Tetramorium snellingi

Identification
The triangular propodeal spines of medium size (PSLI 17 - 22), the presence of standing hairs on the first gastral tergite, and the characteristic bicoloration (with petiole, postpetiole, and gaster very dark brown to black contrasting with the orange or reddish brown head and mesosoma) make Tetramorium snellingi readily identifiable within the species complex.

Distribution
Ranges from Kakamega in Western Kenya through the Ruwenzori Mountains in Western Uganda to the Central African Republic.

Known from Central African Republic, Kenya and Uganda.

This taxon was described from Kenya.

Nomenclature

 *  snellingi. Tetramorium snellingi Hita Garcia, Fischer & Peters, 2010a: 142, figs. 1-6 (w.q.) KENYA. See also: Hita Garcia, Fischer & Peters, 2010b: 80.

Tetramorium snellingi is morphologically very much linked to Tetramorium boltoni, Tetramorium renae, and Tetramorium weitzeckeri while its presence of standing hairs on the first gastral tergite separates it clearly from Tetramorium bendai, Tetramorium humbloti, Tetramorium sepultum, and Tetramorium tanaense, and the absence of conspicuous cephalic ground sculpturation from Tetramorium guineense. The typical coloration of T. snellingi makes it easily separable from T. boltoni and T. weitzeckeri but apart from this they also differ in the length of antennal scapes and propodeal spines. Yet, T. renae is also generally bicoloured but both are difficult to confuse since in T. renae it is the pale yellowish brown gaster, and to a lesser degree the head, too, that are of much lighter colour than the reddish brown mesosoma.

Worker
HL 0.622 - 0.667 (0.646); HW 0.578 - 0.619 (0.604); SL 0.422 - 0.444 (0.436); EL 0.122 - 0.150 (0.137); PW 0.433 - 0.467 (0.448); WL 0.667 - 0.733 (0.711); PSL 0.111 - 0.139 (0.129); PTL 0.089 - 0.111 (0.100); PTH 0.256 - 0.278 (0.265); PTW 0.233 - 0.256 (0.242); PPL 0.156 - 0.183 (0.168); PPH 0.250 - 0.278 (0.265); PPW 0.267 - 0.300 (0.287); CI 91 - 96 (94); SI 70 - 75 (72); OI 21 - 24 (23); PSLI 17 - 22 (20); PeNI 51 - 58 (54); LPeI 34 - 43 (38); DPeI 220 - 265 (243); PpNI 58 - 68 (64); LPpI 56 - 70 (64); DPpI 161 - 179 (170); PPI 109 - 124 (118) (32 measured).

Head slightly longer than wide (CI 90 - 96). Anterior clypeal margin with shallow, but distinct median concave impression. Frontal carinae strongly developed, becoming weaker behind eye level and ending shortly before posterior margin of head. Antennal scrobe narrow, shallow, and without defined ventral margin, ending before posterior margin of head. Antennal scape not reaching posterior margin of head, short to medium-sized (SI 70 - 75). Eyes relatively small to medium sized (OI 21 - 24), with 7 ommatidia in longest row. In profile metanotal groove weakly impressed. Propodeal spines of medium size (PSLI 17 - 22), elongate-triangular with broad base and acute apex. Propodeal lobes small, triangular and acute. Petiolar node strongly squamiform, in dorsal view more than 2 times wider than long (DPeI 220 - 264) and in profile between 2.3 to 3 times higher than long (LPeI 34 - 43). Postpetiole in dorsal view between 1.5 to 2 times wider than long (DPpI 161 - 179) and much more voluminous than petiole; in lateral view weakly to moderately squamiform and thicker compared to petiole, only slightly antero-posteriorly compressed, between 1.4 to 1.8 times higher than long (LPpI 56 - 69). Mandibles distinctly longitudinally striate. Clypeus usually with 3 to 5 longitudinal rugae, median ruga always strongly developed and unbroken, while lateral rugae variable. Clypeus usually with 3, sometimes 5, longitudinal rugae; median ruga always strongly developed and unbroken, while lateral rugae variable. Cephalic dorsum and lateral part of head ventral to scrobe longitudinally rugose with widely spaced rugae, usually with 8 to 10 longitudinal rugae between frontal carinae, almost all running unbroken to posterior margin of head. Spaces between rugae with very weak, nearly effaced ground sculpture or completely unsculptured, generally smooth and shiny. Scrobal area with reduced punctate ground sculpture or completely unsculptured. Mesosoma dorsally and laterally with distinct, mostly longitudinal, widely spaced rugae. Spaces between them and propodeal declivity unsculptured, smooth and shiny. Petiole, postpetiole and gaster completely unsculptured, smooth and shiny. All dorsal surfaces of head, mesosoma, both waist segments and gaster with abundant, long, fine, and simple suberect to erect hairs. Fine pubescence on tibiae appressed, on antennal scapes appressed to decumbent. Head and mesosoma orange to reddish brown with paler, more yellowish legs, contrasting with dark brown to blackish petiole, postpetiole and gaster.

Type Material
Holotype worker, KENYA: Western Province, Kakamega Forest, Salazar, 00° 19' 36 N, 34° 52' 14.6 E, 1650 m, Transect 6, Kakamega survey 2007, primary rain forest, leaf litter, pitfall trap, 17.VIII.2007, leg. M. Peters (: ZFMK_HYM_2009_3105) [examined]. Paratypes, 35 workers and 2 queens from several sub-localities of the Kakamega forest (: 4 workers CASENT0217052, CASENT0217055, CASENT0217056, CASENT0217057; : 4 workers ZFMK_HYM_2009_6186, ZFMK_HYM_2009_6187, ZFMK_HYM_2009_6188, ZFMK_HYM_2009_6189; : 4 workers; MHNG: 4 workers; NMK: 4 workers; ZFMK: 15 workers and 2 queens ZFMK_HYM_2009_3003, ZFMK_HYM_2009_3089, ZFMK_HYM_2009_3090, ZFMK_HYM_2009_3091, ZFMK_HYM_2009_3092, ZFMK_HYM_2009_3093, ZFMK_HYM_2009_3094, ZFMK_HYM_2009_3095, ZFMK_HYM_2009_3096, ZFMK_HYM_2009_3097, ZFMK_HYM_2009_3098, ZFMK_HYM_2009_3099, ZFMK_HYM_2009_3100, ZFMK_HYM_2009_3101, ZFMK_HYM_2009_3103, ZFMK_HYM_2009_3104, ZFMK_HYM_2009_6174) [examined].