Pheidole sabahna

This species inhabits well-developed lowland or hill forests. I found several colonies nesting in the soil at logging fronts near Ranau, Sabah.

Identification
This species and Pheidole quinata both have subcastes with a 5-segmented antennal club. They are well distinguished from each other by the characters given below.

Eguchi (2000):

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia.

Worker
Minor

Nomenclature

 *  sabahna. Pheidole sabahna Eguchi, 2000: 688, figs. 1-10 (s.w.m.) BORNEO. See also: Eguchi, 2001b: 108.

Worker
Eguchi (2001) - Major (n=15): TL 5.5-5.9 mm, HL 2.25-2.62 mm, HW 2.12-2.48 mm, SL 1.33-1.42 mm, FL 1.98-2.17 mm, CI 90-96, SI 56-63, FI 86-94. Head in full-face view broadest at about 2/3 distance of head (as measured from the mid-point of a transverse line spanning the anteriormost and posteriormost projecting points, respectively) (Fig. 44A); head in profile not impressed on vertex (Fig. 44B). Hypostoma with three low median processes. Clypeus with a median longitudinal carina medially, with anterior margin weakly emarginate medially. Eye situated at about 1/3 distance of head; distance between mandibular insertion and anterior margin of eye 1.9-2.0 times as long as maximal diameter of eye. Frontal carina and antennal scrobe present only around antennal insertion. Antenna with 5-segmented club (Fig. 44C); scape reaching about 2/3 distance of head. Promesonotal dome with a small prominence on its posterior declivity (Fig. 44D); the prominence in anterior view very weakly concave medially. Mesopleuron weakly divided by a transverse impression into upper and lower parts. Metanotal groove weak. Propodeal spine horn-like, straight, ca. 4 times as long as diameter of propodeal spiracle. Petiole in profile cuneiform, 1.1-1.2 times as long as postpetiole, bearing a low subpetiolar process (Fig. 44E); petiolar node in posterior view not, or slightly, emarginate at apex. Postpetiole in dorsal view subpentagonal, 1.8-2.0 times as broad as petiole, in profile strongly convex dorsally and almost flat ventrally.

Frons longitudinally rugose; vertex, occipital lobe and lateral face of head rugoso-reticulate, with enclosures very weakly punctured; alitrunk rugoso-reticulate excluding smooth declivitous face of propodeum; petiole (excluding smooth anterodorsal face) and postpetiole weakly punctured and dull; gaster smooth and shining. Body brown to reddish-brown, with darker gaster; legs a little lighter than alitrunk. Outer face of mandible sparsely covered with long decumbent hairs, which are 0.18-0.24 mm in length and, much longer than distance between piligerous punctures.

Minor (n=36): TL 3.5-3.7 mm, HL 0.88-1.08 mm, HW 0.78-0.93 mm, SL 1.15-1.41 mm, AL 1.30-1.58 mm, FL 1.33-1.69 mm, CI 83-89, SI 121-134, FI 165-193. Head in full·face view oval (Fig. 44F); occipital carina well developed. Clypeus with a median longitudinal carina, with anterior margin weakly emarginate medially. Eye situated at or in front of midlength of head; distance between mandibular insertion and anterior margin of eye ca. 1.3 times as long as maximal diameter of eye. Frontal carina and antennal scrobe present only around antennal insertion. Antenna with 5-segmented club (Fig. 44G); in full-face view scape extending well beyond posterior border of head by more than its 1/3 length. Promesonotum forming a relatively low dome, usually with a pair of low tubercles, and with a prominence on its posterior declivity (Fig. 44H). Mesopleuron sometimes with an inconspicuous transverse impression. Metanotal groove relatively deep (Fig. H). Propodeal spine horn-like, slender, directed upward, 6-7 times as long as diameter of propodeal spiracle. Petiole cuneiform, 1.0-1.1 times as long as postpetiole; petiolar node in posterior view not emarginate at apex. Postpetiole 2.0-2.2 times as broad as petiolar node.

Head including clypeus and promesonotum almost smooth and shining; remainder of alitrunk punctured distinctly (occasionally smooth and shining dorsally); petiole (excluding weakly punctured lateral face of pedicel) smooth and shining; postpetiole and gaster almost smooth and shining. In profile dorsum of promesonotal dome in front of the prominence on its posterior declivity bearing more than 20 standing hairs, and remainder of dorsum of alitrunk also bearing more than 20 standing hairs (Fig. 44H). Body brown to dark brown.

Type Material
Eguchi (2001) - Holotype Major. Paratypes majors (7), minors (11) and males (4) (UMS,, , , , ). Logging area or. Kg. Yoshina, Ranau, Sabah, E. Malaysia (Borneo). K Eguchi leg.