Pheidole marcidula

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Pheidole marcidula
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Pheidole
Species: P. marcidula
Binomial name
Pheidole marcidula
Wheeler, W.M., 1908

Pheidole marcidula casent0172967 profile 1.jpg

Pheidole marcidula casent0172967 dorsal 1.jpg

Specimen Label

P. marcidula is evidently a rare species. Wheeler (1908) found one colony, nesting beneath a stone at Barton Creek, Texas. In Hudspeth County, Texas, Moody and Francke (1982) found a single colony at 1300 m, nesting in open sandy loam soil. (Wilson 2003)

Identification

The minor worker of this species is easily recognized by the clavate or spatulate hairs on the dorsum of the mesosoma. The scapes of the minor extend about 1 funicular segment past the posterior lateral corner, the dorsum of the head is nearly completely smooth and glossy, the dorsum and sides of the pronotum are smooth and glossy, the remainder of the mesosoma is punctate, the propodeal spines are well-developed and somewhat curved upwards. The major is small, about 2.5-mm total length. The anterior 1/2 - 2/3 of the head is striate, the posterior part is smooth and glossy. The dorsum of the pronotum is smooth and glossy, the side of the pronotum is punctate and weakly shining, and the remainder of the mesosoma is punctate, except for parts of the mesopleuron, which are smooth and shiny. The propodeal spines are well developed, but thickened. The lateral connules on the postpetiole are not developed. Most hairs on the mesosoma are blunt-tipped, with a few weakly spatulate, but not noticeably so. (Mackay and Mackay 2002)

Also see the description in the nomenclature section.

Keys including this Species

Distribution

Known only from central and western Texas. (Wilson 2003)

Distribution based on Regional Taxon Lists

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


Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Worker

Minor

Major

Queen

Nomenclature

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

  • marcidula. Pheidole marcidula Wheeler, W.M. 1908e: 457 (s.w.) U.S.A. See also: Wilson, 2003: 584.

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 (including Pheidole vinelandica), Pheidole centeotl, Pheidole cerebrosior, Pheidole defecta, Pheidole gilvescens, Pheidole macclendoni, Pheidole macrops, Pheidole marcidula, Pheidole paiute, Pheidole pinealis, Pheidole xerophila, Pheidole yaqui and Pheidole yucatana, which complex is characterized by the large to very large, forward-set eyes in both castes; and, in the major, by 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 angular (cornulate in cerebrosior).

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

Major: clavate hairs occasional on mesosoma, with other ordinary pilosity sparse; apex of petiolar node in side view pointed; postpetiolar node from above laterally subangulate.

Minor: promesonotal dorsal profile lined with evenly spaced pairs of clavate hairs.

MEASUREMENTS (mm) Major (Sierra Blanca, Texas): HW 0.92, HL 1.22, SL 0.56, EL 0.16, PW 0.42.

Syntype minor: HW 0.44, HL 0.48, SL 0.42, EL 0.12, PW 0.28.

COLOR Major: overall yellow, with gaster and legs in lighter shade than rest of body.

Minor: concolorous pale yellow.


Pheidole marcidula Wilson 2003.jpg

Figure. Upper: major. TEXAS: 5 km south of Sierra Blanca, Hudspeth Co. (O. F. Francke and J. V. Moody). Lower: syntype, minor. TEXAS: Barton Creek, Austin (William M. Wheeler). Scale bars = 1 mm.

Syntype Specimen Labels

Type Material

Barton Creek, Texas, American Museum of Natural History and Museum of Comparative Zoology - as reported in Wilson (2003)

Etymology

L marcidula, little and weak, or wasted, allusion unknown. (Wilson 2003)

References

  • Mackay, W. P. and E. Mackay. 2002. The ants of New Mexico (Hymenoptera: Formicidae). Edwin Mellen Press, Lewiston, NY.
  • 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. 1908h. The ants of Texas, New Mexico and Arizona. (Part I.). Bull. Am. Mus. Nat. Hist. 24: 399-485 (page 457, soldier, worker described)
  • Wilson, E. O. 2003. Pheidole in the New World: A dominant, hyperdiverse ant genus. Harvard University Press, Cambridge, MA. (page 584, fig. major, minor described)