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Species: Pheidole senex   Gregg, 1952 

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Taxonomic History (provided by Barry Bolton, 2019)

Pheidole senex Gregg, 1952a PDF: 1 (s.w.) U.S.A. Nearctic. AntCat AntWiki HOL

Taxonomic history

Senior synonym of Pheidole anfracta: Cole, 1953e PDF: 298; Gregg, 1959 PDF: 30.
See also: Wilson, 2003A: 596.


  Geographic regions (According to curated Geolocale/Taxon lists):
    Americas: Mexico, United States
  Biogeographic regions (According to curated Bioregion/Taxon lists):

Taxonomic Treatment (provided by Plazi)

Treatment Citation: Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press

Pheidole senex GreggHNS

Pheidole senex GreggHNS 1952a: 1. Syn.: Pheidole pilifera subsp. anfracta ColeHNS 1952c: 278, synonymy by Cole 1953g: 298.

Types Mus. Comp. Zool. Harvard.

Etymology L senexHNS, old, senior, possibly alluding to rugulose sculpture of head and mesosoma.

diagnosis A member of the " piliferaHNS complex" of the larger piliferaHNS group, comprising calensHNS, californicaHNS, carrolliHNS, cavigenisHNS, clementensisHNS, creightoniHNS, hopliticaHNS, littoralisHNS, miculaHNS, piliferaHNS, polymorphaHNS, rugulosaHNS, senexHNS, soritisHNS, tepicanaHNS, and torosaHNS, which complex is distinguished by the following traits. Major: dorsal head surface extensively sculptured; occipital lobes transversely rugulose (or, in carrolliHNS smooth, in littoralisHNS foveate, and in miculaHNS and soritisHNS carinulate), postpetiole from above diamond-shaped, trapezoidal, or spinose. Minor: eye medium-sized to large.

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

Major: large; mesonotal convexity subangulate in dorsal-oblique view, and descends steeply to metathorax in side view; petiolar node tapers to a point in side view; postpetiole from above spinose; sides of pronotum, mesonotum, and propodeum, longitudinally carinulate; anterior dorsal profde of head flat; cephalic pilosity short and erect.

Minor: entire dorsal surface of head except mid-section of clypeus longitudinally carinulate; all of mesosoma foveolate and opaque. Measurements (mm) Paratype major: HW 1.74, HL 1.86, SL 0.78, EL 0.22, PW 0.82. Paratype minor: HW 0.64, HL 0.66, SL 0.68, EL 0.14, PW 0.40. color Major and minor: light yellowish to reddish brown.

range West-central Arizona through New Mexico to the Texas Panhandle and southern Colorado; apparently rare.

Biology Gregg (1963) reports P. senexHNS from Campo, Colorado, in short grass prairie nesting in clay under rocks at 1300 m. Cole recorded it in New Mexico from 2000 to 2700 m. At Springerville, Arizona, I found a colony under a rock in grassy desert. In the Texas Panhandle, Moody and Francke (1982) found two colonies, one beneath a stone and the other in open soil.

Figure Upper: paratype, major. Lower: paratype, minor. COLORADO: 14 km south of Campo, Baca Co., extreme southeastern Colorado (Robert E. Gregg). Scale bars = 1 mm.

Specimen Habitat Summary

Found most commonly in these habitats: 3 times found in short grass prairie, 2 times found in shrub steppe, 1 times found in salt desert scrub, 1 times found in open grassland-meadow, 1 times found in Roadside meadow, 1 times found in Shiort grass prairie, 1 times found in Cactus- yucca desert, 1 times found in pine oak forest, 1 times found in Pine- oak manzanita.

Found most commonly in these microhabitats: 4 times under rock, 3 times nest in soil, 1 times tumulus nest in exposed roadside.

Collected most commonly using these methods: 3 times search.

Elevations: collected from 1143 - 2910 meters, 1666 meters average

Type specimens: Paratype: fmnhins0000058307, fmnhins0000062770, fmnhins0000062771, fmnhins0000062782, fmnhins0000062783, fmnhins0000062784, fmnhins0000062785, fmnhins0000062794, fmnhins0000062795, fmnhins0000062796, fmnhins0000062797; Paratype, Paratype: fmnhins0000058311, fmnhins0000058538

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