Epopostruma monstrosa

Nests and foragers of E. monstrosa have been found under a stone near the base of a Eucalyptus, in leaf litter, under a rock in an area dominated by Papyrius nitidus, foraging on the trunk of scribbly gum 4 feet off the ground at 6pm, under a tree near a large colony of Notoncus gilberti and in a bare patch of soil. Habitats where it has been found include heath on sandy soil, a swamp, open sclerophyll, dry sclerophyll, medium sclerophyll, flats, coastal scrub and paperbark scrub. It is currently known from four widely separate areas: northern Queensland, south-eastern Queensland, south-coastal New South Wales and the Melbourne area of Victoria.

Epopostruma monstrosa was established by Viehmeyer (1925) for a single queen from north coastal New South Wales. Taylor (1991) provides notes on this specimen and associated it with workers, thus allowing this species to be compared with the remaining species of the genus, all of which are worker-based. Earlier, Brown (1948:119) had transferred this species to Mesostruma, a move later reversed by Taylor (1973), who transferred it back to Epopostruma.

Identification
The shape of the postpetiole, with its relatively long and flat anterior face compared to the dorsal face, will separate this species from others in the quadrispinosa species group. It should be noted that the northern-most collections of this species differ from their southern counterparts in having slightly more distinct large foveae on the petiole and postpetiole. This difference is interpreted as intraspecific geographic variation due to the large distance (over 1300 km) between these collection localities rather than evidence that separate species are involved.

Key to Epopostruma Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  monstrosa. Epopostruma monstrosa Viehmeyer, 1925a: 30 (q.) AUSTRALIA. Combination in Mesostruma: Brown, 1952g: 13; in Epopostruma: Taylor, 1973: 25. See also: Taylor, 1991b: 602; Shattuck, in Bolton, 2000: 64.

Description
In full face view the lateral margin of the head between the eye and the posterior corner a gentle convexity. Pronotal spines distinct. Posterior section of metanotum in approximately the same plane as the dorsal face of propodeum, the junction between these plates a weak, indistinct concavity. Posterior face of propodeum between bases of spines and propodeal lobes with thin flanges. Petiolar spines present, short and thin. Anterior face of postpetiole flat, longer than dorsal face; sides approximately vertical, rounding gradually from dorsal to posterior surfaces and with sharp angles at the anterior and posterior corners, the posterior corners slightly longer and wider than the more rounded anterior angles. Dorsum of petiole, postpetiole and gaster numerous very short erect hairs. First gastral tergite smooth or nearly so, at most with only very weak, indistinct sculpturing; area immediately behind attachment with gaster with short longitudinal rugae. Body colour varying from yellow-red to red-brown; gaster uniform red-brown.

Measurements

Worker (n=6): TL 3.3-4.4mm, HL 0.78-0.98mm, HW 0.66-0.88mm, CI 84-93, MandL 0.40-0.48mm, MandI 44 -51, SL 0.46-0.56mm, SI 61-74, PronW 0.44-0.59mm, ML 0.89-1.14mm.

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.