Tetramorium noeli Hita, 2012

Hita Garcia, F. & B. L. Fisher, 2012, The ant genus Tetramorium Mayr (Hymenoptera: Formicidae) in the Malagasy region - taxonomic revision of the T. kelleri and T. tortuosum species groups., Zootaxa 3592, pp. 1-85 : 61-62

Tetramorium noeli Hita Garcia & Fisher sp. n.

(Figs. 35, 40, 41, 117, 118, 119, 142)

Holotype worker, MADAGASCAR, Antsiranana, Forêt de Binara, 9.1 km 233° SW Daraina, 13.26333 S, 49.60333 E, 800 m, rainforest, sifted litter, (leaf mold, rotten wood), collection code BLF09656, 3.XII.2003 (B.L. Fisher) (CASC: CASENT0043554). Paratypes, nine workers with same data as holotype (BMNH: CASENT0043563; CASC: CASENT0043546; CASENT0043547; CASENT0043549; CASENT0043550; CASENT0043559; CASENT0043571; CASENT0043577; CASENT0043688); and one worker with same data as holotype but collected ex rotten log the 20.XI.2004 and collection code BLF10901 (MCZ: CASENT0053894).

Diagnosis

The following character set distinguishes T. noeli from the remainder of the species group: head distinctly longer than wide (CI 92-95); propodeal spines very long to extremely long (PSLI 38-48); petiolar node rectangular nodiform with the posterodorsal margin situated higher than the anterodorsal margin, and the dorsum convex; postpetiole in lateral view approximately 1.4 to 1.5 times higher than long (LPpI 68-72), and in dorsal view around 1.2 to 1.3 times wider than long (DPpI 119-129).

Description

HL 0.85-1.00 (0.95); HW 0.79-0.94 (0.89); SL 0.64-0.77 (0.72); EL 0.18-0.22 (0.21); PH 0.45-0.55 (0.50); PW 0.65-0.79 (0.71); WL 1.11-1.44 (1.24); PSL 0.33-0.46 (0.41); PTL 0.32-0.39 (0.36); PTH 0.38-0.47 (0.43); PTW 0.26-0.32 (0.30); PPL 0.31-0.35 (0.33); PPH 0.43-0.50 (0.46); PPW 0.37-0.44 (0.41); CI 92-95 (94); SI 79-85 (81); OI 22-24 (23); DMI 55-59 (57); LMI 37-43 (57); PSLI 38-48 (43); PeNI 39-46 (42); LPeI 80-88 (84); DPeI 78-86 (82); PpNI 53-62 (57); LPpI 68-72 (71); DPpI 119-129 (124); PPI 132-145 (137) (15 measured).

Head distinctly longer than wide (CI 92-95); posterior head margin moderately concave. Anterior clypeal margin medially impressed. Frontal carinae strongly developed, diverging posteriorly, and ending at corners of posterior head margin. Antennal scrobes developed, moderately deep, but narrow and without defined posterior and ventral margins. Antennal scapes short to moderate, not reaching posterior head margin (SI 79-85). Eyes of moderate size (OI 22-24). Mesosomal outline in profile weakly convex, moderately marginate from lateral to dorsal mesosoma; promesonotal suture and metanotal groove absent; mesosoma comparatively stout and high (LMI 37-43). Propodeal spines very long, spinose and acute (PSLI 38-48); propodeal lobes well-developed, triangular to elongate-triangular, and acute. Petiolar node in profile rectangular nodiform but comparatively high, approximately 1.1 to 1.3 times higher than long (LPeI 80-88), anterior and posterior faces approximately parallel, posterodorsal margin situated higher than anterodorsal, dorsum convex; node in dorsal view approximately 1.2 to 1.3 times longer than wide (DPeI 78-86). Postpetiole in profile comparatively high and anteroposteriorly compressed, approximately 1.4 to 1.5 times higher than long (LPpI 68-72); in dorsal view around 1.2 to 1.3 times wider than long (DPpI 119-129). Postpetiole in profile noticeably higher and less voluminous than petiolar node, in dorsal view approximately 1.3 to 1.5 times wider than petiolar node (PPI 132-145). Mandibles distinctly longitudinally rugose; clypeus longitudinally rugose, with three to eight rugae, median ruga always present and distinct, remaining rugae variably developed; cephalic dorsum between frontal carinae with 6 to 12 longitudinal rugae, most rugae running unbroken from posterior head margin to anterior clypeus, few rugae interrupted and none with cross-meshes; scrobal area mostly unsculptured; lateral and ventral head longitudinally rugose to reticulate-rugose. Mesosoma laterally and dorsally distinctly longitudinally rugose. Forecoxae unsculptured, smooth, and shining, with weak, superficial ground sculpture. Waist segments strongly and very regularly longitudinally rugose, rugae absent from anterior face, but running unbroken from one side to the other through posterior face. Base of first gastral tergite distinctly costulate, remainder of gaster unsculptured, smooth and shining. Ground sculpture generally faint to absent everywhere on body. All dorsal surfaces of head, mesosoma, waist segments, and gaster with abundant, long, and fine standing hairs; first gastral tergite without appressed pubescence. Anterior edges of antennal scapes suberect to erect hairs. Body a uniform very dark brown to black colour.

