Pogonomyrmex rugosus worker.

This large Pogo is sometimes referred to by its officially sanctioned name 'rough harvester', because of the very coarse rugosity (surface sculpture) on its head, mesosoma, petiolar node, and postpetiolar node. This species is known for being quite aggressive toward human investigators.

Typical length of worker ranges from 7.0mm to 9.5mm, and the color is variable, ranging from (or combinations of) blackish-red, brownish-red, yellowish-red, to brown, to mostly black. There are areas where this ant has hybridized with P. barbatus, resulting in lineages possessing some morphological traits of both species.

The nests of this ant usually take the form of flat gravel discs, though they sometimes construct low gravel-covered mounds. Nest population can reach 8,000 ants in a mature colony. P. rugosus is a trunk-trail forager.

The US range of this ant includes parts of California, Colorado, Nevada, New Mexico, Oklahoma, Texas, and Utah. This ant is also found over a wide area in Mexico.

[IMAGE: Pogonomyrmex rugosus worker - Marathon, Texas USA] [scroll down for additional notes/references]

ADDITIONAL NOTES/REFERENCES:

·Cole, A.C. 1968. Pogonomyrmex Harvester Ants: A Study of the Genus in North America. Knoxville, University of Tennessee Press
·Johnson, R.A. 2000. Seed Harvesting Ants (Hymenoptera: Formicidae) of North America: An Overview of Ecology and Biogeography. Sociobiology Vol.36, No. 1, 2000
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press