Pheidole lucioccipitalis

Heterick & Kitching (2022) collected this species in the canopy and on trunks within a lowland dipterocarp forest in Brunei.

Identification
Eguchi (2001) - This species is characterised among Indo-Chinese and Indo-Malayan congeners by a combination of the following characteristics: vertex and occipital lobe of the major smooth and shining; hypostoma of the major only with an indistinct median process (the process sometimes almost absent); promesonotal dome weakly or very weakly margined laterally, without any prominence on its posterior declivity in both the subcastes; petiole of the minor 1.7-1.9 times as long as postpetiole; occipital carina of the minor weak but complete.

Distribution
Southern Malay Peninsula, Borneo and Sumatra.

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

Worker
Minor

Nomenclature

 *  lucioccipitalis. Pheidole lucioccipitalis Eguchi, 2001b: 73, fig. 26 (s.w.m.) BORNEO.

Worker
Eguchi (2001) - Major (n=6): TL 2.4-2.5 mm, HL 1.06-1.14 mm, HW 1.02-1.08 mm, SL 0.55-0.61 mm, FL 0.75-0.80 mm, CI 94-96, SI 53-57, FI 72-76. Head broadest at 1/3-2/3 distance of head (as measured from the mid-point of a transverse line spanning the anteriormost and posteriormost projecting points, respectively) (Fig. 26A), in profile not impressed on vertex (Fig. 26B). Hypostoma with an indistinct median process (the process sometimes almost absent). 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 1.5-1.8 times as long as maximal diameter of eye. Frontal carina inconspicuous, extending backward to at most 2/3 distance of head. Antennal scrobe present only around antennal insertion. Antenna with 3-segmented club; scape extending backward to 3/5-7/10 distance of head; terminal segment ca. 1.1 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 without any prominence on its posterior declivity (Fig. 26C); dorsal portion of the dome occasionally bordered anterodorsally with 2-3 transverse rugulae, weakly margined laterally. Mesopleuron divided by a distinct transverse impression into two parts, of which lower part occasionally margined dorsally. Propodeal spine horn-like, straight, almost twice as long as diameter of propodeal spiracle. Petiole cuneiform, 1.7-1.8 times as long as postpetiole (excluding helcium); petiolar node high, in posterior view not or slightly emarginate at apex. Postpetiole in dorsal view subhexagonal, 1.8-2.1 times as broad as petiolar node.

Dorsal and lateral faces of head excluding vertex and occipital lobe longitudinally rugose; remainder of head smooth and shining; promesonotal dome smooth and shining; mesopleuron and lateral face of propodeum punctured and weakly shining; lateral faces of petiolar pedicel and postpetiole weakly punctured; dorsa of petiole and postpetiole, and gaster smooth and shining. Outer face of mandible sparsely covered with appressed hairs, which are 0.05-0.07 mm in length and almost as long as distance between piligerous punctures; submarginal zone of masticatory margin of mandible with a row of longer decumbent hairs. Body yellowish-brown to brown, with darker gaster (sometimes mandibles and clypeus also darker); legs a little lighter than alitrunk.

Minor (n=6): TL 1.6-1.8 mm, HL 0.50-0.53 mm, HW 0.44-0.48 mm, SL 0.55-0.59 mm, AL 0.71-0.78 mm, FL 0.58-0.65 mm, CI 86-89, SI 124-129, FI 131-142. Head in full-face view oval (Fig. 260); occipital carina weak but complete. Clypeus without a median longitudinal carina, with anterior margin in full-face view slightly convex or truncate medially. Eyes situated just in front of midlength of head; distance between mandibular insertion and anterior margin of eye 0.8-1.0 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 1/4 length; terminal segment 1.0-1.1 times as long as preceding two segments together. Promesonotal dome without any prominence on its posterior declivity; dorsal portion of the dome relatively flat (Fig. 26E), very weakly margined laterally, bordered anteriorly with 1-2 transverse rugulae. Mesopleuron with a weak transverse impression. Propodeal spine elongatetriangular, ca. 1.5 times as long as diameter of propodeal spiracle. Petiole cuneiform, 1.7-1.9 times as long as postpetiole (excluding helcium); petiolar node in posterior view not emarginate at apex. Postpetiole ca. 1.7 times as broad as petiolar node.

Head including clypeus and promesonotum smooth and shining; mesopleuron and lateral face of propodeum punctured; lateral face of petiolar pedicel very weakly punctured; dorsum of petiole, and postpetiole and gaster smooth and shining. Body yellowish-brown with a little darker gaster; legs a little lighter than alitrunk.

Type Material
Eguchi (2001) - Holotype Major, colony: Eg96-BOR-292, Poring (500-550 malt.), Sabah, E. Malaysia (Borneo), K. Eguchi leg., 1996, deposited in. Paratypes 7 majors, 11 minors and 4 males 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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 * Pfeiffer M., D. Mezger, and J. Dyckmans. 2013. Trophic ecology of tropical leaf litter ants (Hymenoptera: Formicidae) - a stable isotope study in four types of Bornean rain forest. Myrmecological News 19: 31-41.
 * Pfeiffer M., and D. Mezger. 2012. Biodiversity Assessment in Incomplete Inventories: Leaf Litter Ant Communities in Several Types of Bornean Rain Forest. PLoS ONE 7(7): e40729. doi:10.1371/journal.pone.0040813
 * Pfeiffer M., and D. Mezger. 2012. Biodiversity Assessment in Incomplete Inventories: Leaf Litter Ant Communities in Several Types of Bornean Rain Forest. PLoS ONE 7(7): e40729. doi:10.1371/journal.pone.0041007
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