; propodeal spines reduced to small lobes, head elongate and oval and body yellowish brown to dark brown (Fig. 4A, F) . . . . . 3

Major workers. Head, in full-face view elongate, if sub-oval then body orange to yellow or body dark brown with sides of the head with dense, very long, suberect to erect pilosity (Fig. 2 B–E, G–L). Minor workers. Scape, when laid back, reaching the posterior head margin or surpassing it by one-fifth of its length, SI < 115.0; propodeal spines minute to moderately large but always developed; if propodeal spines reduced to small lobes then head more rectangular in shape (Fig. 4 B–E, G–L) . . . . . 4

3

Figure 5. Minor worker, profile. Pheidole andohahela (A). Pheidole beanka (B). Pheidole flavominuta (C). Pheidole havoana (D). Pheidole kely (E). Pheidole lavasoa (F). Pheidole midongy (G). Pheidole mikros (H). Pheidole nitidobruna (I). Pheidole parvula (J). Pheidole parvulogibba (K). Pheidole volontany (L).

return to couplet #2

Major workers. Sides of the head with very dense, short, suberect to erect pilosity, inner hypostomal teeth triangular with rounded apex directed upward, outer hypostomal teeth with dentate sharp apex directed slightly outward (Fig. 2F, N). Minor workers. Head sculpture shiny and smooth but frons with sparse, short, and longitudinal rugulae, mesosoma shiny and smooth, body yellowish brown (Figs 4F, 5F) . . . . . Pheidole lavasoa

major

minor

Major workers. Sides of the head with sparser and longer, suberect pilosity, inner hypostomal teeth with sharp apex directed upward, outer hypostomal teeth lobe-like with apex directed distinctly outward (Fig. 2A, M). Minor workers. Head sculpture shiny and smooth but vertex and frons with sparse, short, and transverse rugulae, anterolateral sides of propodeum and anepisternum with indistinct and sparse rugoreticulae, body dark brown (Figs 4A, 5A) . . . . . Pheidole andohahela

major

minor

4

return to couplet #2

Major workers. Head in full-face view elongate, not widening posteriorly, with anterior and posterior sides slightly convex (Fig. 2B, C, H, I). Minor workers. Head predominantly smooth and in full–face view rectangular with anterolateral sides relatively straight or indistinctly convex, body yellow to brown (Figs 4B, C, H, I, 5B, C, H, I) . . . . . 5

Major workers. Head in full-face view sub-oval, slightly widening posteriorly, with anterior and posterior sides convex (Fig. 2D, E, G, J, K, L). Minor workers. Head foveolate; if predominantly smooth, then in full-face view oval with anterolateral sides distinctly convex or body dark brown (Figs 4D, E, G, J, K, L, 5D, E, G, J, K, L) . . . . . 8

5

return to couplet #4

Major worker. Body yellow, head in lateral view sub-oval and elongate with slightly convex dorsal and ventral sides, base of first gastral tergite smooth (Figs 2C, 3C). Minor worker. Scape, when laid back, reaching the posterior head margin, SI < 96.0, body yellow (Figs 4C, 5C) . . . . . Pheidole flavominuta

major

minor

Major worker. Body brown to orange, head in lateral view sub-oval and short with strongly convex dorsal and ventral sides, base of first gastral tergite shagreened (Figs 2B, H, I, 3B, H, I). Minor workers. Scape, when laid back, exceeding the posterior head margin by one-fifth of its length, body yellowish brown or bright yellow, SI > 98.0 (Figs 4B, H, I, 5B, H, I) . . . . . 6

6

return to couplet #5

Major workers. Medial part of frons with thick, longitudinal, and moderately dense rugae and smooth to indistinctly rugulate interspaces, occipital lobes with dense, irregular rugae, and indistinctly rugoreticulate interspaces, lateral sides of promesonotum with smooth notches (Figs 2I, 3I). Minor workers. Vertex and frons smooth (Fig. 4I) . . . . . Pheidole nitidobruna

major

minor

Major workers. Medial part of frons with thick, longitudinal, and dense rugae and distinctly to indistinctly rugulate interspaces, occipital lobes with irregular rugae and distinctly foveolate or rugoreticulae interspaces, lateral sides of promesonotum entirely sculptured (Figs 2B, H, 3B, H). Minor workers. Vertex and/or frons with additional sculpture (Fig. 4B, H) . . . . . 7

7

return to couplet #6

Major workers. Medial part of frons with thick, longitudinal, and dense rugae and indistinctly rugulate interspaces, propodeal spines moderately long (Figs 2H, 3H). Minor workers. Lateral sides of frons with fine, sparse, and irregular rugulae with smooth interspaces, mesosoma with sparse and moderately thick network of irregular rugulae, mesonotum and katepisternum smooth, body yellowish brown, propodeal spines small, triangular (Figs 4H, 5H) . . . . . Pheidole mikros

major

minor

Major workers. Medial part of frons with thick, longitudinal, and dense rugae and distinctly rugulate interspaces, propodeal spines very small(Figs 2B, 3B). Minor workers. Lateral sides of frons smooth, mesosoma smooth, propodeal spines reduced to small tubercles, body yellow (Figs 4B, 5B) . . . . . Pheidole beanka

major

minor

8

return to couplet #4

Note: Minor workers of Pheidole kely share the same set of characters as Pheidole havoana. These two species can only be separated by characters of the major workers.

