Tetramorium barbigerum Bolton, 1980

Mbanyana, Nokuthula, Garcia, Francisco Hita, Robertson, Hamish Gibson & Roux, Johannes Jacobus Le, 2018, A taxonomic revision of seed harvester ants of the Tetramorium solidum group (Hymenoptera: Formicidae) in southern Africa, European Journal of Taxonomy 454, pp. 1-59 : 13

Tetramorium barbigerum Bolton, 1980

Figs 3J , 6

Tetramorium barbigerum Bolton, 1980: 243 .

Diagnosis

Tetramorium barbigerum is easily distinguished from all species of the T. solidum group by its head shape, which is narrower in front of the eyes than behind ( Fig. 3J ). Morphologically, this species is similar to T. jordani and T. signatum in that they are all black in colour and lack erect hairs on the mesosoma, but the sculpture in T. signatum is much stronger developed compared to T. jordani and T. barbigerum . Tetramorium barbigerum and T. jordani have a feeble cephalic sculpture, fading out at the level of the eyes and replaced by a fine superficial punctation ( Figs 6C , 14C ). These two species can be easily distinguished from each other by the lack of propodeal spines/teeth in T. jordani (PSLI 1–2) ( Fig. 3G ) and the presence thereof in T. barbigerum (PSLI 7–8) ( Fig. 6A ).

Material examined

Holotype

NAMIBIA: worker, 10 mi. (16 km) W of Okombahe, 920 m a.s.l., 10 May 1958, R.E. Ross and R.E. Leech leg. ( CASC: CASTYPE13386 ).

Paratypes

NAMIBIA: 17 pinned workers, same data as holotype ( CASC: CASENT0270787 to CASENT0270792 ); 3 pinned workers, same data as holotype ( BMNH).

Measurements (workers N = 6)

HL 1.214 –1.266 (1.244); HW 1.201 –1.240 (1.223) SL 0.827 –0.891 (0.857); EL 0.297 –0.323 (0.308); PH 0.570 –0.590 (0.583); PW 0.747 –0.806 (0.775); WL 1.227 –1.356 (1.294); PSL 0.089 –0.098 (0.093); PTH 0.354 –0.374 (0.363); PTL 0.354 –0.384 (0.370); PTW 0.364 –0.384 (0.375); PPH 0.517 –0.568 (0.536); PPL 0.295 –0.403 (0.362); PPW 0.443 –0.472 (0.462); OI 24–26 (25); CI 95–101 (98); SI 67–72 (70); DMI 56–62 (60); LMI 42–49 (45); PSLI 7–8 (8); PeNI 46–50 (48); LPeI 95–108 (102) DPeI 108–132 (101); PpNI 58–62 (60); LPpI 57–76 (68); DPpI 117–153 (129); PPI 118–127 (123).

Distribution

Only known from the type locality, Okombahe in Namibia.

Figures

Fig. 3. A–B. Waist segments and gaster oblique lateral view. A. T. setuliferum Emery, 1895 (MCZ_ ENT00512567). B. T. clunum Forel, 1913 (CASENT0764600). C–F. Waist segments in dorsal view. C. T. grandinode Santschi, 1913 (CASENT0764655). D. T. lerouxi Mbanyana, Robertson & Hita Garcia sp. nov. (SAM-HYM-C023329). E. T. signatum Emery, 1895 (SAM-HYM-C020573). F. T. glabratum Stitz, 1923 (SAM-HYM-C024395). G–I. Mesosoma in profile. G. T. jordani Santschi, 1937 (CASENT0248475). H. T. glabratum (SAM-HYM-C024395). I. T. rufescens Stitz, 1923 (CASENT0250852). J–M. Head in full-face view. J. T. barbigerum Bolton, 1980 (CASENT0901181). K. T. pogonion Bolton, 1980 (CASTYPE13390 – Antweb, photographer unknown). L. T. glabratum (SAM-HYM-C024395). M. T. rufescens (CASENT0250852). N–P. Waist segments in profile. N. T. duncani Mbanyana, Robertson & Hita Garcia sp. nov. (SAM-HYM-C027003). O. T. glabratum (SAM-HYM-C024395). P. T. rufescens (CASENT0250852).

Fig. 6. Tetramorium barbigerum Bolton, 1980 (CASTYPE13386 – Antweb, photographer unknown). A. Body in profile. B. Body in dorsal view. C. Head in full-face view.

Fig. 14. Tetramorium jordani Santschi, 1937 (CASENT0248475). A. Body in profile. B. Body in dorsal view. C. Head in full-face view.