Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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Range
Southeastern United States, southern Mexico to Panama. Costa Rica: cloud forests of Cordillera de Tilaran, Cordillera Volcanica Central, Cordillera de Talamanca.
Identification
Cryptopone gilva is the only species of this genus in Costa Rica. It looks similar to several Pachycondyla species, but is distinguishable by a pit at the base of the mandibles (figure). The pit can be difficult to see without high magnification, strong lighting, and the right viewing angle.
Natural History
Cryptopone gilva is restricted to cloud forest habitats. For example, it is common in the ridge crest cloud forest in the Monteverde area (1400-1600m), rare around "El Aleman" at the head of the Penas Blancas Valley (900m), and absent at Casa Eladio further down the valley (800m). In Monteverde it is common under loose bark of dead wood and under epiphyte mats in the low arboreal zone: ground level to a few meters high. I often encounter lone founding queens. I find colonies in logs at a certain stage of decay, when the bark comes off in intact sheets, and there is a thin layer of decayed humus between the bark and the still hard wood. Workers are found thinly scattered in anastomosing tunnels in the humus layer. As a bark sheet is peeled away one to five workers may be revealed, which quickly disappear into holes in the wood and under adjacent bark. I have never been able to collect more than a few dozen workers from a colony, and I have never found an obvious colony center or distinct galleries with aggregations of workers and brood. Occasional larvae and pupae occur in the tunnels. The nesting behavior is very similar to that of Typhlomyrmex rogenhoferi, a species more common at lower elevations.
Specimens are occasionally taken in samples of sifted leaf litter (Winkler samples).
Notes
Brown (1963) redefined the genus Cryptopone, including within it mainly Old World species. He considered Cryptopone to have made a small incursion into the New World, mainly represented by C. gilva, a species endemic to the southern U.S.A. He also included as a "probable" Cryptopone Forel's guatemalensis from Guatemala (known only from the type(s), and presumably Brown was not able to examine the type for the diagnostic mandibular pit). Kempf (1972) listed Cryptopone guatemalensis, and included Nicaragua in its distribution. I cannot distinguish Costa Rican Cryptopone from Florida C. gilva. Thus I consider C. gilva to occur from the southeastern U.S.A. south to the highlands of Costa Rica.
I examined the types of Pachycondyla obsoleta Menozzi, at the DEIC in Eberswalde, Germany, in 1990. They are the typical Cryptopone of Costa Rican cloud forests.
Mackay and Mackay (2010) synonymized guatemalensis under gilva and transferred the species to Pachycondyla. I concur with the synonymy but not the genus transfer. Since Pachycondyla is known to be polyphyletic and more thorough phylogenetic studies are pending, I choose to keep gilva in Cryptopone until the phylogenetic relationships are better understood.
Literature Cited
Brown, W. L., Jr. 1963. Characters and synonymies amoung the genera of ants. Part III. Some members of the tribe Ponerini (Ponerinae, Formicidae). Breviora 190:1-10.
Kempf, W. W. 1972. Catalogo abreviado das formigas da Regiao Neotropical. Studia Entomol. 15:3-344.
Mackay, W. P., and E. E. Mackay 2010. The Systematics and Biology of the New World Ants of the Genus Pachycondyla (Hymenoptera: Formicidae). Edwin Mellon Press, Lewiston.
Page author:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu
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