Major workers. Body dark orange, medial part of frons with longitudinal rugae, rugae in posteromedial part more irregular, interspaces shiny with dense and distinct irregular rugulae, pronotal dorsum and lateral sides of propodeum with reduced sculpture (Figs 2D, 3D). Minor workers. Head foveolate, frons with additional indistinct longitudinal and interrupted rugae in medial part, area posterolateral from eyes smooth (Fig. 4D) . . . . . Pheidole havoana

major

minor

Major workers. Body dark brown; if body orange then medial part of frons with longitudinal and dense rugae and smooth to indistinctly rugulate interspaces or pronotum distinctly foveolate with additional irregular rugae on dorsum and propodeum with fine rugulae and smooth interspaces (Figs 2E, G, J, K, L, 3E, G, J, K, L). Minor workers. Frons and vertex at least partly smooth (Fig. 4E, G, J, K, L) . . . . . 9

9

return to couplet #8

Major and minor workers. Bright body colouration, orange to yellow (Figs 2E, J, K, 3E, J, K, 4E, J, K, 5E, J, K) . . . . . 10

At least major workers brown, minor workers brown to dark yellow (Figs 2G, L, 3G, L, 4G, L, 5G, L) . . . . . 12

10

return to couplet #9

Major workers. Medial part of frons with thick, dense, longitudinal and interrupted rugae and smooth to indistinctly rugulate interspaces, mesosoma with fine and sparse rugofoveolae, pronotum with rugofoveolae reduced and smooth notches on medial parts of dorsum and its lateral sides (Figs 2E, 3E). Minor workers. Frons and vertex distinctly foveolate (Fig. 4E) . . . . . Pheidole kely

major

minor

Major workers. Medial part of frons with thick and dense rugae and distinctly rugulate interspaces; if interspaces smooth or indistinctly regulate, then promesonotum foveolate with sparse and thick to moderately thick transverse to irregular rugae on dorsum, smooth notches absent (Figs 2J, K, 3J, K). Minor workers. Frons and vertex never distinctly foveolae, predominantly smooth (Fig. 4J, K) . . . . . 11

11

return to couplet #1

Major workers. Medial part of frons with thick and dense rugae and distinctly rugulate interspaces (Fig. 2J). Minor workers. Medial frons smooth, lateral sides of frons and vertex with fine, sparse, and irregular rugulae with smooth interspaces (Fig. 4J) . . . . . Pheidole parvula

major

minor

Major workers. Medial part of frons with thick, dense rugae and smooth to indistinctly rugulate interspaces (Fig. 2K). Minor workers. Frons and vertex smooth (Fig. 2k) . . . . . Pheidole parvulogibba

major

minor

12

return to couplet #9

Major workers. Medial part of frons with moderately dense, thick, longitudinal and interrupted rugae, interspaces shiny and smooth, sides of the head with dense, very long, suberect to erect pilosity (Fig. 2L). Minor workers. Body dark brown and head predominantly smooth (Figs 4L, 5L) . . . . . Pheidole volontany

major

minor

Major workers. Medial part of frons with thick, longitudinal and dense rugae and distinctly rugulate interspaces, sides of the head with moderately dense, moderately short, suberect pilosity (Fig. 2G). Minor workers. Frons with sparse and moderately thick, short and predominantly longitudinal rugulae, vertex with transverse, sparse, and moderately thick, short rugulae (Figs 4G, 5G) . . . . . Pheidole midongy

major

minor

13

Figure 6. Major worker. Pheidole gracilis, head (A), profile (E). Pheidole litigiosa Forel, head (B), profile (F). Pheidole masoandro, head (C), profile (G). Pheidole tampony, head (D), profile (H).

Figure 7. Minor worker. Pheidole gracilis, head (A), profile (E). Pheidole litigiosa Forel, head (B), profile (F). Pheidole masoandro, head (C), profile (G). Pheidole tampony, head (D), profile (H).

return to couplet #1

Note Minor workers of Pheidole sikorae, Pheidole antranohofa, and Pheidole befotaka (couplet #17) are extremely similar to those of Pheidole litigiosa, Pheidole masoandro, Pheidole gracilis, and Pheidole tampony (couplet #14) and can be separated only based on major workers. For more details see the individual species accounts.

