Creighton (1958) reports that mature colonies are very large, with numerous majors, and occasionally dominate the immediate surrounding area to the exclusion of other ant species. Winged reproductives are found in the nests from April to at least September, and nuptial flights evidently occur in late August into early September. According to Barry Pullen, the size variation of the workers is continuous, but with sharp modes marking the minor, major, and supermajor castes. (Wilson 2003)
See the description in the nomenclature section.
Keys including this Species
According to Creighton (1958), who studied hirtula closely, the species occurs between 1070 and 2310 m, with most colonies concentrated at 1500–2100 m, from northern Chihuahua southward through Coahuila, Nuevo León, San Luis Potosí and Zacatecas to Hidalgo, Querétaro, and Jalisco. Barry E. Pullen (personal communication) reports the species as common in the suburbs of Mexico City. (Wilson 2003)
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- hirtula. Pheidole vasliti var. hirtula Forel, 1899c: 65 (s.w.) MEXICO. Wheeler, W.M. 1909b: 232 (q.). Raised to species and senior synonym of acolhua: Creighton, 1958: 211. See also: Wilson, 2003: 578.
- acolhua. Pheidole (Cardiopheidole) vasliti var. acolhua Wheeler, W.M. 1914b: 48 (s.w.q.m.) MEXICO. Junior synonym of hirtula: Creighton, 1958: 211.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
From Wilson (2003): DIAGNOSIS A large trimorphic species (major, supermajor, minor) placed in the pilifera group because of the 2-toothed hypostoma but with other traits conforming to the fallax group. Very close to Pheidole obtusospinosa, distinguished most readily in the supermajor, as illustrated, by the rounded foveae of the rear half of the dorsum of the head, with the interspaces smooth and shiny. This form is considered by Ward (1999) to be a likely geographic subspecies of obtusopilosa rather than a full species.
MEASUREMENTS (mm) All from near Chapulco, Puebla. Supermajor: HW 2.60, HL 2.40, SL 1.18, EL 0.32, PW 1.34. Major: HW 1.52, HL 1.60, SL 1.10, EL 0.24, PW 0.82. inor: HW 0.66, HL 0.86, SL 1.04, EL 0.20, PW 0.48.
COLOR Supermajor, major, and minor: head and appendages light reddish brown to plain medium brown, rest of body medium brown.
Figure. Supermajor, head. Scale bars = 1 mm.
MEXICO: km 275, Highway 150 northeast of Chapulco, Puebla. Musee d'Histoire Naturelle Genève - as reported in Wilson (2003)
L hirtula, little hairy one. (Wilson 2003)
- Creighton, W. S. 1950a. The ants of North America. Bull. Mus. Comp. Zool. 104: 1-585 (page 211, raised to species, and senior synonym of acolhua)
- Forel, A. 1899e. Formicidae. [part]. Biol. Cent.-Am. Hym. 3: 57-80 (page 65, soldier, worker described)
- Wheeler, W. M. 1909b. Ants collected by Prof. F. Silvestri in Mexico. Boll. Lab. Zool. Gen. Agrar. R. Sc. Super. Agric. 3: 228-238 (page 232, queen described)
- Wilson, E. O. 2003. Pheidole in the New World: A dominant, hyperdiverse ant genus. Harvard University Press, Cambridge, MA. (page 578, fig. major described)