Crematogaster (Physocrema) onusta Stitz

Hosoishi, Shingo & Ogata, Kazuo, 2009, A taxonomic revision of the Asian endemic subgenus Physocrema of the genus Crematogaster (Hymenoptera: Formicidae), Zootaxa 2062, pp. 15-36 : 26-27

Crematogaster (Physocrema) onusta Stitz

( Figs 7, 15 , 27 )

Crematogaster (Physocrema) onusta Stitz, 1925: 118 . LECTOTYPE worker (ZMHB worker, GBIF-D/FoCol 1439) (by present designation) and seven paralectotype workers from PHILIPPINES: Palawan (G. Boettcher) (MCZC, ZMHB) [examined]. Combination in C. ( Paracrema ) by Donisthorpe, 1941: 226.

Measurements and indices. 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). Description of worker. 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).

Distribution. This species is known from Tioman Island and Borneo ( Fig. 27 ).

Remarks. This species is very similar to C. (P.) 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 .

Specimens examined. MALAYSIA: 3 workers, Tioman Island, 17–22. ix. 1992 (F. I t o); 5 workers, Sepilok, Sandakan, Sabah, 18. viii. 1981 (K. Masuko); 4 workers, 50 ha plot, Lambir N.P., Miri, Sarawak, 22. viii. 1995 (Sk. Yamane); 1 worker, Old Tower R., Lambir N. P., Miri, Sarawak, 23. viii. 1995 (H. Okido); 2 workers, Old Tower R., Lambir N. P., Miri, Sarawak, 25. i. 1993 (Sk. Yamane). INDONESIA: 1 worker, Barito Ulu 150m alt., Kalimantan, 16. viii. 2001 (Syaukani).

Figures

FIGURES 10 − 17. Physocrema species in lateral view. Scale bars are all 0.5 mm. 10 — C. (P.) ampullaris, [Sampulage (1000 m), nr Mangktana, S. Sulawesi]; 11 — C. (P.) aurita, [Maeklong Watershed Research Station, Kanchanaburi Prov.]; 12 — C. (P.) difformis, [Lambir N. P., Miri, Sarawak, Borneo]; 13 — C. (P.) inflata, [Ulu Gombak, Malay Peninsula]; 14 — C. (P.) mucronata, [Satar’s House, Ulu Gadut, nr Padang, Sumatra]; 15 — C. (P.) onusta, [Barito Ulu 150 m alt., Kalimantanm]; 16 — C. (P.) physothorax, [Universiti Kebangsaan Malaysia Forest, Malay Peninsula]; 17 — C. (P.) sewardi, [7 miles, Cameron Highland, Malay Peninsula].

FIGURES 27 – 32. Distribution of Physocrema species in Southeast Asia. 27 — C. (P.) onusta; 28 — C. (P.) physothorax; 29 — C. (P.) sewardi; 30 — C. (P.) tanakai; 31 — C. (P.) vacca; 32 — C. (P.) yamanei.