Major workers. Posterior part of head with distinctly reduced sculpture, occipital lobes entirely or predominantly smooth, area posterolateral from eyes entirely smooth and shiny or with reduced sculpture and smooth notches (Fig. 6). Minor workers. Body orange to yellow, head at least medially foveolate, promesonotal groove present but sometimes indistinct, mesosoma predominantly or entirely smooth and promesonotum short or mesosoma predominantly foveolate and promesonotum low and long (Fig. 7) . . . . . 14

Major workers. Entire head distinctly sculptured, sometimes sculpture weakening posteriorly but always visible, smooth notches, if present, occur only on the posterior-most part of lateral sides of head (Figs 8, 14, 16, 17). Minor workers. Character combination different (Figs 9, 15, 18) . . . . . 17

14

return to couplet #13

Major workers. Body brown, occipital lobes predominantly smooth, area posterolateral from eyes predominantly with dense and thick longitudinal rugae with rugulate interspaces and reduced sculpture and predominantly smooth posteriormost parts (Fig. 6D, H). Minor workers. Promesonotum low and moderately long, mesosoma foveolate, area posterolateral from eyes smooth, body bright brown (Fig. 7D, H) . . . . . Pheidole tampony

major

minor

Major workers. Body yellow to yellowish orange, at least occipital lobes and posteriormost parts of area posterolateral from eyes smooth or occipital lobes predominantly smooth, area posterolateral from eyes with indistinct, dense, thin, and longitudinal rugae and smooth on the posteriormost parts (Fig. 6A–C, D–G). Minor workers. Promesonotum moderately low and short and mesosoma predominantly smooth; if promesonotum low and moderately long and mesosoma foveolate then body yellow and area posterolateral from eyes always with indistinct sculpture (Fig. 7A–C, D–G) . . . . . 15

15

return to couplet #14

Major workers. Medial part of frons with moderately thick, longitudinal, interrupted, and moderately dense rugae, occipital lobes predominantly smooth, only anterior part with indistinct, dense, thin, and longitudinal rugae, promesonotum distinctly foveolate. (Fig. 6A, E). Minor workers. Promesonotum low and moderately long, mesosoma foveolate (Fig. 7A, E). . . . . Pheidole gracilis

major

minor

Major workers. Medial part of frons with thick, longitudinal, interrupted, and moderately dense rugae, occipital lobes smooth, promesonotum predominantly smooth (Fig. 6B, C, F, G). Minor workers. Promesonotum moderately low and short, mesosoma predominantly smooth (Fig. 7B,C, F, G) . . . . . 16

16

return to couplet #15

Major workers. Medial part of frons with thick, longitudinal, interrupted, and moderately dense rugae, interspaces rugulate, sides of the head with moderately dense, short, subdecumbent to suberect pilosity (Fig. 6B, F). Minor workers. Head with foveolate frons and no additional rugae, promesonotal groove indistinct, propodeal spines small, triangular (Fig. 7B, F) . . . . . Pheidole litigiosa

major

minor

Major workers. Medial part of frons with moderately dense, thick, interrupted longitudinal rugae, interspaces smooth, sides of the head with very dense, long, erect pilosity (Fig. 6C, G). Minor workers. Head with foveolate frons with additional rugae, promesonotal groove distinct, propodeal spines minute (Fig. 7C, G) . . . . . Pheidole masoandro

major

minor

17

Figure 8. Major worker. Pheidole alina, head (A), hypostomal teeth (D), profile (F). Pheidole mainty, head (B), hypostomal teeth (E), profile (G). Pheidole trichotos, head (C).

Figure 9. Minor worker. Pheidole alina, head (A), profile (D). Pheidole mainty, head (B), profile (E). Pheidole trichotos, head (C), profile (F).

return to couplet #13

Major workers. Body black or brownish black (Fig. 8). Minor workers. Head and mesosoma black or head and mesosoma brown to dark brown with dense foveolae and no smooth notches (Fig. 9) . . . . . 18

Major workers. Body yellow to dark brown (Figs 14, 16, 17). Minor workers. Body yellow to orange; if head and mesosoma dark brown then sculpture reduced and never entirely foveolae (Figs 15, 18) . . . . . 20

18

return to couplet #17

Major workers. Body brownish black. Medial part of frons with thick, interrupted, dense, and longitudinally irregular rugae with indistinctly to distinctly rugulate interspaces, base of first gastral tergite shagreened (Fig. 8C). Minor workers. Body brown to brownish black, head and mesosoma entirely foveolae, smooth notches absent, scape, when laid back, exceeding the posterior head margin by two-fifths of its length, SI < 153.0 (Fig. 9C, F) . . . . . Pheidole trichotos

major

minor

Major workers. Medial part of frons with thick, interrupted, dense, and longitudinal rugae with smooth to indistinctly rugulate interspaces, base of first gastral tergite smooth (Fig. 8A, B, F, G). Minor workers. Body black to brownish black, head and mesosoma foveolae with smooth notches, if smooth notches absent then scape, when laid back, exceeding the posterior head margin by one-third of its length SI > 163.0 (Fig. 9A, B, D, E . . . . . 19

