Key to Afrotropical Simopone Species

A key to Simopone workers of the Afrotropical region. Based on: Bolton, B. & Fisher, B.L. 2012. Taxonomy of the cerapachyine ant genera Simopone Forel, Vicinopone gen. n. and Tanipone gen. n. (Hymenoptera: Formicidae). Zootaxa, 3283, 1–101. PDF

There are 18 species in the Afrotropical region. This includes all 11 species of the schoutedeni group, 6 species of the emeryi group and a single species of the grandidieri group. S. matthiasi and miniflava are known only from queens.

1

• Mesopleuron entire, without a distinctly incised transverse sulcus that crosses the entire sclerite and is continuous with, and as strongly developed as, the sulcus between mesopleuron and metapleuron. Dorsal apex of pygidium with a conspicuous, stoutly bifid cuticular fork above the sting . . . . . 2

• Mesopleuron divided into upper and lower sections by a distinctly incised transverse sulcus that crosses the entire sclerite; posteriorly the sulcus continuous with, and as strongly developed as, the sulcus between mesopleuron and metapleuron. Dorsal apex of pygidium at most with an inconspicuous pair of somewhat enlarged marginal teeth above the sting . . . . . 6

2

return to couplet #1

• Dorsal surfaces of tergites AII (petiole) and AIII (postpetiole), densely and conspicuously longitudinally costulate at least in the median third of their widths; tergite of AIV densely microreticulate to reticulate-punctate only, strongly contrasting with the sculpture of the two preceding segments. Anterior clypeal margin in dorsal view with a median prominence, not evenly shallowly convex or flat across its width. Eyes located more anteriorly, EP < 1.00. (Ivory Coast, Nigeria, Cameroun, Gabon, Central African Republic, Democratic Republic of Congo, Uganda, Kenya) . . . . . Simopone conradti

• Dorsal surfaces of tergites AII (petiole) and AIII (postpetiole) without longitudinal costulae; sculpture of tergite of AIV basically the same as the two preceding tergites, differing only in density or intensity. Anterior clypeal margin in dorsal view evenly shallowly convex to more or less straight across its width, without a median prominence. Eyes located more posteriorly, EP > 1.00 . . . . . 3

3

return to couplet #2

• With head tilted slightly back from full-face view the clypeo-labral junction is not reflexed and is located almost immediately below the apparent anterior clypeal margin. Scape in dorsal view less flattened; SW/SL 0.42–0.48. Dorsal and lateral surfaces of mesosoma, and abdominal tergites AII and AIII, are conspicuously blanketed with fine, dense, microreticulate to reticulate-punctate ground sculpture . . . . . 4

• With head tilted slightly back from full-face view the clypeo-labral junction is strongly reflexed and is located considerably behind the apparent anterior clypeal margin. Scape in dorsal view more flattened; SW/SL 0.69–0.81. Dorsal surfaces of mesosoma and abdominal tergites AII and AIII either smooth with scattered punctures, or at most with the spaces between thepunctures with inconspicuous, minute, superficial microreticulate patterning . . . . . 5

4

return to couplet #3

• Dorsum of head between frontal carinae, and back between the eyes, with fine longitudinal costulate sculpture that is superimposed upon the reticulate-punctate ground sculpture. Dorsum of mesosoma with numerous setae on pronotum, mesonotum and propodeum. Anterior half of clypeus with a median longitudinal carina that extends to the anterior margin. Larger species with head relatively broad, HW 1.44–1.62, SL 0.74–0.90, MFL 1.54–1.76, CI 83–87. (Cameroun, Democratic Republic of Congo) . . . . . Simopone grandis

• Dorsum of head between eyes densely reticulate-punctate with a few larger shallow punctures, without longitudinal costulate sculpture. Dorsum of mesosoma only with 1–2 pairs of setae near the humeral angles, 1–2 pairs on anterior mesonotum and 1–2 pairs at propodeal declivity. Anterior half of clypeus without a median longitudinal carina. Smaller species with head relatively narrow, HW 1.18–1.36, SL 0.57–0.70, MFL 1.10–1.30, CI 71–76. (Kenya, Tanzania, Mozambique, South Africa) . . . . . Simopone persculpta

