Pogonomyrmex bicolor worker.

Named for its beautiful red and black coloration, Pogonomyrmex bicolor is one of the lesser-known North American Pogos.

The workers of this species have a habit of climbing grass stems, and striking a defensive posture with mandibles open. Cole noted this behavior, and we experienced it also when imaging these ants at their nests, and along their foraging trails. Aside from these displays, these ants are extremely docile, and apparently not inclined to bite or sting.

Typical length of worker ranges from 7.2mm to 8.2mm [Taber 1998].

P. bicolor makes nests in a variety of forms, including low, sandy mounds up to 0.9 m / 3 ft in diameter, circular craters of sand and pebbles (approx. 25 cm / 10 inches in diameter), or very indistinct nest structures surrounded by chaff (discarded plant material from previous foraging activities). In southern Arizona, we found P. bicolor nests with virtually no sand or gravel superstructure, but with relatively large craters (up to 61 cm / 24 inches in diameter) composed entirely of dense chaff.

Colony size is not well know, but P. bicolor nests can probably contain up to several thousand ants. The workers are considered to be 'trunk trail' foragers.

Pogonomyrmex bicolor can be found in the United States in parts of southern Arizona, and in the states of Sonora, and Sinaloa in Mexico.

[IMAGE: Pogonomyrmex bicolor worker in southern Arizona, USA] [scroll down for 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