Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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Identification
Minor worker: head length 0.77mm, head width 0.72mm, scape length 0.73mm, Webers length 0.98mm (n=1). Differing from excubitor in the following respects: face densely foveolate throughout; clypeus with a median keel; metanotal groove less impressed, with less distinct step at anterior border of propodeal dorsum; setae less appressed on scapes; mesosoma more densely foveolate and occasionally with rugae; anterior portion of gaster faintly foveolate; a pair of setae on propodeal dorsum.
Major worker: head length 1.82mm, head width 1.66mm, scape length 0.84mm (n=1). Differing from excubitor in the following respects: clypeus with prominent median keel; more abundant pilosity on mesosomal dorsum and sparse short setae projecting from sides of head.
Range
Costa Rica: Atlantic slope to 1600m.
Natural History
Occurs in mature wet forest habitats (including cloud forest); arboreal, forming large polygynous(?) nests beneath epiphytes in high canopy.
Selected Records
Braulio Carrillo National Park at 950m: mature wet forest gap; incipient colony in 1.5cm dia live melastome vine stem.
Penas Blancas Valley: edge between primary forest and large area of low secondgrowth; nest in a few internodes of Cecropia insignis sapling.
Penas Blancas Valley: mature wet forest; crown and trunk of canopy Guarea; colony under moss on small canopy branch; about 20m high; near end of branch.
Monteverde: mature leeward cloud forest; freshly cut canopy tree, Eugenia cf. acapulcensis (det. B. Haber); column on branch; another group under moss mat.
Monteverde: forest edge; in crowns of recently felled trees, Nectandra(?) and Citharexylum(?); populous colony under epiphyte mat on Nectandra; multiple dealate queens, many alate queens.
Monteverde: cloud forest; fresh treefall, a large Ficus; nest under thick epiphyte clump.
Taxonomy
There is an apparent complex of Pheidole species showing a geographic mosaic of differentiated forms. Members of this complex include excubitor, JTL-119, a common species on BCI, Panama, and the types of Pheidole championi Forel and championi var. sima Forel. Pheidole championi was described from Panama, Volcan de Chiriqui. Pheidole championi var. sima was described from Costa Rica, "Canas Gudas" [Puntarenas Province, Canas Gordas?]. We have not examined these types, and at this point do not know their relationships to the material we have been able to examine. One of the BCI specimens at MCZC bears a determination label indicating that Bill Brown compared it with the type of sima. Which, if any, of excubitor, JTL-119, and the BCI species are conspecific with championi or sima is unknown.
Page authors:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA. longinoj@evergreen.edu
Stefan Cover, Museum of Comparative Zoology, Harvard University, Cambridge MA 02138 USA. scover@oeb.harvard.edu
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