Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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Major dorsal view (reduced, original).
Line drawings of minor worker dorsal view, major worker dorsal view, from Kempf (1958).
Range
Endemic to Costa Rica. Costa Rica: Atlantic slope (Cordillera Volcanica Central) below 500m.
Identification
Minor worker: eyes situated behind the scrobe, which terminates in front of the eye; lateral border of head convex and upturned above eye, without a rounded excision; petiole with distinct anterior and dorsal faces; lateral margins of mesosoma, including propodeal margins, denticulate, concolorous with rest of mesosoma; ventral surface of head coarsely costate; anterior face of petiole flat and meeting dorsal face at sharp right angle; silvery hairs covering much of mesopleuron; postpetiolar lateral lobes elongate, narrowed, coming to points.
Major worker: eyes situated behind the scrobe, which terminates in front of the eye; head with complete and strongly developed cephalic disk; cephalic disk with arcuate notch anteriorly; in full face view dorsal surface of mandibles visible in notch; surface of cephalic disk mostly dark brown or black, with an anterolateral portion of the frontal carinae reddish; cephalic disk with foveae small, separated by distance equal to or greater than their diameters; lateral margins of posterior face of propodeum carinate but without foliaceous crest; first gastral tergite with scattered short, stiff, erect setae.
Natural History
This species is known from few collections. Earlier records are almost all from shipments of orchids intercepted at U.S. quarantine stations (Kempf 1958, Andrade and Baroni Urbani 1999). My own collections have all been from the Atlantic slope rainforest on the Cordillera Volcanica Central. The one nest collection I have made was from a recent treefall at La Selva Biological Station. It was from a part of the treefall with a big branch of Stryphnodendron excelsum, some smaller Pentaclethra macroloba branches, and a tangled mass of Norantea sessilis. There were two Cephalotes nests in different parts of a live Norantea stem. One stem was 12mm and the other 15mm in diameter. In the field I thought they were part of one polydomous colony, because they were in such close proximity, but I later discovered that one nest was C. curvistriatus and the other was C. maculatus.
Other than this nest collection, I have seen workers from three other canopy samples from La Selva, and two canopy samples from a 500m elevation site in Braulio Carrillo National Park above La Selva.
Type Data
Cryptocerus curvistriatus Forel 1899:52. Type worker: Costa Rica, Turrialba. Types not found in MHNG or MCSN (Andrade and Baroni Urbani 1999).
Notes
Kempf (1958) reported this species almost entirely from material intercepted at quarantine stations in the USA, the only exception being the type worker from Turrialba, Costa Rica. All but one of the quarantine interceptions were on orchids from Costa Rica, Honduras, and Guatemala. One interception was from the Dominican Republic, from "a carton containing beans," but Kempf doubted the legitimacy of this collection. Andrade and Baroni Urbani (1999) reidentified the Honduran material as a new species, C. lenca, and the Guatemalan material as C. sobrius Kempf.
Cephalotes curvistriatus is part of Andrade and Baroni Urbani's texanus clade. This clade contains 6 species, all very similar, which appear to form a parapatric or allopatric series from curvistriatus in Costa Rica to texanus in Texas.
Andrade and Baroni Urbani (1999) state "There is abundant presumptive evidence suggesting that most species of this clade should be obligatory inhabitants of epiphytes" (presumably not including texanus itself, which is known to nest mainly in dead wood and oak galls [Creighton 1963, 1967, Creighton and Gregg 1954, Longino and Wheeler 1987]). Many of the collections have come from intercepted orchid shipments, others from the bulbous bases of myrmecophytic Bromeliaceae. My observation of curvistriatus in live stems of Norantea suggests that it is not an obligate inhabitant of epiphytes per se, but an opportunistic user of live stems in the high canopy. Norantea, in the Marcgraviaceae, is an epiphytic vine, but with growth form and stem characteristics very different from Orchidaceae. It is unlikely that the ants are cueing on epiphytism in particular, and it is also clear they are not choosing a particular taxonomic group of epiphytes.
Literature Cited
Andrade, M. L. de, and C. Baroni Urbani. 1999. Diversity and adaptation in the ant genus Cephalotes, past and present (Hymenoptera, Formicidae). Stuttgarter Beitrage zur Naturkunde Serie B (Geologie und Palaontologie) 271:1-889.
Creighton, W. S. 1963. Further studies on the habits of Cryptocerus texanus Santschi (Hymenoptera: Formicidae). Psyche 70:133-143.
Creighton, W. S. 1967. Studies on free colonies of Cryptocerus texanus Santschi (Hymenoptera: Formicidae). Psyche 74:34-41.
Creighton, W. S., Gregg, R. E. 1954. Studies on the habits and distribution of Cryptocerus texanus Santschi (Hymenoptera: Formicidae). Psyche (Camb.) 61:41-57.
Forel, A. 1899. Biologia Centrali-Americana 3 (Formicidae). 169pp, London.
Kempf, W. W. 1958. New studies of the ant tribe Cephalotini (Hym. Formicidae). Stud. Entomol. (n.s.)1:1-168.
Longino, J. T., Wheeler, J. 1987. Ants in live oak galls in Texas. National Geographic Research 3:125-127.
Page author:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu
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