Pogonomyrmex rugosus

This species forms large crater-like mounds similar to those of Pogonomyrmex barbatus. Rarely it forms a small mound a few cm higher than the surface of the ground. Nests are large, containing several thousand workers. Workers are individual or group foragers, depending on the conditions. Food sources are primarily seeds (especially those of Erodium cicutarium), but also includes dead insects. The soil surface temperature limits foraging activity. The myrmecophilous scarabaeid beetle genus Cremastocheilus occurs in the nests. These ants deposit seed hulls and other debris around the edge of the mound, where it is eaten by tenebrionid beetles of the Genus Eleodes. The black widow spider is one of the main predators of this species. (Mackay and Mackay 2002)

Identification
Its color (and large size, over 8-mm total length) usually separates it from all others in the genus: dark brown, almost black head and mesosoma with a somewhat lighter colored gaster. (Mackay and Mackay 2002)

Distribution
United States: southern California, Nevada, New Mexico, southwestern (Washington Co.) and east central (Grant Co.) Utah, southwestern, southeastern and east central Colorado, western part of Oklahoma panhandle (Cimarron Co.), Texas (western part of panhandle, Big Bend region, and along the Rio Grande to Hildago Co.). Mexico: Tamaulipas, Nueva Leon, Coachuila, Zacatecas, Aguacalientes, Nayarit, Durango, Sinaloa, Chihuahua, Sonora, Baja California.

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Mexico.

Habitat
Found primarily in Chihuahuan Desert communities, including grasslands, creosotebush scrub and riparian habitats. (Mackay and Mackay 2002)

Genetics
The genome of P. rugosus was sequenced for a study examining how parasitic ants with no worker caste may have altered their genome to arrive at a workerless state. In comparison to ants with a full complement of castes, there appeared to be no loss of genes in the parasitic ants. This suggests regulatory differences and not sequence differences predominate in gains and losses of castes (phenotypes). (Smith et al. 2015)

Other Ants
A host species for the workerless social parasites and.

Nomenclature

 * fuscatus. Pogonomyrmex barbatus var. fuscatus Emery, 1895c: 309 (w.q.) U.S.A. Subspecies of barbatus and senior synonym of curvispinosus, marfensis: Creighton, 1950a: 119. Junior synonym of barbatus: Cole, 1954b: 117; of rugosus: Cole, 1968: 70.
 *  rugosus. Pogonomyrmex barbatus subsp. rugosus Emery, 1895c: 309 (w.m.) U.S.A. Cole, 1968: 72 (q.); Taber, Cokendolpher & Francke, 1988: 51 (k.). Raised to species: Cole, 1968: 70. Senior synonym of similis: Creighton, 1950a: 120; of fuscatus (and its junior synonyms curvispinosus, marfensis), spadix: Cole, 1968: 70.
 * marfensis. Pogonomyrmex barbatus var. marfensis Wheeler, W.M. 1902a: 98 (diagnosis in key) (w.) U.S.A. Junior synonym of fuscatus: Creighton, 1950a: 119.
 * similis. Pogonomyrmex similis Olsen, 1934: 512, pl. 6, fig. 2 (w.) U.S.A. Junior synonym of rugosus: Creighton, 1950a: 120.
 * curvispinosus. Pogonomyrmex barbatus subsp. curvispinosus Cole, 1936b: 120 (w.) U.S.A. Junior synonym of fuscatus: Creighton, 1950a: 119.
 * spadix. Pogonomyrmex barbatus subsp. spadix Cook, 1953: 98, figs. (w.) U.S.A. Junior synonym of rugosus: Cole, 1968: 70.

Worker
Cole (1968) - HL 1.67-2.47 mm, HW 1.75-2.70 mm, CI 93.8-115.2, SL 1.18-1.67 mm, SI 60.5-71.9, EL 0.34-0.65 mm, EW 0.19-0.42, OI 17.8-28.5, WL 1.75-2.96 mm, PNL 0.34-0.72 mm, PNW 0.38-0.68 mm, PPL 0.38-0.67 mm, PPW 0.53-0.87 mm.

Mandible similar to that of Pogonomyrmex barbatus; subapical and first basal teeth subequal in length; ultimate basal tooth much longer than penultimate, strongly offset from the straight basal margin.

Base of antennal scape as shown in Pl. IV, Fig. 1 5 not discernibly different from that of barbatus. Thoracic, petiolar, and postpetiolar contours in lateral view as illustrated in Pl. V, Fig. 7; pronotum generally less evenly convex than that of barbatus, its dorsum usually flattened; epinotal armature as in barbatus.

Cephalic rugae coarse, wavy, widely and rather unevenly spaced; interrugular spaces shining to subopaque, with broken rugules, granulations, and often also with prominent punctures. Thoracic rugae coarse, especially on the pronotum where they are very strong, uneven, and form very coarse reticulations with deep, flattened interrugal spaces. Rugae on petiolar and postpetiolar nodes strong, uneven, forming definite reticulations.

