Myrmelachista osa Longino 2006

Formicinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker face view

worker lateral view

queen face view

queen lateral view

Queen in images above is holotype.

Additional images:

Holotype queen, lateral view with wings (large); label (large). Worker, maxillary palpus (large).


Costa Rica. In Costa Rica it occurs at Rancho Quemado on the Osa Peninsula.


Diagnosis: Worker with antenna 9-segmented, maxillary palpus 5-segmented, color yellow. Queen black; mandible punctatorugose; face smooth and shining; sides of head with short appressed to suberect pubescence, no longer erect setae; maxillary palpus 6-segmented; CI 79-84.

Worker: Same as M. flavocotea but with tendency to develop faint infuscated bands on gastral tergites.

Measurements: HL 0.518-0.521, HW 0.479-0.511, SL 0.256-0.265, EL 0.097-0.105, CI 92-98 (n=3).

Queen: Antenna 9-segmented; maxillary palpus 6-segmented; labrum short, bilobed, not covering mouthparts; dorsal surface of mandible punctatorugose; face and clypeus largely smooth, variably roughened anteriorly; in full face view, with abundant short suberect setae on rear and side margins of head, longer setae on posterolateral vertex; ventral surface of head with abundant short erect setae; scapes with abundant erect to suberect setae, longer setae subequal to width of scape; outer surface of hind tibia with abundant short subdecumbent setae, longer setae shorter than width of tibia; color solid black.

Measurements: HL 1.181-1.226, HW 0.971-0.997, SL 0.491-0.507, EL 0.283-0.303, OW 0.062-0.081, OD 0.173-0.185, CI 79-84, OI 28-31, OcI 5-7 (n=3).

Male: Unknown.

Natural History

This species is known from mature wet forest at Rancho Quemado on the Osa Peninsula. I collected it from three different Ocotea nicaraguensis trees, and it appears to have a biology similar to M. flavocotea and others.

Literature Cited

Longino, J. T. (2006). A Taxonomic review of the genus Myrmelachista (Hymenoptera: Formicidae) in Costa Rica. Zootaxa 1141:1-54.

Page author:

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

Date of this version: 20 March 2006.
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