Tetramorium guineense

Very common and abundant species in the rain forests of West and Central Africa.

Identification
The distinctive cephalic reticulate-punctate ground sculpturation and the presence of standing hairs on the first gastral tergite make Tetramorium guineense easily distinguishable from other members of the species complex.

A member of the Afrotropical weitzeckeri species complex, which is part of the weitzeckeri species group.

Key to weitzeckeri-group species.

Distribution
This taxon was described from Guinea. It is also found in Ivory Coast, Liberia, Senegal, New Guinea, Canada and Pitcairn. Cameroon, Central African Republic, Democratic Republic of Congo, Gabon, Ghana, Nigeria

Nomenclature

 *  guineense. Xiphomyrmex weitzeckeri r. guineensis Bernard, 1953b: 251, fig. 14 (w.) GUINEA. Combination in Tetramorium: Bolton, 1980: 227. Raised to species: Bolton, 1980: 227. See also: Hita Garcia, Fischer & Peters, 2010b: 70.

Worker
Hita Garcia et al. (2010) - HL 0.656 - 0.856 (0.765); HW 0.644 - 0.833 (0.747); SL 0.556 - 0.700 (0.626); EL 0.122 - 0.178 (0.147); PW 0.478 - 0.611 (0.548); WL 0.800 - 1.089 (0.934); PSL 0.189 - 0.367 (0.275); PTL 0.083 - 0.117 (0.103); PTH 0.267 - 0.400 (0.330); PTW 0.217 - 0.289 (0.247); PPL 0.200 - 0.244 (0.220); PPH 0.267 - 0.389 (0.324); PPW 0.289 - 0.372 (0.325); CI 94 - 100 (98); SI 80 - 89 (84); OI 16 - 23(20); PSLI 28 - 42 (36); PeNI 41 - 49 (45); LPeI 27 - 36 (32); DPeI 220 - 263 (240); PpNI 54 - 65 (59); LPpI 59 - 75 (68); DPpI 137 - 154(147); PPI 122 - 145 (131) (22 measured).

Head slightly longer than wide, sometimes as long as wide (CI 94 - 100). Anterior clypeal margin with distinct median impression, small in some individuals but always present. Frontal carinae strongly developed, becoming weaker behind eye level, but often reaching posterior margin of head. Antennal scrobe narrow, shallow, and without differentiated ventral margin, ending before posterior margin of head. Antennal scape moderate to relatively large, but never reaching posterior margin of head (SI 80 - 89). Eyes very variable in size, from small to moderate (OI 16 - 23), with 8 to 11 ommatidia in longest row. In lateral view metanotal groove weakly impressed. Propodeal spines usually very long and spinose (PSLI 28 - 42). Propodeal lobes small, elongate-triangular and acute. Node of petiole strongly squamiform, in dorsal view 2 to 3 times wider than long (DPeI 220 - 263), in lateral view around 2.7 to 3.6 times higher than long (LPeI 27 - 36). Postpetiole in dorsal view 1 to 1.5 times wider than long (DPpI 137 - 154), much more voluminous and around 1.2 to 1.4 times wider than petiolar node (PPI 121 - 145). In profile postpetiole antero-posteriorly compressed, and much thicker than petiolar node, around 1.3 to 1.6 times higher than long (LPpI 59 - 75). Mandibles distinctly longitudinally striate. Clypeus rugose, mostly longitudinally; median ruga strongly developed. Head longitudinally rugose with widely spaced rugae, dorsum of head with 8 to 11 longitudinal rugae between frontal carinae, almost all running unbroken to posterior margin of head. Spaces between dorsal rugae and scrobal area with very strong and dense reticulate-punctate ground sculpture. Mesosoma dorsally and laterally with distinct, mostly longitudinal, widely spaced rugae. Spaces between them and propodeal declivity unsculptured, smooth and shiny, contrasting strongly with reticulate-punctate ground sculpture on dorsum of head. Petiole, postpetiole and gaster completely unsculptured, smooth and shiny. All dorsal surfaces of head, mesosoma, petiole, postpetiole, and gaster with abundant, long, fine, and simple suberect to erect hairs. Fine pubescence on tibiae appressed, on antennal scapes appressed to decumbent. Body colour ranging from light, reddish brown to dark brown, gaster sometimes darker.

Type Material
Hita Garcia et al. (2010) - Lectotype worker, GUINEA, Foret de Nion, no. 22, 700 m, 15/4, leg. Lamotte [examined].

Additional References

 * Hita Garcia, F., Fischer, G. & Peters, M.K. 2010. Taxonomy of the Tetramorium weitzeckeri species group (Hymenoptera: Formicidae) in the Afrotropical zoogeographical region. Zootaxa 2704, 1-90.