Pheidole marcidula

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.

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

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Mexico.

Worker
Minor

Images from AntWeb
Major

Nomenclature

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

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.



'''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.'''

Type Material
Barton Creek, Texas, and  - as reported in Wilson (2003)

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

References based on Global Ant Biodiversity Informatics

 * Cover S. P., and R. A. Johnson. 20011. Checklist of Arizona Ants. Downloaded on January 7th at http://www.asu.edu/clas/sirgtools/AZants-2011%20updatev2.pdf
 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Hess C. G. 1958. The ants of Dallas County, Texas, and their nesting sites; with particular reference to soil texture as an ecological factor. Field and Laboratory 26: 3-72.
 * Mackay W. P., and E. E. Mackay. 2002. The ants of New Mexico (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 400 pp.
 * Moody J. V., and O. F. Francke. 1982. The Ants (Hymenoptera, Formicidae) of Western Texas Part 1: Subfamily Myrmicinae. Graduate Studies Texas Tech University 27: 80 pp.
 * O'Keefe S. T., J. L. Cook, T. Dudek, D. F. Wunneburger, M. D. Guzman, R. N. Coulson, and S. B. Vinson. 2000. The Distribution of Texas Ants. The Southwestern Entomologist 22: 1-92.
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
 * Wheeler W. M. 1908. The ants of Texas, New Mexico and Arizona. (Part I.). Bulletin of the American Museum of Natural History 24: 399-485.
 * Wheeler, G.C. and J. Wheeler. 1985. A checklist of Texas ants. Prairie Naturalist 17:49-64.
 * Wilson, E.O. 2003. Pheidole in the New World: A Dominant, Hyperdiverse Genus. Harvard University Press