Formicinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
Queen in images above is holotype.
Worker, maxillary palpus (large); Queen, holotype label (large). Male, face view (large); wings (large); abdomen, lateral view (large); genitalia (large).
Costa Rica. In Costa Rica it occurs in mid-montane areas in the Cordillera de Tilar‡n and Cordillera Volc‡nica Central.
Diagnosis: Worker with antenna 9-segmented, maxillary palpus 5-segmented, color yellow. Queen with black head, HW 0.85-0.98. Male with maxillary palpus 5-segmented; pygostyles absent; cuspis very small, thin, sharply pointed; digitus with more or less constant width, gently curved ventrally to a blunt apex. Obligate inhabitant of understory Lauraceae.
Worker: Same as M. flavocotea except for color of the gaster, which may be entirely brown or with posterior bands of infuscation on the tergites.
Measurements: HL 0.566-0.657, HW 0.517-0.649, SL 0.278-0.321, EL 0.107-0.128, CI 89-99 (n=4).
Queen: Antenna 9-segmented; maxillary palpus 5-segmented; labrum short, bilobed, not covering mouthparts; dorsal surface of mandible with large piligerous puncta, interspaces either smooth and shining or coarsely rugose; 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 short subdecumbent 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 0.996-1.115, HW 0.853-0.984, SL 0.430-0.488, EL 0.259-0.297, OW 0.076-0.087, OD 0.166-0.213, CI 83-89, OI 28-32, OcI 7-8 (n=7).
Male: Antenna 10-segmented; maxillary palpus 5-segmented; pygostyles absent; basiparamere lobe thin, sharp, and spine-like, about half the length of the paramere; paramere long, thin, parallel-sided; cuspis very small, thin, sharply pointed; digitus with more or less constant width, gently curved ventrally to a blunt apex, dorsal margin smooth, with no denticles; apodeme of penial valve curving into dorsal margin at obtuse angle.
This species is known from two general areas in Costa Rica: (1) Cordillera de Tilar‡n, 1000-1500m elevation, in patches of moist forest on the Pacific slope near Santa Elena de Monteverde; and (2) Cordillera Volc‡nica Central, 1100m elevation, in mature wet forest on the Barva transect in Braulio Carrillo National Park.
The biology of this species is similar to M. flavocotea. In the forest patches near Santa Elena, colonies have been found in Ocotea nicaraguensis, an understory treelet. The one colony dissected in its entirety was monogynous, and founding queens were found alone in separate chambers in shoot tips from stump sprouts. On the Barva transect, a colony was found in O. dendrodaphne and an alate queen was captured in a Project ALAS Malaise trap.
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. firstname.lastname@example.org
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