Key to Malagasy Simopone Species

A key to Simopone workers of the Malagasy 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

The 16 known species from the Malagasy region are all confined to Madagascar. This total includes 14 species of the emeryi group and two species of the grandidieri group. Workers are unknown for mayri.

1

• Mesopleuron with a sharply incised transverse sulcus present across the entire sclerite; posteriorly the sulcus continuous with, and as strongly developed as, the sulcus between mesopleuron and metapleuron. Dorsal apex of pygidium with a row of 4 small teeth above the sting, without a stoutly bifid cuticular fork. Palp formula 5,3 . . . . . 2

• Mesopleuron entire, without a transverse sulcus across the entire sclerite that is continuous with, and as strongly developed as, the sulcus between mesopleuron and metapleuron. Dorsal apex of pygidium with a stoutly bifid cuticular fork above the sting, without a short row of 4 small teeth. Palp formula 6,4 . . . . . 3

2

return to couplet #1

• Leading edge of scape with 2–3 projecting setae that are inclined toward the scape apex. Dorsum of head between the eyes covered with conspicuous microreticulate ground sculpture, upon which scattered larger punctures are superimposed. Eye located slightly more anteriorly on head, EP 0.74–0.84 . . . . . Simopone elegans

• Leading edge of scape without projecting setae. Dorsum of head between the eyes with scattered small punctures on a pruinose to extremely weakly shagreenate surface, without distinct microreticulate ground sculpture. Eye located slightly more anteriorly on head, EP 0.80–1.00 . . . . . Simopone grandidieri

3

return to couplet #1

• In profile the tergites of AII (petiole), AIII and AIV each with abundant setae that arise over the entire surface of each sclerite; the setae are curved or inclined posteriorly and are somewhat elevated, suberect to subdecumbent, never appressed. Sternites of AIII and AIV with similar setae present but often less dense than on the corresponding tergites. Pubescence on tergite of AIV, if present, is long and setiform, elevated, never appressed. In full-face view the sides of the head, from clypeus to posterior corner, with numerous to abundant curved, freely projecting setae present . . . . . 4

• In profile the tergites of AII (petiole), AIII and AIV are not covered with abundant elevated setae that arise over the entire surface of each sclerite; these tergites usually entirely lack setae but sometimes a transverse row is present at the extreme posterior margin. Sternites of AIII and AIV usually with elevated setae present that have no counterparts on the corresponding tergite. Appressed pubescence is usually present on tergite of AIV; may be sparse and inconspicuous but in some is dense and very obvious. In full-face view the sides of the head, from clypeus to posterior corner, either entirely lack projecting setae, or at most curved, nearly appressed pubescence is present . . . . . 8

4

return to couplet #3

• AII (petiole) in dorsal view with posterolateral corners unevenly bluntly rounded to obtusely angulate, without sharply projecting angles, never produced into a projecting blunt triangular tooth on each side. Lateral surface of AII, below the dorsolateral margin and above the level of the spiracle, usually with a longitudinal ridge or carina that extends the length of the sclerite. Frontal carinae converge posteriorly and terminate in front of the level of the anterior margins of the eyes . . . . . 5

• AII (petiole) in dorsal view with posterolateral corners at least forming sharply projecting angles, more usually produced into a projecting triangular tooth on each side. Lateral surface of AII, below the dorsolateral margin and above the level of the spiracle, without a longitudinal ridge or carina that extends the length of the sclerite. Frontal carinae diverge posteriorly and terminate close to or at the level of the anterior margins of the eyes . . . . . 6

5

return to couplet #4

• With head tilted slightly back from full-face view, so that the anterior margin is clearly visible, the lateral portions of the clypeus, immediately in front of the antennal sockets, are narrow, evenly rounded, and do not project farther forward than the midpoint of the clypeus. Propodeal declivity usually with very fine longitudinal striolae that radiate upwards from the foramen in which AII (petiole) is inserted . . . . . Simopone silens

• With head tilted slightly back from full-face view, so that the anterior margin is clearly visible, the lateral portions of the clypeus, immediately in front of the antennal sockets, form prominent broad blunt triangles that project farther forward than the midpoint of the clypeus. Propodeal declivity without longitudinal striolae that radiate upwards from the foramen in which AII (petiole) is inserted . . . . . Simopone rex

6

return to couplet #4

• Normally exposed portions of tergites AV and AVI with abundant small punctures that cover the entire surface. AII (petiole) in dorsal view usually very obviously broader than long, AIIW/AIIL 1.14–1.30 . . . . . Simopone victrix

• Normally exposed portions tergites AV and AVI mostly smooth; scattered larger punctures are present from which setae arise, and the spaces between these have a few widely spaced, extremely minute, punctulae present. AII (petiole) in dorsal view at most only slightly broader than long, AIIW/AIIL 0.95–1.14 . . . . . 7

