Discothyrea diana

This species has only been collected from closed forest in southern Yunnan (Mengla and Hekou Counties) at elevations of around 700 and 1200 meters above sea level. (Xu et al. 2014)

Identification
Xu et al. (2014) - Close to Discothyrea stumperi and Discothyrea yueshen but in full-face view, posterior margin of head weakly concave medially; in dorsal view, dorsum of petiolar node transversely depressed; in lateral view, subpetiolar process large and roughly triangular; antennae 7-segmented.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Castes
Known only from the worker caste.

Nomenclature

 *  diana. Discothyrea diana Xu, Burwell & Nakamura, 2014: 38, figs 7-12 (w.) CHINA.

Worker
Holotype: TL 1.8, HL 0.58, HW 0.50, CI 87, SL 0.33, SI 65, ED 0.05, PW 0.40, MSL 0.58, PL 0.10, PH 0.26, DPW 0.21, LPI 263, DPI 213.

In full-face view, head longer than broad, roughly trapezoidal, narrowed anteriorly. Posterior margin weakly concave medially, posterolateral corners rounded. Sides evenly convex, deeply notched in front of mandibular insertions. Mandibles triangular, masticatory margins edentate, apical tooth acute. Anterior margin of clypeus weakly convex, anterolateral corners rounded. Frontal lobes fused each other and formed a roughly triangular area, about as broad as long, lateral corners acutely angled and less than 90°, anterolateral margins weakly convex. Frontal carinae short and close to each other, extending posteriorly to about 1/3 of head-length. Antennae 7-segmented, apices of scapes reaching to 3/5 of distance from antennal sockets to posterolateral corners. Eyes small and convex, consisting of about 6 ommatidia, located slightly in front of mid-length of sides. In posterior view, frontal area strongly elevated and rectangular, with a narrow base, anterior and lateral margins nearly straight.

In lateral view, dorsum of mesosoma evenly convex, and sloping down posteriorly, promesonotal suture and metanotal groove absent. Posterodorsal corner of propodeum rightly angled, declivity evenly concave. Propodeal lobe large and rounded. Petiolar node short and low, dorsal face sloping down anteriorly and weakly concave, anterodorsal corner bluntly angled. Subpetiolar process large, roughly triangular, ventrally pointed and translucent. First gastral segment about 2/3 of the total length of gaster. Constriction between the two basal gastral segments narrow and weak.

In dorsal view, mesosoma roughly trapezoidal, narrowed posteriorly, humeral corners bluntly angled, lateral margins straight, propodeum more strongly narrowed, posterior margin weakly concave, posterolateral corners bluntly angled. Petiolar node transverse and rectangular, length/width ratio = 1:3.5, transversely depressed, anterior margin nearly straight, posterior margin weakly concave, anterolateral corners right-angled.

Head, mesosoma, petiole, and first gastral segment densely and coarsely punctured, interface much smaller than puncture diameter, punctures on sides of head and first gastral segment even larger. Rest of gastral segments densely finely punctured. Whole body covered with dense sub-decumbent to decumbent short pubescence, without standing hairs. Scapes and tibiae with dense decumbent pubescence, without standing hairs. Colour reddish brown. Apical antennal segments, legs, and gastral apex yellowish brown. Eyes black.

Paratypes: TL 1.8–1.9, HL 0.55–0.58, HW 0.48–0.50, CI 86–91, SL 0.30–0.33, SI 60–68, ED 0.04–0.05, PW 0.35–0.40, MSL 0.55–0.63, PL 0.09–0.11, PH 0.25–0.28, DPW 0.21–0.23, LPI 244–286, DPI 200–243 (8 individuals measured). As holotype, but color reddish brown to yellowish brown, apical antennal segments, legs, and gastral apex yellowish brown to yellowish.

Type Material
Holotype: worker, China: Yunnan Province, Mengla County, Mengla Town, Bubang Village, QCASsite 800-2, 21.613° N, 101.578° E, 741 m, July 2012, collected in rainforest by Berlese method, Akihiro Nakamura & Chris J. Burwell leg., No. A12-1812.

Paratypes: 2 workers, same data as holotype but QCASsite 800-4, 21.615° N, 101.580° E, 728 m, Nos. A12-1813 and A12-1814; 2 workers, same data as holotype but QCASsite 1000-3, 21.620°N, 101.572° E, 995 m, Nos. A12-1815 and A12-1816; 2 workers, same data as holotype but QCASsite 1000-4, 21.621° N, 101.571° E, 995 m, Nos. A12-1817 and A12-1818; 1 worker, same data as holotype but QCASsite 1200-3, 21.595° N, 101.558° E, 1209 m, No. A12-1819; 1 worker, China: Yunnan Province, Hekou County, Nanxi Town, Laodoutian Village, 22° 48.090’ N, 104° 02.944’ E, 730 m, 05. IV. 2010, collected from a ground sample in monsoon forest, Huiqin Zhu leg., No. A10-2521.

Etymology
The specific epithet refers to an abbreviation for Yunnan Province “Dian”, within which the type locality of this species is situated.

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., C. J. Burwell, and A. Nakamura. 2014. Two new species of the proceratiine ant genus Discothyrea Roger from Yunnan, China with a key to the known Oriental species. Asian Myrmecology 6: 33-41.