Tetramorium salvatum

Tetramorium salvatum was recently found to be common in the Shivalik range of the north-western Himalaya (Bharti and Kumar (2012), reported as T. tonganum).

Identification
A member of the Tetramorium tonganum-species group.

Bolton (1977) - T. salvatum appears to be closely related to Tetramorium difficile of Nepal and Bhutan, but the petiolar peduncle is short, stout and straight in salvatum and the metapleural lobes are rounded, whereas in difficile the peduncle is long, quite slender and downcurved and the metapleural lobes are triangular.

Bharti and Kumar (2012) (reported as T. tonganum) - This species belongs to the Tetramorium tonganum-species group (Bolton 1977) and resembles Tetramorium difficile. It can be distinguished from the latter due to larger size, relatively longer antennal scape, longer legs, broadly rounded pronotal corners and propodeum with long spine.

Distribution based on Regional Taxon Lists
Oriental Region: India.

Nomenclature

 *  salvatum. Tetramorium salvatum Forel, 1902c: 235 (w.) INDIA. See also: Bolton, 1977: 128.

Taxonomic Notes
Note that all records of this species from India reported by Bharti & Kumar (2012) and Bharti et al. (2016) are based on a misidentification in Bharti & Kumar (2012) (Agavekar et al., 2017).

Worker
Bolton (1977) - TL 2.8-2.9, HL 0.64-0.66, HW 0.58-0.60, CI 90-91, SL 0.46, SI 76-79, PW 0.42-0.44, AL 0.70-0.74 (2 measured).

Anterior clypeal margin entire. Frontal carinae extending back beyond the level of the eyes, forming the dorsal margins of shallow but quite broad scrobes. Frontal carinae divergent to level of eyes then roughly parallel, only diverging very slightly. Eyes of moderate size, c. 0.14, about 0.23 x HW. Propodeal spines in profile short and narrow, only slightly longer than the bluntly rounded metapleural lobes. Petiole in profile with a short, stout, straight anterior peduncle. Height of tergal portion of petiole node in profile distinctly greater than the dorsal length of the node, the node itself tending to taper slightly from base to apex. In dorsal view the node of the petiole is slightly broader than long. Dorsum of head with fine longitudinal rugulae which are well spaced out and somewhat irregular; spaces between rugulae with feeble superficial sculpture. Occipital region of head and entire dorsal alitrunk finely reticulate-rugulose. Dorsal surfaces of petiole and postpetiole mostly smooth, with vestigial traces of sculpture in places; gaster smooth and unsculptured. All dorsal surfaces of head and body with numerous elongate fine hairs, but antennal scapes and middle and hind tibiae with only dense, short, decumbent or subdecumbent pubescence, without longer hairs. Colour yellow-brown, the gaster dark brown.

Bharti and Kumar (2012) (reported as T. tonganum) - HL 0.62-0.66, HW 0.56-0.60, SL 0.46-0.48, EL 0.14, WL 0.69-0.75, PW 0.42-0.46, PSL 0.07-0.10, PTL 0.16-0.17, PPL 0.20-0.23, PTW 0.21-0.26, PPW 0.23-0.26, PTH 0.20-0.21, PPH 0.20-0.23, CI 90.32-92.19, OI 23.33-25.00, SI 76.67-85.71, PSLI 11.29-15.63, PeNI 50.00-56.52, LPeI 80.00-85.00, DPeI 131.25-152.94, PpNI 52.27-56.52, LPpI 86.96-115.00, DPpI 100.00-130.00, PPI 100.00-109.52 (7 measured).

Head slightly longer than broad, sides almost straight with rounded posterolateral corners, slightly broader posteriorly than anteriorly; posterior head margin straight with shallow median notch; clypeus convex with steep apical half; anterior margin of clypeus entire without median notch; anterior margin of clypeus with a narrow transverse plate like fringe and having convex anterior margin; mandibles triangular, masticatory margin of mandibles with 7 teeth, large apical and preapical teeth; third tooth slightly smaller than the preapical tooth, fourth tooth smaller than the following teeths; frontal lobes weakly developed and slightly elevated laterally, frontal area distinct; antennal scrobes shallow; eye moderate in size, located laterally and almost at mid-length of head, composed of ca. 38-40 ommatidia; antennae slender, 12-segmented; scape long and just fail to reach posterior head margin; mesosoma longer than head, broader anteriorly than posteriorly, dorsum convex; pro-mesonotal suture and metanotal groove indistinct; propodeal spine longer (PSL 0.07-0.10mm) than propodeal lobes, acute, divergent, directed upwards; propodeal lobes broadly triangular; posterior declivity of propodeum short, concave; petiole with a long peduncle, node subglobular in dorsal view; ventrally petiole downcurved along its length, peduncle with an antero-ventral minute blunt teeth; petiole and postpetiole almost equally broader; gaster oval.

