Incipient P.salinus nest in central washington state.

The nests of Pogonomyrmex salinus, P. occidentalis, and other Pogos, are often conical (or dome-shaped) and covered with gravel - but it takes time for them to reach this 'mature' stage.

The incipient nest begins when a queen mates, sheds her wings, and tunnels down at an angle into the sand - founding a new colony. When the first workers appear (in many cases, the following Spring), they begin to excavate sand as they create the tunnels, galleries, and chambers that comprise the subterranean portions of the nest. The sand and other material being brought up is deposited outside of the entrance. Gradually, a small crater-like structure forms, consisting mostly of sand - up to this point, it can still be called an incipient nest.

The crater is then enlarged, and usually covered with gravel. During this process, grass and plant stems (if present) surrounding the growing colony are usually clipped away, forming a clearing. In many cases the ants will eventually build up one wall of the crater until a more dome-like or conical mound appears, containing its own network of chambers and galleries. This is usually covered with gravel, and represents the mature, or 'adult' nest. The appearance of the mature nest can vary greatly, however, depending on location, soil type and many other factors. [IMAGE: an extremely 'young', incipient nest of Pogonomyrmex salinus in central WA, with tiny nanitic workers - arrow points down into nest entrance] [scroll down for additional notes/references]

REFERENCES FOR ENTIRE PAGE:

·Cole, A.C. 1932e. The Rebuilding of Mounds of the Ant, Pogonomyrmex occidentalis, CRESS. Ohio Journal of Science, v32, n3 (May, 1932) 245-246
·Hölldobler, B. & E.O. Wilson.1990. The Ants. Cambridge, MA, Belknap/Harvard Press
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press