Pheidole sayapensis

This species has so far been collected from only Sayap Kinabalu (ca. 1000 alt.). This species seems to inhabit well-developed hill forests. The colony Eg96-BOR-051 nested in a rotting wood block, and stored up a number of tiny seeds inside the nest. (Eguchi 2001)

Identification
Eguchi (2001) - P. sayapensis is closely related to Pheidole nodgii, Pheidole magrettii, Pheidole tjibodana, Pheidole retivertex and several undescribed species, and all these are peculiar among Indo-Chinese and Indo-Malayan congeners in having the combination of the characteristics noted under P. tjibodana. P. sayapensis is distinguishable from the Bornean relatives in having distinctly reticulate head and alitrunk in the minor, and very long propodeal spine in the minor.

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

Worker
Minor

Nomenclature

 *  sayapensis. Pheidole sayapensis Eguchi, 2001b: 114, fig. 47 (s.w.q.m.) BORNEO.

Worker
Major (n=3): TL 3.2 mm, HL 1.47-1.57 mm, HW 1.32-1.41 mm, SL 0.71-0.72 mm, FL 0.78-0.82 mm, CI 89-90, SI 51-54, FI 57-59. Head with almost parallel sides; posterior margin of head in full-face view emarginate medially (Fig. 47A); head in profile distinctly convex in posterior part of frons; anterior declivity of the convexity flat, and posterior declivity slightly impressed (Fig. 47B). Hypostoma with a large median process. Clypeus without a median longitudinal carina, with anterior margin weakly emarginate medially. Eye situated at about 1/3 distance of head (as measured from the mid-point of a transverse line spanning the anteriormost and posteriormost projecting points, respectively); distance between mandibular insertion and anterior margin of eye 2.0-2.3 times as long as maximal diameter of eye. Frontal carina well developed, horizontal, extending backward to 2/3 distance of head (Fig. 47A). Antennal scrobe extensively overhung by frontal carina. Frontal lobe reduced. Antenna with 3-segmented club; scape extending backward to 3/5 distance of head; terminal segment 1.2-1.3 times as long as preceding two segments together. Masticatory margin of mandible with apical and pre apical teeth, and a denticle in front of basal angle. Promesonotal dome with a low prominence on its posterior declivity (Fig. 47C); the prominence in anterior view not concave medially; each dorsolateral portion of the dome weakly produced outward. Mesopleuron with a weak transverse impression. Propodeal spine horn-like, blunt apically, ca. 5 times as long as diameter of propodeal spiracle. Petiole 1.8-2.0 times as long as postpetiole (excluding helcium); petiolar node distinct, in posterior view slightly emarginate at apex. Postpetiole 1.3-1.5 times as broad as petiole, in dorsal view trapezoidal, in profile right-angled anteroventrally.

Frons longitudinally rugose; vertex, and dorsal and lateral faces of occipital lobe reticulate, with enclosures smooth and shining or very weakly punctured; area between antennal scrobe and eye weakly reticulate, with enclosures punctured and dull; alitrunk largely reticulate, with enclosures smooth and shining; petiole (excluding its smooth and shining anterior face) and postpetiole reticulate; gaster smooth and shining. Outer face of mandible covered with very short appressed hairs (s; 0.02 mm in length), which are much shorter than distance between piligerous punctures; submarginal zone of masticatory margin of mandible with a row of much longer appressed to decumbent hairs. Body dark reddish-brown; flagella and legs lighter than alitrunk.

Minor (n=5): TL 1.8-2.0 mm, HL 0.65-0.68 mm, HW 0.63-0.65 mm, SL 0.55-0.60 mm, AL 0.87-0.90 mm, FL 0.62-0.65 mm, CI 95-98, SI 87-92, FI 97-99. Head in full-face view almost truncate posteriorly (Fig. 47D); occipital carina evanescent dorsally on head. Clypeus with a median longitudinal carina, with anterior margin in full-face view slightly convex medially. Eyes situated just in front of midlength 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 inconspicuous, extending backward to midlength of head. Antennal scrobe present only around antennal insertion. Antenna with 3-segmented club; in full-face view scape extending beyond posterior margin of head by its 1/6 length; terminal segment 1.1-1.2 times as long as preceding two segments together. Promesonotum forming a low dome; dorsum of the dome relatively flat (Fig. 47E). Mesopleuron without a distinct transverse impression. Propodeal spine horn-like, slightly downcurved, ca. 6 times as long as diameter of propodeal spiracle (Fig. 47E). Petiole 1.9-2.0 times as long as postpetiole (excluding helcium); petiolar node in posterior view not emarginate at apex. Postpetiole ca. 1.3 times as broad as petiole.

Clypeus with several irregular rugulae; remainder of head and alitrunk distinctly reticulate; petiole (excluding its anterior face smooth and shining) and postpetiole weakly reticulate; gaster smooth and shining. Body dark brown; flagella and legs lighter than alitrunk.

Type Material
Holotype Major, colony: Eg98-BOR-OSI, Sayap Kinabalu (1000 malt.), Sabah, E. Malaysia (Borneo), K. Eguchi leg., 1996, deposited in. Paratypes 3 majors, 15 minors, 1 queen and 1 male from the same colony to which the holotype belongs, deposited in, , , , , , and UMS.

References based on Global Ant Biodiversity Informatics

 * Eguchi K. 2001. A revision of the Bornean species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae). Tropics Monograph Series 2: 1-154.
 * Eguchi K. 2003. A study on the male genitalia of some Asian species of Pheidole (Hymenoptera, Formicidae, Myrmicinae). Sociobiology 41: 317-355.
 * Kishimoto-Yamata K., F. Hyodo, M. Matsuoka, Y. Hashimoto, M. Kon, T. Ochi, S. Yamane, R. Ishii, and T. Itioka. 2012. Effects of remnant primary forests on ant and dung beetle species diversity in a secondary forest in Sarawak, Malaysia. Journal of Insect Conservation DOI 10.1007/s10841-012-9544-6
 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58