Pheidole coloradensis Emery


Pheidole coloradensis major head view  Pheidole coloradensis major, side view
This species has been synonomized as a junior synonym of Pheidole pilifera by Wilson (2003). This taxonomic decision is not agreeable to all ant taxonomists and we retain the use of this name here. Wheeler (1908) makes a case for this being a distinctive western species but it remains possible that we are incorrect.
The simplest way to distinguish Pheidole from other Navajo ant genera is to find a nest of ants that contains large headed majors and small minors. The 12 segmented antenna of Pheidole coloradensis majors and minors have a 3 segment club and the propodeum is noticeably lower than the promesonotum. Both the majors (~2 mm) and minors of this ant are small and have a pair of spines on their propodeum. Major workers possess well developed humeral angles (a distinctive edge where the top and sides of the front of the pronotum meet) and lateral connules (looking down on a pinned ant, the postpetiole is much wider than long and there are angled projections extending out to the sides of the postpetiole). The head of the major may also have fine striations across the top of the head. Minor workers are small and pale brown.
Mackay (2002): Nests are found under stones or in the soil with the entrance surrounded by a small mound. Pheidole coloradensis is a harvester ant, collecting the seeds of grasses and other plants. This ants nests in grassy areas in pinyon-juniper forests, ponderosa pine, riparian forests, and disturbed urban areas.
additional biology notes...
United States. North Dakota south to Nevada and New Mexico.
Navajo Reservation Records
A colony of Pheidole coloradensis was found on 15 June 2008 by Gary D. Alpert under a rock along a dirt road on Black Mesa, Navajo County, Arizona. Males, queens and brood were collected along with a series of workers.
Additional Notes

Geographic. The types were collected in Colorado.

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Original Combination - Pheidole pilifera var. coloradensis - Emery (1895).

species description for Pheidole coloradensis (first page)species description for Pheidole coloradensis (second page)description of Pheidole coloradensis (third page)

A.M.N.H, M.C.Z.
As stated in Creighton (1950).
Type Locality

Creighton, W. S. 1950. The ants of North America. Bulletin of the Museum of Comparative Zoology at Harvard University. 104:1-585.
Mackay, W. P. and E. Mackay. 2002. The ants of New Mexico (Hymenoptera: Formicidae). Edwin Mellen Press, Lewiston, NY.
Wheeler, W. M. 1908. The ants of Texas, New Mexico and Arizona. (Part I.). Bulletin of the American Museum of Natural History. 24:399-485.
Wilson, E. O. 2003. Pheidole on the New World: A dominant, hyperdiverse ant genus. Harvard University Press, Cambridge, MA.

A note about these publications. The literature cited here is not meant to be an exhaustive list of papers published about this species.

Page authored by David Lubertazzi and Gary Alpert

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