Epopostruma frosti

This species has been collected in mallee, dry sclerophyll, dry sclerophyll on a ridge with much low heath scrub and tall gums on a hillside. Specific collection sites or situations include sugar baits late in the evening and at night, honey bait on tree trunks on a cold, moonless night, diurnal and nocturnal foragers, under logs, under a mossy limestone rock with the nest in carton material, and nests in soil and leaf litter. It is known to occur in southern South Australia and Western Australia.

Epopostruma frosti was described by Brown (1948) as the type of the newly established genus Hexadaceton. It was transferred to Epopostruma when Taylor (1973) synonymised this genus with Epopostruma. Taylor (1991) commented on the type locality of this species while Wheeler and Wheeler (1973) described its larva (currently the only description for any species of the genus).

Identification
This species is immediately recognisable by the sharp angles or small teeth immediately above the eyes.

Key to Epopostruma Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  frosti. Hexadaceton frosti Brown, 1948e: 120, fig. 2 (w.) AUSTRALIA. Wheeler, G.C. & Wheeler, J. 1973c: 211 (l.). Combination in Epopostruma: Taylor, 1973: 26. See also: Shattuck, in Bolton, 2000: 60.

Description
Area immediately above the eye forming a sharp angle or small tooth. Pronotal spines present, elongate. Posterior section of metanotum and dorsal surface of the propodeum forming a continuous surface. Posterior face of propodeum between bases of spines and propodeal lobes with thin flanges. Petiolar spines present, elongate. Anterior face of postpetiole indistinguishable from the dorsal surface; sides of postpetiole expanded laterally in the form of distinct sharp teeth or spines; in dorsal view the anterior and posterior teeth approximately the same length; posterolateral margin of postpetiole (immediately anterior of gaster) flat to weakly concave. Dorsum of petiole, postpetiole and gaster short erect hairs. First gastral tergite smooth. Body colour yellow-red, head. legs and sometimes gaster slightly lighter than mesosoma, petiole and postpetiole.

Measurements

Worker (n=7): TL 4.7-5.6mm, HL 1.14-1.29mm, HW 1.21-1.43mm, CI 103-111, MandL 0.57-0.67mm, MandI 47-52, SL 0.66-0.74mm, SI 52-56, PronW 0.64-0.81mm, ML 1.14-1.36mm.

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.