Pheidole texana

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Pheidole texana
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Pheidole
Species: P. texana
Binomial name
Pheidole texana
Wheeler, W.M., 1903

Pheidole texana casent0103152 profile 1.jpg

Pheidole texana casent0103152 dorsal 1.jpg

Specimen Label

P. texana is evidently a rare species. Wheeler (1903c) discovered only four colonies over many years’ collecting, and all in Travis County, Texas; all were in grassland, nesting in open soil, with the entrances surmounted by small mounds about 10 cm in diameter. During their intensive collecting in western Texas, Moody and Francke (1982) found only two colonies, nesting in open, fully exposed clayey loam. (Wilson 2003)

Identification

See the description in the nomenclature section.

Keys including this Species

Distribution

Known from the type locality, as well as Sutton and Uvalde Counties in western Texas. (Wilson 2003)

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Worker

Minor

Major

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • texana. Pheidole texana Wheeler, W.M. 1903b: 97, fig. 4 (s.w.) U.S.A. See also: Wilson, 2003: 353.

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

Description

From Wilson (2003): A member of the fallax group, distinguished by the following combination of traits.

Major: posterior third of dorsal surface of the head rugoreticulate; scape slightly expanded at the base; promesonotal dorsum transversely carinulate; postpetiolar node from above very wide, and elliptical; small subpostpetiolar process present.

Minor: occiput rugoreticulate; promesonotal dorsum transversely carinulate; postpetiole from above very broad, and bell-shaped; mesosoma, waist, and all head except frontal triangle and middle of clypeus foveolate and opaque.

MEASUREMENTS (mm) Lectotype major: HW 1.40, HL 1.54, SL 0.86, EL 0.26, PW 0.74. Paralectotype minor: HW 0.68, HL 0.78, SL 0.84, EL 0.16, PW 0.48.

COLOR Major and minor: concolorous light reddish brown.


Pheidole texana Wilson 2003.jpg

Figure. Upper: lectotype, major. Lower: paralectotype, minor. Scale bars = 1 mm.

Worker

Major Length 4-5 mm.

Head rather small, but larger than the gaster, a little longer than broad, excluding the mandibles, cordiform, distinctly broader behind than in front, with deeply excised posterior border, rounded posterior angles, and a rather broad median furrow extending from the frontal area to the occiput. Frontal area triangular, about as broad as long. Clypeus short, its anterior border flattened and rather deeply notched in the middle. Frontal carinae short, prominent. Eyes moderate, well in front of the middle of the sides of the head. Mandibles large, convex with flattened blades, which are finely denticulate basally, with two prominent terminal teeth. Antennal scape broadened and flattened, distinctly concave on its anterior surface, hardly reaching to half the distance between the eye and• the posterior corner of the head, funiculus with all its joints longer than broad, the last three joints forming a well-developed club. Thorax not very robust, pronotal angles rounded, pronotum rather flattened above; mesonotum angular, projecting upward, concave in the middle when seen from behind; separated by a distinct suture from the pronotum and by a more distinct constriction from the epinotum. The latter has its basal surface and declivity both in the same plane, gradually sloping backwards and distinctly concave; spines well-developed, blunt, longer than broad at their bases and much farther apart than long, directed upwards, backwards, and outwards. Petiole in profile with long concave ascending nodal surface and convex ventral surface; the node is acute, transverse, with median emargination and short, concave posterior declivity; seen from above the petiole is small, not more than one and a half times as long as broad, broader behind than in front, constricted in the middle, with rather acute posterior angles. Postpetiole three times as broad as the petiole and more than twice as broad as long, with a small, acute projection in the middle on either side; in profile the dorsal surface is evenly convex and longer than the more uneven ventral surface. Gaster rather large, elliptical, flattened on its dorsal surface. Legs of moderate length and of the usual conformation.

Mandibles shining, indistinctly reticulate. covered with large piligerous punctures. Clypeus shining in the middle, faintly reticulate like the mandibles, on either side with a few coarse longitudinal rugae. Frontal area impressed, shining, with a few longitudinal rugae on either side. Head opaque throughout. covered with coarse reticulate rugae enclosing more finely reticulate interrugal spaces; the main rugae with distinctly longitudinal trend only on the front and cheeks. Cephalic furrow crossed by numerous transverse rugae especially towards the occipital border. Antennal scape shining, finely reticulate. Thorax, petiole, and postpetiole opaque like the head, but more finely reticulate rugose; only the dorsal surfaces are roughened, the pro- and mesonotum being crossed by a few coarse and irregular transverse rugae. Postpetiole with about eight shallow longitudinal impressions on its dorsal surface. Gaster and legs shining, their surfaces finely and regularly reticulate.

Body and appendages invested with rather long, more or less erect, tawny hairs. Rich ferruginous red throughout; legs and antennae but little paler than the body; gaster somewhat infuscated posteriorly, anteriorly pellucid and in many specimens appearing as if filled with a wine-red fluid so that this region has a more brilliant color than the remainder of the body.

Minor Length 2.5-3 mm.

Head but little longer than broad. its posterior border rather straight but not concave. Mandibles rather slender, 8-toothed. tile first, second. and fourth teeth from the apex being longer than the others. Clypeus sinuately emarginate in the middle. with a median and on either side two lateral longitudinal ridges or carinulae. Frontal area triangular, as long as broad, with a median longitudinal ridge. Antennal scapes not flattened, distinctly enlarged at their distal ends; exceeding the posterior angles of the head by somewhat more than twice their transverse diameter. Pronotum rounded above and on the sides. spheroidal; mesonotum projecting upwards as a transverse ridge which is not concave in the middle when seen from behind, separated by distinct constrictions from the pro- and epinotum. The latter shaped like that of the soldier. Petiole slender, fully twice as long as broad, in other respects like the corresponding segment of the soldier. Postpetiole nearly three times as broad as the petiole, hardly twice as broad as long. its sides and dorsal surface rounded, the angles of the former being very indistinct.

Sculpture like that of the soldier but feebler, especially on the head. Pilosity and color, too, as in the soldier, except that there is a large black spot on the vertex in many specimens.

Lectotype Specimen Labels

Type Material

TEXAS: Austin, Travis Co., col. W. M. Wheeler. Museum of Comparative Zoology - as reported in Wilson (2003)

Etymology

Named after state of origin of type colony. (Wilson 2003)

References

  • Moody, J. V., Francke, O. F. 1982. The ants (Hymenoptera, Formicidae) of western Texas, Part 1: Subfamily Myrmicinae. Grad. Stud. Tex. Tech Univ. 27: 1–80.
  • Wheeler, W. M. 1903c. A decad of Texan Formicidae. Psyche (Camb.) 10: 93-111 (page 97, fig. 4 soldier, worker described)
  • Wilson, E. O. 2003. Pheidole in the New World: A dominant, hyperdiverse ant genus. Harvard University Press, Cambridge, MA. (page 353, fig. major, minor described)