Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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Image of petiole.
Range
Honduras to Panama. Costa Rica: montane habitats; known from Monteverde and Penas Blancas Valley down to 800m.
Identification
In usual resting position, mandibles flush against anterior border of clypeus; masticatory margin of mandible shorter than basal margin, and without teeth; clypeus large and triangular, completely concealing labrum; body with abundant piligerous puncta, metanotal sulcus well-impressed, propodeum unarmed; petiolar node elongate and wedge shaped in dorsal view, width of anterior petiolar margin less than half the width of posterior margin, in dorsal view strongly constricted anteriorly, sides concave; dorsal face of propodeum punctate (grading to transverse striae on posterior face); body dorsum with abundant decumbent pilosity, and very sparse standing hairs except on head.
Worker metrics (n=7). HL(1.82-2.02); HW (1.21-1.31); ML (0.91-1.01); EL (0.40-0.51); SL (2.12-2.42); WL (2.93-3.33) mm. CI (0.63-0.68); MI (0.69-0.77); OI (0.31-0.38); SI (1.75-1.85).
Natural History
Specimens have been taken mostly in humid forests, including Quercus litter, within or beneath rotten logs, and some records from open pasture. Mann (1922) examined a queen and found it to be quite similar to the worker, with the usual differences in petiole shape and enlarged gaster. This species is relatively common in Monteverde; Longino has collections from four nests, and have seen several other nests from which no collections were made. The colonies are small, and nests are always underground, either with an entrance that is a simple hole at the surface, or emerging into chambers beneath a stone or dead wood. For example, a dead log was turned and workers grabbed brood and vanished down a tunnel. The tunnel extended down about 10cm to a bottom chamber, where only 5 adults, 1 pupa, and 3 larvae were found. Isopods appear to be the main component of the diet, because the nests are usually surrounded by refuse piles of bleached isopod shells. Nests are easy to discover in road banks because there is a telltale whitish-gray streak of isopod shells that pour down the slope from the nest entrance. Longino once excavated a colony and kept it alive for several weeks, offering it a variety of prey. Foragers would take only isopods. Counter to this observation, however, was a worker Longino captured running across the road carrying a spider as prey.
Comments
This species is unusual because of the presence of a mesonotal depression, usually sulcus shaped, which can be situated anterad, posterad or mesad on the mesonotum, and is of variable length.
Type data
Leptogenys (Lobopelta) imperatrix Mann 1922:15, fig. 8. Syntype worker, queen: Honduras, Lombardia, San Juan Pueblo (Mann).
Literature Cited
Mann, W. M. 1922. Ants from Honduras and Guatemala. Proc. U. S. Natl. Mus. 61:1-54.
Page authors:
John E. Lattke piquihuye@gmail.com
John T. Longino longinoj@evergreen.edu
Date of this version: 3 March 2009.
Previous versions of this page: 28 May 1999.
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