Aphaenogaster reichelae, Shattuck, S. O., 2008

Shattuck, S. O., 2008, Australian ants of the genus Aphaenogaster (Hymenoptera: Formicidae)., Zootaxa 1677, pp. 25-45 : 43-44

Aphaenogaster reichelae sp. n.

(Figs 17, 18, 23, 31)

Types. Holotype worker, Australia, Northern Territory, Podocarpus Canyon, 12°38.73'S 133°26.73'E, Dec. 1993, H. Reichel, Nest A3 ( ANIC) ( ANIC 32-031019); paratype workers, 6 (same data as holotype) ( ANIC 32- 031020), 4 (same data as holotype but Nest B2) ( ANIC 32-031021) and 6 (same data as holotype but Nest E9) ( ANIC 32-000327) ( ANIC, MCZC).

Diagnosis. Hairs on venter of head randomly distributed (Fig. 18); scape relatively long (SI greater than 135, Fig. 23); posterior margin of head nearly flat in full face view (Fig. 17); propodeal spines short (Fig. 18). This species is morphologically similar to A. pythia but differing from it in the relatively longer scapes and in having the dorsal and posterior faces of the petiolar node only weakly defined.

Description. Posterior margin of head nearly flat in full face view, extending laterally of the occipital collar before passing through a distinct posterolateral corner into the lateral margin of the head. Hairs on venter of head randomly distributed and not forming a distinct psammophore. Mandibular sculpture composed of regularly sized striations. Shorter erect hairs on mesosomal dorsum generally tapering to sharp points but often those on propodeum thickened and more or less blunt. Propodeal spines short. Dorsal surfaces of propodeum and propodeal spines connected through a gentle concavity (so that the base of each spine is at approximately the same level as the dorsal surface of the propodeum). Petiolar node (in dorsal view) approximately square.

Measurements. Worker (n = 6). CI 83-87; EI 15-19; EL 0.17-0.19; HL 1.12-1.32; HW 0.93-1.14; ML 1.52-1.82; MTL 0.95-1.12; SI 128-139; SL 1.29-1.47.

Comments. This species is currently known from a single location, Podocarpus Canyon, in the East Alligator River catchment, Arnhemland, Northern Territory (Fig. 31). This canyon is approximately 15km long and contains rainforest vegetation. When the type series was collected these ants were fairly common in the upper few kilometres of the canyon, where they were found nesting on the flat sand sheet along the creek which runs through the gorge. The curious thing is that this sand sheet floods during the wet season, completely covering the nesting sites. Even while these collections were being made there were heavy rains overnight which destroyed the conical nest entrances, the ants being forced to repair the damage each morning. It would be interesting to learn how these ants have adapted to life in such a harsh and variable location. (These notes were made by H. Reichel while making the only known collection of this interesting species.)

Conclusion

All Australian species of Aphaenogaster are endemic except pythia , which is shared with Papua New Guinea. Nests are always in soil, often in the open with large funnel-shaped entrances but also under rocks or logs on the ground. Individual species range from common and widespread to rare and with restricted distributions.

The nomenclature of these species was found to be unexpectedly complex given the small number of species involved. This was primarily caused by the large number of studies dealing with these ants and the lack of examination of type material. Provisional names were proposed and several species were established by indication, in one case using specimens which were not directly examined by the author and, in fact, had been destroyed at the time the name was established. While all of these events are common among the ants, it was surprising to find so many among such a small group.