Pheidole magna, Eguchi, Katsuyuki, 2006

Eguchi, Katsuyuki, 2006, Six new species of Pheidole Westwood from North Vietnam (Hymenoptera, Formicidae), Revue Suisse de Zoologie 113 (1), pp. 115-131 : 115

Pheidole magna sp. n.

Figs 5A-I

Pheidole sp. eg-162 : Bui & Eguchi, 2003 (a list of local ant fauna).

HOLOTYPE. - Major from colony Eg02-VN-137 (nesting in the soil of shoulder of a road).

Type locality: Bang Khoang (Site-A: ca. 1700-1800 m alt.), Sa Pa, Lao Cai, Vietnam [K. Eguchi leg., 27/iv/2002]. Depository: IEBR. PARATYPES. - 34 majors and 35 minors from the same colony to which the holotype belongs. Depository: IEBR, MHNG, MCZC, BMNH, NHMW, FSKU, ACEG.

NON-TYPE MATERIAL EXAMINED. - Vietnam: Lao Cai: Sa Pa town [Eg02-VN-087]; Bang Khoang (Site-A: a stream-side secondary forest), ca. 1700-1800 m alt., Sa Pa [Eg02-VN-116, - 124, -129]; Bang Khoang (Site-B: a well-developed forest) [Eg02-VN-165, -169, -175]; Sa Seng (a small fragment of limestone forest), Sa Pa [Eg02-VN-280]; Ha Tay: Ba Vi N. P. [BTV, 2002]. Eguchi’s informal species code “ Pheidole sp. eg-162 ” has been applied to these specimens.

DIAGNOSIS. - Vertexal lobe largely smooth and shining (major); promesonotal dome having a conspicuous prominence on its posterior declivity (major and minor); postpetiole relatively massive (major and minor).

DESCRIPTION. - Major: TL 4.6-6.1 mm, HL 2.21-2.39 mm, HW 2.13-2.32 mm, SL 1.04-1.14 mm, FL 1.59-1.66 mm, CI 92-99, SI 45-51, FI 70-75 (N=6); body deep yellowish-brown or reddish-brown, with paler alitrunk and/or appendages; head in full-face view weakly convex laterad, broadly and deeply concave posteromedially, in profile very weakly impressed or not impressed on vertex; frons and vertex longitudinally rugose; vertexal lobe largely smooth and shining; frontal carina and antennal scrobe absent; median part of clypeus with a median longitudinal carina; hypostoma with 2 processes and one very low or vestigial process (a total of 3 median processes) in addition to the process just mesal to each mandibular base (lateral processes); lateral processes much reduced, much smaller than lateral ones of the three median processes; antenna with a 3-segmented club; scape a little exceeding midlength of head when it laid backward; EL a little more than LASX; LG ca. 1.7-2.0 times as much as EL; promesonotal dome sparsely rugose transversely, with interspaces smooth and shining, with a conspicuous prominence on its posterior declivity; the prominence extending as a transverse ridge; lower part of mesopleuron smooth and shining at least medially; lateral face of propodeum weakly punctured, or almost smooth with several rugulae; propodeal spine small, narrowly based; petiole as long as postpetiole (excluding helcium); petiolar node in anterior view not or very shallowly concave dorsally; postpetiole relatively massive, 2.3-2.5 times as broad as petiolar node; first gastral tergite smooth and shining, often with a weakly punctured area just around its articulation with postpetiole.

Minor: TL 2.7-3.3 mm, HL 0.87-0.94 mm, HW 0.79-0.90 mm, SL 0.94-1.03 mm ML 1.15-1.34 mm, FL 1.12-1.22 mm, CI 91-96, SI 113-122, FI 134-143 (N=7); body yellowish-brown or deep yellowish-brown, with paler appendages; head in full-face view oval, smooth and shining over the surface; median part of clypeus smooth and shining, with a median longitudinal carina on its anterior half; preoccipital carina complete but weak dorsally; antenna with a 3-segmented club; scape extending far beyond posterolateral margin of head; EL<LASX; promesonotal dome smooth and shining, in profile relatively well convex in front of a conspicuous prominence on its posterior declivity, with an inconspicuous mound dorsolaterally; mesopleuron and lateral face of propodeum largely punctured weakly; propodeal spine elongate-triangular, narrowly based; petiole a little shorter than postpetiole (excluding helcium); postpetiole relatively massive, 2.3-2.5 times as broad as petiolar node.

REMARKS. - This large-bodied species is similar to Pheidole dugasi Forel , but well distinguished from the latter by the following characteristics: the major of the latter having vertexal lobes distinctly rugose and first gastral tergite entirely rugosopunctured.

DISTRIBUTION. - N. Vietnam.

BIONOMICS. - This species occurs from relatively open habitats to forests in hilly areas (1000-1800 m alt.), and nests in the soil and rotting logs.