Pristomyrmex modestus

The holotype was collected from a forest.

Identification
Wang (2003) - Worker. Pronotum with a pair of moderately long, robust spines; dorsal surfaces of head and alitrunk, as well as the two sides of pronotum, with a coarse rugoreticulum; petiole node in profile somewhat transrectangular, slightly longer than high, with seven to eight foveolate punctures.

This species must have evolved from the ancestor of Pristomyrmex costatus. It differs from P. costatus in the workers as follows: P. modestus - Petiole node in profile longer than high, somewhat rectangular, with the anterodorsal angle on approximately the same level as the posterodorsal. Dorsum and sides of petiole node with seven to eight foveolate punctures. P. costatus - Petiole node in profile higher than long; its anterodorsal angle is distinctly higher than the posterdorsal. Dorsum and sides of petiole node without foveolate punctures.

A member of the Quadridens species group

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

Castes
Queen and Male are unknown.

Nomenclature

 *  modestus. Pristomyrmex modestus Wang, M. 2003: 452, figs. 148-149 (w.) BORNEO.

Worker
Holotype. TL 4.00, HL 0.99, HW 0.92, CI 93, SL 0.95, SI 103, EL 0.19, PW 0.64, AL 1.04, PPW 0.35, PPL 0.35, PPI 100.

Mandibles with a few longitudinal rugae. Masticatory margin of mandible with two adjacent strong apical teeth + a long diastema + one broad, somewhat concave basal tooth. Basal margin of mandible lacking a distinctly curved lobe or tooth. Clypeus with a strong median carina. Anterior clypeal margin with a median denticle and three others on each side. Ventral surface of clypeus with a short transverse ruga. Frontal carinae strong, extending to the level of the posterior margins of the eyes. Antennal scrobes indistinct. Frontal lobes weak so that the antennal articulations are almost entirely exposed. Antennal scapes, laid on the dorsal head, slightly surpassing the occipital margin of head. Eyes rather large. Pronotal spines robust, ca. 0.14, shorter than the distance between their bases. Propodeal spines acute, slender, ca. 0.11. Metapleural lobes developed, prominent, ca. 0.14, each with a rounded apex. In profile view, petiole node slightly longer than high, somewhat transrectangular, with the anterodorsal angle on approximately the same level as or weakly higher than the posterodorsal; in dorsal view, petiole node longer than broad. Postpetiole in profile rounded dorsally; in dorsal view, approximately quadrate and about as long as broad. Dorsal surfaces of head and alitrunk, as well as the two sides of pronotum, entirely sculptured with coarse rugoreticulum. Dorsum and the sides of petiole node with seven to eight large foveolate punctures. Postpetiole with a few shallow foveolate punctures. Gaster unsculptured, smooth, and shining. Dorsal surfaces of head and alitrunk with numerous erect or suberect hairs. Petiole node and postpetiole each with a few pairs of hairs. First gastral tergite lacking erect or suberect hairs. A few pairs of forward-projecting hairs present near the anterior clypeal margin. Scapes and tibiae with sparse erect or suberect hairs. Color reddish-brown.

Type Material
Holotype Worker. . Malaysia: Sarawak, 4th Division, Gn. Mulu N.P., Kerangas for., leaf litter, 19.iii.1978 (H. Vallack).

References based on Global Ant Biodiversity Informatics

 * 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
 * Wang M. 2003. A Monographic Revision of the Ant Genus Pristomyrmex (Hymenoptera:Formicidae). Bull. Mus. Comp. Zool. 157(6): 383-542.