Crematogaster myops

This species inhabits developed forests and nests in soil.

Identification
Hosoishi and Ogata (2016) - A member of the Crematogaster quadriruga group. In the worker this species is very distinct among the Crematogaster quadriruga group in having reduced compound eyes (with c. 6 ommatidia). It is similar to Crematogaster masukoi (Crematogaster biroi group) in having reduced compound eyes, but can be distinguished by the clypeus with rugulae, smooth surface of propodeum, and the lack of subpostpetiolar process.

Distribution
Malaysia (Peninsula and Borneo), Singapore and Indonesia (Sumatra).

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

Nomenclature

 *  myops. Crematogaster myops Forel, 1911a: 31 (w.q.) BORNEO. Combination in C. (Orthocrema): Santschi, 1918d: 182. See also: Hosoishi, Yamane & Ogata, 2010b: 347.

Worker
Hosoishi and Ogata (2016) - (n=7) HW 0.44–0.48; HL 0.45–0.52; CI 92–98; SL 0.40–0.44; SI 90–94; EL 0.05–0.06; PW 0.27–0.31; WL 0.49–0.58; PSL 0.05–0.08; PtL 0.15–0.21; PtW 0.13–0.16; PtH 0.10–0.12; PpL 0.09–0.13; PpW 0.12–0.16; PtHI 55–67; PtWI 75–89; PpWI 115–150; WI 92–100.

Workers monomorphic. Head subquadratic in full-face view. Mandibles with four teeth, basal tooth arranged away from the third apical one, apical and subapical teeth large, basal two teeth smaller. Anterior clypeal margin convex in medial portion. Compound eyes not projecting beyond lateral margins of head in full-face view. Scapes reaching posterolateral corners of head.

Pronotal collar with weakly concave anterior margin in dorsal view, distinctly lower than pronotum in lateral view. Pronotal dorsum without distinct ridges laterally. Mesonotal dorsum with lateral ridges posteriorly. Pronotum and mesonotum in lateral view forming slightly convex, continuous dorsal outline. Metanotal groove in dorsal view transverse, almost straight in median portion, forming deep concavity that is laterally margined by lamellate ridges. Propodeal spiracles oval, situated at posterolateral corners of propodeum, touching to metapleural gland bullae. Propodeal spines developed, as long as diameter of propodeal spiracles, in dorsal view directed posteriad.

Petiole in dorsal view with subparallel sides and narrow anteriorly, longer than wide. Posterior portion of petiole with short process that is slightly higher than posterior margin of petiole disc in lateral view. Subpetiolar process developed as small acute process. Postpetiole in lateral view with weakly convex dorsum, as high as petiole, in dorsal view as wide as petiole, weakly bilobed posteriorly but without longitudinal sulcus. Subpostpetiolar process undeveloped, but venter of postpetiole convex.

Integument essentially smooth and shining. Dorsal surface of head generally smooth and shining, but with rugulae on surrounding region of antennal sockets. Mandibles with feeble rugulae and smooth interspaces. Clypeus weakly sculptured with one distinct pair of longitudinal rugulae; rugulae not extending to posterior clypeal margin. Dorsal and lateral surfaces of pronotum smooth and shining; anterolateral shoulders of pronotum without rugulae. Mesopleura smooth and shining. Dorsal surface of propodeum generally smooth and shining, but one pair of rugulae running from metanotal groove to tips of propodeal spines. Dorsal surface of petiole smooth and shining. Lateral surface of petiole generally smooth, but with one longitudinal rugula. Dorsal and lateral surfaces of postpetiole smooth and shining.

Standing pilosity sparse. Dorsal face of head with suberect setae sparsely. Clypeus with two pairs of long setae in anterior portion, one directed upward and the other downward. Anterior clypeal margin with one pair of long setae medially and short setae laterally. Scapes with suberect setae. Mesosoma with four pairs of long erect and stout setae (ps1PN, psaMN, pspMN, and ps1PS) that are much longer than other erect setae. Posterolateral tubercles of petiole posteriorly with one pair of stout setae. Postpetiole with several pairs of long setae on disc anteriorly, posteriorly and laterally. Fourth abdominal tergite with suberect setae abundantly, and short decumbent setae sparsely.

Body yellow. All flagellar segments yellow.

Type Material
Hosoishi and Ogata (2016) - Lectotype and five paralectotype workers, Sarawak, Borneo, Malaysia (Haviland) (, examined).

References based on Global Ant Biodiversity Informatics

 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Forel A. 1911. Fourmis de Bornéo, Singapore, Ceylan, etc. récoltées par MM. Haviland, Green, Winkler, Will, Hose, Roepke et Waldo. Rev. Suisse Zool. 19: 23-62.
 * Hosoichi S., and K. Ogata. 2016. Systematics and biogeography of the ant genus Crematogaster Lund subgenus Orthocrema Santschi in Asia (Hymenoptera: Formicidae). Zoological Journal of the Linnean Society 176: 547–606.
 * Hosoishi S. and K. Ogata. 2009. A check list of the ant genus Crematogaster in Asia (Hymenoptera: Formicidae). Bull. Inst. Trop. Agr. Kyushu Univ. 32: 43-83.
 * Hosoishi S., Yamane S., and K. Ogata. 2010. Subterranean species of the ant genus Crematogaster in Asia (Hymenoptera: Formicidae). Entomological Science 13: 345350.
 * 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
 * Wheeler W. M. 1919. The ants of Borneo. Bulletin of the Museum of Comparative Zoology 63:43-147.