Pheidole psammophila

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to: navigation, search
Pheidole psammophila
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Pheidole
Species: P. psammophila
Binomial name
Pheidole psammophila
Creighton & Gregg, 1955

Pheidole psammophila casent0005767 profile 1.jpg

Pheidole psammophila casent0005767 dorsal 1.jpg

Specimen Label

All of the nests found by Creighton and reported in Creighton and Gregg (1955), as well as by Stefan Cover (unpublished notes), were in sand, especially sand subject to frequent shifting, an extreme environment avoided even by other desert-dwelling ants. The remarkable psammophore (basket-like enclosure of hairs between the head, used to carry sand or other loose particles) is likely an adaptation to the environment for which the species is specialized. Chaff piles occurred around the nest entrances of some of the nests, an almost certain sign that psammophila harvests seeds. (Wilson 2003)

Identification

See the description in the nomenclature section.

Keys including this Species

Distribution

Sandy deserts of southern California, western Arizona, and Sonora, northern Mexico, sea level to 75 m (Creighton and Gregg 1955).

Distribution based on Regional Taxon Lists

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

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

The ecological responses of this ant appear to be unusually constant. Twelve colonies were found from stations whose elevation was never more than 250 feet above sea level. All the nests were constructed in areas whose dominating characteristic was an abundance of sand. The region of sand dunes, which extends through much of the Gran Desierto in Sonora and into Imperial County in California, appears to be an exceptionally difficult environment for most ants. Even the strongly xerophilous species avoid this area, presumably because the shifting sand is continually covering the nest openings. The presence of psammophila in this region indicates that the sand-dwelling habit is highly developed in this species. In areas where the sand was not shifting there were chaff piles around the nest entrances, a clear indication that psammophila is a harvester. (Creighton and Gregg 1955)

Castes

Worker

Minor

Nomenclature

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

  • psammophila. Pheidole psammophila Creighton & Gregg, 1955: 15, figs. 4, 5 (s.w.) U.S.A. See also: Wilson, 2003: 593.

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): DIAGNOSIS A member of the “bicarinata complex” of the larger pilifera group, comprising Pheidole agricola, Pheidole aurea, Pheidole barbata, Pheidole bicarinata, Pheidole centeotl, Pheidole cerebrosior, Pheidole defecta, Pheidole gilvescens, Pheidole macclendoni, Pheidole macrops, Pheidole marcidula, Pheidole paiute, Pheidole pinealis, Pheidole vinelandica, Pheidole xerophila, Pheidole yaqui and Pheidole yucatana (psammophila is closest to barbata), which complex is characterized by the large to very large, forward-set eyes of both castes; and, in the major, the occipital lobes lacking any sculpturing (except in aurea); the posterior half of the head capsule almost entirely smooth and shiny; and the postpetiolar node seen from above oval, elliptical, or laterally angulate (cornulate in cerebrosior).

P. psammophila is distinguished within the complex by the following combination of traits.

Major: hypostoma lacking teeth; humerus in dorsal-oblique view subangulate; petiolar node in side view tapered to a point; smallsubpostpetiolar process visible in side view; occipital lobes subangulate.

Minor: lower surface of head flat and bearing very long hairs curved to form a basket (psammophore). Petiole long and thin and petiolar and postpetiolar nodes very low.

MEASUREMENTS (mm) Syntype major: HW 1.60, HL 1.72, SL 0.80, EL 0.30, PW 0.72. Syntype minor: HW 0.54, HL 0.68, SL 0.62, EL 0.24, PW 0.38.

COLOR Major: head and mandibles clear reddish yellow, mesosoma and waist medium reddish brown, gaster and appendages light reddish brown.

Minor: body concolorous medium brown, mandibles a contrasting clear yellow, other appendages light brown.


Pheidole psammophila Wilson 2003.jpg

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

Type Material

CALIFORNIA: 8 km east of Grey’s Well, Imperial Co., 50 m, col. William S. Creighton. Museum of Comparative Zoology - as reported in Wilson (2003)

Etymology

Gr psammophila, sand-lover, referring to the nest-site preference. (Wilson 2003)

References

  • Creighton, W. S.; Gregg, R. E. 1955. New and little-known species of Pheidole (Hymenoptera: Formicidae) from the southwestern United States and northern Mexico. Univ. Colo. Stud. Ser. Biol. 3: 1-46 PDF (page 15, figs. 4, 5 soldier, worker described)
  • Wilson, E. O. 2003. Pheidole in the New World: A dominant, hyperdiverse ant genus. Harvard University Press, Cambridge, MA. (page 593, fig. major, minor described)