Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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SEM images of worker, collection JTL1392-s, La Selva Biological Station, Costa Rica: whole worker lateral view (reduced, original); head, face view (reduced, original); head, lateral view (reduced, original); clypeus (reduced, original).
Range
Guyana (type locality), Panama, Costa Rica.
Identification
Antennae 8 segmented; interantennal lamella forming an obtuse angle between antennal insertions and descending to a somewhat projecting clypeal shelf, so that lamella appears rectangular in lateral view; anterior margin of interantennal lamella with a tooth above clypeal apron; in face view anterior margin of clypeus subtriangular; color light yellow.
Natural History
Discothyrea are extremely small, cryptobiotic inhabitatants of forest leaf litter (see Genus Overview).
In Costa Rica, this species occurs in lowland forests throughout the country. It is common at La Selva Biological Station, and I have collected it at sites in both the wet southern Pacific lowlands and the seasonally dry northern Pacific lowlands. Collections are usually workers with or without dealate queens in Winkler or Berlese samples from the forest floor. At La Selva Biological Station alate queens were relatively common in canopy fogging samples.
Type data
Discothyrea denticulata Weber 1939:100. Holotype worker: "Described from one worker taken by myself in virgin green-heart (Nectandra rodei Schomb.) forest near the Forest Settlement, Mazaruni River, British Guiana, Aug. 23, 1935. The ant was among leaves on the forest floor." "A second specimen (metatype) was taken by myself twenty-two and one-half miles west of Kartabo Point, British Guiana, September 8, 1935." [MCZC] (examined).
I examined the metatype of denticulata; the holotype could not be located (S. Cover, pers. com.). Although Weber claimed there were 7 antennal segments, I see 8. The clypeal structure is subtriangular. Metatype measurements: HW 0.398, HL 0.457.
Comments
I have a collection from Wilson Botanical Gardens tentatively identified as denticulata, but it is larger and is somewhat intermediate in morphology between denticulata and the southern form of JTL-009. At La Selva, D. denticulata and D. horni clearly separate into two morphological clusters, but in some Pacific slope sites I have had difficulty clearly separating them.
Similar taxa: isthmica
Discothyrea isthmica Weber 1940:78. Holotype queen: Panama, Barro Colorado Island (Williams) [MCZC] (examined).
I examined the type of isthmica in 1999. It matched denticulata specimens from the Costa Rican lowlands. Holotype measurements: HW 0.427, HL 0.471.
Literature Cited
Weber, N. A. 1939. New ants of rare genera and a new genus of Ponerine ants. Ann. Entomol. Soc. Am. 32:91-104.
Weber, N. A. 1940. Rare Ponerine genera in Panama and British Guiana (Hym.: Formicidae). Psyche 47:75-84.
Page author:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu
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