Formicinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
Queen in images above is holotype.
Holotype queen, label (large). Male, face view (large); genitalia (large).
Costa Rica. In Costa Rica it occurs in the Atlantic lowlands.
Diagnosis: Worker with antenna 9-segmented, maxillary palpus 5-segmented, color yellow. Queen black; in full face view, with abundant long erect setae projecting from rear margin and sides of head. Obligate inhabitant of Lauraceae.
Worker: Same as M. flavocotea except for color of the gaster, which has faint posterior bands of infuscation on the tergites.
Measurements: HL 0.450-0.588, HW 0.422-0.579, SL 0.217-0.295, EL 0.080-0.130, CI 94-100 (n=5).
Queen: Antenna 9-segmented; maxillary palpus 5-segmented; labrum short, bilobed, not covering mouthparts; dorsal surface of mandible punctate to coarsely punctatorugose; clypeus with large piligerous puncta; malar spaces with variable extent of weak punctatorugose sculpturing, grading to smooth and shining posteriorly; in full face view, with abundant long erect setae projecting from rear margin and sides of head; 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 erect to subdecumbent setae, longer setae shorter than width of tibia; color solid black.
Measurements: HL 0.874-1.08, HW 0.763-0.930, SL 0.380-0.434, EL 0.231-0.286, OW 0.048-0.073, OD 0.170-0.227, CI 83-89, OI 29-33, OcI 5-8 (n=11).
Male: Antenna 10-segmented; maxillary palpus 5 or 6-segmented; pygostyles nearly absent (tiny remnants visible at high magnification); basiparamere lobe pronounced, with broad base, about half the length of the paramere; paramere also with broad base; cuspis small, rectangular, with minute apical denticles; digitus evenly curved downward and tapering to blunt point; apodeme of penial valve curving into dorsal margin at obtuse angle.
This species occurs in mature rainforest habitats in the Atlantic lowlands. It is a specialist inhabitant of live stems of Lauraceae, similar to M. flavocotea. In the forests around the community of Tortuguero on the north Atlantic coast understory Ocotea dendrodaphne and Licaria sp. are common, and nearly all are inhabited by M. lauroatlantica. I dissected numerous small plants with colonies, many of which were monogynous but some of which were polygynous. One small Licaria contained 25 dealate queens, along with workers, brood, and an adult male. One contained a cluster of 3 dealate queens in a colony with abundant workers and brood. A large Licaria tree that had fallen over and produced sucker shoots along its length was packed with a large polygynous colony, with clusters of dealate queens in many chambers. In a forest patch at C.A.T.I.E. near Turrialba colonies were common in O. dendrodaphne and O. atirrensis. A monogynous colony was found in an understory Ocotea (probably dendrodaphne or atirrensis) in Hitoy Cerere Biological Reserve.
Longino, J. T. (2006). A Taxonomic review of the genus Myrmelachista (Hymenoptera: Formicidae) in Costa Rica. Zootaxa 1141:1-54.
John T. Longino, The Evergreen State College, Olympia WA 98505 USA. email@example.com
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