Stigmatomma meilianum

The type worker, the only known specimen, was found in a high elevation (3200+ m) conifer-broad leaf mixed forest.

Identification
Xu & Chu (2012) - This new species is close to Stigmatomma trilobum but in full-face view, occipital margin widely weakly concave, occipital corners more prominent; lateral sides of head nearly straight; eyes present, each with 5 facets; in profile view, subpetiolar process roughly triangular.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 *  meilianum. Amblyopone meiliana Xu & Chu, 2012: 1190, figs. 33-35 (w.) CHINA. Combination in Stigmatomma: Yoshimura & Fisher, 2014: 15.

Worker
Holotype: TL 4.9, HL 1.10, HW 0.95, CI 86, SL 0.63, SI 66, ED 0.05, ML 0.78, PW 0.63, AL 1.50, PL 0.53, PH 0.60, DPW 0.60, LPI 114, DPI 100.

In full-face view, head roughly trapezoidal, widened forward and longer than broad. Occipital margin widely weakly concave, occipital corners rounded. Lateral sides nearly straight, anterolateral corners acutely toothed. Mandibles elongate, masticatory margin about as long as inner margin, with a long apical tooth, a short subapical tooth, and 3 pairs of curved teeth; inner margin with a pair of curved teeth, a short subbasal tooth, and a large basal tooth. Anterior clypeal margin roundly convex, with a broad middle lobe, a narrow lobe on each side, and a simple tooth between the middle and lateral lobes; the broad middle lobe with 4 denticles at apex, the lateral lobes slightly bifid at apices. Antennae short, 12-segmented; apices of scapes reached to 2/3 of the distance from antennal sockets to occipital corners; funiculi incrassate toward apex. Eyes small, each with 5 facets, and located well behind the midpoints of the lateral sides of head.

In profile view, posterior 2/3 of pronotum nearly straight, mesonotum short and convex. Promesonotal suture distinctly notched, metanotal groove weakly depressed. Propodeal dorsum straight, about 1.5 times as long as declivity, posterodorsal corner rounded, declivity nearly straight. Petiole roughly trapezoidal, dorsal and anterior faces nearly straight, anterodorsal corner rounded; ventral face oblique and weakly concave. Subpetiolar process nearly triangular, with a large circular sub-transparent fenestra, anterior face rounded, ventral face straight, posteroventral corner rightly angled.

In dorsal view, mesothorax constricted. Propodeum widened backward. Petiole slightly broader than long, width : length = 1.1:1, anterior and lateral sides weakly convex.

Mandibles and clypeus longitudinally striate. Head densely punctured, interfaces appear as micro-reticulations. Dorsal face of alitrunk densely punctured, the longitudinal middle strip on pronotum and propodeum smooth and shining. Lateral sides of pronotum transversely striate. Lateral sides of mesothorax, metathorax, and propodeum longitudinally striate. Declivity nearly smooth. Dorsal faces of petiole and gaster smooth, lateral sides of petiole finely reticulate, lateral sides of gaster finely punctured. Dorsal surfaces of head and body with sparse suberect short hairs and dense decumbent pubescence. Scapes and tibiae with sparse suberect hairs and dense decumbent pubescence. Color reddish brown. Eyes blackish. Legs yellowish brown.

Type Material
Holotype: worker, China: Yunnan Province, Deqin County, Yunling Town, Mingyong Village, 3250m, 2004.X.10, collected from a ground sample in the conifer-broad leaf mixed forest on the east slope of the Snow Mt. Meili, Sheng-Li Shi leg., No. A04-536.

Etymology
The new species is named after the type locality “Snow Mt. Meili”, the highest mountain in Yunnan Province.

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
 * 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.