Pheidole parvicorpus

This species inhabits well-developed lowland forests, and nests in rotting wood.

Identification
Eguchi (2001) - This tiny species is peculiar among Indo-Malayan small-sized congeners in the following conditions: eye consisting of 5-7 ommatidia in both the subcastes; terminal antennal segment more than 1.6 times as long as preceding two segments together in both the subcastes.

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

Nomenclature

 *  parvicorpus. Pheidole parvicorpus Eguchi, 2001b: 86, fig. 33 (s.w.q.) BORNEO.

Worker
Major (n=6): TL l.7-l.9 mm, HL 0.64-0.74 mm, HW 0.53-0.60 mm, SL 0.28-0.30 mm, FL 0.37-0.40 mm, CI 81-83, SI 47-56, FI 64-73. Head broadest at 1/2-3/5 distance of head (as measured from the mid-point of a transverse line spanning the anteriormost and posteriormost projecting points, respectively (cf. Fig. 2)); in full-face view posterior margin of head shallowly concave (Fig. 33A); head in profile at most very weakly impressed on vertex (Fig. 33B). Hypostoma bearing a pair of distinct median processes. Clypeus without a median longitudinal carina, with anterior margin emarginate medially. Eye situated just in front of 1/3 distance of head, consisting of 5-7 ommatidia (Fig. 33B). Frontal carina and antennal scrobe present only around antennal insertion. Antenna with 3·segmented club; scape extending backward to 1/2-5/9 distance of head; terminal segment 1.6-1.7 times as long as preceding two segments together. Masticatory margin of mandible with apical and preapical teeth, and a denticle in front of basal angle. Promesonotal dome with an inconspicuous prominence on its posterior declivity (Fig. 33C). Mesopleuron without a distinct transverse impression. Propodeal spine almost twice as long as diameter of propodeal spiracle. Petiole l.6-l.7 times as long as postpetiole (excluding helcium); petiolar node in posterior view not emarginate at apex. Postpetiole 1.4-1.5 times as broad as petiolar node.

Dorsum of head above subocular level weakly rugose longitudinally and weakly shining; upper part of mesopleuron dull; dorsum of propodeum punctured; remainder of alitrunk smooth and shining largely; lateral face of petiole very weakly punctured and weakly shining; dorsum of petiole, and postpetiole and gaster smooth and shining. Outer face of mandible sparsely covered with appressed to decumbent hairs, which are 0.02-0.04 mm in length and a little shorter than distance between piligerous punctures. Body light yellowish-brown with darker mandibles.

Minor (n=6): TL 1.1-1.3 mm, HL 0.38-0.42 mm, HW 0.37-0.39 mm, SL 0.24-0.27 mm, AL 0.46-0.49 mm, FL 0.29-0.31 mm, CI 92-96, SI 65-71, FI 78-81. Head in full-face view weakly concave posteriorly (Fig. 330); occipital carina absent dorsally on head. Clypeus without a median longitudinal carina, with anterior margin in full-face view slightly convex or truncate medially. Eye situated at about 2/5 distance of head (as measured from the anteriormost to posteriormost of head), consisting of 5-6 ommatidia. Frontal carina and antennal scrobe present only around antennal insertion. Antenna with 3-segmented club; scape extending backward to about 5/6 distance of head; terminal segment 1.6-1.7 times as long as preceding two segments together. Promesonotum low, relatively flat dorsally (Fig. 33E). Mesopleuron with a weak transverse impression. Propodeal spine ca. 1.5 times as long as diameter of propodeal spiracle. Petiole 1.6-1.7 times as long as postpetiole (excluding helcium). Postpetiole 1.5-1.6 times as broad as petiolar node.

Clypeus almost smooth, or very weakly punctured and weakly shining; remainder of dorsum of head above subocular level weakly rugose longitudinally and weakly shining; venter of head below subocular level largely smooth and shining; remainder of body largely smooth and shining. Body yellow to light yellowish-brown.

Type Material
Holotype Major, colony: Eg97-BOR-S84, Gunong Rara (4°S8'N 117°S'E, ca. 250 malt.), Sabah, E. Malaysia (Borneo), K. Eguchi leg., 1997, deposited in. Paratypes 9 majors, 16 minors and 2 queens from the same colony to which the holotype belongs, deposited in, , , , , , and.