Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
Mexico south to Bolivia, east to Venezuela, Trinidad. Costa Rica: known from mid to upper elevation sites from Cordillera de Guanacaste to Cordillera Volcanica Central; also known from Bocas del Toro region of Panama, so probably continuous in montane sites throughout the country.
Mesosomal dorsum with erect hairs; opening of propodeal spiracle viewed perpendicularly slit-shaped, more than twice as long as wide; mandible with approximately 9 teeth; in side view, dorsal outline of mesosoma forms a continuous convexity including mesonotum, metanotum and propodeal dorsum; propodeal groove obsolete or nearly so, and not strongly impressed; cheeks without a distinct carina between lateral clypeal wing and eye margin; stridulatory file absent; arolia absent; head width greater than 2.0mm; mesosoma greater than 3.6mm long; dorsolateral margin of pronotum uniformly punctate, rounded; clypeus broad front to back, anterior margin truncate, flattened to weakly notched, but with medial margin well in front of frontal lobes.
Similar species: harpax is smaller, and usually has a dorsolateral carina on the pronotum; impressa has a shallower (front to back) clypeus.
This species is a dramatically large ant which I occasionally see as individual workers on roads and trails. I have one nest observation from Cerro Cacao in the Guanacaste Conservation Area:
At the bottom of the forest patch below the station, along the trail back to Quebrada Grande, I observed a nest in the steep bank of the trail. A purpurascens worker captured a Gnamptogenys worker from a nest I was excavating. The purpurascens worker moved irregularly back and forth at first, but then went to a simple circular hole in the bank. I followed the hole, excavating horizontally into the bank, until I was a full arm's length plus trowel length into the bank. At this point I began scooping out a few workers at a time. I obtained about 16 workers this way, but then had to stop.
Pachycondyla purpurascens Forel 1899:12. Lectotype worker: Costa Rica, Cache [MHNG] (examined).
See comments under impressa. Due to an unfortunate choice of lectotype, this species will become a junior synonym of transversa Emery.
Bolton, B. 1995. A New General Catalogue of the Ants of the World. Harvard University Press, Cambridge, Mass.
Emery, C. 1901. Notes sur les sous-familles des Dorylines et Ponerines (Famille des Formicides). Annales de la Societe Entomologique de Belgique 45:32-54.
Emery, C. 1911. Hymenoptera. Fam. Formicidae. Subfam. Ponerinae. Genera Insectorum 1181-125.
Forel, A. 1899. Formicidae. Biologia-Centrali Americana 3:1-169.
Kempf, W. W. 1961. As formigas do genero Pachycondyla Fr. Smith no Brasil (Hymenoptera: Formicidae). Revta Bras. Entomol. 10:189-204.
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.email@example.com
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