Pheidole ajax Forel 1899

Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker face view

worker lateral view

major face view

major lateral view


Minor worker: head length 0.83mm, head width 0.61mm, scape length 1.18mm, Webers length 1.13mm (n=1). Head elongate, subtrapezoidal behind, with distinct vertex collar; promesonotal and metanotal grooves impressed; posterior border of metanotal groove in the form of a pronounced right-angle step; anepisternum impressed relative to katepisternum; propodeal spines very long; face smooth and shiny; pronotum smooth and shiny; katepisternum and lower side of propodeum reticulate rugose foveolate; anepisternum, mesonotal dorsum, and propodeal dorsum smooth and shiny; gaster smooth and shiny; dorsal pilosity moderately abundant, of moderate length, slightly stiff; color red brown.

Major worker: head length 1.36mm, head width 1.23mm, scape length 1.18mm (n=1). Much of face densely rugose foveolate, becoming striatofoveolate medially and on vertex lobes; hypostomal teeth lacking; recessed teeth flanking mandibles present; face and sides of head covered with long, silky, appressed pubescence; gaster with abundant, long, flexuous setae.

Identity as ajax determined by specimen at MCZ, compared with type by E. O. Wilson.


Costa Rica: Atlantic slope to 600m; Central Valley.

Selected Records

San Jose (type locality).

Braulio Carrillo National Park (Carrillo).

Rara Avis: mature wet forest; under bark on rotten stump.

La Selva: at baits.

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: 26 November 1997

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