Pheidole colpigaleata, 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 colpigaleata sp. n.

Figs 1A-H

Pheidole sp. eg-113 : Bui & Eguchi, 2003 (a list of local ant fauna); Eguchi et al., 2004 (ecological study).

HOLOTYPE. - Major from colony Eg01-VN-222 (nesiting in a rotting twig). Type locality: Ba Vi N. P. (21°03’N, 105°22’E, ca. 1100 m alt.), Ha Tay, Vietnam [K. Eguchi leg., 11/xi/2001]. Depository: IEBR.

PARATYPES. - 11 majors, 13 minors and 1 dealate queen from the same colony to which the holotype belongs. Depository: IEBR, MHNG, MCZC, BMNH, NHMW, FSKU, ACEG.

NON-TYPE MATERIAL EXAMINED. - Vietnam: Lao Cai: Y Linh Ho (a small fragment of forest, ca. 1100 m alt.), Sa Pa [Eg02-VN-219]; Bac Giang: W. Yen Tu N. P. (21°10’52.2”N, 106°43’41.3”E, ca. 195 m alt.) [B&E03-04]; Ha Tay (misspelled as “Ha Tai” on the labels): Ba Vi N. P. (21°03’N, 105°22’E, 1100-1200 m alt.) [Eg99-VN-130; Eg01-VN-213; Eg02-VN-038, -039]. Eguchi’s informal species code “ Pheidole sp. eg-113 ” has been applied to these specimens.

DIAGNOSIS. - Dorsal and lateral faces of head and alitrunk punctured and dull (minor); hypostoma with 3 conspicuous median processes in addition to the process just mesal to mandibular base (major); frontal carina well developed horizontally (major); promesonotal dome lacking a conspicuous prominence on its posterior declivity (major and minor).

DESCRIPTION. - Major: TL 2.9-3.5 mm, HL 1.21-1.29 mm, HW 1.16-1.24 mm, SL 0.60-0.63 mm, FL 0.74-0.78 mm, CI 92-96, SI 48-53, FI 61-66 (N=5); body reddish brown; head in full-face view very weakly convex laterad, shallowly and broady concave posteriorly, with an inconspicuous median groove from the concavity to frons, in profile hardly or very weakly impressed on vertex; anterior part of frons longitudinally rugose; posterior part of frons, vertex and dorsal and dorsolateral faces of vertexal lobe reticulate, with enclosures very weakly punctured; frontal carina well developed horizontally, partly overhanging antennal scrobe; median part of clypeus almost smooth, without a median longitudinal carina; hypostoma with 3 median processes in addition to the process just mesal to each mandibular base (lateral processes); lateral processes well developed, as large as lateral ones of the three median processes; antenna with a 3-segmented club; scape exceeding midlength of head; EL>>LASX; LG 1.5-1.7 times as much as EL; promesonotal dome without a prominence on its posterior declivity; dorsolateral part of the dome weakly produced laterad; dorsum of the dome punctured reticulate, with enclosures very weakly punctured; lateral face of the dome, higher part of mesopleuron and lateral face of propodeum punctured and dull; lower part of mesopleuron punctured (sometimes only very weakly); propodeal spine finger-shaped or elongate-triangular, narrowly or sometimes moderately based; petiole much longer than postpetiole (excluding helcium); petiolar node in anterior view not or very weakly concave dorsally; postpetiole not massive, 1.9-2.2 times as broad as petiolar node; first gastral tergite largely smooth and shining except a weakly punctured area around its articulation with postpetiole.

Minor: TL 1.7-1.8 mm, HL 0.53-0.58 mm, HW 0.50-0.54 mm, SL 0.51-0.56 mm, ML 0.72-0.79 mm, FL 0.53-0.58 mm, CI 91-95, SI 98-106, FI 106-110 (N=5); body deep yellowish-brown; head puncutured and dull dorsally and laterally, except anteromedian part of frons dimly punctured; preoccipital carina evanescent or very weak dorsally; median part of clypeus smooth and shining, without a median longitudinal carina; antenna with a 3-segmented club; scape usually exceeding posterior margin of head by the length of second antennal segment or more; EL ≈ LASX; mesosoma punctured well and dull over the surface; dorsum of promesonotal dome often overlain by weak rugulae; promesonotal dome in profile without a prominence on its posterior declivity, very weakly produced dorsolaterally; propodeal spine small and thin; petiole longer than postpetiole (excluding helcium); postpetiole somewhat globular, 2.0-2.2 times as broad as petiolar node; first gastral tergite smooth and shining.

REMARKS. - This species is very similar to Pheidole nodgii Forel and its relatives, e.g., P. tjibodana Forel , P. magrettii Emery and P. retivertex Eguchi , but is well distinguished from the latter which have hypostoma with only one well-developed process (in P. colpigaleata hypostoma with three conspicuous median processes). This species is also similar to Pheidole rabo Forel , P. zoceana, Santschi and P. parva Mayr , but is also well distinguished from the latter which have frontal carinae almost absent or vestigial (in P. colpigaleata well developed). Pheidole colpigaleata actually has a mixture of characteristics seen in P. rabo and P. nodgii .

DISTRIBUTION. - N. Vietnam.

BIONOMICS. - This species inhabits forest from lowland to hilly areas (ca. 1100 m alt.), and nests in rotting twigs and small wood fragments. Colony Eg01-VN-222 stored a lot of small seeds inside the nest.