5

return to couplet #3

• Scape in dorsal view strikingly flattened and extremely broad, SW/SL 0.79–0.81; scape much lighter in colour than the head capsule. Side of pronotum, just above base of anterior coxa, without a translucent fenestra of extremely thin cuticle. Dorsal surfaces of tergites AII, AIII and AIV with abundant long, curved, decumbent setae. Dorsal (outer) surfaces of mesotibiae and metatibiae with numerous long, curved, freely projecting setae that are suberect to erect and almost as long as the tibial width. Head capsule and body black. Larger species, HW 1.32–1.48. (Sierra Leone, Ghana, Gabon) . . . . . Simopone latiscapa

• Scape in dorsal view slightly flattened but not extremely broad, SW/SL 0.69–0.71; scape the same colour as the head capsule. Side of pronotum, just above base of anterior coxa, with a translucent fenestra of extremely thin cuticle. Dorsal surfaces of tergites AII, AIII and AIV with sparse, short decumbent setae. Dorsal (outer) surfaces of mesotibiae and metatibiae with a few short decumbent setae that are only a fraction as long as the tibial width. Head capsule and body yellow, except for pygidium, hypopygium and pretergite of AIV, which are dark brown. Smaller species, HW 0.93–1.07. (South Africa) . . . . . Simopone marleyi

6

return to couplet #1

• With head in profile a short, narrow but deep scrobe present between antennal socket and anterior margin of eye. Metapleuron traversed by a strong sulcus that appears as a direct continuation of the transverse mesopleural sulcus. Tergite of AII longer than AIII. Tergite of AII relatively broad with respect to the pronotum, AIIW/PW 1.14. Tergite of AIV relatively broader, AIVW/AIVL 1.42. Frontal carinae very broad in full-face view, FcW/HW 0.62. Eyes located far back on head, EP 1.90. Scape very short, SI 35. Larger species, HW 0.97, PW 0.78, AIIW 0.89. (Uganda) . . . . . Simopone laevissima

• With head in profile a broad, shallow antennal fossa is present, but there is no narrow deep scrobe between antennal socket and anterior margin of eye. Metapleuron without a transverse strong sulcus that appears as a direct continuation of the transverse mesopleural sulcus. Tergite of AII shorter than AIII. Tergite of AII relatively narrow with respect to the pronotum, AIIW/PW 0.93–1.07. Tergite of AIV relatively narrower, AIVW/AIVL 0.94–1.20. Frontal carinae narrower in full-face view, FcW/HW 0.28–0.45. Eyes located farther forward on head, EP 0.68–1.06. Scape relatively longer, SI 42–54. Smaller species, HW 0.46– 0.80, PW 0.34–0.61, AIIW 0.34–0.62 . . . . . 7

7

return to couplet #6

• In profile the head capsule and mesosoma dark brown, tergites and sternites of AII and AIII dull yellow, tergites and sternites of AIV and AV black; the yellow colour of AII and AIII contrasting strongly with the remainder of the body. Standing setae sparse, on dorsum of head restricted to a single pair near the level of the posterior margins of the eyes, on dorsum of mesosoma restricted to a single pair at the pronotal humeri, on tergites of AIII and AIV restricted to a sparse row at the apex of each segment. (Democratic Republic of Congo) . . . . . Simopone fulvinodis

• In profile the head capsule, mesosoma and AII to AV either brown or black; tergites and sternites of AII and AIII not yellow, not contrasting with the remainder of the body. Standing setae short but numerous on dorsum of head, dorsum of mesosoma and all surfaces of the tergites of AIII and AIV . . . . . 8

8

return to couplet #7

• AIII (postpetiole) relatively long and narrow, AIIIW/AIIIL 0.82. Eye located relatively farther forward on head, EP 0.68. (Kenya) . . . . . Simopone dryas

• AIII (postpetiole) relatively short and broad, AIIIW/AIIIL 0.92–1.05. Eye located relatively farther back on head, EP 0.76–1.06 . . . . . 9

9

return to couplet #8

• With the head in full-face view the outer margins of the eyes are strongly convex and distinctly project far beyond the outlines of the sides of the head; sides of head completely concealed in at least the median third of the eye length. Eyes larger, ES 0.30–0.35. With AII in dorsal view the width of the posterior margin distinctly greater than the width of the anterior margin . . . . . 10

