Crematogaster yappi

This species is known only from the type locality in Malaysia (Peninsula).

Identification
Hosoishi and Ogata (2012) - This species can be easily distinguished from similar Asian Crematogaster species by its undeveloped propodeal spines.

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

Nomenclature

 * . Crematogaster yappi Forel, 1901e: 374 (w.) WEST MALAYSIA.
 * Type-material: lectotype worker (by designation of Hosoishi & Ogata, 2012: 28), 5 paralectotype workers.
 * Type-locality: lectotype Malaysia: Peninsula, Kedah, Gunong Inas (R.H. Yapp); paralectotypes with same data.
 * Type-depositories: MHNG (lectotype); MHNG, NHMB (paralectotypes).
 * Combination in C. (Acrocoelia): Emery, 1922e: 152;
 * combination in C. (Crematogaster): Bolton, 1995b: 166.
 * Status as species: Forel, 1903a: 683; Emery, 1922e: 152; Chapman & Capco, 1951: 94; Bolton, 1995b: 165; Hosoishi & Ogata, 2012: 28 (redescription).
 * Distribution: Malaysia (Peninsula).

Worker
Hosoishi and Ogata (2012) - HW 0.65-0.74; HL 0.66-0.75; CI 94-105; SL 0.48-0.54; SI 70-77; EL 0.11-0.15; PW 0.34-0.4; WL 0.71-0.81; PSL 0; PtL 0.18-0.22; PtW 0.21-0.24; PtH 0.12-0.15; PpL 0.12-0.14; PpW 0.17-0.2; PtHI 67-74; PtWI 105-111; PpWI 129-167; WI 77-90 (Lectotype and five paralectotype workers measured).

Compound eyes slightly projecting from lateral margin of head. Scape reaching posterior corner of head, the scape with standing setae.

Anterior margin of pronotal collar almost straight in dorsal view. Metanotal groove concave in lateral view. Propodeal spines undeveloped. Anterior margin of metapleural gland bulla almost reaching anterior margin of propodeal spiracle.

Petiole in dorsal view broader anteriorly than posteriorly. Postpetiole weakly bilobed, but without a distinct longitudinal median sulcus. Subpetiolar and subpostpetiolar processes undeveloped.

Dorsal surface of head generally smooth and shining, but the lower portion near clypeal margin with longitudinal rugulae. Clypeus relatively smooth, but with feeble rugulae. Dorsal face of mesosoma almost smooth and shining. Dorsolateral face of pronotum smooth in dorsal view. Lateral surface of pronotum smooth and shining. Mesopleuron relatively smooth, but with feeble rugulae on the higher portion.

Fourth abdominal tergite with sparse standing setae.

Type Material
Hosoishi and Ogata (2012) - LECTOTYPE worker (bottom specimen of three on one pin, worker) (by present designation) and five paralectotype workers from MALAYSIA: Gunung Inas, Kedah (M. R. H. Yapp) (MHNG, ) [examined].

References based on Global Ant Biodiversity Informatics

 * Forel A. 1903. Les Formicides de l'Empire des Indes et de Ceylan. Part X. J. Bombay Nat. Hist. Soc. 14: 679-715.