19

return to couplet #18

Major workers. Sides of the head with moderately dense, long, suberect to erect pilosity, inner hypostomal teeth indistinct, low, and wide, closely spaced, bulge-like, propodeal spines moderately long, narrow and with acute apex (Fig. 8A, D, F). Minor workers. Head foveolate, median frons with short and indistinct longitudinal rugulae, area posterolateral from eyes with slightly to distinctly weaker sculpture, mesosoma foveolate, katepisternum with reduced sculpture or with smooth notch (Fig. 9A, D) . . . . . Pheidole alina

major

minor

Major workers. Sides of the head with very dense, moderately long, suberect to erect pilosity, inner hypostomal teeth distinct, moderately large and narrow, closely spaced, triangular with apex directed slightly inward, propodeal spines moderately long, wide, and with acute apex (Fig. 8B, E, G). Minor workers. Head foveolate, vertex with fading foveolae, frons with distinct and sparse, longitudinal rugae, area posterolateral from eyes smooth, mesosoma foveolate, promesonotal dorsum, katepisternum, and propodeum predominantly smooth (Fig. 9B, E) . . . . . Pheidole mainty

major

minor

20

Figure 10. Pheidole ambohimanga Major worker, head (A). Minor worker, head (D), profile (G). Pheidole analavelona Major worker, head (B). Minor worker, head (E), profile (H). Pheidole vadum Major worker, head (C). Minor worker, head (F), profile (I).

Figure 11. Pheidole befotaka Major worker, head (A). Minor worker, head (D). Pheidole mamiratra Major worker, head (B), hypostomal teeth (G). Minor worker, head (E). Pheidole vony Major worker, head (C), hypostomal teeth (H). Minor worker, head (F).

Figure 12. Pheidole anomala Major worker, head (A). Minor worker, profile (D). Pheidole trichotos Major worker, head (B), gaster (G). Minor worker, profile (E). Pheidole veteratrix Forel. Major worker, head (C), gaster (H). Minor worker, profile (F).

Figure 13. Pheidole anosyenne Major worker, head (A), profile (D). Minor worker, profile (G). Pheidole joffreville Major worker, head (B), profile (E). Minor worker, profile (H). Pheidole mivory Major worker, head (C), profile (F). Minor worker, profile (I).

return to couplet #17

Note: At this point, species separation based on minor workers only is very impeded and, in some cases, impossible, therefore we strongly encourage using major workers or relying on nest samples.

Major workers. Medial frons predominantly with dense, irregular, and thick rugae, sometimes longitudinal to longitudinally irregular rugae occur on anterior part of frons but posterior part is always distinctly irregular (Figs 10A–C, 11A–C, 12A–C, 13A–C). Minor workers. Promesonotum low and long, dorsal and lateral sides of pronotum distinctly rugulate with no smooth notches, if smooth notches present then propodeum with indistinct to distinct foveolae or head always with foveolae, at least on frons, promesonotum short and moderately high, surpassing the posterior head margin by one-fifth of its length and mesosoma predominantly foveolate or head with additional thick longitudinal rugae on frons or promesonotal groove absent or indistinct (Figs 10D–I, 11D–F, 12D–F, 13G–I) . . . . . 21

Major workers. Medial frons predominantly with sparser, longitudinal, and sometimes interrupted, rugae, interspaces sometimes with irregular but distinctly thinner rugae (Figs 14, 16). Minor workers. Promesonotum low and long, dorsal and lateral sides of pronotum with reduced sculpture and smooth notches and propodeum with distinct foveolae or predominantly smooth or head predominantly smooth, if foveolae occur and promesonotum short and moderately high then promesonotum predominantly smooth or frons without additional, thick rugae and promesonotal groove very distinct (Figs 15, 18) . . . . . 32

21

return to couplet #20

Major workers. Head in full–face view oval, not widening posteriorly, with strongly convex sides, medial part of frons with thick, moderately sparse, irregular rugae or with moderately dense, thin, longitudinal anteriorly to irregular posteriorly interrupted rugae and very shallow occipital cleft (Fig. 10A–C). Minor workers. Body orange to brown, never yellow, promesonotum short and moderately high, head with additional moderately thick to thick longitudinal and interrupted rugae or head foveolate with no additional sculpture (Fig. 10D–I) . . . . . 22

Major workers. Head in full-face view sub–oval, most often slightly to distinctly widening posteriorly with convex sides, medial part of frons with thick, dense, irregular rugae, sometimes anterior part with rugae more longitudinal (Figs 11A–C, 12A–C, 13A–C). Minor workers. Body yellow, if orange to brown then promesonotum low and moderately long or prome-sonotum short and moderately high, and head predominantly foveolate with rugae very thin and indistinct (Figs 11D–F, 12D–F, 13G–I) . . . . . 24

