Dacetini, Myrmicinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
Additional images: worker, dorsal view (small, large).
line drawing of worker face (from Brown 1958)
Costa Rica (southern Pacific lowlands) to northern Colombia.
Apical fork of mandible without intercalary teeth; mandible with one strong preapical tooth; dorsum of gaster with raised lateral margins; gaster punctulate-striolate, opaque; gaster with long flagelliform setae. Also see Bolton (2000:543).
Head length 0.68-0.73mm, mandible length 0.51-0.57, CI 78-82, MI 75-79 (n=11 workers from 3 localities; Brown 1962).
Similar species: longispinosa.
Brown and Wilson (1959) summarize the genus as follows:
"Widespread in tropics and warm temperate areas. Primarily forest-dwelling; some species occur in grassland and arid scrub. ... Nests mostly in soil and rotting wood; a few species live in arboreal plant cavities in tropical rain forest. Foraging hypogaeic to epigaeic-arboreal. Food: most species are collembolan feeders; a few are polyphagous predators or occasionally feed on sugary substances..."
Members of the genus are all predaceous, with a kinetic mode of attack (Bolton 1999).
Regarding the species marginiventris, Brown (1962) states
"Nests in the soil, often in paths or other openings, in rain forest or plantations, and the workers forage over the open ground among leaves or herbs by day as well as night. Common on Barro Colorado Island [Panama]"
I have never encountered this species in Winkler samples from Costa Rica. My collecting is biased toward closed canopy mature forest, where there is a litter layer. This supports Brown's observations that this species prefers open areas and synanthropic habitats.
Palmar: in soil of banana plantation, several collections (as reported in Brown 1962, Strumigenys review).
Bolton, B. 1999. Ant genera of the tribe Dacetonini (Hymenoptera: Formicidae). J. Nat. Hist. 33:1639-1689.
Bolton, B. 2000. The ant tribe Dacetini, with a revision of the Strumigenys species of the Malagasy Region by Brian L. Fisher, and a revision of the Austral epopostrumiform genera by Steven O. Shattuck. Memoirs of the American Entomological Institute 65:1-1028.
Brown, W. L., Jr. 1958 (1957). The neotropical species of the ant genus Strumigenys Fr. Smith: Group of marginiventris Santschi. Journal of the New York Entomological Society 65:123-128.
Brown, W. L., Jr. 1962. The neotropical species of the ant genus Strumigenys Fr. Smith: Synopsis and keys to the species. Psyche 69:238-267.
Brown, W. L., Jr., Wilson, E. O. 1959. The evolution of the dacetine ants. Quarterly Review of Biology 34:278-294.
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.firstname.lastname@example.org
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