Body color varying from a rather uniform, very deep brownish black or brownish red to various combinations of brown, brownish red, dark red, yellowish red, and brownish black.

Queen
Cole (1968) - HL 2.05-2.20 mm, HW 2.43-2.66 mm, CI 117.3-121.9, SL 1.52-1.63 mm, SI 60.2-63.2, EL 0.57-0.61 mm, EW 0.38-0.16 mm, OI 27.7-28.6, WL 3.53-3.80 mm, PNL 0.57-0.68 mm, PNW 0.68-0.80 mm, PPL 0.53-0.61 mm, PPW 1.10-1.18 mm.

Similar to the female of Pogonomyrmex barbatus, except cephalic and scutal rugae much coarser and notably more widely spaced, dorsum of the petiolar node prominently rugo-reticulose, body color generally black, reddish black, or deep reddish brown, with the gaster often in part or entirely much paler.

Male
Cole (1968) - HL 1.33-1.69 mm, HW 1.64-1.92 mm, CI 113.5-123.4, SL 0.55-0.68 mm, SI 32.1-35.4, EL 0.52-0.60 mm, EW 0.34-0.42 mm, OI 35.3-39.1, WL 2.34-2.94 mm, PNL 0.39-0.44 mm, PNW 0.62-0.78 mm, PPL 0.17-0.57 mm, PPW 0.70-0.91 mm.

Similar to the male of barbatus, but inner dorsal margin of paramere (Pl. X, Fig. 11) without a deep emargination, the terminal lobe not set off strongly from the base; terminal parameral lobe as shown in Pl. XI, Fig. 12. Body color generally a fuscus yellow or brown, somelimes nearly black.

