Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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Identification
The genera Tapinoma and Technomyrmex both have the petiolar node reduced or absent. Tapinoma has four dorsal tergites on the metasoma posterior to the petiole; Technomyrmex has five (Shattuck 1992). Technomyrmex fulvus is the only species of Technomyrmex known from Costa Rica. Technomyrmex albipes is a widespread tropical tramp species that could occur in Costa Rica, but has not been reported yet. Technomyrmex albipes is dark brown; T. fulvus is orange.
Range
Panama, Costa Rica. In Costa Rica it is known from two collections, one from Corcovado National Park on the Osa Peninsula, and one from Tortuguero National Park in the Atlantic lowlands.
Taxonomy
Wheeler (1934) described fulvus and a subspecies sublucidus from three collections from Barro Colorado Island, Panama. Stefan Cover (pers. comm.) examined the types of both and can find no significant differences; the three collections are almost certainly from the same population. Cover also compared the fulvus types to the images on this page, and confirmed their gross similarity.
Additional Records
Ward (pers. comm.) reports that he collected "Technomyrmex sp. prob. fulvus" at Llorona in Corcovado National Park (Costa Rica, Prov. Puntarenas, 8degrees35'N 83degrees42'W, 12 May 1979, Ward colln. no. 3348-12)." This site is lowland rainforest.
Longino made an additional collection in Tortuguero National Park (Costa Rica, Prov. Limon, 10degrees35'N 83degrees31'W, 5m, 20 June 1988, colln. no. 2115). The site was mature rainforest, up the Rio Tortuguero a short way from the town of Tortuguero, on the right bank going upriver.
Natural History
Wheeler reported that his three collections were all from "flat carton sheds with coccids on the bark of living trees." Ward's collection was of four workers on low vegetation, 0.5-2m above the ground. Longino's collection was from a carton nest under a live leaf of Cardulovica (Cyclanthacaceae), at the base of the blade and sheathing the upper portion of the petiole.
Discussion
Wheeler (1934) put fulvus and sublucidus in the genus Tapinoma, but Shattuck (1992) recognized them as Technomyrmex and transferred them there. Shattuck observed that T. fulvus presented a biogeographical puzzle. The genus Technomyrmex is largely Old World, with many species in Africa, southern Asia, and Australia. Only two species are known from outside this region: the widespread tramp species T. albipes and the apparently native Neotropical species T. fulvus. Shattuck proposed that T. fulvus was native, and not a recent introduction, because of its wet forest habitat, and its distinctness from any known Old World species. The new Costa Rican records provide further evidence that T. fulvus is native to the New World. Brandao et al. (1999) report Technomyrmex from Dominican amber, and suggest that this genus is on the verge of extinction in the New World.
Supporting this conclusion, Technomyrmex fulvus appears to be remarkably rare. It's rareness in collections cannot be attributed to being cryptic; it builds conspicuous carton nests in the low arboreal zone. Barro Colorado Island and portions of Costa Rica have received a great deal of attention from collectors and ecologists studying ants, and yet no additional records of this species surfaced between 1934 and those reported here. It remains to be seen whether T. fulvus occurs as small disjunct populations, or is more uniformly distributed but at very low densities.
Literature Cited
Brandao, C. R. F., C. Baroni Urbani, J. Wagensberg, C. I. Yamamoto 1999. New Technomyrmex in Dominican amber (Hymenoptera: Formicidae), with a reappraisal of Dolichoderinae phylogeny. Entomologica scandinavica 29:411-428.
Shattuck, S. O. 1992. Generic revision of the ant subfamily Dolichoderinae (Hymenoptera: Formicidae). Sociobiology 21:1-181.
Wheeler, W. M. 1934. Neotropical ants collected by Dr. Elisabeth Skwarra and others. Bull. Mus. Comp. Zool. 77:157-240.
Page author:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA. longinoj@evergreen.edu
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