Strumigenys micretes Brown 1959

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

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

longinoj@evergreen.edu

22 April 1997


worker lateral view

Specimen: Costa Rica, Prov. Alajuela: Rio Penas Blancas, 800m (J. Longino 2529-s). INBIOCRI001281410. Image by J. Longino.

line drawings of lateral view and face view of lacacoca (from Brown 1962), a species nearly identical to micretes

Identification

Apical fork of mandible with one intercalary tooth; mandible often with acute preapical tooth very close to apical fork, but may be reduced to small denticle or absent; no other preapical teeth; gaster smooth and shining, with long flagelliform setae.

Head length 0.70-0.76mm, mandible length 0.45-0.51, CI 71-74, MI 62-68 (n=18 workers from 2 localities; Brown 1962).

Similar species: nevermanni, JTL-003.

worker face view

Specimen: Costa Rica, Prov. Alajuela: Rio Penas Blancas, 800m (J. Longino 2529-s). INBIOCRI001281410. Image by J. Longino.

Range

Costa Rica (Atlantic and southern Pacific slopes to 1000m).

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..."

micretes occurs in wet forest habitats. It nests in dead wood on the ground.

Selected Records

Winkler and/or Berlese samples from La Selva, Braulio Carrillo National Park at 1000m, Hitoy Cerere, Penas Blancas Valley, Guanacaste Conservation Area (Pitilla), Carara, Manuel Antonio, Osa (Rancho Quemado).

La Selva: a nest was observed in dead wood on the ground. A dead branch was projecting from the leaf litter. The distal, projecting portion of the branch contained the Strumigenys colony. Just basal to the Strumigenys nest was an active Pachycondyla apicalis nest in the same branch.

La Selva: nest in Lecythis pod on ground.

Literature Cited

Brown, W. L., Jr. 1959. The Neotropical species of the ant genus Strumigenys Fr. Smith: Group of emeryi Mann. Entomological News 70:97-104.

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.


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