Tapinoma ramulorum Emery 1896

Dolichoderinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia


Northern Brazil to Mexico (ramulorum s.l.). Costa Rica: throughout the country to 1200m elevation.


Scapes of variable length, extending beyond margin of vertex but never a third their length; in full face view, margin of vertex medially emarginate; gaster the same color as mesosoma and head or darker; nests in live or dead plant cavities.

Natural History

This is the most abundant species in vegetated habitats of Costa Rica. It occurs in most habitats, from sea level to middle elevations. Nests are in almost any kind of preformed plant cavity, but the chambers are usually very small and may not be sharply bounded. Nests can occur in tiny dead twigs (down to 5mm outside diameter, 3mm inside diameter), larger dead branches, under bits of loose bark, in cavities in live stems, under and in epiphyte mats, in the bases of bromeliads, and sometimes in myrmecophytes. Tapinoma ramulorum may be found nesting close to other ant nests. For example, a dead branch with a Camponotus nest in the center may have a T. ramulorum nest under the loose bark or bits of rotten wood on the surface of the branch. Colonies are often polygynous.

Original description

Tapinoma ramulorum Emery 1896:101. Syntype worker, queen, male: Costa Rica, San Jose. Inhabiting dry twigs of a tree (Vernonia brachiata).


Emery described this species as having scape surpassing occiput by one to one and a half times diameter. I am using this name to hold a large number of specimens that exhibit what seems like too much variation to be intraspecific. But at this point I cannot make any further distinctions. The variation is in scape length and color, and this variation is also reflected in the queens.

Literature Cited

Emery, C. 1896. Studi sulle formiche della fauna neotropica. XVII-XXV. Bullettino della Societą Entomologica Italiana 28:33-107.

Page author:

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

Date of this version: 23 October 2006.
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