Tetramorium hector Hita Garcia & Fisher, 2012

Garcia, Francisco Hita & Fisher, Brian L., 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, pp. 1-123 : 93-96

Tetramorium hector Hita Garcia & Fisher sp. n.

(figs 131, 132, 138, 139, 140)

Holotype worker, MADAGASCAR, Toamasina, Montagne d'Anjanaharibe , 19.5 km 27° NNE Ambinanitelo, 15.17833 S, 49.635 E, 1100 m, montane rainforest, sifted litter (leaf mold, rotten wood), collection code BLF8150, 12.–16.III.2003 (B.L. Fisher et al.) ( CASC: CASENT0038460 ) . Paratypes, 14 workers with same data as holotype ( BMNH: CASENT0038428 ; CASC: CASENT0038396 ; CASENT0038399; CASENT0038431; CASENT0038436; CASENT0038438; CASENT0038442; CASENT0038449; CASENT0038451; CASENT0038463; CASENT0038466; MCZ: CASENT0038392 ; MHNG: CASENT0038455 ; NHMB: CASENT0038427 ) ; two workers with same data as holotype except sampled from pitfall trap and collection code BLF8154 ( CASC: CASENT0048692 ; CASENT0048694); and nine workers with same data as holotype except sampled ex rotten stick on ground and collection code BLF8217 ( CASC: CASENT0498042 ; CASENT0498043; CASENT0498044; CASENT0498045; CASENT0498046) .

Diagnosis

The following character combination distinguishes T. hector from the other species of the group: head longer than wide (CI 92–96); petiolar node in profile cuneiform, comparatively thick, and not strongly anteroposteriorly compressed dorsally; mesosomal dorsum completely unsculptured, smooth, and shiny; dark brown to black colouration.

Description

HL 0.69–0.78 (0.74); HW 0.64–0.74 (0.69); SL 0.55–0.60 (0.58); EL 0.15–0.18 (0.16); PH 0.34–0.38 (0.36); PW 0.51–0.56 (0.54); WL 0.86–0.97 (0.91); PSL 0.22–0.27 (0.25); PTL 0.18–0.21 (0.19); PTH 0.29–0.34 (0.31); PTW 0.25–0.29 (0.27); PPL 0.24–0.26 (0.25); PPH 0.29–0.36 (0.31); PPW 0.27–0.32 (0.29); CI 92–96 (94); SI 80–86 (84); OI 22–25 (24); DMI 58–62 (59); LMI 38–41 (39); PSLI 32–36 (34); PeNI 47–53 (50); LPeI 60–66 (63); DPeI 134–147 (140); PpNI 51–57 (54); LPpI 75–85 (81); DPpI 112–124 (117); PPI 100–113 (107) (12 measured).

Head longer than wide (CI 92–96). Anterior clypeal margin with median impression. Frontal carinae weakly developed, ending between posterior eye margin and posterior head margin. Antennal scrobes absent. Antennal scapes of moderate length, not reaching posterior head margin (SI 80–86). Eyes moderate to large (OI 22–25). Mesosomal outline in profile flat, strongly marginate from lateral to dorsal mesosoma; promesonotal suture and metanotal groove absent; mesosoma comparatively high, compact, and stout (LMI 38–41). Propodeal spines long, spinose, and acute (PSLI 32–36); propodeal lobes small and broadly triangular. Petiolar node in profile thickly cuneiform, approximately 1.5 to 1.7 times higher than long (LPeI 60–66), anterior and posterior faces not parallel, anterodorsal margin situated higher than posterodorsal, dorsum distinctly tapering backwards posteriorly; node in dorsal view between 1.3 to 1.5 times wider than long (DPeI 134–147). Postpetiole in profile approximately rounded and weakly anteroposteriorly compressed, approximately 1.2 to 1.3 times higher than long (LPpI 75–85), in dorsal view approximately 1.1 to 1.2 times wider than long (DPpI 112–124). Postpetiole in profile appearing slightly less voluminous than petiolar node, in dorsal view as wide as petiolar node to weakly wider (PPI 100–113). Mandibles mostly unsculptured, smooth, and shining, but usually few rugulae present; clypeus mostly unsculptured, smooth, and shining, few short rugulae or traces of rugulae present; cephalic dorsum between frontal carinae always with one well-developed longitudinal median ruga, often with one or two much shorter and weaker rugulae at each side, median ruga diverging approximately at eye level into two rugae running to posterior clypeal margin, median ruga much shorter than frontal carinae; lateral head only sculptured anteriorly, remainder and ventral head unsculptured. Ground sculpture on head faint to absent. Lateral mesosoma generally completely unsculptured, sometimes weak sculpture present posteriorly; dorsal mesosoma completely unsculptured, smooth, and shiny. Waist segments and gaster unsculptured, smooth, and shiny. All dorsal surfaces of body with comparatively scarce, long, erect pilosity, hairs on mesosomal dorsum not restricted to lateral margins. Body of uniform dark brown to black colour.

Notes

The new species is restricted in its distribution to Ambanizana, Ambohitsitondroina, and Anjanaharibe. All three localities are located in close proximity to each other in the northeast of Madagascar, and they represent montane rainforest or rainforest habitats at elevations of 825 to 1100 m. In addition, T. hector seems to live in leaf litter.

Tetramorium hector is straightforwardly recognisable within the T. marginatum group. It differs conspicuously from T. norvigi and T. shamshir since the latter have a sculptured mesosomal dorsum and a yellowish to brownish colouration, whereas T. hector has a completely unsculptured mesosomal dorsum and very dark brown to black colouration. The remaining three species, T. valky , T. marginatum , and T. silvicola , share the same colour and unsculptured mesosomal dorsum with T. hector , but are not likely to be misidentified with each other. The petiolar node shape of T. hector is thickly cuneiform and much thicker (LPeI 60–66; DPeI 134–147) than in the other three species (LPeI 16–47; DPeI 189–500). In addition, T. hector displays the strongest reduction in cephalic sculpture within the group, which contrasts with the development of this character in T. valky , T. marginatum , and T. silvicola .

Etymology

The new species is named after the noble and heroic Trojan prince " Hector " from Greek mythology mentioned in Homer's epic poem the " Iliad". The species epithet is a noun in apposition, and thus invariant.

Material examined

MADAGASCAR: Toamasina, Ambanizana, Parc National Masoala, 15.57167 S, 50.00611 E, 800–897 m, 26.II.– 2.III.2003 (D. Andriamalala, D. Silva, et al.); Toamasina, Ambanizana, Parc National Masoala, 15.57167 S, 50.00611 E, 900–950 m, 26.II.–6.III.2003 (D. Andriamalala, D. Silva, et al.); Toamasina, Ambohitsitondroina, 6.9 km NE Ambanizana, 15.56667 S, 50 E, 825 m, rainforest, 2.–8.XII.1993 (B.L. Fisher); Toamasina, Montagne d'Anjanaharibe, 19.5 km 27° NNE Ambinanitelo, 15.17833 S, 49.635 E, 1100 m, montane rainforest, 12.- 16.III.2003 (B.L. Fisher et al.).