Pheidole magna Eguchi

Eguchi, K., 2008, A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae)., Zootaxa 1902, pp. 1-118 : 52-55

Pheidole magna Eguchi

Figs. 14a-g

Pheidole magna Eguchi , 2006: 125-127. 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, BMNH, FSKU, IEBR, MHNG, MCZC & ACEG, examined.

Pheidole sp. eg-162. Bui & Eguchi 2003: 9 (checklist), Eguchi, Bui et al. 2005: 91 (checklist).

Other material examined: Vietnam: Lao Cai: Sa Pa town [Eg02-VN-087], Bang Khoang (Site-A: a stream-side secondary forest), 1700-1800 m alt., Sa Pa [Eg02-VN-116, -124, -129], Bang Khoang (Site-B: a well-developed forest), ca. 1700 m alt. [Eg02-VN-165, -169, -175], Sa Seng (small fragment of limestone forest), Sa Pa [Eg02-VN-280]; Ha Tay: Ba Vi N.P. [T.V. Bui]. Eguchi's informal species code " Pheidole sp. eg- 162" has been applied to these specimens.

Worker measurements & indices: 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.

Worker description

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.

Recognition: 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 Forel , 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 & bionomics: Known from N. Vietnam. 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 (e.g., the type series, Eg02-VN-280).