Discothyrea banna

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Castes
Known only from the worker caste.

Nomenclature

 *  banna. Discothyrea banna Xu, Burwell & Nakamura, 2014: 35, figs 1-6 (w.) CHINA.

Description
In full-face view, head longer than broad, roughly trapezoidal and narrowed anteriorly. Posterior margin nearly straight, posterolateral corners rounded. Sides evenly convex, deeply notched in front of mandibular insertions. Mandibles triangular, masticatory margin edentate, apical tooth acute. Anterior margin of clypeus weakly convex. Frontal lobes confused each other and formed a large roughly rhombic frontal area, distinctly longer than broad, lateral corners bluntly angled and more than 90°, anterolateral margins straight, posterolateral margins weakly concave. Frontal carinae relatively long and well separated, extending posteriorly to 1/2 of head-length. Antennae 9-segmented, apices of scapes reaching to 2/3 of distance from antennal sockets to posterolateral corners. Eyes moderately large and convex, with 6 ommatidia on maximum diameter, located at mid-length of sides. In posterior view, frontal area weakly elevated and roughly rhombic, with a broad base, anterior margin weakly convex, lateral corners acutely angled.

In lateral view, dorsum of mesosoma weakly convex and sloping down posteriorly, promesonotal suture and metanotal groove absent. Posterodorsal corner of propodeum rounded, declivity weakly concave. Propodeal lobes large and rounded. Petiolar node high, roughly triangular and narrowed upward, anterior and dorsal faces forming a single arch, strongly convex, anterodorsal corner indistinct. Subpetiolar process short, very bluntly angled ventrally and translucent. First gastral segment large, about 2/3 of the total length of gaster. Constriction between the two basal gastral segments broad and deep.

In dorsal view, mesosoma trapezoidal and narrowed posteriorly, humeral corners bluntly angled, lateral margins nearly straight, posterior margin weakly concave medially. Petiolar node transverse and trapezoidal, length/width ratio = 1:1.5, widening posteriorly, anterior margin nearly straight, lateral and posterior margins straight, anterolateral corners bluntly angled.

Mandibles finely punctured. Head, mesosoma, petiole, and first gastral segment densely and coarsely punctured, interface much smaller than puncture diameter. Punctures on first gastral segment even larger, and foveolate on its sides. Rest gastral segments finely punctured and relatively shining. Whole body covered with dense, suberect to subdecumbent short pubescence, without standing hairs. Scapes and tibiae with dense decumbent short pubescence, without standing hairs. Colour reddish brown. Apical antennal segments, legs, and gastral apex yellowish brown. Eyes black.