Eciton lucanoides Emery 1894

Possible synonyms:
Eciton jansoni Forel 1912
Eciton lucanoides conquistador Weber 1949

Ecitoninae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

major face view

major lateral view

major petiole, lateral view

male face view

male lateral view

Additional images: posterior face of propodeum (large).

Range

Nicaragua to Peru (type locality), Bolivia, western Brazil. Costa Rica: Atlantic slope and montane areas.

Identification

Minor worker: head, mesosoma, and metasoma evenly orange yellow or with some degree of reddish infuscation on mesosoma; occipital tooth present; petiolar teeth in the form of short, acute flanges, joined medially and forming a single median carina descending onto the posterior face, when viewed from the rear appearing as a Y-shaped structure; petiole long and low, subrectangular, or somewhat shortened and approaching the shape of burchellii; petiole never with anterodorsal elevated flange; fourth abdominal tergite with short, sparse appressed pubescence beneath erect setae.

Major worker: face densely micropunctate, matte; long sickle-shaped mandibles with broad tooth on inner margin at midlength; other characters as in minor.

Similar species: hamatum.

Natural History

This species occurs in mature wet forest throughout the Atlantic slope. Its highest density seems to be mid-elevation sites, but it can still be relatively abundant in the lowlands. At La Selva Biological Station it has a density similar to E. hamatum, with which it is often confused.

Raiding is always in columns, never in a carpet like E. burchellii. Raiding can be during the day or at night.

Comments

Eciton lucanoides was described by Emery (1894) based on a soldier from Peru. Weber (1949) described E. conquistador based on workers from Panama. Borgmeier (1955) made conquistador a subspecies of lucanoides. Kempf (1972) listed the range of lucanoides as Peru, Bolivia, Brazil (Rondonia and Acre), Colombia, and the range of l. conquistador as Panama, Costa Rica, and Nicaragua. The males of these forms are unknown. Eciton jansoni was described by Forel (1912) based on a male from Nicaragua, and Kempf (1972) gives the range as Nicaragua, Costa Rica, Panama, Colombia, Ecuador.

By a process of elimination and geographic correspondence in Costa Rica, E. jansoni has to be the male of lucanoides conquistador. The males of the other Eciton species are known. Eciton jansoni males are very common in primary forest areas of the Atlantic slope, which is where E. l. conquistador is also common. Morphologically, there is a slight boss on the inner margin of the male mandible, perhaps corresponding to the pronounced tooth in the same position on the soldier.

Thus, if E. l. conquistador is distinct from E. lucanoides sensu stricto, then the Costa Rican species should be called E. jansoni, with E. l. conquistador a junior synonym. If it is not, then both are junior synonyms of E. lucanoides. Is E. l. conquistador really different from E. lucanoides senso stricto?

Borgmeier (1955) stated (my translation) "Eciton conquistador (the name is tacky) I regard as a subspecies of lucanoides. The differences from lucanoides are the following: the soldier of conquistador differs by the smaller head, the broad tooth on the inside of the mandible, the longer scape, the longer funiculus, the more raised and approximated lateral carinae of the propodeum, and the narrower petiole and postpetiole. The worker differs in the longer scape, the more raised and approximated lateral carinae of the propodeum, the strong central keel on the posterior face of the propodeum, and the narrower petiole." (I enjoyed Borgmeier's little editorial comment on Weber's name.) The range of E. jansoni approximately covers the range of both E. l. conquistador and E. lucanoides senso stricto, which suggests either that there is no difference in the males that corresponds to the worker subspecies or the differences are subtle and have not been discovered. More work is needed on character variation across the range of this lineage.

I have chosen to refer to the Costa Rican material as E. lucanoides, with the possibility that it may later change to E. jansoni.

Literature Cited

Borgmeier, T. 1955. Die Wanderameisen der neotropischen Region. Studia Entomologica 3:1-720.

Emery, C. 1894. Studi sulle formiche della fauna neotropica. VI-XVI. Bullettino della Societą Entomologica Italiana 26:137-241.

Forel, A. 1912. Formicides néotropiques. Part I. Annales de la Société Entomologique de Belgique 56:28-49.

Kempf, W. W. 1972. Catálogo abreviado das formigas da regičo Neotropical. Studia Entomologica 15:3-344.

Weber, N. A. 1949. A new Panama Eciton (Hymenoptera, Formicidae). American Museum Novitates 1441:1-8.


Page author:

John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu


Date of this version: 30 June 2007.
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