Polyrhachis monteithi

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Polyrhachis monteithi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Camponotini
Genus: Polyrhachis
Subgenus: Cyrtomyrma
Species: P. monteithi
Binomial name
Polyrhachis monteithi
Kohout, 2006

Polyrhachis monteithi casent0217435 p 1 high.jpg

Polyrhachis monteithi casent0217435 d 1 high.jpg

Specimen Labels

Polyrhachis monteithi builds nests of silk and vegetation debris between the leaves of low rainforest trees and shrubs. It has also commonly been collected in relatively small rainforest patches and gallery forests along rivers and creeks. (Kohout 2006)


Polyrhachis monteithi is charactersed by a distinctly hairy appearance that is shared by only one other Australian species, Polyrhachis pilosa. Polyrhachis monteithi differs by its larger size (HL 1.43-1.72 versus 1.34-1.43 in P. pilosa) and distinct propodeal spines that are completely absent in P. pilosa (Kohout 2006)

Keys including this Species


Queensland, from about Cooktown south to Mackay.

Latitudinal Distribution Pattern

Latitudinal Range: -16.52° to -21°.

Tropical South

Distribution based on Regional Taxon Lists

Australasian Region: Australia (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


One of the most common Cyrtomyrma species in rainforests of north Queensland.


Associations with other Organisms


  • This species is a host for the nematode Mermithidae (unspec.) (a parasite) in Australia (N. Queensland) (Downes, 2017; Laciny, 2021).


Males (undescribed) and immature stages (eggs, larvae in various stages of development and pupae) deposited in the Queensland Museum spirit collection. (Kohout 2006)


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

  • monteithi. Polyrhachis monteithi Kohout, 2006b: 101, figs. 3A, D-E (w.q.m.) AUSTRALIA.

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



Dimensions (holotype cited first): TL c. 6.50, 5.54-6.75; HL 1.68, 1.43-1.72; HW 1.64, 1.43-1.65; CI 98, 94-100; SL 2.06, 1.75-2.12; SI 126, 119-130; PW 1.31, 1.09-1.40; MTL 2.40, 1.96-2.46 (19 measured).

Clypeus in profile almost straight, weakly rounding posteriorly into moderately impressed basal margin. Frontal triangle indistinct. Frontal carinae sinuate with weakly raised margins; central area with weakly indicated frontal furrow. Sides of head in front of eyes almost straight, converging anteriorly and rounding into mandibular bases; behind eyes sides rounding into convex occipital margin. Eyes convex, in full face view breaking lateral cephalic outline. Ocelli lacking, relative positions indicated by shallow but distinct depressions in cephalic sculpturation. Pronotum in dorsal view widest across narrowly rounded or bluntly angular humeri. Mesosoma in lateral view evenly convex; promesonotal suture distinct; position of metanotal groove weakly indicated by shallow depression in lateral outline; propodeum armed with pair of rather strong, diverging, blunt spines; propodeal declivity almost vertical. Petiole with anterior face weakly convex, posterior face rather strongly convex; dorsum armed with four acute spines, medial pair closer to each other than to lateral spines; lateral pair more slender, longer and strongly diverging. Subpetiolar process acute anteriorly, bluntly angular posteriorly. Anterior face of first gastral segment lower than height of petiole, widely rounding onto dorsum of segment.

Mandibles finely, mostly longitudinally rugose. Head, mesosoma, petiole and gaster finely shagreened with numerous minute punctures and piliferous pits. Sculpturation relatively fine on dorsa of head, mesosoma and gaster; intensity of sculpturation distinctly increasing laterally with sides of mesosoma distinctly reticulate and meso- and metapleurae rather strongly reticulate-rugose. Anterior face of petiole finely, mostly transversely reticulate dorsally, becoming reticulate-rugose on lower parts.

Distinctly hairy. Numerous curved and semierect hairs arising from mandibular masticatory borders, numerous, very short, appressed hairs towards mandibular bases. Anterior clypeal margin with several long, anteriorly directed setae medially and fringe of shorter setae decreasing in length laterally. Several medium to long, erect or somewhat curved, mostly paired hairs near anterior and basal clypeal borders, along frontal carinae and on vertex. Tuft of several hairs on summit of mesonotum with longest hairs reaching greatest diameter of eye in length. Numerous erect, medium length hairs on dorsal and ventral surfaces of gaster. Short, dense, appressed, decumbent or semierect pubescence on most body surfaces, distinctly diluted behind eyes towards occipital corners.

Colour. Black, including antennal scapes, coxae and tarsi. Trochanters, femora and tibiae distinctly light to medium reddish-brown with proximal ends of tibiae a shade darker.


Dimensions: TL c. 7.11-7.76; HL 1.65-1.87; HW 1.56-1.75; CI 93-98; SL 2.03-2.18; SI 123-130; PW 1.62-1.78; MT: 2.46-2.71 (5 measured). Apart from sexual characters, similar to worker except: pronotal humeri evenly rounded; mesoscutum distinctly wider than long with lateral margins converging anteriorly, forming narrowly rounded anterior margin; median line distinct; parapsides flat anteriorly, raised posteriorly; mesoscutum in profile with anterior margin widely rounded, dorsum flat. Mesoscutellum in profile weakly convex, marginally raised above dorsal plane of mesosoma; metanotal groove distinct. Propodeum armed with pair of distinct, dorsoventrally flattened, blunt spines. Lateral petiolar spines more slender and longer than dorsal pair. Sculpturation, pilosity and colour virtually identical to that in worker.

Type Material

HOLOTYPE: QUEENSLAND, Garradunga, Seymour Ra., c. 7km N of Innisfail, 17°28’S, 146°01’E, <100m, 5-6.vi.1996, lowland rf., R.J. Kohout acc. 96.30 (worker). PARATYPES: data (and nest) as for holotype (12 workers, 7 alate queens, 15 males); data as for holotype, except RJK acc. 96.22 (75 workers, 2 dealate, 2 paratype alate queens). Holotype (QMT99338), 6 paratype workers, 4 paratype queens, paratype males (from holotype nest) and most paratype workers and paratype queens in Queensland Museum; 3 paratype workers, 1 paratype queens (from holotype nest) and 2 paratype workers each in Australian National Insect Collection, The Natural History Museum and Museum of Comparative Zoology; 2 paratype workers each in American Museum of Natural History, California Academy of Sciences, James Cook University, Townsville, Musee d'Histoire Naturelle Genève, Los Angeles County Museum of Natural History and National Museum of Natural History.


References based on Global Ant Biodiversity Informatics

  • Kohout R.J. 2006. Review of Polyrhachis (Cyrtomyrma) Forel of Australia, Borneo, New Guinea and the Solomon Islands with descriptions of new species. Memoirs of the Queensland Museum 52: 87-146.