Polyrhachis denticulata

Nothing is known about the biology of .

Identification
A member of the penelope species-group in the Polyrhachis subgenus Hagiomyrma. Kohout (2013): Polyrhachis denticulata is rather similar to Polyrhachis penelope which resulted in specimens collected by F. Dahl at Ralum, being identified as P. penelope by Forel (1901:31). However, the differences separating the species are rather obvious and are discussed in the remarks section under the latter species.

Distribution based on Regional Taxon Lists
Australasian Region: Australia. Indo-Australian Region: Indonesia, New Guinea.

Castes
Males and immature stages were apparently collected by F. Dahl at Ralum (Bismarck Archipelago) and should be lodged in the. However, in a recent visit I failed to locate the material and consider it lost. (Kohout 2013)

Nomenclature

 *  denticulata. Polyrhachis (Hagiomyrma) denticulata Karavaiev, 1927e: 13, fig. 4 (w.) INDONESIA (Ambon I.).

Type locality(-ies): “Amboina, 11.I.1913 (Nr. 3008), ww”.

Original Karawajew label(-s): “Polyrhachis (Hagiomyrma) / denticulata Karav. typus / Amboina, Karavaev, 3008.”.

Material: SYNTYPES, 7 w, 1 q (newly mounted, IN 314/6/1), 134 w (in alcohol, IN 314/BAMS1/Karaw4–6).

Worker
(syntypes cited first): TL c. 6.20-6.70, 6.00-7.43; HL 1.50-1.59, 1.50-1.75; HW 1.22-1.31, 1.22-1.43; CI 81-82, 80- 83; SL 1.68-1.78, 1.68-2.00; SI 136-138, 136-146; PW 1.14-1.25, 1.12-1.34; MW 0.65-0.69, 0.62-0.89; PMI 175-181, 172-185; MTL 1.90-2.00, 1.90-2.37 (2+9 measured).

Mandibles with 5 teeth, distinctly reducing in length towards base. Anterior clypeal margin medially truncate and denticulate, without clearly defined median flange. Clypeus with distinct median carina; sinuate in profile, posteriorly rounding into moderately impressed basal margin. Frontal carinae sinuate with weakly raised margins; central area relatively wide, with medially raised ridge. Sides of head in front of eyes converging towards mandibular bases in straight line; behind eyes, sides rounding into convex occipital margin. Ocelli indistinct. Pronotal dorsum distinctly wider than long; humeri widely rounded with raised, posteriorly converging margins; promesonotal suture distinctly impressed. Mesonotal margins converging posteriorly into medially flat metanotal groove. Propodeal dorsum with lateral margins terminating in more-or-less horizontal, divergent, acute spines. Petiole with anterior face straight, posterior face distinctly swollen; dorsum shallowly concave medially, armed with pair of divergent, weakly elevated, acute spines. Anterior face of first gastral tergite widely rounding onto dorsum.

Mandibles longitudinally striate with numerous piliferous pits; head, mesosoma and petiole reticulate-punctate. Gaster shagreened.

Mandibular masticatory and outer borders with medium length, golden hairs. Anterior clypeal margin medially with several, medium length, golden setae. Numerous, semierect, anteriorly inclined hairs on clypeus, front and vertex of head, a number of hairs fringing outline of head in full face view. Mesosoma and petiole with numerous erect or semierect hairs; gaster with rather abundant, posteriorly inclined, golden hairs, some longer than half of diameter of eyes. Rather sparse and long, silvery, appressed pubescence, covering most body surfaces; pubescence more abundant on gaster, pale golden on dorsum and silvery on sides and venter.

Head and mesosoma black or very dark reddish-brown; mandibles, clypeus, anterior portion of pronotum, appendages and gaster medium reddish-brown. Colour scheme in older specimens, including syntypes, is generally light, reddish-brown, while more recently collected specimens are distinctly darker, with head and mesosoma almost black.

Queen
TL c. 7.15-7.41; HL 1.62; HW 1.31; CI 81; SL 1.78; SI 136; PW 1.51-1.59; MTL 2.09-2.12 (2 measured).

Apart from sexual characters very similar to worker, except: mesoscutum in lateral view relatively low with anterior margin rounding onto flat dorsum; median line bifurcate anteriorly; parapsides flat. Mesoscutellum weakly convex, not elevated above dorsal plane of mesosoma. Propodeal spines very short, subparallel, with tips weakly curved downwards. Petiolar spines very short, divergent. Sculpturation, pilosity, pubescence and colour virtually identical to worker.

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
 * Kohout R. J., and R. W. Taylor. 1990. Notes on Australian ants of the genus Polyrhachis Fr. Smith, with a synonymic list of the species (Hymenoptera: Formicidae: Formicinae). Memoirs of the Queensland Museum 28: 509-522.
 * Kohout R.J. 2013. Revision of Polyrhachis (Hagiomyrma) Wheeler, 1911 (Insecta: Hymenoptera: Formicidae: Formicinae). Memoirs of the Queensland Museum  Nature 56: 487577
 * Latumahina F., M. Borovanska, N. S. Putra, and M. Janda. 2015. Ants of Ambon Island  diversity survey and checklist. ZooKeys 472: 4357.
 * Martynov A. V., and A. G. Radchenko. 2016. Karawajew’s ant type specimens (Hymenoptera, Formicidae) in the National Museum of Natural History of the National Academy of Sciences of Ukraine. Zootaxa 4097 (2): 244–254.
 * Robson Simon Database Polyrhachis -05 Sept 2014