Strumigenys ludia Mann 1922

Dacetini, Myrmicinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker face view

worker lateral view

Additional images: worker, dorsal view (small, large).

line drawing of worker, lateral view, face view (from Brown 1962).


Southern Mexico to Costa Rica. Costa Rica: Atlantic lowlands.


Apical fork of mandible with one intercalary tooth; mandible with no preapical teeth; petiole with node only feebly differentiated from its anterior peduncle; gastral hairs mostly stiff, spatulate. Also see Bolton (2000:528).

Head length 0.67-0.74mm, mandible length 0.49-0.56, CI 81-84, MI 73-76 (n=9 workers from 6 localities; Brown 1962).

Similar species: elongata, precava, consanii.

Natural History

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).

Brown (1962) reports that ludia is a forest species and usually nests in rotten branches or twigs lying on the forest floor. He also reports that the food is chiefly entomobryoid Collembola. In Costa Rica, I have observed ludia in young second growth habitats, and not in Winkler or other samples from mature forest. Thus, this species may be associated with synanthropic habitats.

Selected Records

Abaca plantation, Batan (near Limon): collection reported in Brown (1962).

La Selva: three records of foragers and one ALAS Berlese sample, all from second growth habitat.

Literature Cited

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. 1954(1953). The neotropical species of the ant genus Strumigenys Fr. Smith: Group of elongata Roger. Journal of the New York Entomological Society 61:189-200.

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. Quart. Rev. Biol. 34:278-294.

Page author:

John T. Longino, The Evergreen State College, Olympia WA 98505

Date of this version: 30 September 2008.
Previous versions of this page: 22 April 1997
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