Proposed revised status; currently a junior synonym of striatula Mayr.
Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
Range
Costa Rica (Atlantic lowlands).
Identification
Pronotum separated from remainder of mesosoma by a very distinct suture, completely breaking the sculpture; anteroventral process of petiole square-cut, with sharp posterior angle; metanotal suture not impressed, not breaking sculpture, much weaker than promesonotal suture; mesonotum and dorsal face of propodeum forming concavity (in other words, dorsal face of propodeum somewhat differentiated from mesonotum, more horizontal); scapes surpassing margin of vertex by more than length of first funicular segment; petiole in lateral view symmetrical, with similar anterodorsal and posterodorsal angles.
Natural History
This species inhabits wet forests of the Atlantic lowlands. It nests in dead wood on the ground and in plant cavities in low vegetation.
Selected records from Costa Rica:
Heredia: La Selva Biological Station, 10¡26'N, 84¡01'W, 50m (J. Longino). Lowland rainforest; nest in dead wood on forest floor.
Limon: Hitoy Cerere Biological Reserve, 9¡40'N, 83¡02'W, 100m (J. Longino). Mature wet forest. Nest in the chamber formed by clasping sides of petiole of Diffenbachia. Prey (?) remains in nest were over 4 adult Nematocera.
Taxonomic Notes
Lattke (1995) synonymized wheeleri and curtula under striatula. I agree with his allying wheeleri and curtula with striatula. In his key, striatula is distinguished from strigata by a more symmetrical petiolar node, with similar anterodorsal and posterodorsal angles. In contrast, strigata has the petiole posteriorly inclined, the anterior face joining the dorsal face through a broad convexity that contrasts with a sharper angle between the posterior and dorsal faces. The material I am calling curtula and wheeleri does exhibit the relatively symmetrical petiole shape described by Lattke, and thus is similar to striatula sensu stricto. However, differences between curtula and wheeleri in Costa Rica cause me to maintain them as distinct taxa, with uncertain affinities to true striatula. This is a return to the status quo as presented in Brown (1958). The Costa Rican populations of curtula and wheeleri exhibit consistent differences in the shape of the anteroventral petiolar process and the propodeal profile. Although Lattke discounted the value of the petiolar process, due to variation he observed within sites and within colonies, the trait seems consistent, with little or no variation, in Costa Rican material. curtula and wheeleri both have type localities within Costa Rica (Alajuela for curtula, Limon for wheeleri), while the type locality of striatula is French Guiana. Given the uncertainty of the taxonomic boundaries within the striatula complex, it seems prudent to use the names curtula and wheeleri for the Costa Rican populations, until further understanding of the striatula complex suggests a change.
Type data
Holcoponera wheeleri (Santschi 1929:448). Type worker: Costa Rica, Puerto Limon.
Literature Cited
Brown, W. L., Jr. 1958. Contributions toward a reclassification of the Formicidae. II. Tribe Ectatommini (Hymenoptera). Bulletin of the Museum of Comparative Zoology 118:175-362.
Lattke, J. E. 1995. Revision of the ant genus Gnamptogenys in the New World (Hymenoptera: Formicidae). Journal of Hymenoptera Research 4:137-193.
Santschi, F. 1929. Revision de genre Holcoponera Mayr. Zoologische Anzeiger 82:437-477.
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu