(Ogata & Onoyama, 1998)
A rare species found of the forest floor of broadleaf forests and nesting in the soil (Ogata & Onoyama 1998).
- 1 Identification
- 2 Distribution
- 3 Biology
- 4 Castes
- 5 Nomenclature
- 6 References
A member of the Strumigenys circothrix-group.
Bolton (2000) - S. hiroshimensis: there is a single spoon-shaped hair on the leading edge of the scape (distal of the subbasal angle) that is curved toward the base of the scape; dorsum of the petiole node is without apically thickened to spatulate standing hairs; hairs on the first gastral tergite are simple; fully closed mandibles are as long as maximum length of clypeus; in dorsal view maximum width of lateral spongiform tissue on one side of postpetiole disc is broader than the dorsal width of the hind femur.
Strumigenys circothrix: has all hairs on the scape distal of the subbasal angle curved toward the apex of the scape; dorsum of the petiole node has 2 pairs of apically thickened to spatulate standing hairs; hairs on the first gastral tergite are apically thickened to clavate; fully closed mandibles are slightly shorter than maximum length of clypeus; in dorsal view maximum width of lateral spongiform tissue on one side of postpetiole disc is narrower than the dorsal width of the hind femur.
Keys including this Species
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
Strumigenys were once thought to be rare. The development and increased use of litter sampling methods has led to the discovery of a tremendous diversity of species. Many species are specialized predators (e.g. see Strumigenys membranifera and Strumigenys louisianae). Collembola (springtails) and other tiny soil arthropods are typically favored prey. Species with long linear mandibles employ trap-jaws to sieze their stalked prey (see Dacetine trap-jaws). Larvae feed directly on insect prey brought to them by workers. Trophallaxis is rarely practiced. Most species live in the soil, leaf litter, decaying wood or opportunistically move into inhabitable cavities on or under the soil. Colonies are small, typically less than 100 individuals but in some species many hundreds. Moist warm habitats and micro-habitats are preferred. A few better known tramp and otherwise widely ranging species tolerate drier conditions. Foraging is often in the leaf litter and humus. Workers of many species rarely venture above ground or into exposed, open areas. Individuals are typically small, slow moving and cryptic in coloration. When disturbed individuals freeze and remain motionless. Males are not known for a large majority of species.
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- hiroshimensis. Smithistruma hiroshimensis Ogata & Onoyama, 1998: 281, figs. 5, 6 (w.) JAPAN. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 121. See also: Bolton, 2000: 411.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
TL: 1.35 mm; HL: 0.53 mm; HW: 0.42 mm; CI: 78; ML: 0.13 mm; MI: 25; SL: 0.25 mm; SI: 60; PW: 0.25 mm; WL: 0.57 mm. (1 measured).
Head longer than wide, with roundly convex sides posteriorly; posterior border emarginate with low occipital carina. Mandibles as long as clypeus in full face view; dentition not observed. Clypeus with straight anterior margin and rounded corners, and fringed with spatulate hairs. Antennae 6-segmented; outer margin of scape with angulate elbow at basal ¼; apical segment longer than the rest of funiculus. Eyes small, consisting of 4 facets.
Pronotum angulate anteriorly, but not posteriorly. Propodeum with infradental lamella posteriorly. Petiolar node broader than long in dorsal view. Spongiform appendages of postpetiole well developed, the width of each side thicker than the dorsal width of hind femur in dorsal view.
Head and mesosoma covered with suborbicular hairs. Spatulate hairs present on pronotal humeri, mesonotum, but absent on petiole, postpetiole and gaster.
Lateral surface of mesothorax, propodeum, and whole gaster except for basitergum of 1st segment smooth and shining; the rest of body reticulate-punctate. Body color reddish brown.
Bolton (2000) - TL 2.0, HL 0.55, HW 0.41, CI 75, ML 0.13, MI 24, SL 0.28, SI 68, PW 0.25, AL 0.54. Extremely closely related to circothrix but differing as follows.
Bolton (2000) - Holotype worker, JAPAN: Mt Futabayama, Hiroshima City, Hiroshima Pref., Honshu, 2.viii.1996 (Y. Touyama) (Entomological Laboratory and Institute of Tropical Agriculture, Faculty of Agriculture, Kyushu University) [examined].
The species had not been treated in MSJ (1988) nor Ogata & Onoyama (1992). But later Terayama et al. (1994) nominated the ant from Hiroshima Prefecture in their distribution table as Smithistruma sp. 9 and gave a Japanese name Hiroshima-uroko-ari. The species also corresponds to Smithstruma sp. 3 of Ogata et al. (1994).
- Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria” 99: 1-191.
- Bolton, B. 1999. Ant genera of the tribe Dacetonini (Hymenoptera: Formicidae). Journal of Natural History. 33:1639-1689. PDF (page 1673, combination in Pyramica)
- Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 411, redescription of worker)
- Ogata, K. and Onoyama, K. 1998. A revision of the ant genus Smithistruma Brown of Japan, with descriptions of four new species (Hymenoptera: Formicidae). Entomological Science. 1(2):277-287. PDF (page 281, figs. 5, 6 worker described)