Pheidole harrisonfordi

This species occurs in wet forest habitats, from sea level to 1800m elevation. It is often one of the most abundant species in Winkler or Berlese samples of forest floor litter, and may also recruit to baits. In spite of its abundance in Winkler samples, I have never encountered a nest. (Longino 2009)

Identification
See the description in the nomenclature section.

Distribution
Panama to southern Mexico.

Distribution based on Regional Taxon Lists
Neotropical Region: Belize, Colombia, Costa Rica, Guatemala, Honduras, Mexico, Nicaragua, Panama.

Images from AntWeb
Minor

Biology
The type series was collected on a steep, rocky forested slope by Bill Brown.

Nomenclature

 *  harrisonfordi. Pheidole harrisonfordi Wilson, 2003: 433, figs. (s.w.) HONDURAS. Senior synonym of prolixa, ruida, tenebra: Longino, 2009: 37.
 * prolixa. Pheidole prolixa Wilson, 2003: 488, figs. (s.w.) MEXICO. Junior synonym of harrisonfordi: Longino, 2009: 37.
 * ruida. Pheidole ruida Wilson, 2003: 499, figs. (s.w.) PANAMA. Junior synonym of harrisonfordi: Longino, 2009: 37.
 * tenebra. Pheidole tenebra Wilson, 2003: 519, figs. (s.) MEXICO. Junior synonym of harrisonfordi: Longino, 2009: 37.

Longino (2009) - The leaf litter of Central American wet forest is filled with small, dark-colored Pheidole that share the following characters: minor worker: HW 0.36–0.47, SI 84–92; promesonotal groove not impressed, promesonotum forming a single convexity, dorsal profile of promesonotum subrectangular, not evenly arched; propodeal spines present, short, upturned; dorsal surface of head and entire mesosoma with foveolate sculpture, sometimes overlain with rugulae, never with smooth shiny areas; dorsal surface of first gastral tergite smooth and shining; standing pilosity moderately abundant on head, mesosomal dorsum, and gastral dorsum; hind tibia usually with decumbent short pilosity of uniform length, some populations with 2-3 somewhat longer suberect setae; major worker: HW 0.65-1.00, SI 40-60; mandible and clypeus smooth and shining; hypostomal margin with strongly-developed inner teeth close to midline; face densely and coarsely foveolate throughout, overlain with longitudinal rugulae between frontal carinae and a dense reticulum of rugulae on the rest of the posterior half or more of face, these rugulae completely mesh-like, not parallel, and the sculpture extending all the way to the vertex lobes, with no shiny portions of posterior vertex lobes; postpetiole in dorsal view strongly transverse, with well-developed acute projecting conules; gastral dorsum smooth and shiny; pilosity as in minor worker.

Within this morphological envelope there is wide variation in details of major worker head size and shape, and in the minor worker there is variation in size and the degree of development of irregular rugulae on the face and particularly on the promesonotum. In some cases there appear to be discrete forms in sympatry, and this “species” will almost certainly resolve into multiple cryptic species. There are some morphological patterns that occur over elevational gradients (montane forms tend to have major workers with larger and proportionally longer heads) and over horizontal distance (material from Panama and Costa Rica's southern Pacific coast looks slightly different from material from Costa Rica's Atlantic slope, which looks slightly different from material from southern Mexico).

The types of Wilson's Pheidole harrisonfordi, P. ruida, P. prolixa, and P. tenebra are very similar. Their measurements fall very close to each other among the larger spread of measurements in the complex as a whole. They match the dominant, somewhat uniform lowland form of P. harrisonfordi, and not the most conspicuous variants, which tend to be mid-elevation or montane. These names could come out of synonymy with further resolution of the complex, but at this point there are no morphological grounds for separating them.

