Tetramorium philippwagneri

Identification
The following character set distinguishes Tetramorium philippwagneri from other species of the species complex: small eyes (OI 21 - 22); mandibles longitudinally rugose; all dorsal surfaces with simple long, erect to suberect hairs; distinctly bicoloured with dark brown to black gaster contrasting with the orange-brown head, mesosoma, petiole, and postpetiole.

Distribution
Known from Cameroon, Gabon, and Zambia.

This taxon was described from Zambia. It is also found in Tanzania.

Nomenclature

 *  philippwagneri. Tetramorium philippwagneri Hita Garcia, Fischer & Peters, 2010b: 28, figs. 19B, 20B, 22A, 31-33 (w.) ZAMBIA.

It mey be that Tetramorium philippwagneri is conspecific with Tetramorium schoutedeni. Both are morphologically very close and the main separating character is the mandibular sculpturation which is smooth and shiny in T. schoutedeni and finely to strongly longitudinally rugose in T. philippwagneri. Another difference is the length of the hairs on the cephalic and mesosomal dorsum that seem to be longer in all examined T. philippwagneri specimens that in the holotype of T. schoutedeni. Yet this is considered a weak diagnostic difference since hair length can vary to the observed degree in one and the same species. A third argument is the measured variation in antennal scape length because it is shorter in T. schoutedeni (SI 75) than in all examined T. philippwagneri specimens (SI 78 - 83) but, as noted in the description T. schoutedeni, this should be treated with caution, too. The last difference to mention is that the frontal carinae of T. philippwagneri are much more sinuate than in T. schoutedeni.

Taking into account that in the species group the mandibular sculpturation is generally stable at species level, in combination with the above mentioned arguments, the species status of T. philippwagneri seems to be justified at present. However, T. schoutedeni in only known from its type locality in Western D.R. Congo while T. philippwagneri occurs in Northern Zambia, Cameroon, and Gabon. So, at present, if one considers both as different species it seems that they occur in allopatry, and more material from the interconnecting areas is necessary to clarify the relationship of both species.

Another species morphologically very close to T. philippwagneri and T. schoutedeni is Tetramorium pinnipilum. It shares most characters with the first two mentioned, especially the small eyes, distinct coloration, shape and sculpturation of both waist segments, but differs in its pinnate, pectinate pilosity. The simple pilosity of T. philippwagneri separates it also from Tetramorium rogatum and Tetramorium zonacaciae that show strongly modified bizarre pilosity, too, and also from Tetramorium mkomazi which has no standing hairs on mesosoma, petiole, postpetiole, and gaster. Furthermore, T. philippwagneri (SI 78 - 83) can be well distinguished from Tetramorium rubrum (SI 85 - 93) through the length of the antennal scape that is much longer in the latter. The last two species in the complex, Tetramorium edouardi (OI 26 - 29) and Tetramorium robertsoni (OI 25 - 27), possess larger eyes than T. philippwagneri (OI 20 - 22), and in addition, they are uniformly coloured.

Worker
HL 0.739 - 0.883 (0.838); HW 0.722 - 0.867 (0.820); SL 0.578 - 0.694 (0.654); EL 0.156 - 0.194 (0.178); PW 0.528 - 0.611 (0.585); WL 0.889 - 1.111 (1.035); PSL 0.222 - 0.300 (0.267); PTL 0.178 - 0.239 (0.211); PTH 0.311 - 0.367 (0.344); PTW 0.256 - 0.294 (0.276); PPL 0.217 - 0.267 (0.238); PPH 0.300 - 0.361 (0.336); PPW 0.300 - 0.356 (0.338); CI 95 - 100 (98); SI 78 - 83 (80); OI 21 - 22 (22); PSLI 29 - 35 (32); PeNI 44 - 53 (47); LPeI 55 - 67 (61); DPeI 121 - 144 (131); PpNI 56 - 64 (58); LPpI 63 - 79 (71); DPpI 129 - 155 (143); PPI 115 - 129 (123) (25 measured).

Head slightly longer than wide to as long as wide (CI 95 - 100), posterior margin of head deeply and broadly concave. Anterior clypeal margin with distinct median impression. Frontal carinae well developed, becoming weaker behind eye level, fading out shortly before posterior margin of head. Antennal scrobe shallow and without defined posterior and ventral margins. Antennal scape of medium length, not reaching posterior margin of head (SI 78 - 83). Eyes relatively small (OI 21 - 22), with 8 to 9 ommatidia in longest row. In profile metanotal groove weakly impressed. Propodeal spines long, spinose, and acute (PSLI 29 - 35). Propodeal lobes small and triangular. Petiolar node high nodiform, in dorsal view around 1.2 to1.4 times wider than long (DPeI 121 - 144), in profile around 1.5 to 1.8 times higher than long (LPeI 55 - 67). Postpetiole in dorsal view between 1.3 and 1.5 times wider than long (DPpI 129 - 155); in lateral view weakly antero-posteriorly compressed, around 1.3 to 1.6 times higher than long (LPpI 63 - 79). Mandibles distinctly longitudinally rugose. Clypeus with 3 to 5 longitudinal rugae, median ruga often developed, lateral rugae sometimes irregularly shaped. Head mostly longitudinally rugose with 8 to10 widely spaced rugae between frontal carinae, most running unbroken to posterior margin of head, few cross-meshes near posterior head margin. Cephalic ground sculpturation finely punctulate, relatively shiny. Mesosoma irregularly longitudinally rugose, spaces between rugae and propodeal declivity mostly unsculptured and shiny. Petiole and postpetiole with few longitudinal rugae, but generally smooth and shiny. Gaster unsculptured, smooth and shiny. All dorsal surfaces with numerous, long, suberect to erect simple hairs. Fine pubescence on tibiae and antennal scapes appressed to decumbent. Head, mesosoma, petiole, and postpetiole orange-brown, gaster very dark brown to black.

Type Material
Holotype worker, ZAMBIA, North Western Province, Ikelenge, Hillwood Farm, 11° 14'57.45 N, 24° 18' 50.82 E, 1392m, hand collected, VIII.2008, leg. Philipp Wagner (ZFMK: ZFMK_HYM_2009_6178). Paratypes, 14 workers with same data as holotype (BMNH: 2 workers ZFMK_HYM_2009_6183, ZFMK_HYM_2009_6184; CASC: 1 worker ZFMK_HYM_2009_6105; FMNH: 1 worker ZFMK_HYM_2009_6107; MHNG: 3 workers ZFMK_HYM_2009_6179, ZFMK_HYM_2009_6180, ZFMK_HYM_2009_6181; NHMB: 1 worker ZFMK_HYM_2009_6106; NMK: 1 worker ZFMK_HYM_2009_6182; SAMC: 1 worker ZFMK_HYM_2009_6108; ZFMK: 4 workers ZFMK_HYM_2009_6109, ZFMK_HYM_2009_6110, ZFMK_HYM_2009_6111, ZFMK_HYM_2009_6112).

Etymology
The new species is dedicated to Philipp Wagner from Bonn for his assistance in sampling and providing ants from several Afrotropical localities.