Head longitudinally rugose with few cross-meshes upto vertex, posteriorly reticulate, interrugal space punctured and shiny; frontal carinae more conspicuous than other cephalic sculpture and reaching to posterior head margin; mandibles longitudinally rugulose; clypeus longitudinally rugulose; dorsum and sides of mesosoma reticulate-rugulose; petiolar node with weak rugosity; postpetiole unsculptured; propodeal declivity and gaster smooth and shiny, legs smooth except coxae with punctures. Body yellowish brown while gaster somewhat darker; body covered with suberect abundant hairs of varying length; antennal scapes and hind tibiae with decumbent short pubescence.

Queen
Bharti and Kumar (2012) (reported as T. tonganum) - HL 0.69-0.70, HW 0.64-0.66, SL 0.50-0.52, EL 0.20-0.21, WL 1.00-1.02, PW 0.64-0.66, PSL 0.12-0.13, PTL 0.16-0.17, PPL 0.27-0.28, PTW 0.31-0.32, PPW 0.31-0.32, PTH 0.27, PPH 0.27-0.28, CI 92.75-94.29, OI 30.77-31.82, SI 78.13-80.00, PSLI 17.14-18.84, PeNI 48.44-48.48, LPeI 59.26-62.96, DPeI 182.35-193.75, PpNI 48.44-50.00, LPpI 96.43-103.70, DPpI 114.29-114.81, PPI 100-103.23 (3 measured).

Similar to the worker in structure, sculpture and pilosity except the following characters (besides characters related to wings ): eyes large in size and with ca.10-12 ommatidia in a series along its maximum length, head with three ocelli, dorsum of mesosoma flat, propodeal spines slightly longer, petiolar node transverse, broad, pronotum reticulate; mesoscutum, mesoscutellum, anepisternum and sides of propodeum longitudinally rugulose; katepisternum smooth, base of propodeum transversally rugulose; petiolar node rugo-reticulate; postpetiole smooth with traces of sculpture on sides, coxae with faint transverse rugulae.

Male
Bharti and Kumar (2012) (reported as T. tonganum) - HL 0.55-0.56, HW 0.52-0.53, SL 0.27-0.30, EL 0.28-0.31, WL 1.07-1.12, PW 0.69-0.74, PTL 0.16-0.19, PPL 0.25-0.27, PTW 0.24-0.27, PPW 0.25-0.28, PTH 0.20-0.21, PPH 0.23-0.27, CI 92.86-94.64, OI 53.85-59.62, SI 51.92-56.60, PeNI 34.78-36.99, LPeI 80.00-95.00, DPeI 142.11-158.82, PpNI 36.23-38.36, LPpI 100.00-117.39, DPpI 92.59-112.00, PPI 103.70-104.17 (3 measured).

Head slightly longer than broad, sides convex, posterior head margin straight or weakly convex, with three ocelli; mandibles with well developed 6 pointed teeth; apical tooth large followed by 5 short teeth; clypeus convex and its anterior margin entire, convex with a narrow transverse plate like fringe and not impressed medially; frontal lobes reduced; antennae 9-segmented; scape short and not reach to posterior head margin and almost 0.5x times head length; apical segment longer and more than twice of preapical segment; second flagellar segment longer than scape (0.34mm); antennal scrobes absent; eyes large, convex, situated laterally and more towards lower half of head; pronotum broader than head with rounded anterior lateral angles; mesoscutum convex and mesoscutellum flat; propodeal dorsal face flat and oblique with vertical declivitous part; propodeal spines absent; propodeal lobes almost rounded; petiole longer, almost 1.4 × times its width, petiolar node subglobular and medially sulcate shallowly; Postpetiole slightly broader than long; gaster convex, broadly oval; longer legs.

Head and clypeus longitudinally rugulose and spaces between them punctured; mandibles smooth with traces of sculpture, frontal carinae continued to the each side of anterior ocellus; dorsum and sides of mesosoma mostly smooth with traces of sculpture and shiny except propodeum; propodeum finely longitudinally rugulose and punctured; node of petiole longitudinally rugulose except median sulcate region; postpetiole, gaster and legs smooth and shiny; wings transparent.

Body yellowish brown except 1st gastral tergite brownish and area between ocelli blackish; body covered with short and long suberect pilosity.

Type Material
Bolton (1977) - Syntype workers, India: 'Inde septentrionale' (Wroughton) and 'Nord-ouest de l'Himalaya' (Smithies) [examined].