Pheidole magna

This species occurs from relatively open habitats to forests at relatively high altitude (1000 m alt. or higher), and nests in the soil and rotting logs (Eguchi 2006). Majors serve as repletes (Eguchi 2008).

Identification
Eguchi (2008) - This species is characterized among Indo-Chinese species by the combination of the following features:
 * in the major vertexal lobe largely smooth and shining
 * in the major and minor promesonotal dome having a conspicuous prominence on its posterior slope
 * in the major and minor postpetiole relatively massive.

This large-bodied species is similar to Pheidole dugasi, but well distinguished from the latter which has the following characteristics in the major: dorsum of vertexal lobes distinctly rugose; first gastral tergite entirely rugoso-punctured (see also Eguchi 2006).

Distribution
Known from N. Vietnam.

Distribution based on Regional Taxon Lists
Oriental Region: Vietnam.

Nomenclature

 *  magna. Pheidole magna Eguchi, 2006: 125, figs. (s.w.) VIETNAM. See also: Eguchi, 2008: 52.

Worker
Eguchi (2008) - Major (data from the original description). — HL 2.21–2.39 mm; HW 2.13–2.32 mm; CI 92–99; SL 1.04–1.14 mm; SI 45–51; FL 1.59–1.66 mm; FI 70–75. Minor (data from the original description). — HL 0.87–0.94 mm; HW 0.79–0.90 mm; CI 91–96; SL 0.94– 1.03 mm; SI 113–122; FL 1.12–1.22 mm; FI 134–143.

Major — Head in lateral view not or very weakly impressed on vertex; frons and vertex longitudinally- obliquely rugose; vertexal lobe largely smooth and shining; frontal carina and antennal scrobe absent; clypeus with a median longitudinal carina which is sometimes reduced into a weak rugula; hypostoma with a low or inconspicuous median and moderately to strongly developed submedian processes; lateral processes present but reduced, much smaller than submedian processes; antenna with a 3-segmented club; maximal diameter of eye a little longer than antennal segment X. Promesonotal dome with a conspicuous prominence on its posterior slope; humerus not or very weakly produced laterad; the dome at the humeri narrower than at the bottom; propodeal spine small. Petiole almost as long as postpetiole (excluding helcium); postpetiole relatively massive. First gastral tergite smooth and shining, often with a weakly punctured area just around its articulation with postpetiole.

Minor — Head smooth and shining; preoccipital carina complete but weak dorsally; median part of clypeus smooth and shining, with a median longitudinal carina in its anterior half; 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 smooth and shining, in lateral view raised relatively highly in front of a conspicuous prominence/mound on its posterior slope; humerus in dorso-oblique view not produced, or very weakly produced; mesopleuron, metapleuron and lateral face of propodeum largely punctured weakly. Petiole almost as long as or a little shorter than postpetiole (excluding helcium); postpetiole massive.

Type Material
Eguchi (2008) - Holotype: major, “Bang Khoang (Site-A: ca. 1700–1800 m alt.), Sa Pa, Lao Cai, Vietnam, Eg02-VN-137”, IEBR, examined; paratypes: 34 majors & 35 minors, same data as holotype,, FSKU, IEBR, , & ACEG, examined.

References based on Global Ant Biodiversity Informatics

 * Eguchi K. 2006. Six new species of Pheidole Westwood from North Vietnam (Hymenoptera, Formicidae). Revue Suisse de Zoologie 113:115-131
 * 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