Colobostruma unicorna

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Colobostruma unicorna
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Colobostruma
Species: C. unicorna
Binomial name
Colobostruma unicorna
Shattuck, 2000

Colobostruma unicorna P casent0900009.jpg

Colobostruma unicorna D casent0900009.jpg

Specimen Label

The only known nest was found in open sclerophyll under rocks in soil on slope of ridge, and in nests of Polyrhachis ammon and Pseudoneoponera mayri.


Shattuck (2000) - The raised frontal lobes and extreme lateral margins of the clypeus combined with a projection on the centre of the clypeus will readily separate this species from all others in the genus, including the similar Colobostruma bicorna.

Keys including this Species


Mid to southern coastal Queensland

Distribution based on Regional Taxon Lists

Australasian Region: Australia (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


Beyond what is stated in the introduction at the top of this page, little is know about the biology of Colobostruma unicorna. Until further studies reveal more about this species we can infer that its natural history and biology should be similar to other species in this genus. In general Colobostruma can be locally common although they are often overlooked. Most species have small colonies with less than 100 workers, and workers will lie motionless when disturbed. Nests can occur in soil usually under rocks, in cracks in rocks or in rotten logs. Only a single rainforest species is known to nest arboreally. Foraging is usually on the ground at night but occasionally they are found foraging on mallee. They are also commonly found in leaf litter.



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

  • unicorna. Colobostruma unicorna Shattuck, in Bolton, 2000: 46, figs. 37, 48 (w.q.) AUSTRALIA.

Type Material

Paratype Specimen Labels

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



HOLOTYPE WORKER. TL 3.0, HL 0.70, HW 0.60, CI 86, ML 0.14, MI 20, SL 0.32, SI 53, PW 0.39, AL 0.80. Anterior region of head raised slightly above the posterior region and separated from it by a rounded angle, thus the head weakly but not obviously phragmotic. In full-face view ridge immediately in front of eye weakly concave. Frontal lobes immediately above the antennal insertions and the lateral margins of clypeus immediately above the mandibular insertions raised above the surrounding surface of the head; the centre of the clypeus with a distinct, raised pointed projection. Mandibles broadly triangular. Hairs absent from dorsum of head. Posterior margin of head deeply concave. Antenna with 5 or 6 segments, when 6-segmented the fourth funicular segment from the base is much shorter than the third segment. Scape weakly elbowed and without a subbasal lobe. In dorsal view the widest point of the pronotum is at the humeral angles. Propodeum high, its declivity approximately the same height as the petiolar node and with broad, thin lamellae; in profile the dorsum of the alitrunk flat with a weak convexity at the metanotal groove. Petiole with a broad, irregular ventral lamella. Lateral postpetiole drawn outwards into thin flange-like wings, the wings with translucent windows along both their anterior and posterior margins, the windows separated by a narrow band of thickened integument, the anterior windows smaller than the posterior windows. First gastral tergite with delicate reticulate sculpture which is stronger anteriorly and weaker posteriorly, the anterior one-third superimposed with low, closely spaced carinae. Body colour honey yellow, dorsum of head slightly darker.


  • Shattuck, S. O. 2000. Genus Colobostruma. Genus Mesostruma. Genus Epopostruma. Pp. 31-67 in: Bolton, B. The ant tribe Dacetini. Mem. Am. Entomol. Inst. 65: 1-1028. (page 46, figs. 37, 48 worker, queen described)

References based on Global Ant Biodiversity Informatics

  • Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65