Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
|
|
|
|
|
|
Dorsal view of face of major, showing clypeal keel.
Additional images of upland form: minor worker lateral view (original, reduced), major worker lateral view (original, reduced), minor worker face view (original, reduced), major worker face view (original, reduced).
Identification
Minor worker: head length 0.62mm, head width 0.56mm, scape length 0.54mm, Webers length 0.78mm (n=1). Head somewhat flattened behind; promesonotum evenly arched, mesonotal suture absent; propodeal spines short, sharp, upturned; face smooth and shining, or with faint sculpture on vertex and stronger punctatorugose sculpture between eye and frontal carinae; mesosoma sculpture variable (see Variation); dorsal pilosity abundant, long, flexuous; color red brown.
Major worker: head length 1.45mm, head width 1.27mm, scape length 0.61mm (n=1), CI 88-91 (n=3). Face punctatorugose on anterior half lateral to frontal carinae; areas beneath sweep of scapes shallowly foveolate; medial area between frontal carinae with parallel longitudinal carinae; posterior half of face smooth and shining; clypeus with prominent medial tooth, tooth laterally compressed, keel-like, concave shiny area on each side of tooth, bounded laterally by prominent carinae extending obliquely from base of frontal carinae; bases of frontal carinae elevated, tooth-like; hypostomal margin with no medial tooth, pair of subtriangular teeth located close to midline, less than one quarter distance to recessed teeth flanking mandibles; dorsal pilosity abundant; head with abundant setae projecting from sides of head in face view.
Variation: collections vary in mesosomal sculpture of minor workers. In some, the pronotum is punctatorugose anterodorsally, foveolate posteriorly and on humeri, with large shiny patches dorsomedially and laterally. The katepisternum and lateral propodeum are entirely foveolate. In others, the pronotum is smooth and shining, with small areas of faint rugae on humeri and margins of katepisternum, and a few transverse carinae on anterodorsal margin. The anterior katepisternum is smooth and shining, leaving only the posterior margin foveolate, and the punctation on propodeum is faint. In others, the katepisternum and lateral propodeum are largely smooth and shining, with some rugulation in the suture between the two, but no trace of punctation. The foveolate forms seem somewhat larger and generally more robust. In Honduras, there is a collecton of the foveolate form from a 1040m elevation site, and a collection of the shiny form from a 650m site. In Costa Rica, the foveolate form occurs in the Monteverde and Penas Blancas area above 800m, Braulio Carrillo above 800m, and in the San Vito and Las Alturas area above 1100m. The shiny form occurs in the Cordillera de Guanacaste at 650m (Pitilla) and 1500m (Cacao), in Carara at 500m, and in Braulio Carrillo at two different 500m sites. In Panama, the foveolate form occurs at Volcan de Chiriqui (near type locality of rhinoceros), and at Cerro Campana. A collection from Colombia, near Cali, is largely smooth and shiny, but shows traces of punctation at the suture between katepisternum and propodeum.
In Costa Rica, the two forms are nowhere sympatric, but are narrowly parapatric in Braulio Carrillo, being separated by 300m elevation and about 5km distance.
Range
Costa Rica, Panama (type locality).
Natural History
This species occurs in mature wet forest. It is very common in Winkler samples, and occurs in leaf litter up to the highest elfin forest in Monteverde. Nests have been found under loose bark of dead trees, in dead wood on the ground, in rotten stumps, and in dead sticks in the low arboreal zone (1-2m above the ground). Occasionally nests are in live stems of plants with soft pith such as Piper coenocladum and Myriocarpa.
Selected Records
Numerous collections from Braulio Carrillo National Park (500 to 1000m), Penas Blancas Valley, Monteverde. Three collections from nests in dead wood on the ground.
Carara Biological Reserve (Bijuagual at 500m): mature wet forest; nest under loose bark of 1m dia tree trunk in old treefall.
Guanacaste Conservation Area (Cacao): montane evergreen forest; tending homoptera under loose bark.
Guanacaste Conservation Area (Pitilla): wet forest; under loose bark in treefall.
Page authors:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA. longinoj@evergreen.edu
Stefan Cover, Museum of Comparative Zoology, Harvard University, Cambridge MA 02138 USA. scover@oeb.harvard.edu
Go back to top
