Pheidole nebulosa Wilson 2003

Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker face view

worker lateral view

major face view

major lateral view


Minor worker: head length 0.47mm, head width 0.41mm, scape length 0.43mm, Webers length 0.53mm (n=1). Head rounded behind; mesonotal suture absent; promesonotum evenly arched; propodeal spines medium length; face and mesosoma uniformly foveolate; first gastral tergum smooth and shining; promesonotal dorsum usually with 10 medium length, moderately stiff setae, four pairs distributed along the lateral margins, and one anteromedian pair; setae on gastral dorsum stiff; color orange.

Major worker: head length 0.91mm, head width 0.89mm, scape length 0.48mm (n=1). Face largely foveolate; puncta overlain with longitudinal rugae between eyes and frontal carinae, and medially between frontal carinae; hypostomal margin angular, with flat sides meeting at an obtuse angle; median tooth very large, larger than recessed teeth flanking mandible bases; lateral teeth completely absent (Figure); dorsal pilosity abundant; head with abundant erect setae projecting from sides of head in face view.


Costa Rica (Atlantic lowlands).

Natural History

Inhabits mature wet forest; appears to be both arboreal and terrestrial, occurring commonly in forest floor leaf litter and in the canopy; nests in dead wood, irregular cavities.

Wilson (2005) observed that P. nebulosa and two other species of small Pheidole (flavens and bilimeki) frequently prey on oribatid mites in the leaf litter.

Selected Records

La Selva: Berlese, Winkler, and canopy fogging samples; at baits on forest floor.

La Selva: 4-day old treefall; around a big branch of Stryphnodendron excelsum, some Pentaclethra, and a tangled mass of Norantea sessilis; 2cm dia wet mossy dead branch, lodged 1m high, with nest under loose crumbly bark and mosses; probably colony fragment; workers, males, a single soldier found.

La Selva: Mature wet forest; treefall gap, fallen trees leafless, with scattered epiphyte clumps on fallen branches; nest with 1 dealate queen, alate queens, males, in myrmecophytic bromeliad, Tillandsia bulbosa; eucharitid (?) adult in nest.

La Selva: Arboretum, in dead Cecropia branch.

Braulio Carrillo National Park, 300m: Winkler sample.

Literature Cited

Wilson, E. O. 2003. Pheidole in the New World: A Dominant, Hyperdiverse Ant Genus. Harvard University Press, Cambridge, Mass

Wilson, E. O. 2005. Oribatid mite predation by small ants of the genus Pheidole. Insectes Sociaux 52:263-265.

Page authors:

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

Stefan Cover, Museum of Comparative Zoology, Harvard University, Cambridge MA 02138 USA.

Date of this version: 10 September 2005.
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