Myrmelachista lauropacifica

Longino, J. T., 2006, A taxonomic review of the genus Myrmelachista (Hymenoptera: Formicidae) in Costa Rica., Zootaxa 1141, pp. 1-54: 31-33

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Myrmelachista lauropacifica


Myrmelachista lauropacifica   HNS   NEW SPECIES

Figures 4, 6, 11, 13

Holotype alate queen: Costa Rica, Prov. Puntarenas, Cedral, Corcovado National Park , 8°33’N, 83°33’W, 50m , 15 Jul 1982 (J. Longino) [ INBC, specimen code JTLC000006213]. GoogleMaps  

Paratypes: workers and queens, from same nest as holotype, specimen codes JTLC000006214 - JTLC000006218, distributed to MCZC, USNM, UCDC, LACM, BMNH. GoogleMaps  


Worker with antenna 9-segmented, maxillary palpus 5-segmented, color yellow. Queen with orange head, eyes relatively large (OI 33-37), HW less than 0.8mm. Obligate inhabitant of understory Lauraceae.


Same as M. flavocotea   HNS   . Measurements: HL 0.468-0.596, HW 0.414-0.537, SL 0.223-0.285, EL 0.098-0.110, CI 87-95 (n=4).


Antenna 9-segmented; maxillary palpus 5 or 6-segmented; labrum short, bilobed, not covering mouthparts; dorsal surface of mandible with piligerous puncta, interspaces smooth or slightly roughened; face and clypeus smooth and shining; in full face view, with abundant long erect to suberect setae projecting from sides of head, setae on posterior margin shorter; 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 light yellow orange with infuscated bands on gastral terga.

Measurements: HL 0.900-0.966, HW 0.738-0.787, SL 0.363-0.402, EL 0.261-0.276, OW 0.076-0.089, OD 0.133-0.155, CI 77-82, OI 33-37, OcI 8-9 (n=4).


Antenna 10-segmented; maxillary palpus 6-segmented; pygostyles absent; basiparamere lobe short, weakly sclerotized, half the length of paramere or less, in one collection drawn out as thin, sharp point, in another reduced to short triangular tooth; paramere weakly sclerotized, parallel-sided with rounded apex; cuspis absent (at high magnification, barely visible as tiny remnant); digitus evenly curved downward, tapering to rounded point; apodeme of penial valve curving into dorsal margin at obtuse angle.


The name refers to its association with plants in the family Lauraceae and its geographic distribution in the Pacific lowlands.


Costa Rica. In Costa Rica it occurs in the southern Pacific lowlands.


This species occurs in mature wet forest in the southern Pacific lowlands. I have collected it in Corcovado National Park and Carara Biological Reserve. Colonies have been in live stems of Lauraceae, with a biology similar to M. flavocotea   HNS   . I found nests in O. cf. atirrensis   and O. nicaraguensis   . In Carara, O. nicaraguensis   was common along the Quebrada Bonita. Small plants in the forest understory all contained M. lauropacifica   HNS   , while larger plants in more insolated areas along the stream edge contained Azteca cf. pittieri   HNS   and Pseudomyrmex viduus   HNS   .

Material Examined

COSTA RICA, Puntarenas: Cedral, Corcovado National Park , 8°33’N, 83°33’W, 50m (J. Longino) GoogleMaps   ; Bijagual, Carara Biol. Reserve , 9°47’N, 84°36’W, 500m (J. Longino) GoogleMaps   ; Carara Biological Reserve, Estacion Quebrada Bonita , 9°47’N, 84°36’W, 30m (J. Longino, 2 collections) GoogleMaps   .


Costa Rica, Santo Domingo de Heredia, Instituto Nacional de Biodiversidad (INBio)


USA, Massachusetts, Cambridge, Harvard University, Museum of Comparative Zoology


USA, Washington D.C., National Museum of Natural History, [formerly, United States National Museum]


USA, California, Davis, University of California, R.M. Bohart Museum of Entomology


USA, California, Los Angeles, Los Angeles County Museum of Natural History


United Kingdom, London, The Natural History Museum [formerly British Museum (Natural History)]