Based on the hundreds of litter samples that have recorded this species, Strumigenys trieces occurs in mature wet forest habitats. It nests in dead wood on the forest floor. Workers forage in the leaf litter. (Longino, Ants of Costa Rica)
Longino (Ants of Costa Rica) - Mandibles in full-face view linear, elongate and narrow; ventral surface of petiole without spongiform tissue; leading edge of scape with freely projecting hairs; inner margin of mandible without a tooth or distinctly enlarged denticle at or near the midlength; labral lobes short, trigger hairs at apices of lobes long; outer margins of mandibles relatively straight; mandibles short and thick, with inner margin convex; mandible with exactly 3 small preapical teeth; ground pilosity of head nearly or quite obsolete. Similar to: Strumigenys gundlachi, Strumigenys eggersi and Strumigenys subedentata.
Longino (2006) - Intensive collecting at La Selva Biological Station and the Barva Transect has revealed a complex of five closely similar but consistently separable species related to Strumigenys subedentata. Strumigenys subedentata occurs throughout the Neotropics, usually in lowland wet to somewhat seasonal sites, in both mature and second growth forests. It is often collected in samples of litter and rotten wood from the forest floor. Strumigenys trieces occurs on the Atlantic slope of Central America from Nicaragua to Panama, from sea level to 1100 m elevation. It occurs most abundantly in mature wet forest where, like S. subedentata, it inhabits leaf litter and rotten wood on the forest floor. Three species – Strumigenys oconitrilloae, Strumigenys cascanteae, and Strumigenys paniaguae – occur as a graded series of elevational specialists, with S. oconitrilloae occurring at La Selva and the 300 m site on the Barva Transect, S. cascanteae occurring at the 300 m site and at a 600 m site in the nearby Arenal National Park, and S. paniaguae occurring at the 500 m, 1100 m, and 1500 m sites on the Barva Transect. These three all show a tendency to be arboreal, nesting under bark flaps or epiphytes and rarely occurring in samples of litter and rotten wood from the forest floor. A sixth species in this complex, Strumigenys connectens (Kempf, 1958), occurs in Colombia and Ecuador.
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.
- trieces. Strumigenys trieces Brown, 1960b: 50, fig. 8 (w.) COSTA RICA. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 129. See also: Bolton, 2000: 194.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Bolton (2000) - TL 2.3-2.4, HL 0.57-0.62, HW 0.45-0.49, CI 77-82, ML 0.27-0.30, MI 46-52, SL 0.22-0.26, SI 46-53, PW 0.33-0.35, AL 0.62-0.68 (10 measured). Characters of gundlachi complex. Inner margins of mandibles strongly convex in full-face view, at full closure touching at about the midlength and diverging both proximally and distally. Apex of mandible with 3 minute intercalary denticles between apicodorsal and apicoventral teeth. Preapical denticles 3 in number, spaced out and located in the apical third of the mandible length, the proximal (basalmost) denticle usually the largest (rarely otherwise); denticles usually about equidistant but sometimes the proximal more widely separated from the other two. Scape broadening medially but not expanded into a wide lobe, SL ca 3.5 X the maximum scape width. Eye usually with 4 ommatidia in the longest row. Pronotum markedly depressed, the dorsum only weakly convex, bluntly marginate dorsolaterally. Ground-pilosity of head and alitrunk of sparse minute appressed pubescence. Apicoscrobal hair short. Cephalic dorsum with a pair of short erect hairs at highest point of vertex and another pair close to occipital margin. Pronotal humeral hair present. Mesonotal dorsum with a single pair of erect hairs. Head , alitrunk and waist segments reticulate-punctate except for katepistemum which is mostly smooth. First gastral stemite smooth, not reticulate basally.
Holotype worker, COSTA RICA: no locality data, 18.vii.1931 (F. Nevennann) (Museum of Comparative Zoology) [examined].
- 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 194, fig. 138 redescription of worker)
- Brown, W. L., Jr. 1960c . The neotropical species of the ant genus Strumigenys Fr. Smith: group of gundlachi (Roger). Psyche (Camb.) 66: 37-52 (page 50, fig. 8 worker described)
- Brown, W. L., Jr. 1962c. The neotropical species of the ant genus Strumigenys Fr. Smith: synopsis and keys to the species. Psyche. 69:238-267. PDF
- Longino, J.T. 2006b. New species and nomenclatural changes for the Costa Rican ant fauna. Myrmecologische Nachrichten. 8:131-143. PDF