22

return to couplet #21

Major workers. Medial part of frons with moderately dense, thin, longitudinal anteriorly to irregular posteriorly interrupted rugae and very shallow occipital cleft (Fig. 10C). Minor workers. Head predominantly foveolate with no additional sculpture (Fig. 10F) . . . . . Pheidole vadum

major

minor

Major workers. Medial part of frons with thick, moderately sparse, irregular rugae, occipital cleft deeper (Fig. 10A, B). Minor workers. Head with additional moderately thick to thick longitudinal and interrupted rugae (Fig. 10D, E) . . . . . 23

23

return to couplet #22

Major workers. Frons with thick, irregular rugae, interspaces shiny with distinct and sparse rugoreticulae (Fig. 10B). Minor workers. Head sculpture foveolate, medial frons with foveolae sparser, area posterolateral from eyes with reduced sculpture and smooth notches, mesonotum, anepisternum, katepisternum, and propodeum with sparse and indistinct rugofoveolae (Fig. 10E, H) . . . . . Pheidole analavelona

major

minor

Major workers. Frons with thick, irregular rugae, interspaces smooth and sometimes with indistinct rugulae (Fig. 10A). Minor workers. Head with sparse foveolae, frons with foveolae reduced to absent medially, area posterolateral from eyes with reduced sculpture, predominantly smooth, mesonotum, anepisternum, katepisternum and propodeum predominantly smooth, with sparse and indistinct foveolae on anterolateral and anterior sides (Fig. 10D, G) . . . . . Pheidole ambohimanga

major

minor

24

return to couplet #21

Major and minor workers. Body uniformly yellow or minors yellow and majors orange (Fig. 11) . . . . . 25

At least major workers with darker with legs and antenna distinctly brighter (Fig. 12, 13) . . . . . 27

25

return to couplet #24

Major workers. Body orange, lateral sides of head slightly convex, lateral sides of frons with distinctly irregular rugae, large species HL > 1.1, WL > 1.05 (Fig. 11A). Minor workers. Head predominantly foveolate, vertex and lateral sides of frons with additional, irregular to arcing rugae, large species HL > 0.65, WL > 0.8 (Fig. 11D) . . . . . Pheidole befotaka

major

minor

Major workers. Body yellow, lateral sides of head relatively straight, lateral sides of frons distinctly longitudinally irregular, smaller species HL < 1.05, WL < 1.05 (Fig. 11B, C). Minor workers. Head predominantly smooth, if foveolae then without additional rugae, smaller species HL < 0.6, WL < 0.75 (Fig. 11E, F) . . . . . 26

26

return to couplet #25

Major workers. Medial part of frons with moderately dense and thin rugae, inner hypostomal teeth large, triangular, with rounded apex directed outward and outer hypostomal teeth lobe-like, lower, and more narrow than inner hypostomal teeth (Fig. 11C, H). Minor workers. Head foveolate, only area posterolateral from eyes smooth (Fig. 11F) . . . . . Pheidole vony

major

minor

Major workers. Medial part of frons with moderately sparse and thick rugae, inner hypostomal teeth small, triangular, with rounded apex directed upward and outer hypostomal teeth lobe-like, wider and higher than inner hypostomal teeth (Fig. 11B, G). Minor workers. Head foveolate, medial part of frons and vertex with strongly reduced sculpture and predominantly smooth, area posterolateral from eyes smooth (Fig. 11E) . . . . . Pheidole mamiratra

major

minor

27

return to couplet #24

Major workers. Medial part of frons with thick, interrupted, dense, and irregular to longitudinally irregular rugae with indistinctly to distinctly rugulate interspaces, base of first gastral tergite smooth to shagreened (Fig. 12A–C, G, H). Minor workers. Mesosoma foveolate, sometimes with smooth notch on katepisternum, propodeal spines minute (Fig. 12D–F) . . . . . 28

Major workers. Anteromedial part of frons with thick, interrupted, dense to sparse and predominantly longitudinal rugae with smooth to rugulate interspaces, posteromedial frons with rugae irregular, base of first gastral tergite always smooth (Fig. 13A–C). Minor workers. Mesosoma with smooth areas more expanded, if only katepisternum with smooth notch then propodeal spines well developed (Fig. 13G–I) . . . . . 30

28

return to couplet #27

Major workers. Body ferruginous, frons with distinctly rugulate interspaces (Fig. 12A). Minor workers. Body yellow, katepisternum entirely foveolate (Fig. 12D) . . . . . Pheidole anomala

major

minor

Major workers. Body brown to blackish brown, frons with interspaces predominantly smooth or indistinctly regulate (Fig. 12B, C). Minor workers. Body brown to dark brown, if yellowish brown then katepisternum with smooth notch (Fig. 12E, F) . . . . . 29

