Polyrhachis inermis

Polyrhachis inermis
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Formicinae
Tribe:	Camponotini
Genus:	Polyrhachis
Subgenus:	Myrma
Species:	P. inermis
Binomial name
	Polyrhachis inermis; Smith, F., 1858 Specimen Labels
Synonyms
	Polyrhachis bryanti Donisthorpe, 1942;

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

Latitudinal Distribution Pattern

Latitudinal Range: 4.95° to 1.068237°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo, Indonesia (type locality), Malaysia, Philippines, Singapore, Sulawesi.
Oriental Region: Thailand.

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Castes

Worker


.	Owned by Museum of Comparative Zoology.

Images from AntWeb


Holotype of Polyrhachis inermis. Worker. Specimen code casent0903430. Photographer Z. Lieberman, uploaded by California Academy of Sciences.	Owned by NHMUK, London, UK.


Holotype of Polyrhachis bryanti. Worker. Specimen code casent0903431. Photographer Z. Lieberman, uploaded by California Academy of Sciences.	Owned by NHMUK, London, UK.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

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.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Type Material

Kohout (2008) - Holotype worker. INDONESIA, SULAWESI, The Natural History Museum (examined).

References

Bolton, B. 1974b [1973]. New synonymy and a new name in the ant genus Polyrhachis F. Smith (Hym., Formicidae). Entomol. Mon. Mag. 109: 172-180 (page 176, Senior synonym of bryanti)
Emery, C. 1925d. Hymenoptera. Fam. Formicidae. Subfam. Formicinae. Genera Insectorum 183: 1-302 (page 204, Combination in P. (Myrma))
Khachonpisitsak, S., Yamane, S., Sriwichai, P., Jaitrong, W. 2020. An updated checklist of the ants of Thailand (Hymenoptera, Formicidae). ZooKeys 998, 1–182 (doi:10.3897/zookeys.998.54902).
Kohout, R.J. 2008a. 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.
Smith, F. 1858b. Catalogue of hymenopterous insects in the collection of the British Museum. Part VI. Formicidae. London: British Museum, 216 pp. (page 68, pl. 4, figs. 25, 26 worker described)
Yamane, S., Tanaka, H.O., Hasimoto, Y., Ohashi, M., Meleng, P., Itioka, T. 2021. A list of ants from Lambir Hills National Park and its vicinity, with their biological information: Part II. Subfamilies Leptanillinae, Proceratiinae, Amblyoponinae, Ponerinae, Dorylinae, Dolichoderinae, Ectatomminae and Formicinae. Contributions from the Biological Laboratory, Kyoto University 31, 87–157.

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.