Proposed revised status; currently a junior synonym of striatula Mayr.
Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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Range
Costa Rica, Guatemala, Mexico (Brown 1958). Costa Rica: Pacific lowlands from Punta Quepos northward.
Identification
Pronotum separated from remainder of mesosoma by a very distinct suture, completely breaking the sculpture; anteroventral process of petiole a broad lobe with evenly rounded posterior margin, not square-cut; petiolar node erect, in side view the posterodorsal angle not very much more sharply rounded than anterodorsal angle, and not overhanging posterior face.
Natural History
This species appears to prefer dryer habitats, including disturbed areas (Brown 1958). Kaptein et al. (2004) (as G. striatula) show that larvae have a food begging behavior in which they lift their neck and head and perform a waving motion at workers and food items.
Selected records from Costa Rica:
Guanacaste: Finca La Pacifica, 10¡27'N, 85¡08'W, 40m (J. Longino). Riparian forest in seasonally dry region, surrounded by pastures. Ex sifted leaf litter from forest floor (Winkler sample).
Guanacaste: Santa Rosa National Park, 10¡51'N, 85¡37'W, 300m (J. Longino). Tropical dry forest.
Puntarenas: La Pita, rd to Monteverde, 10¡10'N, 84¡55'W, 120m (J. Longino). Road edge vegetation and pastures.
Puntarenas: Punta Quepos, 9¡24'N, 84¡10'W, 5m (J. Longino). Degraded patch of wet forest surrounded by pastures.
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
Ectatomma (Holcoponera) curtulum Emery 1896:47. Syntype workers: Costa Rica, Alajuela.
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.
Emery, C. 1896. Studi sulle formiche della fauna neotropica. XVII-XXV. Bolletino della Societa Entomologica Italiana 28:33-107, pl. 1.
Kaptein, N., J. Billen, and B. Gobin. 2005. Larval begging for food enhances reproductive options in the ponerine ant Gnamptogenys striatula. Animal Behaviour 69:293-299.
Lattke, J. E. 1995. Revision of the ant genus Gnamptogenys in the New World (Hymenoptera: Formicidae). Journal of Hymenoptera Research 4:137-193.
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu
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