Pheidole harrisonfordi

Longino, J. T., 2009, Additions to the taxonomy of New World Pheidole (Hymenoptera: Formicidae)., Zootaxa 2181, pp. 1-90 : 37

Pheidole harrisonfordi

Pheidole harrisonfordi Wilson, 2003: 433 , figs. 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) [ MCZ] (examined).

Pheidole ruida Wilson, 2003: 499 , figs. Holotype major worker and associated paratype minor worker: Panama, Canal Zone, Barro Colorado Island, Jan 1960 (W. L. Brown & E. S. McCluskey) [ MCZ] (examined). New synonymy.

Pheidole prolixa Wilson, 2003: 488 , figs. 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). New synonymy.

Pheidole tenebra Wilson, 2003: 519 , figs. 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). New synonymy.

Geographic Range

Panama to southern Mexico.

Biology

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.

Comments

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 P. 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.