Pheidole gilvescens

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

Pheidole gilvescens casent0005759 profile 1.jpg

Pheidole gilvescens casent0005759 dorsal 1.jpg

Specimen Label

In southern California, Snelling and George (1979) found gilvescens common at 150–1500 m in grassland, creosote bush scrub, wash woodlands, and joshua tree woodlands. Small crater nests are built in sand and are often surrounded by chaff. The colonies contain up to 500 workers. The ants are primarily granivorous but also collect arthropods, apparently as scavengers. Repletes are occasionally found. Foraging begins at dusk, continues through the night, and ends early in the morning. Winged queens have been found in nests in late May, and males in May and September. (Wilson 2003)

Identification

See the description in the nomenclature section.

Keys including this Species

Distribution

Creighton and Gregg (1955) and Wheeler and Wheeler (1986) report the species (and I have mostly confirmed) as occurring from south-central Arizona through southern Nevada to the eastern slope of the California Sierras. (Wilson 2003)

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 type specimens, which appear to have been strays, came from Phoenix and Tucson. The insect is quite scarce in both stations, its main range lying further west as the following records show: ARIZONA: Organpipe Cactus National Monument, Headquarters (1600'); Growler Mountains, Abra Wash (1300'); Quitobaquito (900'); 5 miles east of Aguila (2200'). CALIFORNIA: 21 miles east of Indio (1600'); 9 miles north of Llano (2800'); Bartlett (3700'); Yaqui Well, Anza Desert State Park (1300'); Borrego Wells (300'). A single colony was taken by the senior author in each of these stations except at Abra Wash in the Growler Mountains, where eight colonies were secured. The nests of Pheidole gilvescens are invariably small, often containing no more than half a dozen majors and two or three dozen minors. The insect shows little tendency to forage in files, and the majors rarely leave the nest. (Creighton and Gregg 1959)

Langen et al. (2000) examined aggression between colonies by placing sets of workers from different colonies together in an arena. The source population for the studied colonies were from Mojave Bajada habitat within the Eastern Mojave desert (San Bernardino Co., Calfornia). Levels of aggression were found to be higher for non-neighboring colonies, i.e., those greater than 2.6 m apart.

Castes

Worker

Minor

Major

Nomenclature

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

  • gilvescens. Pheidole gilvescens Creighton & Gregg, 1955: 5 (s.w.) U.S.A. [First available use of Pheidole xerophila subsp. tucsonica var. gilvescens Wheeler, W.M. 1908e: 448; unavailable name.] See also: Wilson, 2003: 577.

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 small, large-eyed member of the pilifera group, close to Pheidole xerophila and distinguished from it as follows.

Major: body almost entirely reddish yellow; postpetiolar node transversely oval in shape; sides of pronotum carinulate.

Minor: entirely yellow (as opposed to yellowish brown).

With xerophila, the entire head of the major tapers conspicuously from midlevel to the occiput in side view.

MEASUREMENTS (mm) Lectotype major: HW 1.42, HL 1.48, SL 0.66, EL 0.22, PW 0.66. Paralectotype minor: HW 0.58, HL 0.80, SL 0.52, EL 0.18, PW 0.32.

COLOR Major: body and appendages dark reddish yellow; gaster partly light brown.

Minor: body medium yellow, appendages pale yellow.


Pheidole gilvescens Wilson 2003.jpg

Figure. Lectotype, major. Scale bars = 1 mm.

Lectotype Specimen Labels

Type Material

From Wilson (2003): ARIZONA: Tucson, col. W. M. Wheeler. Museum of Comparative Zoology and American Museum of Natural History - as reported in Wilson (2003)

Etymology

L gilvescens, pale yellow, pertaining to the color of the minor, distinguishing the species from Pheidole xerophila. (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 (page 5, soldier, worker described)
  • Langen, T. A., F. Tripet, and P. Nonacs. 2000. The red and the black: habituation and the dear-enemy phenomenon in two desert Pheidole ants. Behavioral Ecology and Sociobiology. 48(6):285-292. doi:10.1007/s002650000223
  • Snelling, R. R. and C. D. George. 1979. The taxonomy, distribution and ecology of California desert ants. Report to California Desert Plan Program, Bureau of Land Management, U.S. Dept. Interior., 335 + 89 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. 1908h. The ants of Texas, New Mexico and Arizona. (Part I.). Bull. Am. Mus. Nat. Hist. 24: 399-485 (page 448, first available use of Pheidole xerophila subsp. tusconica var. gilvencens Wheeler; unavailable name.)
  • Wilson, E. O. 2003. Pheidole in the New World: A dominant, hyperdiverse ant genus. Harvard University Press, Cambridge, MA. (page 577, fig. major, minor described)