Crematogaster jacobsoni

Identification
Hosoishi and Ogata (2012) – Examination of syntype workers in and  reveals that C. jacobsoni is not similar to the C. brevis group or C. treubi group in Asia. Characteristic features include: occipital carinae developed; petiole weakly broader anteriorly, but without angular corners; postpetiole weakly bilobed with longitudinal median sulcus. This species is similar to Crematogaster semperi or Crematogaster simoni. We hereby transfer C. jacobsoni to the subgenus Crematogaster, to compare it with closely related species in this group in the future.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia.

Nomenclature

 * . Crematogaster jacobsoni Forel, 1911b: 201 (w.) INDONESIA (Java).
 * Type-material: syntype workers (number not stated).
 * Type-locality: Indonesia: Java, Semarang (E. Jacobson).
 * Type-depositories: MHNG, NHMB.
 * Combination in C. (Orthocrema): Emery, 1922e: 132;
 * combination in C. (Acrocoelia): Santschi, 1928b: 34;
 * combination in C. (Mesocrema): Santschi, 1937e: 310.
 * Status as species: Emery, 1922e: 132; Menozzi, 1935a: 112 (in key); Chapman & Capco, 1951: 98; Bolton, 1995b: 155.
 * Distribution: Indonesia (Java).

Type Material
Hosoishi and Ogata (2012) –Three syntype workers from INDONESIA: Semarang, Java and one syntype worker  [examined].

References based on Global Ant Biodiversity Informatics

 * 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
 * Forel A. 1911. Ameisen aus Java beobachtet und gesammelt von Herrn Edward Jacobson. II. Theil. Notes Leyden Mus. 33: 193-218.
 * 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.
 * Hosoishi S., K. Ogata. 2012. Revision of the Crematogaster brevis complex in Asia (Hymenoptera: Formicidae). Zootaxa 3349: 18-30.
 * Hosoishi, S., and K. Ogata. "Revision of the Crematogaster brevis complex in Asia (Hymenoptera: Formicidae)." Zootaxa 3349 (2012): 18-30.
 * Yamane S. 2013. A Review of the ant fauna of the Krakatau Islands, Indonesia. Bull. Kitakyushu Mus. Nat. Hist. Hum. Hist. Ser: A, 11: 1-66