Polyrhachis equina

AntWiki: The Ants --- Online
Polyrhachis equina
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Camponotini
Genus: Polyrhachis
Subgenus: Campomyrma
Species: P. equina
Binomial name
Polyrhachis equina
Smith, F., 1857

Polyrhachis equina casent0901858 p 1 high.jpg

Polyrhachis equina casent0901858 d 1 high.jpg

Specimen Labels

Synonyms

Identification

Polyrhachis equina and Polyrhachis gribodoi are very similar and share numerous characters including almost identical, bilobed anterior clypeal margins, distinctly concave mesonotal and propodeal dorsa, dorso posteriorly extended propodeal spines and similarly shaped petioles. They differ in their relative size (HL <1.80 in P. equina versus HL >1.90 in P. gribodoi) and in several other characters, including the shape of the head and the sculpturation of the mesosomal dorsum. In P. equina, the sides of the head in front of the eyes converge towards the mandibular bases in an almost straight line, while behind the eyes the sides round into a moderately convex occipital margin. In P. gribodoi the sides of the head in front of the eyes are distinctly convex, and behind the eyes the sides round into a virtually flat occipital margin. The mesosomal dosum of P. equina is finely, rather irregularly, reticulate-punctate, with the reticulae on the pronotum somewhat bowed towards its lateral margins. The sculpturation of the mesosomal dorsum in P. gribodoi is distinctly more intense and more regularly, longitudinally striate on pronotum. (Kohout 1988)

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 7.158611111° to 1°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo (type locality), Indonesia, Malaysia.

Distribution based on AntMaps

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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.
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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.
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Biology

Castes

Images from AntWeb

Polyrhachis equina casent0906322 d 1 high.jpgPolyrhachis equina casent0906322 p 1 high.jpgPolyrhachis equina casent0906322 l 1 high.jpgPolyrhachis equina casent0906322 h 1 high.jpg
Worker. Specimen code casent0906322. Photographer Michele Esposito, 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.

  • equina. Polyrhachis equinus Smith, F. 1857a: 63 (w.) BORNEO. Combination in P. (Campomyrma): Wheeler, W.M. 1919e: 122. Senior synonym of biloba: Wheeler, W.M. 1919e: 122. See also: Kohout, 2007c: 10.
  • biloba. Polyrhachis biloba Forel, 1911a: 58 (w.) BORNEO. Junior synonym of equina: Wheeler, W.M. 1919e: 122.

The following notes on F. Smith type specimens have been provided by Barry Bolton (details):

Polyrhachis equinus

Holotype worker in Oxford University Museum of Natural History. Labelled “SAR. 21” (= Sarawak) and with a Donisthorpe type-label.

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

Description

Worker

Kohout (1988) - Dimensions (holotype cited first): TL c. 6.40, 6.05- 6.65; HL 1.72, 1.56-1.80; HW 1.43, 1.25-1.50; CI 83, 79-83; SL (missing), 2.03-2.18; SI (missing), 159- 164; PW 0.87, 0.75-0.90; MTL 2.09, 2.00-2.25 (12 measured).

References

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
  • 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
  • Fayle T. M., D. P. Edwards, E. C. Turner, A. J. Dumbrell, P. Eggleton, and W. A. Foster. 2012. Public goods, public services and by-product mutualism in an ant–fern symbiosis. Oikos 121(8): 1279-1286.
  • Forel A. 1911. Fourmis de Bornéo, Singapore, Ceylan, etc. récoltées par MM. Haviland, Green, Winkler, Will, Hose, Roepke et Waldo. Rev. Suisse Zool. 19: 23-62.
  • Kohout R.J. 2007. A review of the subgenus Polyrhachis (Campomyrma) Wheeler from Borneo with descriptions of new species. Asian Myrmecology 1: 7-17.
  • 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
  • Smith, F. "Catalogue of the hymenopterous insects collected at Sarawak, Borneo; Mount Ophir, Malacca; and at Singapore, by A. R. Wallace." Journal of the Proceedings of the Linnean Society of London, Zoology 2 (1857): 42-88.
  • Wheeler W. M. 1919. The ants of Borneo. Bulletin of the Museum of Comparative Zoology 63:43-147.
  • 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.
  • Woodcock P., D. P. Edwards, T. M. Fayle, R. J. Newton, C. Vun Khen, S. H. Bottrell, and K. C. Hamer. 2011. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants. Phil. Trans. R. Soc. B. 366: 3256-3264.
  • Yamane S.; Nona, A. R. 1994. Ants from Lambir Hills National Park, Sarawak. Pp. 222-226 in: Inoue, T.; Hamid, A. A. (eds.) 1994. Plant reproductive systems and animal seasonal dynamics. Long-term study of dipterocarp forests in Sarawak. Kyoto: Center for Ecological Research, Kyoto University, vii + 255 pp. 
  • Yusah K. M., T. M. Fayle, G. Harris, and W. A. Foster. 2012. Optimizing diversity assesment protocols for high canopy ants in tropical rain forest. Biotropica 44(1): 73-81.