Epopostruma mercurii

This species, known from a single Western Australian collection, is very similar to Epopostruma sowestensis, another Western Australian species. They differ in that E. mercurii has spines on dorsum of petiole and flanges on propodeum. Nothing is known of the biology of this species.

Identification
This species has expanded, wing-like lateral extensions of the postpetiole. It is similar to Epopostruma sowestensis but differs in that E. mercurii has the petiolar spines well developed and distinct while in E. sowestensis these spines are indistinct and reduced to sharp angles. In addition, E. mercurii lacks flanges between the bases of the propodeal spines and propodeal lobes while E. sowestensis has broad, distinct flanges connecting these structures.

Key to Epopostruma Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  mercurii. Epopostruma mercurii Shattuck, in Bolton, 2000: 58, figs. 60, 70, 85 (w.) AUSTRALIA.

Description
In full face view the lateral margin of the head between the eye and the posterior corner generally angular, sometimes weakly so. Pronotal spines present, distinct. Posterior section of metanotum in approximately the same plane as the dorsal face of propodeum, the junction of these plates either indistinct or in the form of a shallow trough or depression. Posterior face of propodeum between bases of spines and propodeal lobes with rugose sculpturing, flanges absent. Petiolar spines present, distinct. Anterior face of postpetiole much shorter than the dorsal face; sides of postpetiole expanded laterally in the form of thin, solid wings, their lateral margins weakly concave to weakly convex; posterolateral margin of postpetiole (immediately anterior of gaster) varying from flat to concave. Dorsum of petiole, postpetiole and gaster with straight erect hairs. First gastral tergite smooth, area immediately behind attachment with gaster with weak, indistinct rugae. Body colour yellow-red; dorsal surface of head generally with a weak infuscated spot; gaster uniform golden brown or indistinctly banded with light and dark golden brown.

Measurements

Holotype worker. TL 4.4mm, HL 0.94mm, HW 0.88mm, CI 94, MandL 0.51mm, MandI 54, SL 0.62mm, SI 70, PronW 0.54mm, ML 1.09mm.

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.