Stenamma ailaoense

The type worker, the only specimen of this species, was collected in a soil sample from a sub-alpine moist evergreen broadleaf forest.

Identification
Liu & Xu (2011) - This new species is close to Stenamma nipponense but head and scapes comparatively longer, with CI 80 and SI 109; metanotal groove shallowly depressed; propodeal plates broader and roughly trapezoid; propodeal dorsum retirugose; head and body reddish brown.

Distribution
Yunnan Province, China.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 *  ailaoense. Stenamma ailaoense Liu & Xu, 2011: 740, figs. 1-3 (w.) CHINA.

Worker
Holotype worker: HL 1.03, HW 0.83, CI 80, SL 0.90, SI 109, PW 0.60, AL 1.38, ED 0.11, PL 0.60, PH 0.28, PI 46, DPW 0.21. In full face view, head roughly rectangular, longer than broad. Occipital margin straight, occipital corners roundly prominent, lateral sides weakly convex. Anterior margin of clypeus convex, and concave in the middle. Mandibles with 3 distinct apical teeth and followed by 8 indistinct denticles. Antennae long, 12-segmented, scapes surpassing occipital corners by 1/6 of its length, antenna! clubs 5-segmented. Eyes located before the midpoints of lateral sides of head, with 5 ommatidia in the maximum diameter.

In profile view, promesonotum high and convex, nearly arched, the middle portion relatively straight, with trace of promesonotal suture. Metanotal groove wide, but shallowly depressed. Propodeum distinctly lower than promesonotum, dorsum straight and formed a gentle slope. Propodeal spines slender, about 1/2 length of declivity. Declivity straight, about 1/2 length of dorsum. Propodeal plates broad, nearly trapezoidal, slightly shorter than propodeal spines, posterodorsal corner bluntly angled, posteroventral corner rounded. Petiole long, length: height: width = 3: 1.4: 1. Petiolar node low, shorter than anterior peduncle, and roundly prominent at top. Anteroventral corner of petiole weakly convex, anterior 2/5 of ventral face straight, posterior 3/5 depressed. Postpetiole and gaster lost.

Mandibles finely longitudinally striate. Head retirugose, but longitudinally rugose before eyes and between frontal carinae. Median portion of clypeus smooth and shining. Alitrunk retirugoe. Posterior 2/3 of pronotum with posteriorly divergent longitudinal rugae. Lateral sides of mesothorax and propodeum finely retirugose. Metapleuron with 3 coarse longitudinal rugae, interspaces smooth. Petiole with interweaved fine longitudinal rugae, and densely finely punctuate behind petiolar node. Fore coxae transversely rugose, middle and hind coxae finely reticulate.

Dorsa of head and body with sparse erect to suberect hairs and abundant decumbent pubescence. Dorsum of petiolar peduncle without erect hairs. Antennal scapes and hind tibiae with dense decumbent pubescence, but without erect hairs. Head and body reddish brown, appendages yellowish brown, eyes and masticatory margins of mandibles black.

Type Material
Holotype: worker, CHINA: Yunnan Province, Jingdong County, Taizhong Town, Xujiaba, 2500m, collected from a soil sample in the primitive sub-alpine moist evergreen broadleaf forest of Mt. Ailao, 2002. IV. 7, Zheng-Qun CHAI leg., No. A00831.

Etymology
The new species is named after the type locality Mt. Ailao in central Yunnan Province.

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.
 * Liu X., and Z. H. Xu. 2011. Three New Species of the Ant Genus Stenamma (Hymenoptera: Formicidae) from Himalaya and the Hengduan Mountains With a Revised Key to the Known Species of the Palaearctic and Oriental Regions. Sociobiology 58: 733-748.