Pheidole modiglianii

This species inhabits lowland rainforests. It is very rare on the ground, while I found two nests in trunks of newly logged trees in Danum Valley, and a migrating column near a newly logged tree in Gunong Rara. Thus this species is very probably arboreal. (Eguchi 2001a)

Identification
Eguchi (2001a) - This relatively large-sized species is characterised by its exceptionally long propodeal spine in both the subcastes.

Distribution
Southern Malay Peninsula, Borneo, Sumatra and Mentawai Is. (Eguchi 2001)

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

Worker
Minor

Nomenclature

 *  modiglianii. Pheidole modiglianii Emery, 1900d: 684 (s.w.q.) INDONESIA (Mentawei I.). See also: Eguchi, 2001a: 16; Eguchi, 2001b: 81.

Worker
Eguchi (2001a) - Major (n=4): TL 4.3-5.0 mm, HL 1.88-2.08 mm, HW 2.00-2.18 mm, SL 1.13-1.18 mm, FL 1.70-1.78 mm, CI 105-106, SI 53-57, FI 80-85. Head 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. 30A), in profile not impressed on vertex (Fig. 30B). Hypostoma with three median processes, of which medianmost one is lower. Clypeus with a 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 ca. 2.0 times as long as maximal diameter of eye. Frontal carina weak, extending backward to about ¾ distance of head. Antennal scrobe present only around antennal insertion. Antenna with 3-segmented club; scape reaching 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 low prominence on its posterior declivity (Fig. 30C); the prominence in anterior view not concave medially. Mesopleuron with an inconspicuous transverse impression. Propodeal spine horn-like, exceptionally long, extending above petiolar node (Fig. 30C). Petiole cuneiform, 1.5-1.6 times as long as postpetiole (excluding helcium); petiolar node very low, in posterior view slightly emarginate at apex. Postpetiole 1.5-1.7 times as broad as petiolar node.

Frons longitudinally rugose, with smooth and shining inters paces; longitudinal rugulae curving outward on occipital lobes (Fig. 30A); anterolateral face of head rugoso-reticulate; dorsum of promesonotum transversely rugose, with smooth and shining interspaces; mesopleuron and lateral face of propodeum rugoso-reticulate, with enclosures punctured and very weakly shining; lateral face of petiole punctured; dorsum of petiole smooth and shining; postpetiole smooth and shining, or partly punctured and dull; gaster smooth and shining. Outer face of mandible sparsely covered with appressed hairs, which are 0.04-0.10 mm in length and almost as long as, or shorter than, distance between piligerous punctures; submarginal zone of masticatory margin of mandible with a row of longer decumbent hairs. Body dark reddish-brown with darker head (excluding mandible and anterior 1/3 of head) and gaster; flagella and tarsi lighter than alitrunk.

Minor (n=5): TL 3.3-3.5 mm, HL 0.88-0.98 mm, HW 0.77-0.87 mm, SL 1.10-1.13 mm, AL 1.33-1.47 mm, FL 1.34-1.43 mm, CI 85-88, SI 131-143, FI 165-177. Head in full-face view oval (Fig. 300); occipital carina well developed. Clypeus usually with a distinct median longitudinal carina, with anterior margin in full-face view slightly convex or truncate medially. Eyes situated at about 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 and antennal scrobe present only around antennal insertion. Antenna with 3-segmented club; scape extending beyond posterior border of head by 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. 30E). Mesopleuron without a transverse impression. Propodeal spine horn-like, exceptionally long, extending beyond posterior node (Fig. 30E). Petiole in profile elongate cuneiform, 1.4-1.5 times as long as postpetiole (excluding helcium); petiolar node low, in posterior view not emarginate at apex. Postpetiole ca. 1.7 times as broad as petiolar node.

Clypeus sparsely rugose (interspaces occasionally very weakly punctured and weakly shining); area between antennal insertion and eye weakly punctured and with several rugulae; remainder of head largely smooth and shining; in dorsal view promesonotal dome (excluding irregularly rugose central part) concentrically rugose with interspaces punctured very weakly and shining; mesopleuron and propodeum rugoso-reticulate, with weakly punctured enclosures; lateral face of petiole very weakly punctured; dorsum of petiole, and postpetiole and gaster smooth and shining. Body dark reddish-brown with lighter alitrunk; flagella and tarsi lighter than alitrunk.

Type Material
Eguchi (2001b) - major, minor and queen; type locality: Sereinu, Sipora, Mentawai. Two syntypes (1 major and 1 minor, ) were examined.

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. 2001. A taxonomic study on Asian Pheidole (Hymenoptera, Formicidae): new synonymy, rank changes, lectotype designations and redescriptions. Insecta Koreana 18: 1-35.
 * Emery, C. "Formiche raccolte da Elio Modigliani in Sumatra, Engano e Mentawei." Annali del Museo Civico di Storia Naturale Giacomo Doria (Genova) (2) 20, no. 40 (1900): 661-722.
 * 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