Eurhopalothrix biroi

Wilson made all of his collections in lowland rain forest, where the ants were foraging in leaf litter and in and beneath rotten logs. He found one small shallow nest in the soil under a rotting log. His observations indicate that the food of this species is principally small, soft-bodied arthropods, particularly entomobryid Collembola, which are stealthily stalked and caught by a sudden jaw snap. (Brown and Kempf 1960)

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

Nomenclature

 *  biroi. Rhopalothrix biroi Szabó, 1910a: 365, fig. 2 (w.) NEW GUINEA. Brown & Kempf, 1960: 223 (m.). Combination in Eurhopalothrix: Brown & Kempf, 1960: 222.

Worker
Brown and Kempf (1960) - TL 2.5-3.0, HL 0.62-0.68, HW 0.68-0.75 (CI 109-111), scape L 0.35-0.38, greatest diameter of eye 0.08, WL 0.70-0.78 mm, measurements from 16 workers representing at least 8 separate collections, all from the Huon Peninsula, New Guinea.

Note especially the striking development of the dorsal cephalic squamiform ground pilosity behind the eye level; the larger specialized hairs in this species are reduced to nearly the same size and shape as the ground hairs, though their arrangement remains fairly typical for the genus. The front half of the head often carries a thin grayish or whitish incrustation, which may be a secretion.

Seen from above, the petiolar node is rather large, about half again as broad as long, with rounded sides and straight anterior margin. Petiolar peduncle with a small, oblique anteroventral tooth, wholly visible only when the gaster and pedicel are raised. Postpetiole renitorm, shallowly longitudinally sulcate above, less than twice as wide as petiolar node.

Color deep reddish-brown, the white squamiform hairs in striking contrast, especially on the head.

Male
TL 2.9, HL 0.52, HW including compound eyes 0.55, WL 0.87, forewing L ca. 2.7 mm. Head, note the median pit between the antennal insertions. Compound eye nearly round, diameter about 0.20 mm. Mandibles slender, apparently not opposable, with 1 or 2 vestigial teeth near apices. Mesonotul11 with shallow but distinct notauli, becoming indistinct posteriad at the stem of the Y. Propodeal teeth small, suhrectangular. Petiole subclavate, the node low and rounded, with a distinct posterior peduncle and a small anteroventral tooth. Most of postpetiolar disc and most of gaster (above and below) smooth and shining; sides and apex of gaster finely punctate and only weakly shining. Body otherwise reticulate-punctate and opaque. Forewing venation much as for Creightonidris, except that Rsf 4 fades out before reaching the wing margin (radial cell open), and M is lacking beyond Rs+M. Genitalia unremarkable, with blunt, rounded parameres. Color medium orange-brown; ocellar triangle, mesonotum and gastric dorsum infuscated; extremities of appendages lighter, more yellowish.

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
 * 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.
 * Lucky A., E. Sarnat, and L. Alonso. 2011. Ants of the Muller Range, Papua New Guinea, Chapter 10. In Richards, S. J. and Gamui, B. G. (editors). 2013. Rapid Biological Assessments of the Nakanai Mountains and the upper Strickland Basin: surveying the biodiversity of Papua New Guineas sublime karst environments. RAP Bulletin of Biological Assessment 60. Conservation International. Arlington, VA.
 * 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. 1970. Notes on some Australian and Melanesian basicerotine ants (Hymenoptera: Formicidae). Journal of the Australian Entomological Society 9: 49-52.
 * 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.
 * Wilson E. O. 1956. Feeding behavior in the ant Rhopalothrix biroi Szabó. Psyche (Cambridge) 63: 21-23.
 * Wilson E. O. 1959. Some ecological characteristics of ants in New Guinea rain forests. Ecology 40: 437-447.