Pheidole parvicorpus

This species inhabits well-developed lowland forests, and nests in rotting wood.

Identification
Eguchi (2001) - This tiny species is peculiar among Indo-Malayan small-sized congeners in the following conditions: eye consisting of 5-7 ommatidia in both the subcastes; terminal antennal segment more than 1.6 times as long as preceding two segments together in both the subcastes.

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

Worker
Minor

Nomenclature

 *  parvicorpus. Pheidole parvicorpus Eguchi, 2001b: 86, fig. 33 (s.w.q.) BORNEO.

Worker
Major (n=6): TL l.7-l.9 mm, HL 0.64-0.74 mm, HW 0.53-0.60 mm, SL 0.28-0.30 mm, FL 0.37-0.40 mm, CI 81-83, SI 47-56, FI 64-73. Head broadest at 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); in full-face view posterior margin of head shallowly concave (Fig. 33A); head in profile at most very weakly impressed on vertex (Fig. 33B). Hypostoma bearing a pair of distinct median processes. Clypeus without a median longitudinal carina, with anterior margin emarginate medially. Eye situated just in front of 1/3 distance of head, consisting of 5-7 ommatidia (Fig. 33B). Frontal carina and antennal scrobe present only around antennal insertion. Antenna with 3·segmented club; scape extending backward to 1/2-5/9 distance of head; terminal segment 1.6-1.7 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 an inconspicuous prominence on its posterior declivity (Fig. 33C). Mesopleuron without a distinct transverse impression. Propodeal spine almost twice as long as diameter of propodeal spiracle. Petiole l.6-l.7 times as long as postpetiole (excluding helcium); petiolar node in posterior view not emarginate at apex. Postpetiole 1.4-1.5 times as broad as petiolar node.

Dorsum of head above subocular level weakly rugose longitudinally and weakly shining; upper part of mesopleuron dull; dorsum of propodeum punctured; remainder of alitrunk smooth and shining largely; lateral face of petiole very weakly punctured and weakly shining; dorsum of petiole, and postpetiole and gaster smooth and shining. Outer face of mandible sparsely covered with appressed to decumbent hairs, which are 0.02-0.04 mm in length and a little shorter than distance between piligerous punctures. Body light yellowish-brown with darker mandibles.

Minor (n=6): TL 1.1-1.3 mm, HL 0.38-0.42 mm, HW 0.37-0.39 mm, SL 0.24-0.27 mm, AL 0.46-0.49 mm, FL 0.29-0.31 mm, CI 92-96, SI 65-71, FI 78-81. Head in full-face view weakly concave posteriorly (Fig. 330); occipital carina absent dorsally on head. Clypeus without a median longitudinal carina, with anterior margin in full-face view slightly convex or truncate medially. Eye situated at about 2/5 distance of head (as measured from the anteriormost to posteriormost of head), consisting of 5-6 ommatidia. Frontal carina and antennal scrobe present only around antennal insertion. Antenna with 3-segmented club; scape extending backward to about 5/6 distance of head; terminal segment 1.6-1.7 times as long as preceding two segments together. Promesonotum low, relatively flat dorsally (Fig. 33E). Mesopleuron with a weak transverse impression. Propodeal spine ca. 1.5 times as long as diameter of propodeal spiracle. Petiole 1.6-1.7 times as long as postpetiole (excluding helcium). Postpetiole 1.5-1.6 times as broad as petiolar node.

Clypeus almost smooth, or very weakly punctured and weakly shining; remainder of dorsum of head above subocular level weakly rugose longitudinally and weakly shining; venter of head below subocular level largely smooth and shining; remainder of body largely smooth and shining. Body yellow to light yellowish-brown.

Type Material
Holotype Major, colony: Eg97-BOR-S84, Gunong Rara (4°S8'N 117°S'E, ca. 250 malt.), Sabah, E. Malaysia (Borneo), K. Eguchi leg., 1997, deposited in. Paratypes 9 majors, 16 minors and 2 queens from the same colony to which the holotype belongs, deposited in, , , , , , and.

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.
 * 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.
 * Mezger D., and M. Pfeiffer. 2011. Partitioning the impact of abiotic factors and spatial patterns on species richness and community structure of ground ant assemblages in four Bornean rainforests. Ecography 34: 39-48.
 * Mezger D., and M. Pfeiffer. 2011. Partitioning the impact of abiotic factors and spatial patterns on species richness and community structure of ground assemblages in four Bornean rainforest. Ecography 34: 39-48.
 * 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.0041037
 * 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