Pheidole tawauensis

Nothing is known about the biology of .

Identification
Eguchi (2001) - This species is very similar to Pheidole butteli among Indo-Chinese and Indo-Malayan congeners (for the difference between the two, see under P. butteli).

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

Nomenclature

 *  tawauensis. Pheidole tawauensis Eguchi, 2001b: 119, fig. 50 (s.w.) BORNEO.

Worker
Major (n=4): TL 2.5-2.7 mm, HL 1.23~1.28 mm, HW 1.05-1.08 mm, SL 0.47-0.51 mm, FL 0.69-0.77 mm, CI 83-86, SI 44-49, FI 66-73. Head broadest at about midlength of head (Fig. 50A), in profile not impressed on vertex (Fig. 50B). Hypostoma bearing three median processes, of which medianmost one is inconspicuous. Clypeus without a median longitudinal carina, with anterior margin 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 1.7-2.0 times as long as maximal diameter of eye. Frontal carina and antennal scrobe present only around antennal insertion. Frontal lobe relatively developed and erect (Fig. 50B). Antenna with 3-segmented club; scape extending backward to or slightly passing midlength of head; terminal segment 1.0-1.1 times as long as preceding two segments together. Mandible with apical and preapical teeth, and a distinct denticle in front of basal angle. Promesonotum forming a high dome, without any distinct prominence on its posterior declivity (Fig. 50C); each dorsolateral portion of the dome weakly produced. Mesopleuron sometimes divided by a weak transverse impression into two parts, of which lower part is margined dorsally. Propodeal spine triangular, 2-2.5 times as long as diameter of propodeal spiracle. Petiole 1.7-1.9 times as long as postpetiole (excluding helcium); petiolar node in posterior view weakly emarginate at apex. Postpetiole 2.0-2.1 times as broad as petiolar node, in dorsal view strongly angulate laterally.

Frons longitudinally rugose, with enclosures smooth and shining; vertex, and dorsal and lateral faces of occipital lobe weakly rugoso-reticulate, with enclosures weakly punctured and weakly shining; dorsum of promesonotal dome rugose at least partly; anterior and lateral faces of the dome, and lower part of mesopleuron largely smooth and shining; upper part of mesopleuron and large part of lateral face of propodeum weakly punctured and less shining; or whole alitrunk smooth and shining; lateral faces of petiolar pedicel and postpetiole very weakly punctured; dorsa of petiole and postpetiole smooth and shining; first gastral tergite around its articulation with postpetiole weakly punctured. Outer face of mandible sparsely covered with appressed to decumbent hairs, which are 0.03-0.05 mm in length and shorter than distance between piligerous punctures. Body brown to dark brown; antennae and legs lighter than alitrunk.

Minor (n=5): TL 1.6-1.8 mm, HL 0.48-0.53 mm, HW 0.43-0.47 mm, SL 0.47-0.53 mm, AL 0.67-0.72 mm, FL 0.53-0.58 mm, CI 89-90, SI 107-113, FI 122-124. Head in full-face view almost flat medioposteriorly; occipital carina weak but complete (Fig. 50D). Clypeus without median longitudinal carina, with anterior margin in full-face view slightly convex medially. Eye situated just in front of midlength of head; distance between mandibular insertion and anterior margin of eye 1.0-1.1 times as long as maximal diameter of eye. Frontal carina and antennal scrobe present only around antennal insertion. Antenna with 3-segmented club; scape extending beyond posterior border of head by a little more than its 1/5 length; terminal segment 1.0-1.1 times as long as preceding two segments together. Promesonotum convex, without any prominence on its posterior declivity (Fig. 50E). Mesopleuron occasionally divided by a weak transverse impression into two parts. Metanotal groove in profile deep (Fig. 50E). Propodeal spine almost twice as long as diameter of propodeal spiracle. Petiole 1.7-1.8 times as long as postpetiole (excluding helcium); petiolar node in posterior view not emarginate at apex. Postpetiole in dorsal view subhexagonal, 1.8-2.1 times as broad as petiolar node.

Head including clypeus smooth and shining; alitrunk almost smooth and shining; lateral face of petiolar pedicel very weakly punctured; dorsum of petiole, and postpetiole and gaster smooth and shining. Body yellowish-brown to brown.

Type Material
Holotype Major, soil-9 (soil sample), Tawau Hills Park, Sabah, E. Malaysia (Borneo), K. Eguchi leg., 1996, deposited in. Paratypes 2 majors and 7 minors from the same soil sample 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., S. Yamane, and S.Y. Zho. 2007. Taxonomic revision of the Pheidole rinae Emery complex. Sociobiology 50 (1): 275-284.
 * Eguchi K., and S. Yamane. 2003. Species diversity of ants (Hymenoptera, Formicidae) in a lowland rainforest, northwestern Borneo. New Entomol. 52(1,2): 49-59.
 * Hashimoto Y., and M. Mohamed. 2011. Ground-dwelling ant diversity in Maliau Basin, Borneo: evaluation of hand-sorting methods to estimate ant diversity. Tropics 19(2): 85-92.
 * 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
 * Ohasi M., Y. Maekawa, Y. Hashimoto, Y. Takematsu, S. Hasin, and S. Yamane. 2017. CO2 emission from subterranean nests of ants and termites in a tropical rain forest in Sarawak, Malaysia. Applied Soil Ecology 117–118: 147–155.
 * 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