Eurhopalothrix brevicornis

E. O. Wilson collected a small series of workers and a stray at the Lower Busu River, near Lae, New Guinea, hy Berlese funnel from rain forest leaf litter. The MCZ has two workers taken by K. P. Schmidt from a bird's-nest fern at Rabaul, New Britain. (Brown and Kempf 1960)

Distribution based on Regional Taxon Lists
Indo-Australian Region: New Guinea, Solomon Islands.

Nomenclature

 *  brevicornis. Rhopalothrix brevicornis Emery, 1897c: 572, fig. 19 (w.) NEW GUINEA. Szabó, 1910a: 367 (q.). Combination in Eurhopalothrix: Brown & Kempf, 1960: 215. Senior synonym of mixta: Brown & Kempf, 1960: 215.
 * mixta. Rhopalothrix mixta Szabó, 1910a: 366, fig. 4 (w.) NEW GUINEA. Junior synonym of brevicornis: Brown & Kempf, 1960: 215.

Worker
Brown and Kempf (1960) - TL 1.7-1.8, HL 0.42-0.46, HW 0.46-0.50 (CI 109-110), scape L 0.26-0.27, greatest diameter of eye ca. 0.02, WL 0.46-0.47 mm; based on 7 workers from New Guinea and New Britain.

Differs from other members of its group in its smaller size and in shape of alitrunk with its abruptly sloping concave dorsal face of propodeum and small subrectangular propodeal teeth. Also the following distinctive characters:

1. Clypeus traversed by a distinct, arcuate carina, separating a large, concave anterior part (covered with small squamiform hairs and opaque) and a small, feebly convex, triangular posterior part (which is nearly smooth, naked, weakly shining). In this feature, surprisingly, brevicornis resembles Eurhopalothrix clypeata of the New World (q. v.).

2. The arcuate row of 8 large specialized hairs stretching across the vertex between the eyes stands upon a feeble carina that follows the same course. Sometimes a faint trace of such a carina may be seen in other species of the genus, and it appears to be a homologue of the similarly placed carina in Octostruma rugifera, Octostruma rugiferoides, and some of the Rhopalothrix species.

3. Erect specialized hairs short and thick, clavate; 16 on cephalic dorsum; 1 pair straddling mesonotum, in most specimens missing and possibly rubbed off; first gastric tergite with 3 pairs, forming a double longitudinal row, and outside of third (posterior) pair are two more hairs, so that a transverse row of 4 is formed near the posterior edge of the segment. Both petiole and postpetiole lack larger specialized hairs entirely.

4. Petiolar node small and rather rounded above as seen from the side; as seen from above, node transverse, with rounded sides and feebly concave anterior border. Postpetiolar node about twice as wide as petiolar node, and very nearly three times as wide as long, 3/4 as wide as gaster.

5. Ground pilosity of appressed and subappressed hairs well developed on head (except for indistinct "bald area" on verticocciput), mandibles, scapes, promesonotum, legs, both nodes and gastric dorsum. Color medium ferruginous.

Queen
Brown and Kempf (1960) - Female, dealate: TL 2.3, HL 0.52, HW 0.56 (CI 108), scape L 0.31, greatest diameter of eye ca. 0.12, WL 0.62 mm. With the usual differences of caste. Dorsolateral margins of rnesonoturn with 6 short, inconspicuous, subreclinate clavate hairs. Color as in worker.

References based on Global Ant Biodiversity Informatics

 * Brown W. L., Jr., and W. W. Kempf. 1960. A world revision of the ant tribe Basicerotini. Stud. Entomol. (n.s.) 3: 161-250.
 * CSIRO Collection
 * Emery C. 1897. Formicidarum species novae vel minus cognitae in collectione Musaei Nationalis Hungarici quas in Nova-Guinea, colonia germanica, collegit L. Biró. Természetrajzi Füzetek 20: 571-599.
 * Greenslade P.J.M. and Greenslade Penelope. 1977. Some Effects of Vegetation Cover and Disturbance on a Tropical Ant Fauna. Insectes Sociaux 24(2): 163-182
 * Greenslade P.J.M. and P. Greenslade. 1977. Some effects of vegetation cover and disturbance on a tropical ant fauna. Insectes Sociaux 24(2): 163-182.
 * Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on http://www.newguineants.org/. Accessed on 24th Feb. 2011.
 * Snelling R. R. 1998. Insect Part 1: The social Hymenoptera. In Mack A. L. (Ed.) A Biological Assessment of the Lakekamu Basin, Papua New Guinea, RAP 9. 189 ppages
 * Szabó J. 1910. Formicides nouveaux ou peu connus des collections du Musée National Hongrois. [part]. Ann. Hist.-Nat. Mus. Natl. Hung. 8: 364-368.
 * Taylor R. W. 1968. Notes on the Indo-Australian basicerotine ants (Hymenoptera: Formicidae). Australian Journal of Zoology 16: 333-348.
 * Taylor R. W. 1980. Australian and Melanesian ants of the genus Eurhopalothrix Brown and Kempf - notes and new species (Hymenoptera: Formicidae). Journal of the Australian Entomological Society 19: 229-239.
 * Viehmeyer H. 1912. Ameisen aus Deutsch Neuguinea gesammelt von Dr. O. Schlaginhaufen. Nebst einem Verzeichnisse der papuanischen Arten. Abhandlungen und Berichte des Königlichen Zoologischen und Anthropologische-Ethnographischen Museums zu Dresden 14: 1-26.