7

return to couplet #6

• In profile the dorsal outline of the pronotum forms a distinctly domed or humped convexity that is conspicuously differentiated from the remainder of the dorsal mesosoma; highest point of the convexity is markedly anterior to the promesonotal suture. Eye averages slightly smaller, EL/HW 0.31–0.37 . . . . . Simopone dux

• In profile the dorsal outline of the pronotum is shallowly, evenly convex, not domed or humped, so that the line of the pronotal dorsum is more or less continuous with the line of the remainder of the mesosoma. Eye averages slightly larger, EL/HW 0.36–0.42 . . . . . Simopone sicaria

8

return to couplet #3

• Leading edge of scape without projecting setae; apical margin of scape, adjacent to first funicular segment, usually with 1–2 short setae that more or less continue the line of the long axis . . . . . 9

• Leading edge of scape with 1–3 projecting strong setae that are curved or inclined toward the scape apex; apical margin of scape, adjacent to first funicular segment, usually with 1–2 short setae that more or less continue the line of the long axis . . . . . 10

9

return to couplet #8

• In full-face view the midpoint of the anterior clypeal margin, between the frontal lobes, projects forward as a bluntly triangular tubercle, so that the margin is not evenly transverse. Sternite of AIII with conspicuous dense grey pubescence that obscures the surface of the sclerite. Dorsum of head between eyes blanketed by very dense fine longitudinal striolae; shallow punctures are also present that are obviously secondary to the dense striolate sculpture . . . . . Simopone inculta

• In full-face view the midpoint of the anterior clypeal margin, between the frontal lobes, does not project forward as a triangular tubercle, so that the margin is evenly transverse. Sternite of AIII almost devoid of pubescence; what little is present is minute and extremely sparse so that the glossy surface of the sclerite is plainly visible. Dorsum of head between eyes predominantly punctate; surface sculpture between the punctures weak and faint, secondary to the punctate component . . . . . Simopone fera

10

return to couplet #8

• Tergite of AII (petiole) in dorsal view with the posterior corners produced into a bluntly triangular tooth on each side, the tooth directed outwards posterolaterally from the line of the side of the tergite; AII usually distinctly broader than long, AIIW/AIIL 1.05–1.18 . . . . . 11

• Tergite of AII (petiole) in dorsal view with the posterior corners not produced into a bluntly triangular, posterolaterally projecting tooth on each side; AII at most as broad as long, AIIW/AIIL 0.88–1.01 . . . . . 12

11

return to couplet #10

• Lateral surface of AII, below the dorsolateral margin and above the level of the spiracle, with a longitudinal carina that extends the length of the sclerite. Tergite of AII (petiole) carinate between its dorsal and anterior surfaces; the carina takes the form of a low transverse crest that extends across the entire width of the sclerite . . . . . Simopone trita

• Lateral surface of AII, below the dorsolateral margin and above the level of the spiracle, without a longitudinal carina that extends the length of the sclerite. Tergite of AII (petiole) not carinate between its dorsal and anterior surfaces; the two surfaces are separated by a narrowly rounded angle across the entire width but there is no trace of a transverse carina . . . . . Simopone dignita

12

return to couplet #10

• With mesosoma in dorsal view its maximum width is conspicuously across the midlength of the mesonotum. Eyes situated relatively more anteriorly, EP 0.81–0.85. AII relatively long, AIIW/AIIL 0.88–0.89 . . . . . Simopone consimilis

• With mesosoma in dorsal view its maximum width is conspicuously across the midlength of the propodeum. Eyes situated relatively more posteriorly, EP 0.90–1.08. AII relatively short, AIIW/AIIL 0.92–1.01 . . . . . 13

13

return to couplet #12

• Punctate sculpture on pronotal dorsum strikingly more dense than that on mesonotum; the latter, especially medially, with extensive smooth areas . . . . . Simopone merita

• Punctate sculpture on pronotal dorsum about equally as dense as that on mesonotum . . . . . 14

14

return to couplet #13

• Dorsum of propodeum separated from declivity by an angle that extends right across the dorsum, but without a transverse carina. On dorsum of head striolate or reticulate sculpture, between the punctures, is absent or restricted to the area between the frontal carinae and sometimes a small patch immediately above each eye; such sculpture always absent from median area of dorsum between the eyes . . . . . Simopone emeryi

• Dorsum of propodeum separated from declivity by a low transverse carina that is distinct on its lateral thirds but usually interrupted medially. On dorsum of head striolate or reticulate sculpture, between the punctures, occurs between the frontal carinae and across the entire dorsum between the eyes . . . . . Simopone nonnihil