Strumigenys dyschima

The few known specimens are from a soil core in mixed dipterocarp forest (type) and limestone-rainforest litter sampling.

Identification
Bolton (2000) - A member of the Strumigenys murphyi-group. Closely related to the Malaysian species Strumigenys murphyi, the two are distinguished as follows.

S. dyschima: Minute species, HW 0.37. Apicodorsal tooth of mandible not overlapping outer margin of opposite mandible at full closure. Flattened hairs that project from inner margin of mandible shorter than longest preapical tooth. Small orbicular hairs on head restricted to area immediately behind clypeus. Pronotal dorsum longitudinally costulate.

S. murphyi: Larger species, HW 0.45 or more. Apicodorsal tooth of mandible strongly overlapping outer margin of opposite mandible at full closure. Flattened hairs that project from inner margin of mandible longer than longest preapical tooth. Small orbicular hairs on head present from posterior margin of clypeus to transverse crest on vertex. Pronotal dorsum reticulate-punctate.

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

Nomenclature

 *  dyschima. Pyramica dyschima Bolton, 2000: 451, fig. 264 (w.) BORNEO. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 119

Worker
Holotype. TL 1.5, HL 0.34, HW 0.37, CI 109, ML 0.14, MI 41, SL 0.22, SI 59, PW 0.24, AL 0.40. Inner margin of mandible with a series of medially directed small flattened hairs and with 2-3 small preapical teeth; basal most preapical tooth the largest, triangular and located at about the midlength of the mandible. Apicodorsal tooth the longest and overlapping its counterpart from the opposing mandible, but not massively enlarged nor spiniform, not extending beyond the outer margin of the opposing mandible at full closure. Anterior clypeal margin with a few flattened projecting hairs, the clypeal dorsum only with minute inconspicuous ground-pilosity. Cephalic dorsum immediately behind clypeus with two arched transverse rows of small orbicular hairs, with 6 hairs in each row. There may be 2-3 minute flattened hairs immediately posterior to the second row, but orbicular hairs similar to those in the two rows are absent from head behind this level. Transverse crest of vertex conspicuous, approximately straight across most of vertex but on each side weakening and angled forward toward the anterolateral angle of the occipital lobe. S ides of occipital lobes in full-face view more or less straight, distinctly convergent posteriorly. Leading edge of scape with 6-7 small spoon-shaped hairs that are curved toward the base of the scape and decrease in size toward the scape apex. Apex of the subbasal lobe of the scape with a larger flattened anteriorly directed hair; inner margin of lobe with 2 flattened hairs that curve toward the apex of the scape. Head and alitrunk otherwise with minute inconspicuous ground-pilosity but without standing hairs of any form. Eye minute, of a single ommatidium. Head finely and densely reticulate-punctate. Pronotal dorsum with posteriorly divergent fi ne longitudinal costulae. Mesonotum in profile saddle-shaped, its dorsal outline concave medially. Sides of alitrunk more or less smooth. Petiole and postpetiole without standing hairs but first gastral tergite with short erect straight pilosity that is clavate apically. Petiole node broader than long in dorsal view, finely shagreenate and dull. Basigastral costulae short but strongly developed.

Type Material
Holotype worker, Malaysia: Sarawak, 4th Division, Gn. Mulu N. P., ii.1978, soil core, mixed dipterocarp forest (N. M. Collins).

References based on Global Ant Biodiversity Informatics

 * Liu C, B. Guénard, F Hita Garcia, S. Yamane, B. Blanchard, and E. Economo. New records of ant species from Yunnan, China. Submitted to Zookeys
 * 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.0040786
 * 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