Crematogaster yappi Forel

(Fig 12)

Crematogaster yappi Forel, 1901: 374.

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

Combination in C. (Acrocoelia) by Emery, 1922: 152.

Measurements and indices. 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).

General description of worker. 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.

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

Remarks. This species can be easily distinguished from other species of the C. brevis complex found in Asia by its undeveloped propodeal spines.