Crematogaster (Physocrema) difformis F. Smith

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 : 22-23

Crematogaster (Physocrema) difformis F. Smith

( Figs 8 , 12 , 24 )

Crematogaster difformis F. Smith 1857: 76 . LECTOTYPE worker (large worker from SINGAPORE, TYPE HYM: 1017 1-2 / 6) (by present designation) and five paralectotype workers: one paralectotype worker from SINGAPORE; four paralectotype workers from MALAYSIA: Sarawak, Borneo (OXUM) [examined]. Misspelled deformis by Roger. 1863: 37. Description of queen by Emery, 1901: 574. Description of male by Forel, 1909: 225. Combination in C. ( Physocrema ) by Forel, 1912: 220. Description of larva by Wheeler, G. C. & Wheeler, J. 1952: 261. Senior synonym of edentata by Emery, 1901: 574.

Crematogaster edentata Mayr, 1867: 104 . Holotype queen from INDONESIA: Java [not seen; location of type not known]. [junior synonym of difformis by Emery, 1901: 574].

Measurements and indices. HW 0.88–1.5; HL 0.84–1.34; CI 105–112; SL 0.74–1.06; SI 71–85; EL 0.15–0.28; PW 0.46–0.82; WL 1.01–1.74; PSL 0; PtL 0.26–0.48; PtW 0.19–0.4; PtH 0.15–0.26; PpL 0.16–0.28; PpW 0.2–0.4; PtHI 54–65; PtWI 74–95; PpWI 121–143; WI 90–107 (Three workers measured).

Description of worker. Workers with pronounced size polymorphism.

Scape just or not reaching posterior corner of head in large workers. Anterior-most portions of clypeus distinctly protruded anteriorly in large workers.

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. Promesonotal suture sometimes visible in large workers. Metanotal groove convex posteriorly in dorsal view, deep and situated posteriorly to the posterior ridge of pronotum in lateral view; thorax strongly constricted in middle in dorsal view. In dorsal view, some longitudinal rugulae connecting between mesonotum and propodeum; the boundary distinct. Propodeal spiracle situated away from the metapleural gland orifice, the distance between them much greater than the propodeal spiracle diameter. Propodeal spines absent.

Clypeus sculptured with longitudinal rugulae.

Standing pilosity sparse on dorsal face of head, abundant on promesonotum. Dorsal face of head with decumbent setae. Clypeus with short setae. Fourth abdominal tergite with appressed setae. Dorsal setae on fourth abdominal tergite appressed and directed medially in the posterior portion.

Body color black.

Distribution. This species is known from Malay Peninsula and Borneo ( Fig. 24 ).

Remarks. We have not been able to examine type-material of C. edentata Mayr. Although Emery synomymised it with C. (P.) difformis , it is impossible to clarify the synonymy from the original description and figure.

This species is similar to C. (P.) ampullaris and C. (P.) sewardi , but can be distinguished by the medially directed setae on the posterior portion of the fourth abdominal tergite.

Specimens examined. MALAYSIA: 1 worker, 1 male, 1 queen, Tower Region, Lambir N. P., Miri, Sawarak, 17. viii. 1995 (T. Yumoto); 7 workers, Tower Region, Lambir N. P., Miri, Sarawak (Sk. Yamane); 1 worker, 1 male, 1 queen, Lambir N. P., Miri, Sarawak, Borneo, 28. ix. 2005 (from epiphyte Coronarium sp.) (H. Tanaka); 2 workers, Gn. Mulu NP., 4th Division, Sarawak, ii. 1978 (light trap) (G. H o l l o w a y); 10 workers, 2 males, 1 queen, Lambir N. P., Miri, Sarawak, Borneo, 28. ix. 2005 (from Platycerium sp.) (H. Tanaka); 5 workers, 1 male, 1 queen, Lambir N. P., Miri, Sarawak, Borneo, 18. ix. 2005 (from Platycerium sp.) (H. Tanaka); 6 workers, Lambir N. P., Miri, Sarawak, Borneo, 18. ix. 2005 (from Lecanopteris sp.) (H. Tanaka); BRUNEI: 1 worker, Mixed Dipt. For., Dryobalanops beccarii, Site 7. 50m alt., Fog 11, Andalau, viii. 1991 (N. Mawdsley).

Figures

FIGURES 8 − 9. Setae on the fourth abdominal tergite: 8 — C. (P.) difformis; 9 — C. (P.) sewardi.

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 21 – 26. Distribution of Physocrema species in Southeast Asia. 21 — All Physocrema species; 22 — C. (P.) ampullaris; 23 — C. (P.) aurita; 24 — C. (P.) difformis; 25 — C. (P.) inflata; 26 — C. (P.) mucronata.