Aphaenogaster barbigula

This species occurs in semi-arid areas of eastern South Australia, south-central Queensland, western New South Wales and north-western Victoria. It is generally found in forested habitats including Callitris and mulga (Acacia sp.) woodlands (including on red soils), mallee (with and without spinifex grass (Triodia)) and in savannah woodlands, but is occasionally found in grasslands, especially with scattered trees. It is most often found on sandy soils. Nests are always in soil and almost always have large, deep craters around the entrance (Shattuck, 2008). The biology of this species was discussed by Crawley (1922:122).

Identification
Majority of hairs on underside of head located laterally and forming a distinct psammophore; eye relatively small (EI less than 21); scape relatively short (SI less than 106); mandibular sculpture composed of regularly sized striations; petiolar node (in dorsal view) approximately square. The presence of a psammophore will separate this species from all others except A. mediterrae and A. poultoni. It can be separated from these species as outlined in the key to Australian species.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  barbigula. Aphaenogaster (Nystalomyrma) barbigula Wheeler, W.M. 1916j: 221, pl. 21, figs. 7-9 (w.q.) AUSTRALIA. Forel, 1918a: 720 (m.). See also: Shattuck, 2008a: 30.

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. Majority of hairs on venter of head located laterally and forming a distinct psammophore, only scattered hairs on central portion. Mandibular sculpture composed of regularly sized striations. Erect hairs on mesosomal dorsum tapering to sharp points. Propodeal spines reduced to small denticles, or sometimes essentially absent. Petiolar node (in dorsal view) approximately square.

Measurements
Worker (n = 8, units = mm). CI 84-92; EI 22-27; EL 0.23-0.27; HL 1.12-1.26; HW 0.97-1.16; ML 1.58-1.84; MTL 0.96-1.08; SI 104-115; SL 1.11-1.25.


 * CI: Cephalic index: HW/HL x 100.
 * EI: Eye index: EL/HW x 100.
 * EL: Maximum eye length with eye in full face view.
 * HL: Maximum head length in full face (dorsal) view, measured from the anterior-most point of the clypeal margin to the posterior-most point of the head proper (excluding the occipital collar).
 * HW: Maximum head width in full face (dorsal) view excluding the eyes.
 * ML: Mesosomal length measured from the anterior surface of the pronotum proper (excluding the collar) to the posterior extension of the propodeal lobes.
 * MTL: Maximum length of mid tibia, excluding the proximal part of the articulation which is received into the distal end of the femur.
 * SI: Scape index: SL/HW x 100.
 * SL: Length of the scape (first antennal segment) excluding the basal neck and condyle.