Tetramorium tonganum

A widely ranging species. Tetramorium tonganum was recently found to be common in the Shivalik range of the north-western Himalaya, representing a new record for India.

Identification
Bharti and Kumar (2012) - This species belongs to the 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
Australasian Region: New Caledonia. Indo-Australian Region: Borneo, Cook Islands, Fiji, French Polynesia, Guam, Marshall Islands, Micronesia (Federated States of), New Guinea, Niue, Palau, Philippines, Samoa, Solomon Islands, Tokelau, Tonga, Vanuatu, Wallis and Futuna Islands. Oriental Region: India, Sri Lanka. Palaearctic Region: China, Japan.

Nomenclature

 *  tonganum. Tetramorium tonganum Mayr, 1870b: 976 (w.) TONGA. Santschi, 1928a: 50 (q.); Bharti & Kumar, 2012b: 23 (m.). Senior synonym of magitae: Bolton, 1977: 129.
 * magitae. Tetramorium magitae Forel, 1911i: 224 (w.) SRI LANKA. [Misspelled as mayitae in original.] Junior synonym of tonganum: Bolton, 1977: 129.

Worker
Bharti and Kumar (2012) - 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) - 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) - 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.