Strumigenys smithii

Occurs in wet forest habitats. In Costa Rica, it perhaps nests and forages in the low arboreal zone. The few collections are from that zone, and I have never observed it in Winkler samples. (Longino, Ants of Costa Rica)

Identification
Bolton (2000) - A member of the mandibularis complex in the Strumigenys mandibularis-group. Close to Strumigenys biolleyi, but that species has all hairs on the leading edge of the scape curved or inclined toward the apex of the scape, and the propodeal declivity only has a triangular lobe or tooth at the base, there being no upper tooth or spine where dorsum meets declivity.

Longino (Ants of Costa Rica) - Apical fork of mandible with a single intercalary tooth; mandible with two conspicuous preapical teeth; gastral dorsum smooth and shining; mandibles shorter than head; propodeal lamellae with dorsal and ventral teeth or angles (dorsal angle absent in biolleyi).

In Costa Rica, smithii has a conspicuous ring of basal costulae on the gaster, these being approximately 0.10mm long on the midline. Strumigenys biolleyi has these costulae essentially absent or very short, less than 0.05mm on the midline. This difference is true for specimens from 28 different collections of biolleyi and 4 different collections of smithii that I have examined.

Distribution based on Regional Taxon Lists
Neotropical Region: Belize, Brazil, Colombia, Costa Rica, Ecuador, El Salvador, Grenada, Guadeloupe, Guatemala, Honduras, Lesser Antilles, Mexico, Panama, St. Vincent, Venezuela.

Biology
Brown (1962) - Nests in rotten logs, rotten twigs or, on St. Vincent, rarely in sod. Primarily a forest species.

DaRocha et al. (2015) studied the diversity of ants found in bromeliads of a single large tree of Erythrina, a common cocoa shade tree, at an agricultural research center in Ilhéus, Brazil. Forty-seven species of ants were found in 36 of 52 the bromeliads examined. Bromeliads with suspended soil and those that were larger had higher ant diversity. Strumigenys smithii was found in a single bromeliad and was associated with the suspended soil and litter of the plant.

Nomenclature

 *  smithii. Strumigenys smithii Forel, 1886a: 215 (w.) BRAZIL. Forel, 1893g: 375 (q.m.). Senior synonym of inaequalis: Brown, 1953f: 104. See also: Bolton, 2000: 539.
 * inaequalis. Strumigenys smithi var. inaequalis Emery, 1890b: 67, pl. 7, fig. 3 (w.) BRAZIL. Junior synonym of smithii: Brown, 1953f: 104.

Worker
Bolton (2000) - TL 2.7-3.3, HL 0.65-0.77, HW 0.54-0.64, CI 81-85, ML 0.36-0.42, MI 52-60, SL 0.44-0.53, SI 79-86, PW 0.34-0.44, AL 0.68-0.84 (15 measured).

Characters of mandibularis-complex. Proximal preapical tooth located just distal of midlength on inner border of mandible. Outer margins of mandibles only shallowly curved at full closure. Leading edge of scape with 1-2 hairs in the basal third that are distinctly curved toward the base of the scape. Propodeal declivity with upper and lower teeth linked by a lamella, the teeth variable in shape and size but lower tooth somewhat longer than the upper. Disc of postpetiole broader than long, with very variably developed costulate sculpture. At minimum costulae extremely short and weak, restricted to anterior margin of disc; at maximum costulae strong and traversing entire length of disc; many intermediate stages known. First gastral tergite with fine hairs on basal quarter to third; at minimum a single transverse row close to base but usually with others also present. Basigastral costulae distinct, longer than thickness of postpetiolar posterior spongiform collar.

Type Material
Bolton (2000) - Syntype workers, BRAZIL: Itajahy [examined].