29

return to couplet #28

Major workers. Body brownish black, base of first gastral tergite shagreened (Fig. 12B, G). Minor workers. Mesosoma distinctly foveolate, body dark brown (Fig. 12E) . . . . . Pheidole trichotos

major

minor

Major workers. Body brown to dark brown, base of first gastral tergite smooth (Fig. 12C, H). Minor workers. Body yellowish brown to brown, if dark brown then katepisternum at least with smooth notch (Fig. 12F) . . . . . Pheidole veteratrix

major

minor

30

return to couplet #27

Major workers. Sides of the head with moderately dense, short, decumbent to subdecumbent pilosity, lateral sides of pronotum and katepisternum with smooth notches, body ferruginous (Fig. 13A, D). Minor workers. Body dark orange, mesosomal dorsum rugofoveolate, lateral sides of pronotum foveolate, anepisternum and katepisternum smooth, lateral sides of propodeum with smooth notches (13G) . . . . . Pheidole anosyenne

major

minor

Major workers. Sides of the head with sparse to moderately sparse, moderately long to long, decumbent to erect pilosity, body brown, mesosoma with no smooth notches (Fig. 13B, C, E, F). Minor workers. Body brown to bright brown, mesosoma entirely foveolate with smooth notch on katepisternum or mesosoma with sparse foveolae and dorsal promesonotum and medial parts of lateral sides of pronotum, propodeum and katepisternum with smooth notches (Fig. 13H, I) . . . . . 31

31

return to couplet #30

Major workers. Frons with interspaces distinctly rugofoveolate, rugae on posteromedial part directed outward, lateral sides of frons with thick, sparse, and irregular rugae with distinctly rugofoveolate interspaces (Fig. 13B, E). Minor workers. Mesosoma foveolate, katepisternum with big smooth notch (Fig. 13H) . . . . . Pheidole joffreville

major

minor

Major workers. Frons with interspaces with sparse rugofoveolae, lateral sides of frons with dense, thick, predominantly irregular rugae with few distinct longitudinal rugae, interspaces with sparse rugulae, gaster with slightly shagreened base of first tergite (Fig. 13C, F). Minor workers. Mesosoma with sparse foveolae, dorsal promesonotum and medial parts of lateral sides of pronotum, propodeum, and katepisternum with smooth notches (Fig. 13I) . . . . . Pheidole mivory

major

minor

32

Figure 14. Major worker. Pheidole antranohofa, head (A), gaster (F), hypostomal teeth (H). Pheidole itremo, head (B), profile (J). Pheidole mavohavoana, head (C), gaster (G), hypostomal teeth (I). Pheidole sava, head (D), profile (K). Pheidole sikorae Forel, head (E).

Figure 15. Minor worker. Pheidole antranohofa, head (A), profile (F). Pheidole itremo, head (B), profile (G). Pheidole mavohavoana, head (C), profile (H). Pheidole sava, head (D), profile (I). Pheidole sikorae Forel, head (E), profile (J).

return to couplet #20

Major workers. Impressed and smooth concavity placed lateral to antennal socket and tentorial pit present (Fig. 14E). Minor workers. Body yellow to orange, head always with reduced sculpture, mesosomal dorsum with few transverse, thick rugulae and propodeum with indistinct and sparse foveolae, propodeal spines very small, triangular, promesonotal groove present, promesonotum moderately high, short (Fig. 15E,J) . . . . . Pheidole sikorae

major

minor

Major workers. Impressed and smooth concavity placed lateral to antennal socket and tentorial pit absent (Figs 14A–D, 16). Minor workers. Combination of characters different (Figs 15A–D, F–I, 18) . . . . . 33

33

return to couplet #32

Major workers. Head in full-face view widening posteriorly, with lateral sides distinctly convex (Fig. 14A–D). Minor workers. Body brown to dark brown, head predominantly foveolate, mesosoma predominantly smooth and propodeal spines minute or body yellow to orange, promesonotal groove deep, mesosoma predominantly or entirely smooth (Fig. 15A–D, F–I) . . . . . 34

Major workers. Head in full-face view not widening posteriorly, with lateral sides relatively straight or slightly convex (Fig. 16). Minor workers. Body brown to dark brown, head predominantly foveolate and mesosoma foveolate with smooth notch on katepisternum or mesosoma predominantly smooth and propodeal spines moderate or body yellow to orange, promesonotal groove absent or indistinct, if present then mesosoma with distinct foveolae (Fig. 18) . . . . . 37

34

return to couplet #33

Major and minor workers. Body colouration bright yellow to orange (Figs 14A, C, 15A, C, F, H) . . . . . 35

Major and minor workers. Body colouration darker, brown to dark brown. Sometimes minors yellowish brown (Figs 14B, J, D, K, B, G, D, I) . . . . . 36

