Polyrhachis inermis

Identification
A member of the Polyrhachis inermis species group in the subgenus Myrma

Kohout (2008) - The holotype worker of P. inermis is very similar to specimens from Dumoga-Bone NP and other recently collected material from elsewhere in Sulawesi. However, the modern specimens are generally more slender than the holotype, due to a narrow pronotal dorsum. Their pronotal spines are also slightly less divergent, with the lateral pronotal margins at the bases of spines less emarginate. In addition they have rather distinct longitudinal striation on the mesosomal dorsum which is rather vague in the holotype, notably on the pronotal dorsum. The eyes are fairly convex in the holotype and clearly exceed the outline of the head in full face view, while in most of the recently collected specimens the eyes do not, or only marginally, exceed the lateral cephalic outline.

In Sulawesi there are two inermis-group species:


 * Black throughout . . . . . Polyrhachis inermis


 * Body black; tibiae light to medium reddish-brown with rest of legs distinctly darker . . . . . Polyrhachis orsylla

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia, Philippines, Singapore, Sulawesi. Oriental Region: Thailand.

Nomenclature

 *  inermis. Polyrhachis inermis Smith, F. 1858b: 68, pl. 4, figs. 25, 26 (w.) INDONESIA (Sulawesi). Combination in P. (Myrma): Emery, 1925b: 204. Senior synonym of bryanti: Bolton, 1974b: 176.
 * bryanti. Polyrhachis (Myrma) bryanti Donisthorpe, 1942e: 707 (w.) BORNEO. Junior synonym of inermis: Bolton, 1974b: 176.

Type Material
Kohout (2008) - Holotype worker. INDONESIA, SULAWESI, (examined).

References based on Global Ant Biodiversity Informatics

 * Bolton B. 1974. New synonymy and a new name in the ant genus Polyrhachis F. Smith (Hym., Formicidae). Entomol. Mon. Mag. 109: 172-180
 * 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
 * Dorow W. H. O., and U. Maschwitz. 1990. The arachne-group of Polyrhachis (Formicidae: Formicinae): weaver ants cultivating Homoptera on bamboo. Insectes Sociaux. 37: 73-89.
 * Emery C. 1886. Saggio di un catalogo sistematico dei generi Camponotus, Polyrhachis e affini. Memorie della Reale Accademia delle Scienze dell'Istituto di Bologna 5: 363-382
 * Emery C. 1901. Formiciden von Celebes. Zoologische Jahrbücher. Abteilung für Systematik, Geographie und Biologie der Tiere 14:565-580.
 * Floren A., W. Wetzel, and M. Staab. 2013. The contribution of canopy species to overall ant diversity (Hymenoptera: Formicidae) in temperate and tropical ecosystems.  Myrmecological News 19: 65-74.
 * Helms J. A., S. M. Helms, N. I. Fawzi, Tarjudin, F. Xaverius. 2017. Ant community of an Acacia mangium forest in Indonesian Borneo. Serangga 22(1): 147-159.
 * Ito, F.; Yamane, S.; Eguchi, K.; Noerdjito, W. A.; Kahono, S.; Tsuji, K.; Ohkawara, K.; Yamauchi, K.; Nishida, T.; Nakamura, K. 2001. Ant species diversity in the Bogor Botanic Garden, West Java, Indonesia, with descriptions of two new species of the genus Leptanilla (Hymenoptera, Formicidae). Tropics 10:379-404.
 * Jaitrong W.; Nabhitabhata, J. 2005. A list of known ant species of Thailand. The Thailand Natural History Museum Journal 1(1): 9-54.
 * Kohout R.J. 2008. A new Polyrhachis (Myrma) vestita-group species from Sulawesi. Zoologische Mededeelingen, Leiden 82: 297-302.
 * Kohout R.J., and M. Mohamed. 2008. A preliminary list of the Polyrhachis ants of the Maliau Basin Conservation area in Sabah, Borneo (Hymenoptera: Formicidae: Formicinae). Asian Myrmecology 2: 63-70.
 * Kohout, R. J. 2008. A review of the Polyrhachis ants of Sulawesi with keys and descriptions of new species (Hymenoptera: Formicidae: Formicinae). Memoirs of the Queensland Museum 52:255-317.
 * Pfeiffer M., D. Mezger, and J. Dyckmans. 2013. Trophic ecology of tropical leaf litter ants (Hymenoptera: Formicidae) - a stable isotope study in four types of Bornean rain forest. Myrmecological News 19: 31-41.
 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
 * Robson Simon Ant Collection, 05-Sept-2014
 * Robson Simon Database Polyrhachis -05 Sept 2014
 * Sukimin S., M. Mohamed, and H. Aris. 2010. Ant diversity of Maliau Basin Conservation Area, Sabah, Malaysia. Journal of Tropical Biology and Conservation 6:89-101.
 * Widodo E.S., M. Mohamed, and Y. Hashimoto. 2001. Canopy ant diversity assessment in the fragmented rainforest of Sabah, East Malaysia. Nature and Human activities 6: 13-23.