Strumigenys fridericimuelleri

In Costa Rica, this species occurs in wet forest habitats. One small colony was collected in Braulio Carrillo National Park. It was in a rotten stump at the forest edge. (Longino, Ants of Costa Rica)

Identification
Bolton (2000) - A member of the Strumigenys alberti-group.

Longino (Ants of Costa Rica) - Mandibles in side view straight, not broadly curved ventrally; mandibles relatively short, subtriangular, much of the apical portion meeting along a serially toothed masticatory margin when closed (former Smithistruma); leading edge of scape with a row of conspicuous projecting curved hairs, of which those distal to the subbasal bend distinctly curve toward the base of the scape; pronotal humeral hair present; ventral surface of petiole in profile with a deep, conspicuous and very obviously spongiform curtain, its maximum depth at least half that of the peduncle and usually more; disc of postpetiole completely unsculptured and glassy smooth; anterior border of clypeus broadly rounded; basal lamella of mandible immediately followed distally by the tooth-row, without a second lamella that extends forward for half the exposed length of the fully closed mandible; mandibles short, MI 19-24; eye with ten or more ommatidia in total; promesonotal dorsum with a fine median longitudinal carina through most or all of its length; pronotal dorsum partially to mostly sculptured; propodeal dorsum weakly to strongly reticulate-punctate; in full-face view anterior clypeal margin transverse to extremely shallowly convex between points where outer margins of fully closed mandibles intersect the clypeal margin; basal tooth-row of mandible consisting only of narrowly triangular high acute teeth; disc of petiole node in dorsal view as long as broad and with the sides of the node converging anteriorly.

Carara specimens are larger, darker, and with longer propodeal spines than Atlantic slope specimens. I predict this will be a consistent difference between Pacific slope and Atlantic slope material, following a trend of diagnostically distinct forms on the two sides of Costa Rica (pers. obs.).

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil, Colombia, Costa Rica, Guadeloupe, Guatemala, Honduras, Panama, Paraguay, Peru, Trinidad and Tobago, Venezuela.

Nomenclature

 *  fridericimuelleri. Strumigenys fridericimuelleri Forel, 1886a: 213 (w.) BRAZIL. Combination in S. (Cephaloxys): Emery, 1924d: 325; in Smithistruma: Brown, 1953g: 98; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 120. See also: Bolton, 2000: 155.

Worker
Bolton (2000) - TL 1.8-2.2, HL 0.50-0.56, HW 0.35-0.39, CI 68-73, ML 0.08-0.11, MI 16-21, 0.25-0.28, SI 69-74, PW 0.24-0.28, AL 0.50-0.72 (20 measured). Masticatory margin of mandible with a basal series of 5 narrow acutely triangular teeth that immediately follow the basal lamella. Distal of these are two smaller but similarly shaped teeth; no long secondary lamella, no alternation of high acute and low rounded teeth. Anterior clypeal margin broadly and very shallowly convex between the points where the outer margins of the closed mandibles intersect the clypeal margin, sometimes almost transverse. Apicoscrobal hair flagellate, long and fine, sometimes looped. Eye with 4 - 5 ommatidia in the longest row. Promesonotum with a variably developed median longitudinal carina. At maximum the carina distinct through entire length of pronotum and most of mesonotum; at minimum conspicuous only posteriorly on pronotum and anteriorly on mesonotum. Dorsum of pronotum partially to mostly smooth, with fine costulate or punctate sculpture, or both, at least posteriorly and dorsolaterally. Petiole node in dorsal view about as broad as long to slightly broader than long, the sides diverging posteriorly. Lateral spongiform lobes of node extending forward almost to the anterolateral angles.

Type Material
Bolton (2000) - Syntype workers, BRAZIL: Itajahy (w. Muller), (examined).