Key to Afrotropical Nesomyrmex angulatus group workers

This worker key is modified from: Hita Garcia, F., N. Mbanyana, T.L. Audisco, and G.D. Alpert. 2017. Taxonomy of the ant genus Nesomyrmex Wheeler (Formicidae, Myrmicinae) in the Afrotropical region, with a review of current species groups and description of a new species of the N. angulatus group from Mozambique. European Journal of Taxonomy. 258:1–31. (DOI:10.5852/ejt.2017.258).

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1

• In profile mesosomal dorsum forming a single, uninterrupted flat surface without any trace of metanotal groove; petiolar peduncle short (Fig. 8A) . . . . . 2

• In profile mesosomal dorsum always with conspicuously impressed metanotal groove; petiolar peduncle long (Fig. 8B) . . . . . 3

Fig. 8. Body in profile. A. Nesomyrmex angulatus (Mayr, 1862) (CASENT0922010). B. N. stramineus (Arnold, 1948) (CASENT0922011).

2

return to couplet #1

• Body colour yellow to very light brown (Fig. 9A) . . . . . Nesomyrmex angulatus

• Body colour very dark brown to black (Fig. 9B) . . . . . Nesomyrmex grisoni

Fig. 9. Body in profile. A. Nesomyrmex angulatus (Mayr, 1862) (CASENT0922010). B. N. grisoni (Forel, 1916) (CASENT0908994).

3

return to couplet #1

• First gastral tergite lacking standing hairs except for single transverse row on posterior end of tergite (Fig. 10A) . . . . . Nesomyrmex evelynae

• First gastral tergite with standing hairs evenly distributed throughout (Fig. 10B) . . . . . 4

Fig. 10. Body in profile. A. Nesomyrmex evelynae (Forel, 1916) (CASENT0413068). B. N. denticulatus (Mayr, 1901) (CASENT0908992).

4

return to couplet #3

• Antennal scapes conspicuously longer (SI 95–98); in dorsal view sides of petiolar node straight to weakly rounded, not laterally denticulate (Fig. 11A); dorsum of propodeum without standing hairs (Fig. 11B) . . . . . Nesomyrmex inhaca

• Antennal scapes conspicuously shorter (SI 67–77); in dorsal view petiolar node laterally denticulate (Fig. 11C); dorsum of propodeum with short standing hairs (Fig. 11D) . . . . . 5

Fig. 11. Waist segments in dorsal view and mesosoma in profile. A–B. Nesomyrmex inhaca sp. nov. (CASENT0790016). C. N. denticulatus (Mayr, 1901) (CASENT0914923). D. N. denticulatus (Mayr, 1901) (CASENT0908992).

5

return to couplet #4

• Eyes larger, with 10–12 ommatidia in longest row (Fig. 12A); subpetiolar process with a conspicuous tooth anteriorly, followed by a long cuticular flange running back to the postpetiolar junction (Fig. 12A) . . . . . Nesomyrmex denticulatus

• Eyes smaller, with 7–9 ommatidia in longest row (Fig. 12B); subpetiolar process with or without a conspicuously developed tooth anteriorly, but without a long cuticular flange running back to the postpetiolar junction (Fig. 12B) . . . . . 6

Fig. 12. Head, mesosoma, and waist segments in profile. A. Nesomyrmex denticulatus (Mayr, 1901) (CASENT0914923). B. N. innocens (Forel, 1913) (CASENT0906195).

6

return to couplet #5

• Propodeal spines shorter and thicker, elongate-triangular and only weakly longer than their basal width; in profile petiolar node nodiform, appearing approximately as long as high (Fig. 13A) . . . . . Nesomyrmex innocens

• Propodeal spines longer and thinner, several times longer than their basal width; in profile petiolar node high, rectangular nodiform, appearing around twice as high as long (Fig. 13B) . . . . . Nesomyrmex stramineus

Fig. 13. Mesosoma and waist segments in profile. A. Nesomyrmex innocens (Forel, 1913) (CASENT0908995). B. N. stramineus (Arnold, 1948) (CASENT0922011).