Crematogaster onusta

A specimen from Borneo was found in primary lowland forest.

Identification
A member of the Crematogaster inflata species-group. Hosoishi and Ogata (2009) - This species is very similar to Crematogaster physothorax, but can be distinguished by the rugulae on the pronotum. This species was transferred to Paracrema by Donisthorpe (1941), but is here replaced in Physocrema.

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

Nomenclature

 * . Crematogaster (Physocrema) onusta Stitz, 1925: 118 (w.) PHILIPPINES (Palawan I.).
 * Type-material: lectotype worker (by designation of Hosoishi & Ogata, 2009b: 26), 7 paralectotype workers.
 * Type-locality: lectotype Philippines: Palawan (G. Boettcher); paralectotypes with same data.
 * Type-depositories: MNHU (lectotype); MCZC, MNHU (paralectotypes).
 * Combination in C. (Paracrema): Donisthorpe, 1941l: 226.
 * Status as species: Chapman & Capco, 1951: 103; Baltazar, 1966: 251; Bolton, 1995b: 159; Hosoishi & Ogata, 2009b: 26 (redescription); Pfeiffer, et al. 2011: 46; Khachonpisitsak, et al. 2020: 91.
 * Distribution: Indonesia (Kalimantan), Malaysia (Peninsula, Sabah, Sarawak), Philippines (Palawan), Thailand.

Worker
Hosoishi and Ogata (2009) - HW 0.82–1.05; HL 0.76–0.95; CI 109–111; SL 0.66–0.85; SI 80–81; EL 0.18–0.22; PW 0.46–0.51; WL 1–1.22; PSL 0; PtL 0.28–0.34; PtW 0.22–0.26; PtH 0.14–0.16; PpL 0.16–0.19; PpW 0.2–0.24; PtHI 42–52; PtWI 67–86; PpWI 125–129; WI 94–100 (Three workers measured).

Workers monomorphic in size.

Scape reaching posterior corner of head.

In lateral view, pronotum and mesonotum forming a single convexity; propodeum slightly raised relative to promesonotum. Anterior margin of pronotal collar slightly concave in dorsal view. Metanotal groove almost straight in dorsal view, not so deep and situated posterior to the posterior ridge of pronotum in lateral view; thorax not strongly constricted in middle in dorsal view. In dorsal view, several longitudinal rugulae connecting between mesonotum and propodeum; the boundary indistinct. Propodeal spiracle situated near the metapleural gland orifice, the distance between them about the same as the propodeal spiracle diameter. Propodeal spines absent.

Clypeus sculptured with longitudinal rugulae. Pronotum punctate, but without distinct rugulae.

Standing pilosity sparse, a few pairs on dorsal face of head and dorsal portion of mesonotum. Dorsal face of head with decumbent setae. Clypeus with setae. Fourth abdominal tergite with decumbent setae.

Body color varies from red (specimens from Tioman Island) to brown (specimens from other localities).

Type Material
Hosoishi and Ogata (2009) - LECTOTYPE worker ( worker, GBIF-D/FoCol 1439) (by present designation) and seven paralectotype workers from PHILIPPINES: Palawan (G. Boettcher) (, ZMHB) [examined].

References based on Global Ant Biodiversity Informatics

 * Blaimer B. B. 2012. Acrobat ants go global  Origin, evolution and systematics of the genus Crematogaster (Hymenoptera: Formicidae). Molecular Phylogenetics and Evolution 65: 421-436.
 * 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
 * Hosoichi S., and K. Ogata. 2009. A taxonomic revision of the Asian endemic subgenus Physocrema of the genus Crematogaster (Hymenoptera: Formicidae). Zootaxa 2062: 15-36.
 * 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.
 * 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