References based on Global Ant Biodiversity Informatics

 * Alatorre-Bracamontes, C.E. and M Vasquez-Bolanos. 2010. Lista comentada de las hormigas (Hymenoptera: Formicidae) del norte de México. Dugesiana 17(1):9-36
 * Allred D. M. 1982. Ants of Utah. The Great Basin Naturalist 42: 415-511.
 * Allred, D.M. 1982. The ants of Utah. Great Basin Naturalist 42:415-511.
 * Anderson K. E., L. Zeltzer, R. P. Overson, and W. H. Clark. 2010. Identification of cryptic hosts for two inquiline parasites of the seed-harvester ant Pogonomyrmex and new localities for P. anergismus (Hymenoptera: Formicidae). The Southwestern Naturalist 55: 532-538.
 * Bestelmeyer B. T., and J. A. Wiens. 2001. Local and regional-scale responses of ant diversity to a semiarid biome transition. Ecography 24: 381-392.
 * Boulton A.M. and P.S. Ward. 2002. Ants. Chapter 5 in A New island Biogeography of the Sea of Cortes. T.J. Case, M.L. Cody and E. Ezcurra. Oxford university Press.
 * Cole A. C., Jr. 1942. The ants of Utah. American Midland Naturalist 28: 358-388.
 * Cole A. C., Jr. 1966. Keys to the subgenera, complexes, and species of the genus Pogonomyrmex (Hymenoptera: Formicidae) in North America, for identification of the workers. Annals of the Entomological Society of America 59: 528-530.
 * Cole, A.C. 1968. Pogonomyrmex harvester ants: A study of the genus in North America. University of Tennesee Press. Knoxville
 * Cover S. P., and R. A. Johnson. 20011. Checklist of Arizona Ants. Downloaded on January 7th at http://www.asu.edu/clas/sirgtools/AZants-2011%20updatev2.pdf
 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Des Lauriers J., and D. Ikeda. 2017. The ants (Hymenoptera: Formicidae) of the San Gabriel Mountains of Southern California, USA with an annotated list. In: Reynolds R. E. (Ed.) Desert Studies Symposium. California State University Desert Studies Consortium, 342 pp. Pages 264-277.
 * DuBois M. B. 1985. Distribution of ants in Kansas: subfamilies Ponerinae, Ecitoninae, and Myrmicinae (Hymenoptera: Formicidae). Sociobiology 11: 153-1235
 * DuBois M. B. 1985. Distribution of ants in Kansas: subfamilies Ponerinae, Ecitoninae, and Myrmicinae (Hymenoptera: Formicidae). Sociobiology 11: 153-1236
 * DuBois M. B. 1985. Distribution of ants in Kansas: subfamilies Ponerinae, Ecitoninae, and Myrmicinae (Hymenoptera: Formicidae). Sociobiology 11: 153-1237
 * DuBois M. B. 1985. Distribution of ants in Kansas: subfamilies Ponerinae, Ecitoninae, and Myrmicinae (Hymenoptera: Formicidae). Sociobiology 11: 153-1238
 * DuBois M. B. 1985. Distribution of ants in Kansas: subfamilies Ponerinae, Ecitoninae, and Myrmicinae (Hymenoptera: Formicidae). Sociobiology 11: 153-1239
 * DuBois M. B. 1985. Distribution of ants in Kansas: subfamilies Ponerinae, Ecitoninae, and Myrmicinae (Hymenoptera: Formicidae). Sociobiology 11: 153-1240
 * DuBois M. B. 1985. Distribution of ants in Kansas: subfamilies Ponerinae, Ecitoninae, and Myrmicinae (Hymenoptera: Formicidae). Sociobiology 11: 153-1241
 * DuBois M. B. 1985. Distribution of ants in Kansas: subfamilies Ponerinae, Ecitoninae, and Myrmicinae (Hymenoptera: Formicidae). Sociobiology 11: 153-1242
 * DuBois M. B. 1985. Distribution of ants in Kansas: subfamilies Ponerinae, Ecitoninae, and Myrmicinae (Hymenoptera: Formicidae). Sociobiology 11: 153-1243
 * Emery C. 1895. Beiträge zur Kenntniss der nordamerikanischen Ameisenfauna. (Schluss). Zoologische Jahrbücher. Abteilung für Systematik, Geographie und Biologie der Tiere 8: 257-360.
 * Fernandes, P.R. XXXX. Los hormigas del suelo en Mexico: Diversidad, distribucion e importancia (Hymenoptera: Formicidae).
 * Gadau, J., C.-P. Strehl, J. Oettler and B. Holldobler. 2003. Determinants of intracolonial relatedness in Pogonomyrmex rugosus (Hymenoptera; Formicidae): mating frequency and brood raids. Molecular Ecology 12:1931-1938.
 * Gregg, R.T. 1963. The Ants of Colorado.
 * Johnson R. A., J. D. Parker, and S. W. Rissing. 1996. Rediscovery of the workerless inquiline ant Pogonomyrmex colei and additional notes on natural history. Insectes Sociaux 43: 69-76.
 * Johnson R. Personnal Database. Accessed on February 5th 2014 at http://www.asu.edu/clas/sirgtools/resources.htm
 * Johnson, R.A. 1994. Distribution and natural history of the workerless inquiline ant Pogonomyrmex anergismus Cole (Hymenoptera: Formicidae). Psyche 101:257-262.
 * Johnson, R.A. 2000. Reproductive biology of the seed-harvester ants Messor julianus (Pergande) and Messor pergandei (Mayr) (Hymenoptera: Formicidae) in Baja California, Mexico. Journal of Hymenoptera Research 9(2):377-384.
 * Johnson, R.A. 2002. Semi-Claustral Colony Founding in the Seed-Harvester Ant Pogonomyrmex californicus: A Comparative Analysis of Colony Founding Strategies. Oecologia 132(1):60-67
 * Johnson, R.A. and P.S. Ward. 2002. Biogeography and endemism of ants (Hymenoptera: Formicidae) in Baja California, Mexico: a first overview. Journal of Biogeography 29:10091026/
 * Kansas State Entomology Collection. Dowloaded the 30th of May 2011 at http://biodis.k-state.edu/collections/entomology/
 * La Rivers I. 1968. A first listing of the ants of Nevada. Biological Society of Nevada, Occasional Papers 17: 1-12.
