Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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Range
Colombia, Costa Rica. Costa Rica: widespread in wet to moist habitats, to 1400m in Monteverde area, to 1100m on Barva Transect.
Identification
Size small; color dirty yellow brown; mandible with basal tooth small relative to third tooth, mandibles subfalcate; clypeal carinae moderately divergent and projecting as strong clypeal teeth; compound eye circular, black, composed of several fused ommatidia; metanotal groove weakly impressed, promesonotum and dorsal face of propodeum more or less in same plane; postpetiole with pronounced anteroventral process; polymorphic, with a distinct major worker caste.
Natural History
Solenopsis JTL-015 occurs in wet to moist forest habitats, in the leaf litter on the ground. Workers are most often encountered in Winkler and Berlese samples. Minor and major workers occasionally recruit to baits on the ground.
I have never found a nest of this species but it must be subterranean. In the Project ALAS sampling at La Selva, collections of minor workers together with major workers are relatively frequent in Berlese samples, which incorporate soil to 15cm deep. In contrast, minor workers are common but major workers rare in Winkler samples, which sample only the surface litter.
Comments
This species exhibits worker polymorphism. Workers vary in size, and there are strongly developed major workers with allometrically enlarged heads. Many of the large fire ants in the geminata group have strong worker polymorphism, but it is rare among other Solenopsis. The minor workers of Solenopsis JTL-015 are difficult to distinguish from other small Solenopsis, but the majors are distinctive and serve to immediately identify this species.
There is strong variation in both the size and sculpture of major workers. Some have the face with pronounced, widely spaced punctures separated by smooth and shiny interspaces. Others have the face punctatorugose, finely etched over the entire surface and without smooth and shiny interspaces. Minor workers associated with these different majors (in same Berlese sample or recruiting together to bait) look identical. I have found both major worker forms together in the same Berlese sample and there are occasional intermediate forms, thus it is almost certainly intraspecific variation. It is not related to the size of major workers. Small to very large major workers can occur with either morphology.
Page author:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu
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