Dolichoderus inermis MacKay 1993

Dolichoderinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker lateral view

worker dorsal view

worker face view


Costa Rica (southern Pacific lowlands).


Color black; scapes and mesosomal dorsum with abundant delicate erect setae; dorsal and posterior faces of propodeum meeting at rounded angle and not produced as a projecting flange; face and mesosomal dorsum sublucid; pronotum transverse, with spiniform humeri.

Natural History

This species is a moderately abundant element of the fauna in Corcovado National Park, but so far it is known only from Corcovado. Within Corcovado I collected it at Sirena, Los Patos, Los Planes, Cerro Rincon, and Llorona, so it is widely distributed on the Osa Peninsula. Three times I observed clusters of workers on inflorescences, once on Acanthaceae, once on Hamelia axillaris (Rubiaceae), and once on Melastomataceae. In the first two cases, the inflorescences also had abundant Membracidae and Coccoidea (scale insects). At Sirena I observed workers foraging parabiotically with Crematogaster carinata. The workers were together on low vegetation, moving together in columns and forming clumps of stationary workers. Thus D. inermis is probably parabiotic, much like D. debilis. The workers move very slowly and seem relatively passive, in contrast to many other species of Dolichoderus that either flee or aggressively attack in response to disturbance. The workers often move with their gasters twisted laterally, a distinctive posture I have also seen in some species of Myrmelachista.

Page author:

John T. Longino, The Evergreen State College, Olympia WA 98505

Date of this version: 8 March 2003.
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