Tetraponera concava

Known from two higher elevation forest collections.

Identification
Xu & Chai (2004) - Close to Tetraponera rufonigra, but median lobe of clypeus broad and shorter, anterior margin distinctly concave. In dorsal view, humeral corners of pronotum bluntly angled and much more than 90°. Scape shorter with Sl 56-57. Propodeum relatively lower with PDI 90-94. Pronotum black in contrast to the orange remainder of alitrunk.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 *  concava. Tetraponera concava Xu & Chai, 2004: 65, figs. 6-10 (w.) CHINA.

Worker
Holotype. TL 9.7, HL 1.90, HW 1.73, CI 91, SL 0.97, SI 56, PW 1.17, AL 2.80, EL 0.60, REL 32, PDH 0.87, MTW 0.97, PDT 90, PL 1.23, PH 0.53, DPW 0.57, PLI 43, PWI 46. Head nearly square and weakly narrowed forwards, slightly longer than broad. In full-face view, occipital margin straight, occipital corners rounded. Anterior half of lateral side slightly concave and posterior half weakly convex. Mandible broad and robust, with 5 teeth on the masticatory margin and 1 denticle on the basal margin. Median lobe of clypeus distinct, broad and shorter, anterior margin concave in the middle, lateral lobelets roundly convex. Apex of scape reached to 3/5 of the distance from antennal socket to occipital corner. Eyes relatively smaller and not reached to lateral sides of head. Vertex with 3 distinct ocelli. In profile view, pronotum moderately convex, lateral margins blunt. Promesonotal suture impressed. Mesonotum flat and slope down backward. Metanotal groove deeply impressed. Anterior end of propodeum raised up, dorsum relatively straight and weakly slope down backward. Posterodorsal corner blunt. Declivity straight and shorter the dorsum. In dorsal view, humeral corners of pronotum bluntly angled and much more than 90°. Dorsum of propodeum relatively flat. In posterior view, pronotum moderately convex, laterodorsal corners bluntly angled. In profile view, petiole with short down-curved peduncle, anteroventral corner with a blunt tooth. Anterior and posterior faces of petiolar node sloped, dorsum long and moderately convex. Postpetiolar node as high as petiolar node.

Mandible with longitudinal rugae. Head and pronotum densely and coarsely punctate, distance between punctures about equal to puncture diameter. Punctures on occipital area sparse, distance between punctures about 2-3 times of the puncture diameter. Interspace appears as microreticulations. Lateral sides of pronotum, mesonotum and dorsum of propodeum densely and finely punctured. Lateral sides of propodeal dorsum with dense large punctures. Metanatal groove with short longitudinal rugae. Mesopleuron, metapleuron, and lateral sides of propodeum densely and longitudinally striate. Declivity and dorsum of petiolar node sparsely and finely punctate. Lateral sides of petiole with sparse large punctures. Postpetiole and gaster relatively smooth. Head, prothorax and mesothorax with sparse erect hairs and dense decumbent pubescences. Propodeum, petiole, postpetiole and gaster with abundant erect hairs and dense decumbent pubescences. Scapes and tibiae with sparse suberect hairs and dense decumbent pubescences. Head, pronotum, procoxae, postpetiole and gaster black. Mesothorax, metathorax, propodeum and petiole orange. Mandibles, scapes, coxae, femora and tibiae blackish brown. Flagella and tarsi yellowish brown.

Paratype. TL 10.2, HL 2.10, HW 1.87, CI 89, SL 1.07, SI 57, PW 1.30, AL 3.07, EL 0.63, REL 30, PDH 1.07, MTW 1.13, PDI 94, PL 1.37, PH 0.67, DPW 0.70, PLI 49, PWI 51 ( 1 individual measured). As holotype, but mandibles reddish brown, scapes and lower half of postpetiole yellowish brown, upper half of postpetiole blackish brown.

Type Material
Holotype. worker, No. A95-53, 1100 m, Tongbiguan Nature Reserve, Tongbiguan Town, Yingjiang County, Yunnan Province, 23 Apr. 1995, collected by Mr. Yang Bi-Lun in a mountain rain forest.

Paratype. Xishuangbanna Nature Reserve, Yunnan Province: 1 worker, No. A98-279, 1600 m, Papo Village, Meng' a Town, Menghai County, 8 Mar. 1998, collected by Mr. HE Yun-Feng in a deciduous broad-leaf forest.

References based on Global Ant Biodiversity Informatics

 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Xu Z. and Z.-Q. Chai. 2004. Systematic study on the ant genus Tetraponera F. Smith (Hymenoptera, Formicidae) of China. Acta Zootaxonomica Sinica 29(1): 63-76.