35

return to couplet #34

Major workers. Sides of the head with dense, short, suberect pilosity, lateral sides of frons with longitudinally irregular and thick rugae with distinctly rugofoveolate interspaces, gaster with sparse pilosity, outer hypostomal teeth distinct and wide (Fig. 14A, F, H). Minor workers. Head foveolate with additional indistinct rugulae on frons and vertex, area posterolateral from eyes with reduced sculpture, posteriormost parts predominantly smooth, promesonotum moderately high and short (Fig. 15A, F) . . . . . Pheidole antranohofa

major

minor

Major workers. Sides of the head with very dense, short, suberect to erect pilosity, lateral sides of frons with thick, dense, and irregular rugae with sparsely rugulate interspaces, gaster with very dense pilosity, outer hypostomal teeth reduced (Fig. 14C, G, I). Minor workers. Head smooth, lateral sides of frons with longitudinal, short, and thick rugae, vertex with very short, sparse, and transverse rugae, promesonotum moderately low and moderately long (Fig. 15C, H) . . . . . Pheidole mavohavoana

major

minor

36

return to couplet #34

Major workers. Sides of the head with dense, short, suberect pilosity, inter-spaces on medial frons with sparse and distinct rugulae, dorsal and lateral sides of pronotum with smooth notches (Fig. 14D, K). Minor workers. Head foveolate with additional indistinct longitudinal rugulae on medial frons, area posterolateral from eyes smooth, mesosoma predominantly smooth, only promesonotal dorsum with arched rugae and indistinct foveolae, mesonotum and lateral sides of propodeum with indistinct and sparse foveolae (Fig. 15D, I) . . . . . Pheidole sava

major

minor

Major workers. Sides of the head with moderately dense, moderately long, suberect to erect pilosity, interspaces on medial frons smooth, pronotum never with smooth notches (Fig. 14B, J). Minor workers. Head predominantly smooth with posterolateral sides of frons with sparse and indistinct foveolae, mesosoma smooth (Fig. 15B, G) . . . . . Pheidole itremo

major

minor

37

Figure 16. Major worker, head. Pheidole dasos (A). Pheidole haboka (B). Pheidole hazo (C). Pheidole mahamavo (D). Pheidole manantenina (E). Pheidole renirano (F). Pheidole sofia (G). Pheidole sparsa (H). Pheidole tsaravoniana (I).

Figure 17. Major worker. Pheidole dasos, profile (A). Pheidole haboka, profile (B). Pheidole hazo, profile (C). Pheidole mahamavo, profile (D). Pheidole manantenina, profile (E). Pheidole renirano, gaster (H), profile (J). Pheidole sofia, profile (F). Pheidole sparsa, profile (G). Pheidole tsaravoniana, gaster (I), profile (K).

Figure 18. Minor worker. Pheidole dasos, head (A), profile (J). Pheidole haboka, head (B), profile (K). Pheidole hazo, head (C), profile (L). Pheidole mahamavo, head (D), profile (M). Pheidole manantenina, head (E), profile (N). Pheidole renirano, head (F), profile (O). Pheidole sofia, head (G), profile (P). Pheidole sparsa, head (H), profile (Q). Pheidole tsaravoniana, head (I), profile (R).

return to couplet #33

Major workers. Head in full-face view sub-oval and elongate with lateral sides slightly convex and narrowing posteriorly, medial frons with sparse, interrupted, and longitudinal rugae with predominantly smooth interspaces, lateral sides of frons with dense, irregular rugae with distinctly foveolate interspaces (Fig. 16E, G). Minor workers. Promesonotal groove present but indistinct, body yellowish brown and head and mesosoma entirely or predominantly smooth or body brown and head with sparse foveolae and smooth notches on frons and mesosoma with sparse and indistinct foveolae with smooth notches on dorsum and anepisternum and katepisternum (Fig. 18E, G, N, P) . . . . . 38

Major workers. Head in full-face view sub-oval but not elongate with lateral sides relatively straight or slightly convex but never narrowing posteriorly, medial frons with dense, sometimes interrupted and longitudinal rugae with predominantly sculptured interspaces, lateral sides of frons with dense to sparse longitudinal to longitudinally irregular rugae with interspaces smooth to rugoreticulate or rugofoveolate (Fig. 16A–D, F, H, I). Body yellow, if yellowish brown then head and mesosoma predominantly with dense foveolae, if brown then head and mesosoma predominantly with dense foveolae or mesosoma almost entirely smooth and promesonotal groove absent (Fig. 18A–-D, F, H, I, J–M, O, Q, R) . . . . . 39

38

return to couplet #37

Major workers. Medial part of frons with interspaces finely foveolate, lateral sides with more longitudinally irregular rugae, body ferruginous, promesonotum never with reduced sculpture (Figs 16G, 17F). Minor workers. Head predominantly smooth or foveolae with foveola sparse and fading on medial frons and area posterolateral from eyes; vertex with sparse and short rugulae; frons with very sparse, short, and irregular rugae; mesosoma with sparse rugofoveolae; promesonotal dorsum and katepisternum with smooth notches or smooth; pronotum with additional sparse, short, and transverse rugulae (Fig. 18G, P) . . . . . Pheidole sofia

major

minor

Major workers. Medial part of frons with smooth or indistinct rugofoveolae, lateral sides of frons with rugae predominantly irregular, body brownish to dark orange, promesonotum with reduced sculpture (Figs 16E, 17E). Minor workers. Head predominantly smooth; frons with longitudinal, short, and thick rugae and sometimes foveolate interspaces, promesonotum predomi-nantly smooth (Fig. 18E, N) . . . . . Pheidole manantenina

major

minor

39

return to couplet #37

Major workers. Base of first gastral tergite shagreened (Fig. 17H, I). Minor workers. Scape, when laid back, exceeding the posterior head margin by one-third of its length, SI > 157.0, promesonotal groove present, promesonotum predominantly sculptured, vertex without arching rugae (Fig. 18F, I, O, R) . . . . . 40

