Tetramorium mallenseana

Tetramorium mallenseana is only known from the Parc National de Ranomafana and its vicinity, which is a montane rainforest situated at an altitude of 1000 to 1100 m.

Identification
A member of the Tetramorium dysalum-species group

The following character combination distinguishes T. mallenseana from the other species of the group: short antennal scapes (SI 72 - 75); long and curved propodeal spines (PSLI 38 - 43); very short propodeal lobes; petiolar node rounded high nodiform, in dorsal view only slightly wider than long (DPel 110 - 123), petiolar dorsum only weakly tapering backwards posteriorly; postpetiole in dorsal view 1.7 to 2 times wider than petiolar node (PPI 168 - 200); dorsum of mesosoma with longitudinally rugose sculpture. (Hita Garcia and Fisher 2012)

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  mallenseana. Tetramorium mallenseana Hita Garcia & Fisher, 2012: 70, figs. 77, 104-106 (w.) MADAGASCAR.

Worker
HL 0.67 - 0.71 (0.70); HW 0.67 - 0.72 (0.70); SL 0.49 - 0.54 (0.51); EL 0.12 - 0.15 (0.14); PH 0.37 - 0.40 (0.38); PW 0.50 - 0.54 (0.52); WL 0.84 - 0.95 (0.88); PSL 0.27 - 0.29 (0.28); PTL 0.15 - 0.17 (0.16); PTH 0.30 - 0.33 (0.31); PTW 0.17 - 0.20 (0.19); PPL 0.20 - 0.23 (0.22); PPH 0.29 - 0.32 (0.30); PPW 0.29 - 0.38 (0.34); CI 99 - 101 (100); SI 72 - 75 (73); OI 18 - 21 (20); DMI 57 - 61 (59); LMI 42 - 44 (43); PSLI 38 - 43 (40); PeNI 33 - 38 (36); LPeI 48 - 53 (51); DPeI 110 - 123 (117); PpNI 58 - 76 (72); LPpI 66 - 79 (72); DPpI 145 - 165 (156); PPI 168 - 200 (182) (seven measured).

Head as long as wide (CI 99 - 101). Anterior clypeal margin with distinct median impression. Frontal carinae strongly developed, usually ending at posterior head margin. Antennal scrobes narrow and faint. Antennal scapes short, not reaching posterior head margin (SI 72 - 75). Eyes comparatively small (OI 18 - 21). Mesosomal outline in profile comparatively flat, moderately weakly marginate from lateral to dorsal mesosoma, promesonotal suture and metanotal groove absent; mesosoma comparatively stout and compact (LMI 42 - 44). Propodeal spines relatively thin, very long, and back-curved (PSLI 38 - 43). Propodeal lobes weakly developed, very short and triangular. Petiolar node in profile rounded high nodiform, approximately two times higher than long (LPeI 48 - 53), anterior and posterior faces almost parallel, anterodorsal margin situated higher than posterodorsal margin, dorsum weakly tapering backwards posteriorly; node shape in dorsal view only weakly elliptical, almost rounded, only between 1.1 to 1.2 times wider than long (DPeI 110 - 123). Postpetiole in profile rounded, approximately 1.3 to 1.5 times higher than long (LPpI 66 - 79), in dorsal view 1.4 to 1.7 times wider than long (DPpI 145 - 165). Postpetiole in profile a bit more voluminous than petiolar node, in dorsal view much wider than petiolar node, between 1.7 to 2 times wider (PPI 168 - 200). Mandibles distinctly longitudinally rugose, in some specimens unsculptured and smooth or weakly sculptured; clypeus with strong median longitudinal ruga and one often weaker ruga at each side; cephalic dorsum between frontal carinae with six to eight longitudinal rugae running to posterior head margin, some rugae broken or with cross-meshes; lateral and ventral head with weak reticulate-rugose sculpture; head with faint reticulate-punctate to punctate ground sculpture. Mesosoma laterally and dorsally strongly longitudinally rugose, rugae moderately meandering but distinctly longitudinally arranged with few cross-meshes. Petiole and postpetiole almost unsculptured, with few weak rugulae. Gaster unsculptured, smooth and shining. All dorsal surfaces of body with long, erect or suberect pilosity. Head, mesosoma, waist segments dark brown, appendages of lighter brown.

Type Material
Holotype worker, MADAGASCAR, Fianarantsoa, Parc National de Ranomafana, Vatoharanana River, 4.1 km 231° SW Ranomafana, 21.29 S, 47.43333 E, 1100 m, montane rainforest, sifted litter (leaf mold, rotten wood), collection code BLF08400, 21.-31.III.2003 (B.L. Fisher, C. Griswold et al.) (: CASENT0039659). Paratypes, one worker with same data as holotype (CASC: CASENT039656); five workers from Fianarantsoa, 7 km W of Ranomafana, montane rainforest, pitfall trap 1000 m, 23.-28.II.1999 (W.E. Steiner) (: CASENT0247148; CASENT0247157); and six workers from Fianarantsoa, 7 km W of Ranomafana, montane rainforest, pitfall trap 1000 m, 8.-13.III.1999 (W.E. Steiner) (: CASENT0247153; CASENT0247154; CASENT0247155; CASENT0247156).

Etymology
The species epithet is an arbitrary combination of letters, and the new species is dedicated to Sean Allen for his support to discover and identify life on earth.

References based on Global Ant Biodiversity Informatics

 * Garcia H. F. and B. L. Fisher. 2012. The ant genus Tetramorium Mayr (Hymenoptera: Formicidae) in the Malagasy regiontaxonomy of the T. bessonii, T. bonibony, T. dysalum, T. marginatum, T. tsingy, and T. weitzeckeri species groups. Zootaxa 3365: 1-123