Pheidole annexa

This inhabits well-developed forests. I have never encountered colonies which include more than one dealate queen. (Eguchi 2001)

Identification
Eguchi (2001) - This medium-sized species with general habitus is distinguished from other Indo-Malayan congeners by a combination of the following characteristics: hypostoma of the major bearing three poorly developed median processes of which each lateral one is partly combined with the process just mesal to mandibular insertion; posterior declivity of promesonotal dome having a prominence in both the subcastes; petiole 0.9-1.0 times as long as postpetiole in both the subcastes; promesonotum of the minor unarmed without any kind of tubercle.

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

Castes
Minor

Nomenclature

 *  annexa. Pheidole annexus Eguchi, 2001b: 32, fig. 6 (s.w.q.) BORNEO.

Worker
Major (n=5): TL 2.4-2.7 mm, HL 1.08-1.22 mm, HW 1.03-1.16 mm, SL 0.64-0.78 mm, FL 0.85-1.03 mm, CI 95-96, SI 60-67, FI 81-89. Head broadest at about 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) (Fig. 6A), in profile not impressed on vertex (Fig. 6B). Hypostoma with three poorly developed median processes, of which each lateral one is partly combined with the process just mesal to mandibular base (Fig. 6C). Clypeus with a weak median longitudinal carina, with anterior margin emarginate medially. Eye situated at about 1/3 distance of head; distance between mandibular insertion and anterior margin of eye 1.5-1.7 times as long as maximal diameter of eye. Frontal carina extending backward to 3/4 distance of head. Antennal scrobe inconspicuous, running along frontal carina. Antenna with 3-segmented club; scape extending backward to about 3/4 distance of head; terminal segment ca. 0.9 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 a distinct prominence on its posterior declivity (Fig. 6D); the prominence in anterior view not or very weakly concave medially. Mesopleuron without a distinct transverse impression. Propodeal spine horn-like, straight or slightly curved, 2.5-3 times as long as diameter of propodeal spiracle. Petiole cuneiform, 0.9-1.0 times as long as postpetiole (excluding helcium) (Fig. 6D); petiolar node low, in posterior view not or hardly emarginate at apex. Postpetiole in dorsal view subpentagonal, 2.3-2.4 times as broad as petiolar node.

Frons and area between mandibular insertion and eye longitudinally rugose; area between antennal scrobe and subocular level, vertex, and dorsal and lateral faces of occipital lobe rugosoreticulate; dorsum of promesonotum with transverse rugulae but shining; lateral face of promesonotum weakly rugose or rugoso-reticulate; mesopleuron and lateral face of propodeum very weakly punctured, or partly smooth and shining; lateral faces of petiolar pedicel and postpetiole weakly or very weakly punctured; dorsa of petiole and postpetiole, and gaster smooth and shining. Outer face of mandible covered with relatively long decumbent hairs, which are 0.06-0.13 mm in length and (a little) longer than distance between piligerous punctures. Body brown with a little darker gaster; legs sometimes a little lighter than alitrunk.

Minor (n=5): TL 1.8-2.1 mm, HL 0.56-0.64 mm, HW 0.48-0.53 mm, SL 0.70-0.82 mm, AL 0.80-0.91 mm, FL 0.80-0.93 mm, CI 81-85, SI 147-162, Fl168-183. Head in full-face view oval (Fig. 6E), with distinct occipital carina. Clypeus without a median longitudinal carina, with anterior margin in full-face view truncate, or slightly concave medially. Eyes situated just in front of mid length of head; distance between mandibular insertion and anterior margin of eye 1.1-1.2 times as long as maximal diameter of eye. Frontal carina and antennal scrobe present only around antennal insertion. Antenna with 3-segmented club; in full-face view scape extending beyond posterior border of head by more than its 1/3 length; terminal segment ca. 0.8 times as long as preceding two segments together. Promesonotal dome with a low prominence on its posterior declivity (Fig. 6F). Mesopleuron without a distinct transverse impression. Propodeal spine small, elongate-triangular, almost twice as long as diameter of propodeal spiracle. Petiole cuneiform, 0.9-1.0 times as long as postpetiole (excluding helcium) (Fig. 6F); petiolar node low, in posterior view not emarginate at apex. Postpetiole in dorsal view subpentagonal, 2.0-2.3 times as broad as petiolar node.

Head and promesonotum smooth and shining; mesopleuron and lateral face of propodeum almost smooth and shining, or very weakly punctured partly; lateral face of petiolar pedicel very weakly punctured: dorsum of petiole, and postpetiole and gaster smooth and shining. Body light yellowish-brown.

Type Material
Holotype Major, colony: Eg96-BOR-478, Sepilok forest, Sabah, E. Malaysia (Borneo), K. Eguchi leg., 1998, deposited in. Paratypes 5 majors and 6 minors from the same colony to which the holotype belongs, deposited in, , and UMS.

References based on Global Ant Biodiversity Informatics

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 * Bruhl C.A. 2001. Leaf litter ant communities in tropical lowland rain forests in Sabah, Malaysia: effects of forest disturbance and fragmentation. PHD thesis Wurzburg Universitat, 168 pp.
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