Pheidole creightoni

Pheidole creightoni
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Pheidole
Species:	P. creightoni
Binomial name
	Pheidole creightoni; Gregg, 1955 Specimen Label

William S. Creighton (in Gregg 1955) found 18 earthen nests of creightoni at the type locality, frequently near nests of the much larger ant Messor (= Veromessor) andrei. The entrances were surrounded by large rings of chaff, indicating that seeds are an important part of the diet. Tissue of freshly killed ground squirrels was also accepted by the majors and minors, which foraged in files. Soil nests have also been recorded on museum labels, in California by Diane W. Davidson and in Nevada by Philip S. Ward. Nuptial flights were recorded in August and September by Davidson and by Creighton respectively; they occurred about an hour before sunset. (Wilson 2003)

Identification

The Pheidole californica complex comprises three closely related and partly sympatric species of seed harvesting ants restricted to the western Nearctic region. Pheidole clementensis Gregg may be distinguished from both Pheidole californica Mayr and Pheidole creightoni Gregg by the diagonal rather than longitudinal rugulae between the clypeus and the eye in lateral View. The closely related P. californica and P. creightoni are most readily distinguished from one another by the angle of their lateral cephalic setae. Pheidole californica has decumbent setae forming an angle of forty-five degrees or less with the lateral margins of the head in full face view, while the cephalic setae of P. creightoni emerge at an angle of approximately ninety degrees. (Burge, 2005.)

See also the description in the nomenclature section.

Keys including this Species

Distribution

Pheidole creightoni is found in foothill or plateau habitats in northern California, Oregon, Washington, and Nevada (Burge, 2005).

Latitudinal Distribution Pattern

Latitudinal Range: 42.5° to 39°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).

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.

Biology

Nevada, Wheeler and Wheeler (1986) - One nest was surmounted by a 25-cm crater and had an entrance 1 mm in diameter. We found the beetle conibiosoma elongatum (Hom) (Coleoptera: Tenebrionidae; det. T. J. Spilman) in a nest.

Castes

Worker

Minor

Images from AntWeb


Worker. Specimen code casent0005758. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by UCDC, Davis, CA, USA.

Nomenclature

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

creightoni. Pheidole creightoni Gregg, 1955a: 19, pl. 2, figs. a-c; pl. 3, figs. a-c (s.w.q.m.) U.S.A. See also: Wilson, 2003: 573.

Description

From Wilson (2003): DIAGNOSIS A member of the “pilifera complex” of the larger pilifera group; for a characterization of the complex, see under Pheidole pilifera. P. creightoni is distinguished within the complex by the following combination of traits.

Major: occiput in side view very broad, as much as 1.5X the anterior cephalic capsule border; promesonotum forms a smooth, single convexity; petiolar node tapering to a blunt point in side view and with a deeply concave border seen from behind; postpetiole from above spinose.

Minor: yellowish brown; eye very large; humerus subangulate in dorsal-oblique view; petiolar node tapers to a blunt point in side view; postpetiole seen from above trapezoidal.

MEASUREMENTS (mm) Paratype major: HW 1.22, HL 1.32, SL 0.58, EL 0.16, PW 0.48. Paratype minor: HW 0.54, HL 0.60, SL 0.52, EL 0.14, PW 0.32.

COLOR Major: most of body and head, as well as mandibles, light reddish yellow; gaster plain light brown; legs clear dark yellow.

Minor: body light yellowish brown, appendages clear dark yellow.

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

Type Material

OREGON: Applegate, Jackson Co. Museum of Comparative Zoology - as reported in Wilson (2003)

Etymology

Named after the pioneering American myrmecologist William S. Creighton. (Wilson 2003)

References

Burge, D.O. 2005. Taxonomy, biology, and distribution of seed harvesting ants in the Pheidole californica complex (Hymenoptera Formicidae). Journal of Hymenoptera Research 14, 137-150.
Gregg, R. E. 1955. A new species of ant belonging to the Pheidole pilifera complex (Hymenoptera: Formicidae). Psyche (Camb.) 62: 19-28. (page 19, pl. 2, figs. a-c; pl. 3, figs. a-c soldier, worker, queen, male described)
Wheeler, G. C. and J. Wheeler. 1986. The ants of Nevada. Natural History Museum of Los Angeles County, Los Angeles.
Wilson, E. O. 2003. Pheidole in the New World: A dominant, hyperdiverse ant genus. Harvard University Press, Cambridge, MA. (page 573, fig. major, minor described)

References based on Global Ant Biodiversity Informatics

Burge D. O. 2005. Taxonomy, biology, and distribution of seed harvesting ants in the Pheidole californica complex (Hymenoptera: Formicidae). Journal of Hymenoptera Research 14: 137-150
La Rivers I. 1968. A first listing of the ants of Nevada. Biological Society of Nevada, Occasional Papers 17: 1-12.
Ostoja S. M., E. W. Schupp, and K. Sivy. 2009. Ant assemblages in intact big sagebrush and converted cheatgrass-dominates habitats in Tooele County, Utah. Western North American Naturalist 69(2): 223234.
Wheeler G. C., and J. Wheeler. 1986. The ants of Nevada. Los Angeles: Natural History Museum of Los Angeles County, vii + 138 pp.
Wilson, E.O. 2003. Pheidole in the New World: A Dominant, Hyperdiverse Genus. Harvard University Press