Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
SEM images of worker, adapted from Bolton 1994: face view (reduced, original); lateral view (reduced, original).
Identification (the genus has been revised by Andrade 1998)
Worker and queen: ocelli present and well defined; frontal carinae not projecting over clypeus anteriorly; mandibles striate; metatarsus (basal segment) of middle leg relatively long and thin, longer than following three tarsomeres combined; AT2 and AT3 coarsely striate; AT4 and following terga smooth and shining.
Male (from Andrade 1998): frontal carinae not strongly converging posteriorly; head and dorsal face of propodeum with thick striae.
Guatemala, Costa Rica, Ecuador, Galapagos, Peru, Bolivia, Chile, southern Brazil (Brazil record questionable; see Andrade 1998).
The ants of this genus are rarely collected, and very little is known about them. Cylindromyrmex species nest in cavities in sound or rotten wood, under bark, in hollow stems, or in termite galleries (Brown 1975, Andrade 1998).
At La Selva I collected fragments of dead workers from a dead Piper stem, in mature forest understory.
Dr. Bruno Gobin sent me specimens to identify. The material he sent included workers and a dealate queen. He stated "We collected them from a forager raid of about 100 workers in Rincon de la Vieja (along the Volcano trail, not far beyond the suspension bridge). Unfortunately, we could not see what they were raiding, but in the lab they readily recuited to some termites." These results were later published (Goben et al. 2001), along with a description of a novel exocrine gland. The abstract follows:
Workers of the ant Cylindromyrmex whymperi display mass trail recruitment. Bioassays show that the trail pheromone originates from a unique gland between abdominal sternites 6 and 7. The gland has a hitherto unknown structural organization. Upon leaving the secretory cell, the duct cell widens to form a sclerotized pear-shaped reservoir chamber, lined with multiple duct cells. Each duct thus forms a miniature reservoir for the secretions of each single secretory cell, a novel structural arrangement in exocrine glands of social Hymenoptera.
Costa Rican Specimen Records
Cartago: CATIE, nr. Turrialba, 9”54'N, 83”39'W, 550m, 25 May 1995 (coll. J. Rifkind), adult queen; Guanacaste: West side Volcan Cacao, 10”56'N, 85”27'W, 1100m, Feb 1989 (coll. I. Gauld), adult worker; Arenales, W side Volcan Cacao, 10”56'0"N, 85”28'0"W, 900m, 1988-1989 (coll. unknown), adult worker; Santa Rosa National Park, 0-300m, tropical dry forest, 20 Oct 1996 (coll. F. Fernandez-C.), adult worker; Rincon de la Vieja (coll. B. Gobin), adult workers and queen; Heredia: La Selva Biological Station, 10”26'N, 84”01'W, 50m, 14 Jul 1992 (coll. J. Longino), adult workers; same locality, 10 Aug 1996 (coll. H. A. Hespenheide), adult worker; San Jose: La Caja, 8km W San Jose, 9”58'N, 84”07'W, 1100m (coll. H. Schmidt), adult worker.
Holcoponera whymperi Cameron 1891:92. Syntype worker: Ecuador [BMNH].
Andrade (2001) confirmed many of the above identifications.
Andrade, M. L. de 1998. Fossil and extant species of Cylindromyrmex (Hymenoptera: Formicidae). Revue Suisse de Zoologie 105:581-664.
Andrade, M. L. de 2001. A remarkable Dominican amber species of Cylindromyrmex with Brazilian affinities and additions to the generic revision (Hymenoptera: Formicidae). Beitrge zur Entomologie 51:51-63.
Bolton, B. 1994. Identification Guide to the Ant Genera of the World. Harvard University Press, Cambridge, Mass.
Brown, W. L., Jr. 1975. Contributions toward a reclassification of the Formicidae. V. Ponerinae, tribes Platythyreini, Cerapachyini, Cylindromyrmecini, Acanthostichini, and Aenictogitini. Search Agri., Entomol. (Ithaca) 5:1-115.
Cameron, P. 1891. Appendix. Hymenoptera, Formicidae (pp. 89-95). In Whymper, E. Travels Amongst the Great Andes of the Equator: 147 pp. London.
Gobin, B., O. Rppell, A. Hartmann, H. Jungnickel, E. D. Morgan, J. Billen 2001. A new type of exocrine gland and its function in mass recruitment in the ant Cylindromyrmex whymperi (Formicidae, Cerapachyinae). Naturwissenschaften 88:395Š399.
John T. Longino, The Evergreen State College, Olympia WA 98505 USA. firstname.lastname@example.org
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