Notes

Tetramorium noeli appears to be moderately common in the tropical dry forests and rainforests of the northeastern tip of Madagascar. Currently its distribution extends from Ambanitaza north to Montagne des Français, but it might well occur in other forest localities in northeastern Madagascar not yet explored. The new species appears to be a leaf litter inhabitant on the basis of available collection data.

Within the T. noeli species complex, T. noeli cannot be confused with either T. aherni or T. singletonae since these have a petiolar node shape with the anterodorsal and posterodorsal margins at about the same height, whereas the node of T. noeli has a posterodorsal margin which is situated much higher than the anterodorsal. The fourth species of the complex, T. ambanizana, has a node shape similar to T. noeli, and both species are morphologically very similar. Indeed, as noted in the description of T. ambanizana, it is possible that both are conspecific. However, we treat them as distinct species here, and both differ in the length of the propodeal spines and the shape of the head and postpetiole. In T. noeli the head is distinctly longer than wide (CI 92-95), whereas the head of T. ambanizana is only weakly longer than wide (CI 97-98). Additionally, despite both species having extremely long propodeal spines, this character is better developed in T. ambanizana (PSLI 60-65) than in T. noeli (PSLI 38-48). Also, the postpetiole of the latter species is relatively higher (LPpI 68-75) and broader (DPpI 119-129) than in T. ambanizana (LPpI 77-81; DPpI 104-112).

Etymology

The new species is dedicated to Noel Hita Garcia from Remscheid, Germany.

Material examined

MADAGASCAR: Antsiranana, Forêt Ambanitaza, 26.1 km 347° Antalaha, 14.67933 S, 50.18367 E, 240 m, rainforest, 26.XI.2004 (B.L. Fisher); Antsiranana, Parc National Montagne d'Ambre, 3.6 km 235° SW Joffreville, 12.53444 S, 49.1795 E, 925 m, montane rainforest, 20.-26.I.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Réserve Spéciale de l'Ankarana, 13.6 km 192° SSW Anivorano Nord, 12.86361 S, 49.22583 E, 210 m, tropical dry forest, 16.-21.II.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Forêt de Binara, 9.1 km 233° SW Daraina, 13.26333 S, 49.60333 E, 800 m, rainforest, 3.XII.2003 (B.L. Fisher); Antsiranana, Forêt de Binara, 9.1 km 233° SW Daraina, 13.26333 S, 49.60333 E, 800 m, rainforest, 20.XI.2004 (B.L. Fisher); Antsiranana, Montagne des Français, 7.2 km 142° SE Antsiranana, 12.32278 S, 49.33817 E, 180 m, tropical dry forest, 22.-28.II.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Makirovana forest, 14.1707 S, 49.9541 E, 415 m, rainforest, 28.-29.IV.2011(B.L. Fisher et al.); Antsiranana, Makirovana forest, 14.1651 S, 49.9477 E, 900 m, montane rainforest, 30.IV.-1.V.2011 (B.L. Fisher et al.); Antsiranana, Makirovana forest, 14.16044 S, 49.95216 E, 550 m, rainforest, 1.-2.V.2011 (B.L. Fisher et al.).