Polyrhachis levior

Polyrhachis levior is known only by the unique holotype (missing its head) from Aru Island, Indonesia (Kohout 2006). Nothing is known about this species' biology.

Identification
Its distinctly bilobed pronotal humeri resemble those of Polyrhachis albertisi. The mesosoma features a rather steeply raised pronotum and weakly convex mesonotum and propodeum. The promesonotal suture is distinct but the metanotal groove lacking, its position indicated only by a slight depression in the mesosomal outline. The propodeal spines are relatively long, somewhat dorso-ventrally compressed, directly dorso-laterally and posteriorly, with their bases set well apart. The dorsum of the petiole is furnished with four sharp teeth of equal length. (Kohout 2006)

Distribution
Known only from the type locality - Aru Island, Indonesia.

Abundance
Known only from the single type specimen.

Castes
Known only from the (type) worker.

Nomenclature

 * laevissimus. Polyrhachis laevissimus Smith, F. 1859a: 141 (w.) INDONESIA (Aru I.). [Junior primary homonym of laevissima Smith, above.] Replacement name: levior Roger, 1863b: 8.
 *  levior. Polyrhachis levior Roger, 1863b: 8. Replacement name for laevissimus Smith, F. 1859a: 141. [Junior primary homonym of laevissima Smith, 1858b: 64.] Combination in P. (Cyrtomyrma): Forel, 1915b: 110. Subspecies of rastellata: Forel, 1902h: 527. Revived status as species: Donisthorpe, 1938c: 248; Taylor & Brown, D.R. 1985: 137. See also: Kohout, 2006b: 130.

Polyrhachis laevissimus

Holotype worker in. Labelled “Aroo 25” (= Aru I., New Guinea) and with a Donisthorpe type-label, and also with a Donisthorpe det. label “levior Roger.” Head of holotype is missing.

Worker
Length 2 3/4 lines. Black, very smooth and shining; the legs ferruginous, with the coxae, articulations, and the tarsi black. The thorax: not flattened above, or margined at the sides; the division between the pro- and mesothorax distinct, that between the meso and metatborax not discernible, the latter with two erect acute spines; the scale of the petiole with four short acute spines. Abdomen globose.

Type Material
Holotype worker. ; Junior homonym of P. laevissima Fr. Smith, 1858:64 – as reported in Kohout (2006).

Type Locality Information
INDONESIA, Aru Island, col. A.R. Wallace.

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

Roger, J. 1863. Verzeichniss der Formiciden-Gattungen und Arten. Berliner Entomologische Zeitschrift 7 (Beilage): 1-65.

Smith, F. 1859. Catalogue of hymenopterous insects collected by Mr A.R. Wallace at the Islands of Aru and Key. Journal of the Proceedings of the Linnean Society of London, Zoology 3: 132-158.