Heteroponerinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
|
|
|
Range
Costa Rica, Panama, Colombia. Costa Rica: montane forests throughout, down to about 500m elevation.
Identification
Petiole with posteriorly-directed tooth; mandible triangular, with differentiated basal and masticatory margins; eyes large, with many facets.
Natural History
Heteroponera panamensis is relatively common but inconspicuous in montane forests throughout Costa Rica. It occurs in closed-canopy forest, near ground level. The small colonies may be in dead sticks on the ground, but more often are in chambers in live plant stems. These may be irregular chambers and necrotic areas in stems that are not usually hollow, or preformed chambers in myrmecophytes such as Cecropia. When the latter, they occupy single chambers in saplings, when the plant has not been dominated by one of its usual associates (e.g. Azteca in the case of Cecropia). Workers occasionally appear in leaf litter samples (Winkler samples) from the forest floor.
Regular winged queens appear to be rare in this species. I have dissected numerous nests and never found a dealate queen or new alate queens. However, I do have a normal alate queen collected as a stray. Close inspection of nest populations reveals what may be ergatoid queens. They have a single, very small ocellus interrupting the median carina on the frons. Also, they appear slightly larger than the average worker. The mesosoma is a bit more robust, and the petiole in profile is thicker, with the posterior margin less concave than in workers. Several other species in the genus are known to have wingless ergatoid queens instead of normal winged queens (Brown 1958).
Selected Observations of H. panamensis in Costa Rica:
Penas Blancas: (1) Nest in lower internode of Cecropia insignis sapling. Active colony of Azteca constructor in upper internodes. (2) An old dead trunk of a formerly Myrmelachista-occupied Ocotea contained three ant nests: Pheidole, Camponotus, and Heteroponera. (3) Nest in live Piper stem. (4) Nest in stem of dead fern. (5) Nest in dead stick. (6) Nest in dead Piper auritum stem. Large larvae and prepupae were in intact cocoons; cocoons with pupae all had posterior tip missing. (7) Cecropia insignis; 3m tall sapling at edge of river. A Heteroponera colony occupied a lower part of the stem. (8) Nest in chamber in live stem Myriocarpa; 10cm long chamber; entire nest contents = 10 workers. (9) Nest in chamber in live stem Myriocarpa; collection includes two adult males. (10) Nesting in live terminal branch of undergrowth plant (tree sapling?) in forest. Entire nest contents collected. Stem outer diameter 13mm. The chamber inside was 9cm long and 5mm wide. Pupae and large larvae were in thin cocoons. All but one cocoon was missing the posterior portion, about 1/5th of the length of an intact cocoon. The edges of the terminal, open part of the cocoon were ragged. There was one intact cocoon; it contained a large larva. Nest contents: 13 workers (one of which callow), 3 males, 11 pupae, 4 prepupae/larvae in cocoons, 12 larvae of various sizes, a few eggs.
Volcan Arenal: forested ravine below Arenal Observatory Lodge; in live stem understory Rubiaceae.
Rara Avis: Primary forest. (1) Nest in 5mm dia dead stick. Almost entire nest collected; contained 11 workers. (2) Fresh treefall in primary forest. In 7mm dia dead vine stem.
Wilson Botanical Garden: Cecropia obtusifolia sapling along river contained nest of Heteroponera in one internode (#2393, entire nest collected), another Heteroponera nest in a different internode (#2394, entire nest collected), and Camponotus nesting in one or more other internodes. Another Cecropia obtusifolia sapling along river contained two nests: Procryptocerus (#2403) and Heteroponera (#2404), each in single internode. Entire contents of nests collected.
Notes
At the time of Brown's 1958 revision, the genus Heteroponera was virtually unknown from Central America. A single specimen, the type of panamensis, was known from Volcan Chiriqui in Panama. I have not examined the type, but I am assuming it is the same as this widespread species in Costa Rica.
Kempf (1962) described a very similar species, H. flava, from southern Brazil. Regarding flava, he stated:
In Jan 1960 Brown and Fairchild collected Heteroponera from Cerro Campana, Prov. Panama, and I have 3 workers. These workers are extremely similar to flava, which I just described, differing in the very dark color of the head and gaster. The petiole is identical in both forms. Since we don't know if these workers match the type of panamensis, I prefer to propose flava as a new species, adding that later, upon examination of type, it may be possible to synonymize it.
Type data
Ectatomma (Acanthoponera) dentinode var. panamense Forel 1899:9. Worker, Panama: Volcan de Chiriqui, 3000' (Champion).
Literature Cited
Brown, W. L., Jr. 1958. Contributions toward a reclassification of the Formicidae. II. Tribe Ectatommini (Hymenoptera). Bull. Mus. Comp. Zool. 118:175-362.
Forel, A. 1899. Formicidae. Biol. Cent.-Am. Hym. 3:1-160.
Kempf, W. W. 1962. Retoques a classificacao das formigas neotropicais do genero Heteroponera Mayr (Hym., Formicidae). Papeis Avulsos Zool. 15:29-47.
Page author:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu
Go back to top