Description
A small light-colored member of the flavens group similar to Pheidole ceibana, Pheidole lignicola, Pheidole metallescens and Pheidole ruida, distinguished in the major by the bulbous pronotum in dorsal-oblique view, set off from a small but distinct mesonotal convexity, and the cephalic rugoreticulum, which starts as a patch at each occiput corner and runs anteriorly in a thin band to a patch just mesad to the eye. The minor is distinctive in the steep, nearly vertical descent of the posterior mesonotal face to the metanotum.

MEASUREMENTS (mm) Holotype major: HW 0.70, HL 0.80, SL 0.40, EL 0.08, PW 0.36. Paratype minor: HW 0.40, HL 0.44, SL 0.34, EL 0.06, PW 0.26.

COLOR Major: body light reddish brown, appendages dark yellow. Minor: concolorous light reddish yellow.



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

Type Material
Longino (2009):

Holotype major worker and associated paratype minor worker: Honduras, Depto. Santa Barbara, El Sauce, 700m, Mar 1979, steep, rocky forest slope, rotten wood (W. L. Brown) (examined).

Pheidole ruida Holotype major worker and associated paratype minor worker: Panama, Canal Zone, Barro Colorado Island, Jan 1960 (W. L. Brown & E. S. McCluskey) MCZ (examined).

Pheidole prolixa Holotype major worker and associated paratype minor worker: Mexico, Veracruz, Los Tuxtlas, 10km NNW Sontecomapan, 18°35'N 95°05'W, 200m, 20 Mar 1985, sifted litter, rainforest (P. S. Ward 7333-49), MCZ (examined).

Pheidole tenebra Holotype major worker and associated paratype minor worker: Mexico, Veracruz, Cordoba, Paraje Nuevo, Nacimiento, 7 Aug 1969, tropical evergreen forest, Berlese 176 (S. & J. Peck) MCZ (examined).

Etymology
Named in honor of Harrison Ford, in recognition of his outstanding contribution in service and support to tropical conservation, hence the habitats in which the Pheidole ants will continue to exist.

References based on Global Ant Biodiversity Informatics

 * Ahuatzin D. A., E. J. Corro, A. Aguirre Jaimes, J. E. Valenzuela Gonzalez, R. Machado Feitosa, M. Cezar Ribeiro, J. Carlos Lopez Acosta, R. Coates, W. Dattilo. 2019. Forest cover drives leaf litter ant diversity in primary rainforest remnants within human-modified tropical landscapes. Biodiversity and Conservation 28(5): 1091-1107.
 * Castano-Meneses, G., M. Vasquez-Bolanos, J. L. Navarrete-Heredia, G. A. Quiroz-Rocha, and I. Alcala-Martinez. 2015. Avances de Formicidae de Mexico. Universidad Nacional Autonoma de Mexico.
 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * LaPolla, J.S. and S.P. Cover. 2005. New species of Pheidole (Hymenoptera: Formicidae) from Guyana, with a list of species known from the country. Tranactions of the American Entomological Society 131(3-4):365-374
 * Lapolla, J. S., and S. P. Cover. "New species of Pheidole (Hymenoptera : Formicidae) from Guyana, with a list of species known from the country." Transactions of the American Entomological Society 131, no. 3-4 (2005): 365-374.
 * Lapolla, J.S., T. Suman, J. Soso-Calvo and T.R. Schultz. 2006. Leaf litter ant diversity in Guyana. Biodiversity and Conservation 16:491510
 * Longino J. T. 2009. Additions to the taxonomy of New World Pheidole (Hymenoptera: Formicidae). Zootaxa 2181: 1-90.
 * Longino J. T. 2013. Ants of Nicargua. Consulted on 18 Jan 2013. https://sites.google.com/site/longinollama/reports/ants-of-nicaragua
 * Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.
 * Longino J. T., and R. K. Colwell. 2011. Density compensation, species composition, and richness of ants on a neotropical elevational gradient. Ecosphere 2(3): 16pp.
 * Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
 * Wilson, E.O. 2003. Pheidole in the New World: A Dominant, Hyperdiverse Genus. Harvard University Press