• With the head in full-face view the outer margins of the eyes are shallowly convex and fail to reach, or at most just barely interrupt, the outlines of the sides of the head at the midlength of eye; sides of head visible for most or all of the eye length. Eyes smaller, ES 0.21–0.28. If midlength of outer margin of eye just breaks the outline of the side then with AII in dorsal view the width of the posterior margin of AII is the same as the width of the anterior margin, or only fractionally greater . . . . . 11

10

return to couplet #9

• Mesosoma black. Cephalic dorsum between eyes with distinct ground sculpture between punctures that usually appears as very fine, dense, longitudinal costulae or striolae. AII and AIII in dorsal view both relatively narrower, AIIW/AIIL 0.93–0.98, AIIIW/AIIIL 0.94–1.00. (Cameroun, Gabon, Democratic Republic of Congo) . . . . . Simopone wilburi

• Mesosoma glossy brown. Cephalic dorsum between eyes either without ground sculpture between punctures, or at most with feeble, patchy, unorganised microsculpture that is not arranged longitudinally. AII and AIII in dorsal view both relatively broader, AIIW/AIIL 1.02–1.06, AIIIW/AIIIL 1.08–1.09. (Ghana) . . . . . Simopone vepres

11

return to couplet #9

• Punctures on disc of tergite AIII (postpetiole) minute, pinprick-like and widely separated; diameters of most or all the punctures obviously less than the distances that separate them. Head and body uniformly medium to dark brown. (Gabon, Democratic Republic of Congo) . . . . . Simopone brunnea

• Punctures on disc of tergite AIII (postpetiole) large and conspicuous, foveolate and close together; diameters of most or all the punctures greater than distances that separate them, or the punctures adjacent. Head and body uniformly black . . . . . 12

12

return to couplet #11

• Mesofemora and metafemora brown, mesotibiae and metatibiae yellow, the two colours contrasting. Slightly larger species, HW 0.67–0.80, SL 0.32–0.34, PW 0.51–0.61. In dorsal view the width across the anterior margin of AII (petiole) is equal to the width across the posterior margin, or very nearly so . . . . . 13

• Mesofemora, metafemora, mesotibiae and metatibiae all approximately the same colour, the femora and tibiae not contrasting. Slightly smaller species, HW 0.49–0.59, SL 0.22–0.28, PW 0.38–0.45; but if HW 0.55 or more, SL 0.25 or more and PW 0.40 or more, then in dorsal view the width across the anterior margin of AII (petiole) is usually obviously less than the width across the posterior margin . . . . . 14

13

return to couplet #12

• In dorsal view AII longer than broad (AIIW/AIIL 0.94), the sides straight and parallel. Smaller species with slightly larger eyes, HW 0.67, AIIW 0.49, AIIIW 0.71; EL/HW 0.48; minimum distance between eyes 0.32. (Democratic Republic of Congo) . . . . . Simopone schoutedeni

• In dorsal view AII broader than long (AIIW/AIIL 1.07), the sides weakly convex. Larger species with slightly smaller eyes, HW 0.80, AIIW 0.62, AIIIW 0.71; EL/HW 0.39; minimum distance between eyes 0.41. (Tanzania) . . . . . Simopone rabula

14

return to couplet #12

• AII (petiole) in dorsal view slightly broader than long, AIIW/AIIL 1.03–1.07. (Ghana, Cameroun, Gabon, Central African Republic, Democratic Republic of Congo) . . . . . Simopone annettae

• AII (petiole) in dorsal view slightly longer than broad, AIIW/AIIL 0.92–0.98 . . . . . 15

15

return to couplet #14

• With AII (petiole) in dorsal view the width across the anterior margin is almost exactly the same as across the posterior margin. Dorsum of head between eyes with traces of superficial ground sculpture in places but without longitudinal striolae. Head slightly narrower and eyes located somewhat more anteriorly, CI 63, EP 0.76. (Gabon) . . . . . Simopone occulta

• With AII (petiole) in dorsal view the width across the anterior margin is notably less than across the posterior margin. Dorsum of head between eyes with longitudinal finely striolate sculpture present. Head slightly broader and eyes located somewhat more posteriorly, CI 68, EP 0.92. (Gabon) . . . . . Simopone amana