Myrmoteras cuneonodus

In Khao Yai National Park in northeastern Thailand, nests were found in soil at altitudes between 600 and 1,000 m.

Identification
Xu (1998) - Close to Myrmoteras marianneae, but occipital corners extruding, nearly in right angles; genae below eyes with only short oblique rugae; dorsum of mesothorax granulate except the anterior 1/4 portion.

Bui, Eguchi and Yamane (2013) - Our species seems closely related to Myrmoteras estrudae (holotype examined) from Sumatra and Myrmoteras cuneonodum (holotype not examined) from Yunnan, southern China. All these have a smooth pronotal dorsum. Compared with M. estrudae, in our species the propodeal side is much more strongly sculptured (often metapleuron also sculptured) and the propodeal dorsum is densely transversely striate. In the latter condition it is more similar to M. cuneonodum (see Xu, 1998, p. 125), and we tentatively identified our species as M. cuneonodum. However, among the specimens examined we have found variation in the sculpture of pronotum, propodeum and side of mesosoma. Furthermore, in some specimens the propodeum is very convex dorsally, the condition approaching that of Myrmoteras karnyi from the Mentawai Islands, Sumatra.

Distribution based on Regional Taxon Lists
Oriental Region: Thailand, Vietnam. Palaearctic Region: China.

Castes
Known only from the worker caste.

Nomenclature

 *  cuneonodum. Myrmoteras cuneonodum Xu, 1998a: 125, figs. 12, 13 (w.) CHINA.

Worker
Holotype. TL 5.0, HL 1.10, HW 1.03, CI 94, SL 1.10, SI 106, PW 0.60, AL 1.40, ED 0.63, ML 1.53, MI 139. Head nearly triangular, occipital corners extruding, nearly in right angle. Frontal sulcus distinct, narrow and deep, from middle ocellus to the level of antenna1 foveae. Mandibles long and slender, filiform, inner margin with 11 long teeth, becoming shorter successively from apex to base; with 2 small denticles between the apical 1st and 2nd teeth, the posterior one is smaller than the anterior one; between apical 2nd and 3rd, and 3rd and 4th teeth, each with 1 small denticle. Anterior margin of labrum straight, without a pair of long trigger hairs. Anterior margin of clypeus roundly concave, lateral sides extruding into sharp angles. Transverse sulcus behind clypeus distinct. Antennal scapes surpass occipital corners by about 1/2 of their length, flagella filiform. Eyes long elliptic, with 3 ocelli. In profile view, mesothorax constricted and cylindrical, metanotal spiracles protruding. Pronotum slightly convex. Dorsum and declivity of propodeum very weakly convex, nearly straight, declivity shorter than dorsum. In profile view, petiolar node cuneiform, narrowering upword, anterior face nearly straight, upper portion of posterior face slightly convex. Head and mandibles smooth and shining; central dorsum of head finely rugose, the rugae branching backward; genae below eyes with short oblique rugae. Pronotum, anterior part of mesonotum, and mesopleura smooth and shining; cervicum and propodeum transversely rugose; dorsum of the cylindrical portion of mesothorax granulate, the lateral sides roughly longitudinally rugose. Petiolar node and gaster smooth and shining. Dorsa of head and body with sparse erect hairs, pubescences absent, hairs on gaster abundant. Antennal scapes and hind tibiae with rich suberect hairs. Body in colour reddish brown; gaster dark reddish brown; mandibles, antennae, and legs brownish yellow.

Bui, Eguchi and Yamane (2013) - TL 3–3.5, HL 0.92–1.00 (0.95), HW 0.92–0.98 (0.95), EL 0.58–0.62 (0.60), ML 1.21–1.33 (1.27), SL 0.92–1.02 (1.00), PrW 0.52–0.58 (0.55), HfL 0.94–1.04 (1.00), CI 98–102 (100), SI 100–108 (104). (5 non-type workers were measured.)

Body yellowish brown; mandible and leg pale yellow. Body with sparse standing hairs; dorsum of head and pronotum often with faint pubescence. Clypeus faintly rugose; frons irregularly rugose; vertex of head (including occipital lobe) smooth; frontal sulcus wide and deep, reaching median ocellus; anterior clypeal margin concave; mandible with ca. 10 teeth; two tiny denticles present between first (apical) and second (penultimate) teeth; the posterior one of the two very tiny; one relatively large denticle present between second and third teeth, and between third and fourth teeth; palp formula 6,4. Orbital grooves present, but narrow and shallow; scape distinctly shorter than funicular segments combined; funicular segments longer than broad. Pronotum in lateral view flattened dorsally; anteriormost part of pronotum rugose transversely; dorsum of pronotum smooth or faintly rugoso-punctate; dorsum of mesonotum rugoso-punctate; side of mesonotum with several irregular rugae; mesopleuron smooth; metapleuron and lateral face of propodeum obliquely rugose; metanotal groove shallow; dorsal face of propodeum transversely rugose; propodeum in lateral view relatively strongly convex. Petiolar node in lateral view with a vertical anterior face and steep posterior slope; ventral outline of petiole beneath the node slightly sinuate or concave.

Type Material
Holotype: Worker, Sanchahe 950 m, Mengyang Town, Jinghong County, Yunnan Province, Feb. 28, 1997, No. A97-79 (Yuchu Lai).