Epopostruma inornata

This rare species is currently known from a single specimen. It belongs to the quadrispinosa species group and is one of only two members of this group to occur west of the Adelaide region (the other being Epopostruma quadrispinosa).

Identification
Epopostruma inornata can be separated from other species in this genus by having the following combination of characters:
 * Lateral margin of the head between the eye and the posterior corner forming a gentle convexity.
 * Humeral angles of pronotum rounded, lacking spines.
 * Dorsum of petiole lacking elongate spines.
 * Anterior face of postpetiole shorter than the dorsal and posterior faces.
 * Sides of postpetiole approximately vertical and rounding gradually from dorsal to posterior surfaces.
 * In dorsal view the postpetiole lacking lateral teeth.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  inornata. Epopostruma inornata Shattuck, 2007: 48, figs. 1-4 (w.) AUSTRALIA.

Holotype worker from Western Australia, Karragullen (misspelled as “Karagullen” on the label, located at 32°06'S 116°07'E), 1978 (J. D. Majer) (, ANIC32-007280).

Description
In full face view lateral margin of head between eye and posterior corner forming a gentle convexity. Pronotal spines absent, anterolateral corners of pronotum very slightly angular. Posterior section of metanotum in approximately same plane as dorsal face of propodeum, junction of these plates indistinct. Posterior face of propodeum between bases of spines and propodeal lobes with thin flanges. Petiolar spines reduced to a small protuberance or angle. Anterior face of postpetiole shorter than dorsal face and separated from it by a broadly rounded angle; lateral surface of postpetiole approximately vertical and rounding gradually from dorsal to posterior surfaces, in dorsal view lateral margins parallel. Dorsum of petiole, postpetiole and gaster with short, appressed hairs. First gastral tergite smooth. Body colour yellowish brown, dorsum of head and gaster slightly darker, mandibles and legs lighter.

Measurements

Holotype worker. TL 2.8mm, HL 0.67mm, HW 0.57mm, CI 85, MandL 0.30mm, MandI 45, SL 0.33mm, SI 58, PronW 0.41mm, ML 0.75mm.

CI (cephalic index) - HW/HL X 100. HL (head length) - The length of the head capsule excluding the mandibles, measured in full face view in a straight line from the mid point of the anterior clypeal margin to the mid point of the occipital margin. In species where one or both of these margins is concave the measurement is taken from the mid point of a transverse line that spans the apices of the projecting portions. HW (head width) - The maximum width of the head in full face view, excluding the eyes. MandI (mandibular index) - ML/HL X 100. MandL (mandible length) - The straight line length of the mandible at full closure, measured in the same plane for which the HL measurement is taken (i.e. full face view), from the mandibular apex to the anterior clypeal margin, or to the transverse line connecting the anteriormost points in those taxa where the margin is concave medially. ML (mesosomal length) (= Weber's length) - The diagonal length of the mesosoma in profile from the point at which the pronotum meets the cervical shield to the posterior basal angle of the metapleuron. PronW (pronotal width) - The maximum width of the pronotum in dorsal view. (Projecting spines, tubercles or other cuticular prominences at the pronotal humeral angles are ignored.) SI (scape index) - SL/HW X 100. SL (scape length) - The maximum straight line length of the scape, excluding the basal constriction or neck that occurs just distal of the condylar bulb. TL (total length) - The total outstretched length of the ant from the mandibular apex to the gastral apex; when measured in profile the sum of ML + HL + ML + lengths of waist segments + length of gaster.