P.salinus mandibles

The mandibles of a Pogo are a multipurpose tool - especially for the workers, who employ them for a wide variety of essential tasks.

Some uses include: cutting down grass/plants stems from the nest mound/area, removing seeds from plants and transporting them back to the nest, 'processing' the seeds for consumption, holding of food items during consumption, removal of soil during nest excavation and repair (along with the psammophore, and mandibular hairs), building the exterior nest mound (including the transport of large amounts of gravel), movement of eggs and larvae within the nest, removal of dead nest-mates and inedible food items from the nest, transportation of live nestmates by carrying, removal of spider webs from the nest vicinity, and for direct defensive or offensive purposes (either by using the mandibles directly to inflict injury, or by using them to grasp the intended victim while applying the sting). Pogos will also 'menace' an intruder by holding the head erect, and opening the mandibles.

The size, shape, angle, number, and placement of the denticles (tiny 'teeth' located along the cutting margins of the mandibles) can be used in conjunction with other characters to differentiate between the various Pogonomyrmex species.

Many exterior workers, especially foragers, typically show a substantial degree of wear along the cutting margins of the mandibles. This is due to the type of work that these ants perform, and to the fact that workers of many Pogo species progress from interior to exterior duties as they age [1].

[IMAGE: [IMAGE: Pogonomyrmex salinus worker specimen from central Oregon (LOC 050), showing mandibles in lower half of image] [scroll down for additional notes/references]


·Hölldobler, B. & E.O. Wilson. 1990. The Ants. Cambridge, MA, Belknap/Harvard Press
·Porter, S.D., and C.D. Jorgensen. 1981. Foragers of the Harvester Ant, Pogonomyrmex owyheei: a Disposable Caste? Behavioral Ecology and Socialbiology (1981) 9:247-256
·Tschinkel, WR. 1999. Sociometry and Sociogenesis of Colonies of the Harvester Ant, Pogonomyrmex badius: Distribution of Workers, Brood and Seeds within the Nest in Relation to Colony Size and Season. Ecological Entomology (1999) 24, 222-237


·Cole, A.C. 1968. Pogonomyrmex Harvester Ants: A Study of the Genus in North America. Knoxville, University of Tennessee Press
·Fisher, B.L. & S.P. Cover. 2007. Ants of North America: A Guide to the Genera. Berkeley and Los Angeles, CA, University of California Press
·McCook, H.C. 1880. The Natural History of the Agricultural Ant of Texas. A Monograph of the Habits, Architecture, and Structure of Pogonomyrmex barbatus. Philadelphia: J.B. Lippincott & Co. 1880
·Taber, S.W., J.C. Cokendorfer & O.C. Franke.1987. Scanning Electron Microscopic Study of North American Pogonomyrmex (Hymenoptera:Formicidae). Proceedings of the Entomological Society of Washington. 89(3), 1987, pp. 512-526
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press