Austromorium hetericki

Austromorium hetericki is confined to a narrow coastal strip from Perth northwards to about Geraldton, Western Australia, where it is found in woodland and heathland habitats. Little else is known about its biology.

Identification
Body dull red, much darker than A. flavigaster, the gaster uniform in colour (rather than being yellowish-red to reddish-brown with a bicoloured gaster), sculpturing rugose (rather than areolate-rugose), dorsal face of propodeum much longer than posterior face (rather than similar in length), propodeal lobes rounded posteriorly (rather than developed as sharp spines), ventral surface of petiole with a small tooth anteriorly, and petiolar node with dorsal and posterior faces forming a continuous surface (rather than with distinct and separate faces). In addition, A. hetericki is much larger than A. flavigaster (head width > 1.30mm vs. head width < 0.85mm).

Identification Key
Key to species of Austromorium

Nomenclature
Holotype worker from Lexia, 31°46’48S”115°56’49”E, 9 October 2005, B.E.Heterick, Banksia open woodland, Adenanthos understory, white quartz sand. One paratype worker, same data as holotype.

Description
Mandibles triangular, with 4-5 teeth. Clypeus projecting slightly forward, bicarinate. Frontal lobes narrow but covering antennal insertions, diverging throughout their length. Eyes with 15-18 ommatidia in greatest diameter, located laterally on head slightly anterior of the midpoint of its length. Sides of head weakly convex, the vertex flat, the two surfaces connected by a narrow, rounded curve. Antennae 12 segmented with a 3-segmented club.

Mesosoma moderately elongate. Anterior face of pronotum rising strongly from the collar and rounding gradually into the dorsal surface. Posterior pronotum, mesonotum and dorsal surface of propodeum forming a continuous flat surface, the metanotal groove essentially absent. Dorsal face of propodeum noticeably longer than the posterior face. Propodeal spines well developed. Propodeal lobes large and rounded posteriorly (lacking sharp angles). Propodeal spiracle small, located anterior of the base of the propodeal spine, approx. 6x its diameter from the posterior propodeal face. Tibial spurs absent from middle and hind legs.

Petiolar peduncle about 1/3 as long as petiolar node. Venter of petiole gently concave across its length, with a small tooth anteriorly. Node with distinct anterior, dorsal faces, the dorsal face gradually curving into the indistinct posterior face, the anterior and dorsal faces approximately the same length. Venter of postpetiole flat. Postpetiolar node with the anterior and dorsal faces forming a continuous curve, the posterior face separate and very short.

Mandibles smooth but overlain with weak, ill-defined carinae. Head costate but tending towards rugose posteriorly, the individual carinae fairly widely separated and the underlying integument roughly sculptured (but the pattern ill-defined). Mesosoma, petiole and postpetiole rugose, the rugae running roughly transverse on the anterior pronotum, propodeum, petiole and postpetiole, and longitudinal on the posterior pronotum and mesonotum. Legs and gaster smooth. Entire body with elongate erect or suberect hairs. Anterior clypeal margin with a row of long, curved setae which extend anteriorly about 1/2 the length of the mandibles.

Colour dull red, the head and legs dull red to red-black, gaster always red-black and uniformly coloured.

Measurements. Worker (n=2). CI 96-97, EI 15-16, EL 0.21-0.23, HL 1.41-1.44, HW 1.35-1.40, ML1.48-1.59, MTL 0.81-0.83, SI 66-68, SL 0.92-0.93.