Solenopsis krockowi

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Solenopsis krockowi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Solenopsidini
Genus: Solenopsis
Species complex: fugax
Species: S. krockowi
Binomial name
Solenopsis krockowi
Wheeler, W.M., 1908

Solenopsis krockowi casent0104467 profile 1.jpg

Solenopsis krockowi casent0104467 dorsal 1.jpg

Specimen labels

This species nests under stones in dry shrubland including sparse mesquite scrub on rocky slopes. Specimens were collected in a variety of leaf litter, ranging from desert scrub (creosotebush) to cottonwood tree leaves. Brood and sexuals were found in a nest in June (Mexico), and it has been collected in surface and subterranean Vienna sausage baits, and in pitfall traps. (Pacheco and Mackay 2013)


A New World thief ant that is a member of the fugax species complex

Pacheco and Mackay (2013) – Worker - This is a relatively large, bright yellow species, with coarse cephalic punctures. The head is nearly quadrate, a little longer than wide. The clypeal teeth are widely spaced, with a distance of about 0.100 mm between the tips of the teeth. The extralateral teeth are often well developed. It has a large, extended subpeduncular process; the postpetiole is oval-shaped as seen from above and has a large flange ventrally. Queen The queen is very large, over 7 mm in total length. It is golden yellow with the head wider than long and coarsely punctate. Four clypeal teeth are present and well developed, while the clypeal carinae are weakly defined. The pronotum is coarsely punctate and horizontal striae are present on the metapleuron.

Solenopsis krockowi could be confused with the widely distributed Solenopsis molesta, but is easily separated by its rectangular-shaped head. The punctures on the head are very coarse, whereas they are fine in S. molesta. It can be separated from Solenopsis pergandei (southern USA) on the basis of the oval-shaped postpetiole (round in S. pergandei). The widely diverging clypeal carinae separate it from Solenopsis pilosula (Texas), in which the carinae are nearly parallel and closely spaced. The widely spaced clypeal carinae and monomorphism separate it from the similar Solenopsis johnsoni (Mexico) and Solenopsis vinsoni (Central America).

Keys including this Species


United States: Arizona, New Mexico and Texas. Mexico: San Luis Potosi.

Latitudinal Distribution Pattern

Latitudinal Range: 39.767453° to 23.644803°.

Tropical South

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).
Neotropical Region: Mexico.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.


Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.



Chihuahuan Desert scrub, riparian, juniper, sagebrush, urban habitats. (Mackay and Mackay 2002)


Solenopsis krockowi nests under stones, or simply in the soil with no external evidence of the nest. This species is predominantly subterranean. Sexuals were found in nests in July and August. Foragers can be captured with subterranean traps in southern NM. (Mackay and Mackay 2002)

Flight Period

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Source: Mackay & Mackay, 2002.




The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • krockowi. Solenopsis krockowi Wheeler, W.M. 1908e: 428, pl. 26, figs. 28, 29 (w.q.) U.S.A. (New Mexico).
    • Type-material: lectotype worker (by designation of Pacheco & Mackay, 2013: 198), 6 paralectotype workers, 1 paralectotype queen.
    • Type-locality: lectotype U.S.A.: New Mexico, Sacramento Mts, Box Cañon, 6.vii.1906 (G. von Krockow); paralectotypes with same data.
    • [Note: other original syntypes in LACM.]
    • Type-depository: MCZC.
    • Status as species: Wheeler, W.M. 1910g: 563; Emery, 1922e: 200; Smith, M.R. 1943a: 211 (in key); Creighton, 1950a: 236; Smith, M.R. 1951a: 813; Cole, 1953g: 299; Smith, M.R. 1958c: 129; Ettershank, 1966: 141; Smith, D.R. 1979: 1387; Dlussky, 1981a: 48; Mackay, Lowrie, et al. 1988: 101; Bolton, 1995b: 388; Mackay & Mackay, 2002: 230; Pacheco & Mackay, 2013: 196 (redescription).
    • Distribution: Mexico, U.S.A.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.