 * Larios, E., A. B–rquez, G. Valenzuela, P. Chesson,and D. L. Venable. 2017. Post-dispersal seed predation in relation to selection on seed size in Dithyrea californica. Evolutionary Ecology Research 18: 651-662.
 * MacGown J. A., T. L. Schiefer, and M. G. Branstetter. 2015. First record of the genus Leptanilloides (Hymenoptera: Formicidae: Dorylinae) from the United States. Zootaxa 4006 (2): 392–400.
 * MacKay W. P. 1981. A comparison of the nest phenologies of three species of Pogonomyrmex harvester ants (Hymenoptera: Formicidae). Psyche (Cambridge) 88: 25-74.
 * Mackay, W.P., E.E. Mackay, J.F. Perez Dominguez, L.I. Valdez Sanchez and P.V. Orozco. 1985. Las hormigas del estado de Chihuahua Mexico: El genero Pogonomyrmex (Hymenoptera: Formicidae) . Sociobiology 11(1):39-54
 * Mackay W. P., and E. E. Mackay. 2002. The ants of New Mexico (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 400 pp.
 * Mackay, W., D. Lowrie, A. Fisher, E. Mackay, F. Barnes and D. Lowrie. 1988. The ants of Los Alamos County, New Mexico (Hymenoptera: Formicidae). pages 79-131 in J.C. Trager, editor, Advances in Myrmecololgy.
 * Mackay, W.P. and E. Mackay. XXXX. The Ants of New Mexico
 * Mallis A. 1941. A list of the ants of California with notes on their habits and distribution. Bulletin of the Southern California Academy of Sciences 40: 61-100.
 * Matsuda T., G. Turschak, C. Brehme, C. Rochester, M. Mitrovich, and R. Fisher. 2011. Effects of Large-Scale Wildfires on Ground Foraging Ants (Hymenoptera: Formicidae) in Southern California. Environmental Entomology 40(2): 204-216.
 * McDonald D. L., D. R. Hoffpauir, and J. L. Cook. 2016. Survey yields seven new Texas county records and documents further spread of Red Imported Fire Ant, Solenopsis invicta Buren. Southwestern Entomologist, 41(4): 913-920.
 * Michigan State University, The Albert J. Cook Arthropod Research Collection. Accessed on January 7th 2014 at http://www.arc.ent.msu.edu:8080/collection/index.jsp
 * Moody J. V., and O. F. Francke. 1982. The Ants (Hymenoptera, Formicidae) of Western Texas Part 1: Subfamily Myrmicinae. Graduate Studies Texas Tech University 27: 80 pp.
 * Mott, B. M., J. Gadau, and K. E. Anderson. 2015. Phylogeography of Pogonomyrmex barbatus and P. rugosus harvester ants with genetic and environmental caste determination. Ecology and Evolution 5: 2798-2826.
 * Nash M. S., Bradford D. F., Franson S. E., Neale A. C., Whitford W. G. and Heggem D. T. 2004. Livestock grazing effects on ant communities in the eastern Mojave Desert, USA. Ecological Indicators 4: 199-213
 * Nash M. S., W. G. Whitford, J. Van Zee, and K. M. Havstad. 2000. Ant (Hymenoptera: Formicidae) responses to environmental stressors in the Northern Chihuahuan Desert. Environ. Entomol, 29(2): 200-206.
 * O'Keefe S. T., J. L. Cook, T. Dudek, D. F. Wunneburger, M. D. Guzman, R. N. Coulson, and S. B. Vinson. 2000. The Distribution of Texas Ants. The Southwestern Entomologist 22: 1-92.
 * Olsen O. W. 1934. Notes on the North American harvesting ants of the genus Pogonomyrmex Mayr. Bulletin of the Museum of Comparative Zoology 77: 493-514.
 * Parker, J.D. and S.W. Rissing. 2002. Molecular Evidence for the Origin of Workerless Social Parasites in the Ant Genus Pogonomyrmex. Evolution 56(10):2017-2028
 * Smith M. R. 1936. A list of the ants of Texas. Journal of the New York Entomological Society 44: 155-170.
 * Snelling, R.R. 1981. The taxonomy and distribution of some North American Pogonomyrmex and descriptions of two new species (Hymenoptera: Formicidae). Bulletin of the Southern California Academy of Science 80(3):97-112.
 * Taber S. W., J. C. Cokendolpher, and O. F. Francke. 1988. Karyological study of North American Pogonomyrmex (Hymenoptera: Formicidae). Insectes Soc. 35: 47-60.
 * Van Pelt, A. 1983. Ants of the Chisos Mountains, Texas (Hymenoptera: Formicidae) . Southwestern Naturalist 28:137-142.
 * Vasquez Bolanos M., and J. Escoto Rocha. 2018. Ants (Hymenoptera: Formicidae) of Aguascalientes. Investigacion y Ciencia 24(68): 36-40.
 * Vasquez-Bolanos M. 2011. Checklist of the ants (Hymenoptera: Formicidae) from Mexico. Dugesiana 18(1): 95-133.
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
 * Ward P.S. and A.M. Boulton. 2002. Checklist of the ants of the Gulf of California Islands. In Island Biogeography of the sea of Cortes. T.J. Case, M.L. Cody and E. Ezcurra Editors. 690 pp.
 * Wheeler G. C. and Wheeler J. 1973. Ants of Deep Canyon. Riverside, Calif.: University of California, xiii + 162 pp
 * Wheeler G. C., and J. Wheeler. 1986. The ants of Nevada. Los Angeles: Natural History Museum of Los Angeles County, vii + 138 pp.
 * Wheeler W. M. 1902. New agricultural ants from Texas. Psyche (Cambridge). 9: 387-393.
 * Whitford W. G. 1978. Structure and seasonal activity of Chihuahua desert ant communities. Insectes Sociaux 25(1): 79-88.
 * Zimmer, K. and R.R. Parmenter. 1998. Harvester ants and fire in a desert grassland: Ecological responses of Pogonomyrmex rugosus (Hymenoptera: Formicidae) to experimental wildfires in central New Mexico. Environmental Entomology 27(2):282-287