Diacamma schoedli

This species extends along the eastern coast of Queensland from Torres Strait and Bamaga (at the tip of Cape York Peninsula) south to Innisfail. There is also a single record from the western Queensland Gulf Country (Lyrian Downs, N of Julia Creek), well outside the main distribution and the inland-most record of the genus in Australia. It is sympatric with Diacamma australe in the area south of Cooktown. While it is currently unknown from Papua New Guinea (based on material examined during this study) it may well occur there as these two countries share many species across a range of taxonomic groups.

Identification
Anterior clypeal margin weakly angular medially. Entire mandible (except along mandibular teeth) finely striate, occasionally with small foveae. Smaller body size (compare head length, head width, mesosomal length, mid-tibial length and scape length). Dorsal surfaces of pronotum and head with distinct rugae. Petiolar spines relatively narrowly spaced, anterior and dorsal faces of node similar in length and separated by a broad, rounded angle.

Diacamma schoedli differs from the similar Diacamma colosseense in being smaller, in the pattern of mandibular sculpturing and having the anterior clypeal mar-gin weakly angular medially (it is rounded in D. colosseense). It differs from Diacamma australe in the shape of the petiolar spines, shape of the node and sculpturing on the first gastral segment as outlined above under that species and in the key. Note, however, that the petiolar node shows variation in northern populations, where the shape is sometimes similar to that found in D. australe. In southern regions (and in areas of sympatry) the differences outlined above are consistent.

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

Nomenclature

 *  schoedli. Diacamma schoedli Shattuck & Barnett, 2006: 17, figs. 11-13 (w.) AUSTRALIA.

Worker
Head slightly longer than broad; erect hairs present on all surfaces as well as scapes; longitudinal rugae present posterior to frontal lobes, converging medially anterior of eyes, parallel posterior of eyes. Mandibles weakly striate along most of its length, the tip and ventral surfaces smooth. Anterior clypeal margin weakly angular medially. Mesosoma distinctly sculptured, most strongly dorsally, less so laterally and ventrally. Erect hairs present on entire dorsal surface. Petiolar node with anterior and dorsal faces rounding gently into each other; dorsal spines distinct, set relatively closely together; rugae present, horizontal, strongest anteriorly, weakest posteriorly. Gaster with first tergite essentially smooth (at most with very weak rugae), erect hairs and pubescence present. Entire body dark reddish-black to black, legs (especially near joints) often slightly lighter.

Measurements (n = 13): HL 2.47 - 2.76 mm, HW 2.00 - 2.22 mm, CI 78 - 84, SL 2.75 - 3.20 mm, SI 136 - 149, ML 3.62 - 4.08 mm, MTL 2.22 - 2.60 mm, PH 1.25 - 1.53 mm, PL 0.96 - 1.08 mm, PI 67 - 83.

References based on Global Ant Biodiversity Informatics

 * CSIRO Collection
 * Shattuck S. O., and N. J. Barnett. 2006. Australian species of the ant genus Diacamma (Hymenoptera: Formicidae). Myrmecologische Nachrichten 8: 13-19.