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 nodus 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 nodus and other Indo-Chinese species.

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

Distribution based on Regional Taxon Lists
Oriental Region: Laos, 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.

References based on Global Ant Biodiversity Informatics

 * Eguchi K. 2008. A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae). Zootaxa 1902: 1-118.
 * Eguchi K.; Bui T. V.; Yamane S. 2011. Generic synopsis of the Formicidae of Vietnam (Insecta: Hymenoptera), part I  Myrmicinae and Pseudomyrmecinae. Zootaxa 2878: 1-61.
 * 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
 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Jaitrong W., B. Guenard, E. P. Economo, N. Buddhakala, and S. Yamane. 2016. A checklist of known ant species of Laos (Hymenoptera: Formicidae). Asian Myrmecology 8: 1-32. DOI: 10.20362/am.008019
 * Leong C. M., S. F. Shiao, and B. Guenard. 2017. Ants in the city, a preliminary checklist of Formicidae (Hymenoptera) in Macau, one of the most heavily urbanized regions of the world. Asian Myrmecology 9: e009014.
 * Liu C, B. Guénard, F Hita Garcia, S. Yamane, B. Blanchard, and E. Economo. New records of ant species from Yunnan, China. Submitted to Zookeys
 * Zryanin V. A. 2011. An eco-faunistic review of ants (Hymenoptera: Formicidae). In: Structure and functions of soil communities of a monsoon tropical forest (Cat Tien National Park, southern Vietnam) / A.V. Tiunov (Editor). – M.: KMK Scientific Press. 2011. 277 р.101-124.