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.
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.
Keys including this Species
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
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While Epopostruma can be fairly common they are often overlooked. Workers are slow-moving and most lie motionless when disturbed. Their nests are small, with up to about 100 workers, and are found in open soil or in soil under rocks, logs or small sticks. They also nest in cracks in large rocks. When nesting in open soil they are often found near the bases of trees. Tree-trunks are clearly an important substrate for foraging workers.
Almost all species forage at night although one species is known to occasionally forage on mallee stems during the day. They are also regularly found in leaf litter. Workers have been attracted to honey baits on trees in the late evening and at night. Their elongate and specialised mandibles form a type of snap-trap which is used to captured soft-bodied prey such as Collembola.
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- 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.
- Holotype, queen or gynandromorph (specimen fragmentary), Trial Bay, New South Wales, Australia, Berlin Museum für Naturkunde der Humboldt-Universität.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
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.
Shattuck (2000) - 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.
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.
- Bolton, B. 2000. The ant tribe Dacetini. Mem. Am. Entomol. Inst. 65: 1-1028 (page 64, redescription of worker)
- Brown, W. L., Jr. 1952j. The dacetine ant genus Mesostruma Brown. Trans. R. Soc. S. Aust. 75: 9-13 (page 13, Combination in Mesostruma)
- Shattuck, S. O. 2000. Genus Colobostruma. Genus Mesostruma. Genus Epopostruma. Pp. 31-67 in: Bolton, B. The ant tribe Dacetini. Mem. Am. Entomol. Inst. 65: 1-1028 (page 63, worker, queen described)*Taylor, R. W. 1973. Ants of the Australian genus Mesostruma Brown (Hymenoptera: Formicidae). J. Aust. Entomol. Soc. 12: 24-38 (page 25, Combination in Epopostruma)
- Taylor, R. W. 1991b. Nomenclature and distribution of some Australasian ants of the Myrmicinae (Hymenoptera: Formicidae). Mem. Qld. Mus. 30: 599-614 (page 602, taxonomic status)
- Viehmeyer, H. 1925a. Formiciden der australischen Faunenregion. (Fortsetzung.). Entomol. Mitt. 14: 25-39 (page 30, queen described)