Major workers. Base of first gastral tergite smooth. Minor workers. Scape, when laid back, exceeding the posterior head margin by one- to two-fifths of its length, SI < 157.0, if exceeds by one-third of its length then promesonotal groove absent and promesonotum predominantly smooth or promesonotal groove present and vertex with distinct, arching rugae (Fig. 18A–-D, H, J–M, Q) . . . . . 41

40

return to couplet #39

Major workers. Body yellow, promesonotal dorsum with short, transverse rugae with smooth to indistinctly foveolate interspaces (Fig. 17J). Minor workers. Body yellowish brown, dorsal side of promesonotum and lateral sides of pronotum with reduced sculpture and smooth notches on medial parts (Fig. 18F, 0) . . . . . Pheidole renirano

major

minor

Major workers. Body ferruginous, promesonotal dorsum with short, transverse, and more irregular rugae with distinctly rugofoveolate interspaces (Fig. 17K). Minor workers. Body brown, dorsal side of promesonotum and lateral sides of pronotum with sparse foveolae but never with smooth notches (Fig. 18I, R) . . . . . Pheidole tsaravoniana

major

minor

41

return to couplet #39

Major workers. Body brown, lateral sides of pronotum with distinct sculpture (Fig. 17D). Minor workers. Head with distinct, arcing rugae on vertex, body brown (Fig. 18D, M) . . . . . Pheidole mahamavo

major

minor

Major workers. Body yellow to orange, lateral sides of pronotum with smooth notches or sparse sculpture with smooth interspaces (Fig. 17A–C, G). Minor workers. Head never with distinct, arcing rugae on vertex, body yellow (Fig. 18A–-C, H, J–L, Q) . . . . . 42

42

return to couplet #41

Major workers. Area posterolateral from eyes with sculpture weakening posteriorly and smooth notch (Fig. 17B). Minor workers. Head and mesosoma predominantly smooth and never foveolate (Fig. 18B, K) . . . . . Pheidole haboka

major

minor

Major workers. Area posterolateral from eyes with sculpture well developed and never with smooth notch (Fig. 17A, C, G). Minor workers. At least head predominantly foveolate, mesosoma at least partially foveolate (Fig. 18A, C, H, J, L, Q) . . . . . 43

43

return to couplet #42

Major workers. Medial part of frons with moderately sparse rugae, interspaces with sparse and indistinct rugofoveolae, promesonotum predominantly smooth, with indistinct rugofoveolae on lateral sides (Figs 16H, 17G). Minor workers. Body dark yellow, scape, when laid back, surpassing the posterior head margin by one-fifth of its length, SI < 123.0, pronotum with very indistinct and sparse foveolae; mesonotum, anepisternum, katepisternum, and propodeum smooth (Fig. 18H, Q) . . . . . Pheidole sparsa

major

minor

Major workers. Medial part of frons with moderately dense to dense rugae, interspaces with distinct rugofoveolae or indistinct foveolae, promesonotum entirely rugofoveolate and sometimes with smooth notches on lateral sides (Figs 16A, C, 17A, C). Minor workers. Body brown and scape, when laid back, exceeding the posterior head margin by one-third of its length, SI > 153.0, or body yellow, scape, when laid back, surpassing the posterior head margin by one-fifth of its length, SI < 123.0, and mesosoma distinctly foveolate and lateral sides of propodeum, katepisternum, and anepisternum with smooth notches (Fig. 18A, C, J, L) . . . . . 44

44

return to couplet #43

Major workers. Interspaces on medial frons distinctly rugofoveolate, propodeal spines moderately long and relatively narrow, pronotum with no smooth (Figs 16C, 17C). Minor workers. Scape, when laid back, surpassing the posterior head margin by one-fifth of its length, SI < 123.0, mesosoma with thick foveolae; lateral sides of propodeum, katepisternum, and anepisternum with smooth notches, body yellow (Fig. 18C, L) . . . . . Pheidole hazo

major

minor

Major workers. Interspaces on frons indistinctly foveolate, propodeal spines short, with wide base, lateral sides of pronotum with smooth notches (Figs 16A, 17A). Minor workers. Scape, when laid back, exceeding the posterior head margin by one-third of its length, SI < 153.0, mesosoma predominantly smooth, lateral sides with very sparse, indistinct, and thin rugulae, body brown (Fig. 18A, J) . . . . . Pheidole dasos

major

minor