Pacheco and Mackay (2013) - Measurements (n=5). TL 2.22-2.34 (2.29); HL 0.564-0.600 (0.575); HW 0.510-0.570 (0.533); EL 0.060-0.066 (0.062); ED 0.042; SL 0.396-0.444 (0.412); FSL 0.186-0.198 (0.191); CI 90.4-95.0 (92.7); SI 70.2-74.0 (71.6); PL 0.102-0.120 (0.106); PW 0.168-0.180 (0.170); PI 60.7-66.7 (61.9); PPL 0.132-0.150 (0.137); PPW 0.174-0.192 (0.180); PPI 73.3-79.3 (75.9); WL 0.420-0.480 (0.443); PSL 0.042-0.048 (0.044); PSW 0.042-0.048 (0.043).

Moderately large, concolorous yellow; head longer than wide, coarsely punctate; clypeallateral teeth widely spaced, distance of 0.1 0 mm between tips of teeth; extralateral teeth often well developed; clypeal carinae well defined; eyes small, 5-6 ommatidia; mesosoma smooth and shiny, pronotum with coarse punctures; notopropodeal suture well depressed; posterior propodeal margin rounded; propodeal spiracle large; extended subpeduncular process large; petiole oval-shaped viewed dorsally, with large flange at subpeduncular process; postpetiolar node globose, without flange or tooth ventrally.

Hairy with erect and sub erect hairs of various lengths on all body surfaces; cephalic hairs short, central portion of head without hair; hairs on remainder of body, including petiole and postpetiole, mixture of long (0.070 mm) and short (0.040 mm) hairs.


Pacheco and Mackay (2013) - Measurements (n=1). TL 7.32; HL 0.990; HW 1.02; EL 0.360; ED; 0.252; MOL 0.114; MOD 0.108; SL 0.720; FSL 0.540; CI 102; SI 35.3; PSL 0.120; PSW 0.090; PL 0.138; PW 0.420; PI 32.9; PPL 0.360; PPW 0.480; PPI 75.0; WL 1.80.

Very large, concolorous golden yellow; head quadrate, slightly wider than long, narrowed anteriorly, coarsely punctate; lateral clypeal teeth well developed; space between lateral teeth wide at 0.210 mm; extralateral teeth well developed; scapes long, do not reach posterior lateral corner of head; minor funicular segments long; eyes large; medial ocellus large; pronotum coarsely punctate; mesopleuron smooth and shiny; metapleuron horizontally striated; posterior propodeal margin rounded; propodeal spiracle large; petiole wider than postpetiole viewed laterally; large flange ventrally on petiolar peduncle; both petiole and postpetiole striated basally on nodes.

Abundantly hairy, pilosity yellow; erect and suberect hairs covering all body surfaces.

Type Material

New Mexico, Sacramento Mts., Box Canon, 06-vii-1906, Wheeler, type, Von Krockow type #1-13 20907 (lectotype worker, 6 paralectotype workers and 1 paralectotype queen [here designated] Museum of Comparative Zoology).


References based on Global Ant Biodiversity Informatics

  • Cole A. C., Jr. 1953. Studies of New Mexico ants. VI. The genera Monomorium, Solenopsis, Myrmecina, and Trachymyrmex (Hymenoptera: Formicidae). [part]. Journal of the Tennessee Academy of Science 28: 299-300.
  • Cover S. P., and R. A. Johnson. 20011. Checklist of Arizona Ants. Downloaded on January 7th at
  • Johnson R. Personnal Database. Accessed on February 5th 2014 at
  • 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.
  • 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.
  • 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.
  • 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.
  • Pacheco J. A., and W. P. Mackay. 2013. The systematics and biology of the New World thief ants of the genus Solenopsis (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 501 pp.
  • Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
  • Wheeler, G.C. and J. Wheeler. 1985. A checklist of Texas ants. Prairie Naturalist 17:49-64.
  • Whitford W. G. 1978. Structure and seasonal activity of Chihuahua desert ant communities. Insectes Sociaux 25(1): 79-88.
  • Whitford W.G., Zee J.V., Nash M.S., Smith W.E. and Herrick J.E. 1999. Ants as Indicators of Exposure to Environmental Stressors in North American Desert Grasslands. Environmental Monitoring and Assesment. 54: