Stigmatomma crenatum

The type material was found in a semi-evergreen monsoon forest and from a fragment of mountain rain forest.

Identification
Xu (2001) - This new species is close to Stigmatomma rothneyi, but eye much smaller, with only 18 – 19 facets; body smaller with TL 6.7 - 7.3 mm; body in color black with appendages reddish brown. This new species is also close to Stigmatomma quadratum, but head distinctly longer than broad; eye smaller with ED 0.11 - 0.13 mm; body smaller with TL 6.7 - 7.3 mm; body in color black with appendages reddish brown.

Distribution
Yunnan Province, China.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 *  crenatum. Amblyopone crenata Xu, 2001d: 553, figs. 18-20 (w.) CHINA. Combination in Stigmatomma: Yoshimura & Fisher, 2012: 19.

Worker
Holotype worker. TL 7.4, HL 1.53, HW 1.28, CI 84, SL 0.90, SI 71, PW 0.85, AL 2.00, ED 0.11, ML 1.18, DPW 0.78, DPL 0.78, PH 0.83. Head roughly trapezoid, longer than broad, weakly widened forward. Occipital margin weakly concave, occipital corners rounded, Lateral sides weakly convex, anterolateral corner of head with small genal tooth. Mandibles slender, relatively straight, with 2 rows of teeth, the dorsal row with 6 teeth, the ventral row with 5 ones. Anterior margin of clypeus weakly convex, with 12 minute denticles. Median furrow present on the anterior 2/3 dorsum of head. Antennae 12-segmented, apex of scape reached to 3/4 of the distance from antennal socket to occipital corner, segments 4-10 about as broad as long. Eyes relatively large, situated behind the midline of head, each with 19 facets. In profile view, pronotum weakly convex, both promesonotal suture and metanotal groove distinctly notched. Dorsum of propodeum evenly convex, longer than declivity, the latter truncate, posterodorsal corner of propodeum rounded. In profile view, petiolar node roughly trapezoid, narrowed backward, anterior face trpncate and straight, dorsum evenly convex, an terodorsal corner bluntly prominent and close to a right angle, ventral face oblique. Subpetiolar process nearly rectangular, without fenestra, rounded anteriorly, posteroventral corner toothed. In dorsal view, mesothorax strongly constricted, petiolar node nearly square, as broad as long, anterior and lateral borders weakly convex, posterior border straight. Constriction distinct between the 2 basal segments of gaster. Mandibles longitudinally and obliquely striate, with apex smooth. Clypeus longitudinally striate. Head with dense large punctures, dull. Thorax, petiole and first segment of gaster with dense mid-size punctures, less dull. Segments 2-5 of gaster with sparse fine punctures, relatively shining. The whole body surface and appendages with sparse suberect hairs and dense decumbent pubescence. Body in color black. Mandibles, clypeus, antennae, legs and apex of gaster reddish brown.

Paratype workers. TL 6.7-7.3, HL 1.43-1.53, HW 1.25-1.30, CI 85-88, SL 0.90, SI 69-72, PW 0.83-0.85, AL 1.88-2.00, ED 0.13, ML 1.00-1.10, DPW 0.75-0.80, DPL 0.73-0.78. PH 0.78-0.85 (3 individuals measured). As holotype but eye with 18-19 facets, gaster black or brownish black.

Type Material
Deposited in the Insect Collection, Southwest Forestry College, Kun-ming, Yunnan Province, China. Holotype worker, No. A97-1680, 900 m, Manzhuang Village, Mengla County, Yunnan Province, 14.Aug.1997, collected by Mr. HE Yun-Feng in semi-evergreen monsoon forest of Xishuangbanna Nature Reserve in southern Yunnan. Para types: 3 workers, No. A97-3042, 1000 m, Man' gang Village, Menglun Town, Mengla County, Yunnan Province, 9 July 1997, collected by Mr. HU Gang in a fragment of mountain rain forest of Xishuangbanna Nature Reserve.

References based on Global Ant Biodiversity Informatics

 * Fontanilla A. M., A. Nakamura, Z. Xu, M. Cao, R. L. Kitching, Y. Tang, and C. J. Burwell. 2019. Taxonomic and functional ant diversity along tropical, subtropical, and subalpine elevational transects in southwest China. Insects 10, 128; doi:10.3390/insects10050128
 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Xu Z. H. 2001. A systematic study on the ant genus Amblyopone Erichson from China (Hymenoptera: Formicidae). Acta Zootaxonomica Sinica 26: 551-556.
 * Xu Z.-H., and J. J. Chu. 2012. Four New Species of the Amblyoponine Ant Genus Amblyopone (Hymenoptera: Formicidae) from Southwestern China with a Key to the Known Asian Species. Sociobiology 59(4): 1175-1196.
 * Xu Zheng-hui. 2001. A systematic study on the ant genus Amblyopone Erichson from China (Hymenoptera: Formicidae). Acta Zootaxonomica Sinica 26(4): 551-556.
 * Zryanin V. A. 2011. An eco-faunistic review of ants (Hymenoptera: Formicidae). In: Structure and functions of soil communities of a monsoon tropical forest (Cat Tien National Park, southern Vietnam) / A.V. Tiunov (Editor). – M.: KMK Scientific Press. 2011. 277 р.101-124.