Pheidole tumida

Ranging from forests edges to well-develop forests. Nesting in the soil and rotting logs.

Identification
Eguchi (2008) - This species has the following combination of diagnostic characteristics: in the minor head and promesonotal dome largely smooth and shining; in the major hypostoma without median and submedian processes; in the major and minor promesonotal dome in lateral view with a conspicuous prominence or mound on its posterior slope; in the major subpetiolar process lobate; in the major and minor postpetiole massive.

Pheidole tumida, Pheidole noda and Pheidole nodifera are not distinguished from each other in minor’s morphology. Thus, there is a certain possibility that P. tumida is conspecific with P. nodifera which was described by F. Smith (1874) based on the minor alone from N. China. Pheidole tumida, characterised by a lobate subpetiolar process in the major, is easily distinguished from Pheidole noda and other Indo-Chinese species.

Key to Pheidole of North Vietnam

Distribution
Known from the Indo-Chinese and Indo-Malayan subregions.

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

Nomenclature

 *  tumida. Pheidole tumida Eguchi, 2008: 97, figs. 27a-g (s.w.q.) VIETNAM.

Worker
Holotype (major). — HL 1.98 mm; HW 1.99 mm; CI 101; SL 1.11 mm; SI 56; FL 1.58 mm; FI 79. Nontype major (n=4). — HL 1.63–1.90 mm; HW 1.63–1.98 mm; CI 100–105; SL 0.93–1.07 mm; SI 52– 60; FL 1.38–1.54 mm; FI 78–85. Minor (n=5, including one paratype minor). — HL 0.71–0.78 mm; HW 0.57–0.66 mm; CI 79–87; SL 0.91–1.04 mm; SI 147–166; FL 1.03–1.18 mm; FI 166–192.

Major — Head in lateral view not or very weakly impressed on vertex; frons and anterior part of vertex rugose longitudinally; posterior part of vertex and dorsal and dorsolateral faces of vertexal lobe rugoso-reticulate obliquely, or reticulate; frontal carina weak, or present just as rugula(e); antennal scrobe inconspicuous or absent; median longitudinal carina of clypeus usually conspicuous, but sometimes weak or just present as weak rugula(e); median and submedian processes of hypostoma absent, or sometimes present but inconspicuous; lateral processes conspicuous but often small; antenna with a 3-segmented club; maximal diameter of eye longer than or almost as long as antennal segment X. Promesonotal dome in dorsal view rugoso-reticulate transversely or irregularly, in lateral view with a conspicuous prominence or at least low mound on its posterior slope; humerus (very) weakly produced laterad; the dome at the humeri narrower than at the bottom (or sometimes almost as broad as or a little broader than at the bottom); propodeal spine usually finger-shaped or spatulate. Petiole shorter than postpetiole (excluding helcium), in dorsal view with a well-developed flange laterally; subpetiolar process extremely developed, lobate; postpetiole massive. First gastral tergite rugoso-punctate or at least shagreened over the surface.

Minor — Frons and vertex largely smooth; area between antennal insertion and eye often rugose or rugoso-punctate; preoccipital carina conspicuous dorsally and laterally; median part of clypeus smooth and shining; median longitudinal carina often present; antenna with a 3-segmented club; scape extending far beyond posterolateral margin of head; maximal diameter of eye shorter than antennal segment X. Promesonotal dome largely smooth, but sometimes shagreened dorsolaterally and/or with several short rugulae on humerus, in lateral view with a conspicuous mound on its posterior slope; humerus of the dome in dorso-oblique view not or hardly produced (rarely produced weakly as a mound); mesopleuron, metapleuron and lateral face of propodeum dimly to weakly punctured at least partly; propodeal spine usually reduced to a short and thin spine or a small dent, or sometimes almost absent. Petiole shorter than postpetiole (excluding helcium); subpetiolar process absent, or present as a longitudinal carina; postpetiole massive.

Type Material
Holotype: major, Cuc Phuong N.P., Ninh Binh, Vietnam (20°14’N, 105°36’E, 370 m alt.) [K. Eguchi leg., colony: Eg01-VN-176], examined; paratypes: 18 majors, 20 minors & 1 queen from the same colony as holotype (IEBR, , & ), examined.