Strumigenys biolleyi Forel 1908

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

worker face view

worker lateral view

Additional images: worker dorsal view.


Southern Mexico (Chiapas) to Ecuador, Jamaica. In Costa Rica common on the Atlantic slope and montane areas to 1600m; appears absent from lower Pacific slopes.


Apical fork of mandible with a single intercalary tooth; mandible with two conspicuous preapical teeth; gastral dorsum smooth and shining; mandibles shorter than head; propodeal lamellae without dorsal teeth or angles (dorsal angle present in smithii), ventral angle present and prominent. Also see Bolton (2000:530).

Head length 0.60-0.81mm, mandible length 0.35-0.51, CI 78-85, MI 58-66 (n=51 workers from 11 localities; Brown 1962).

Similar species: smithii, godmani

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).

biolleyi occurs in wet forest habitats. It nests on the forest floor, in dead wood, rotten twigs, and under loose bark. Workers forage nocturnally.

Selected Records

Winkler samples from La Selva, Tortuguero, Rara Avis, Hitoy Cerere, Penas Blancas Valley, Monteverde, Est. Biol. Pittier, San Vito.

Braulio Carrillo National Park at 500m: mature wet forest. Colony in small, 2cm long chamber in rotten log.

Braulio Carrillo National Park, Bajo la Hondura: under loose bark of rotten log.

Monteverde: nest with queen; entire nest collected; in cavity in rotten wood on ground. 134 workers, 1 queen in collection. Also 3 small live millipedes were in the nest. Possible inquilines?

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. 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: 7 May 2001
Previous versions of this page: 14 April 1997
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