Nesomyrmex humerosus (Emery, 1896)

Sharaf, Mostafa R., Akbar, Shahid Ali, Aldawood, Abdulrahman S. & Garcia, Francisco Hita, 2017, Review of the ant genus Nesomyrmex Wheeler, 1910 (Hymenoptera, Formicidae, Myrmicinae) from the Arabian Peninsula, African Invertebrates 58 (2), pp. 21-37 : 26-28

Nesomyrmex humerosus (Emery, 1896) Figs 2A, B, 5

Leptothorax (Goniothorax) humerosus Emery, 1896: 62 (w.) EAST AFRICA (no locality given, very likely KENYA). [Combination in Nesomyrmex : Bolton 2003: 272. See also: Bolton 1982: 329; Hita Garcia et al. 2017: 8].

Material examined.

KENYA: Coast Province, Malindi, Arabuko Sokoke Forest, -3.321, 39.929, 50 m, coastal dry forest, VI.2009 (F. Hita Garcia & G. Fischer) (FHGC: 3w, 1q).

Diagnosis.

The following character combination distinguishes N. humerosus from the other members of the group in the Arabian Peninsula: anterior clypeal lobe short, flat-margined, and never convex, with small median triangular projection; clypeus without median longitudinal carina; pronotum anterodorsally sharply marginate, with sharp, dentate corners; in profile mesosomal outline conspicuously concave; petiole barrel-shaped with very weakly developed, short and triangular petiolar node.

Worker measurements

(n=3). HL 0.74-0.75; HW 0.70-0.71; SL 0.58-0.59; EL 0.27-0.28; PH 0.34-0.35; PW 0.52-0.53; WL 0.89-0.92; PSL 0.19-0.20; PTL 0.12-0.13; PTH 0.24-0.25; PTW 0.21-0.22; PPL 0.15-0.16; PPH 0.21-0.22; PPW 0.33-0.34; OI 39; SI 83; CI 95; DMI 58; LMI 38; PSLI 26-27; LPeI 50-52; DPeI 169-175; LPpI 71-73; DPpI 213-220; PPI 155-157.

Distribution.

Nesomyrmex humerosus is currently only known to occur in Kenya, Tanzania, and Yemen. Very little is known about the biology of the species. Rarely collected species seems to live on vegetation but has also been sampled from the ground ( Hita Garcia et al. 2017).

Comments.

Nesomyrmex humerosus is the only member of the N. humerosus group and possesses an unusual character combination for an Afrotropical species due to its flat anterior clypeal margin, dentate pronotum, and barrel-shaped petiole. For more details see Hita Garcia et al. (2017). This species has been infrequently collected and is apparently known from four separate collections. More intensive sampling in East Africa and Yemen should yield more material. It is noteworthy that we were not able to examine any material of this species from Yemen and all our knowledge of the species is based on literature ( Collingwood and Agosti 1996, Borowiec 2014).