Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
Southern Mexico to northern Argentina. Costa Rica: widespread and very common in wet forest; sea level to at least 1000m.
Mesosomal dorsum with erect hairs; opening of propodeal spiracle viewed perpendicularly slit-shaped, more than twice as long as wide; mandible with ten or more 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; distinct carina runs from the lateral wing of the clypeus near the mandibular insertion to or nearly to the anteromesal quarter of the margin around the eye; acrotergite of second gastral tergum (when exposed) with a distinctly differentiated median stridulatory file with bands of rainbow colors; arolia present; petiolar node as seen from the side more or less subquadrate, with vertical anterior and posterior faces and a horizontal but convex dorsal face; color red orange.
This species is a very common arboreal forager, and may be particularly abundant in second growth vegetation. It is an opportunistic cavity nester, and will nest in live and dead stems. My impression is that they are occupying preexisting cavities, and not excavating cavities themselves. Colonies are never very large; a few dozen workers at most.
In Corcovado National Park, I made a detailed observation of a nest inside a petiole of Calathea lutea. The nest was in the upper portion of the petiole, where the inside chamber tapered to solid stem. The nest consisted of 4 or 5 small chambers separated by horizontal partitions. There was a thick plug of plant debris at the base of the nest. The lower-most chamber had pupae, the next chamber large larvae, the next small larvae, and the upper-most chamber had eggs.
In the Penas Blancas Valley I observed two queens together in a small dead stick, which suggests pleometrotic (multiple queen) founding.
Ponera crenata Roger 1861:3. This was a replacement name for Ponera pallipes F. Smith 1858:98, a primary junior homonym of Ponera pallipes F. Smith 1858:87. Bolton (1995) lists a queen from Brazil as the type. Kempf (1972) lists Venezuela, Carabobo, Puerto Cabello as the type locality.
Pachycondyla crenata has a number of synonyms as follows (Bolton 1995):
confusa Santschi 1921. Brazil.
fiebrigi Forel 1912. Panama.
lata Santschi 1921 [unavailable name]. Argentina.
moesta Mayr 1870. Colombia.
stipitum Forel 1901. Colombia.
sulcatula Santschi 1919. Argentina.
Bolton attributes these synonymies to Brown (1957), although Brown merely discussed variation and stated "I have left formal synonymy in this group to some future worker." Brown saw a weak separation into large and small forms. crenata s.s. conformed to the large form, stipitum to the small form, and moesta was intermediate. Brown was not able to examine confusa, fiebrigi, lata, or sulcatula, but concluded from the published descriptions that they were "minor ... nest variants in the small-to-medium size range of the crenata complex." In 1990 I examined material in the Emery collection in Genoa. Material that Emery identified as P. crenata was all Brasilian. These were large and uniform brown. Material identified as P. moesta was also Brasilian, and these were smaller and lighter-colored, matching Costa Rican crenata. Material identified as P. stipitum also matched Central American crenata. Thus, if crenata s.l. is revealed to be a species complex, the name could change for Costa Rican material, and would probably be moesta or stipitum.
Bolton, B. 1995. A New General Catalogue of the Ants of the World. Harvard University Press, Cambridge, Mass.
Brown, W. L., Jr. 1957. Biological investigations in the Selva Lacandona, Chiapas. 4. Ants from Laguna Ocotal (Hymenoptera: Formicidae). Bulletin of the Museum of Comparative Zoology 116:228-237.
Kempf, W. W. 1972. Catalogo abreviado das formigas da Regiao Neotropical. Stud. Entomol. 15:3-344.
Roger, J. 1861. Die Ponera-artigen Ameisen (Schluss). Berl. Entomol. Z. 5:1-54.
Smith, F. 1858. Catalogue of hymenopterous insects in the collection of the British Museum. Part VI. Formicidae. London: British Museum (Natural History), 216 p.
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.email@example.com
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