Strumigenys laevipleura

Identification
Bolton (2000) - Within the gundlachi-complex Strumigenys laevipleura has three close relatives, Strumigenys gemella, Strumigenys vartana and Strumigenys xenognatha, all currently known only from Colombia. These species share the following characters.

1 Mandibles are moderate to long, MI 55 - 70, and their inner margins in full-face view are shallowly concave to only shallowly convex around their midlengths.

2 Two intercalary denticles are present but these arise from the ventral base of the apicodorsal tooth, not independently from the space between the apicodorsal and apicoventral fork teeth.

3 Preapical dentition consists of 2 - 3 denticles or small teeth.

4 Flagellate hairs entirely absent; hairs on leading edge of scape are slender and narrowly spatulate.

5 The postpetiole is smooth and shining, without sculpture.

The four species are mainly differentiated by the preapical armament of the mandible. In xenognatha each mandible has only 2 preapical denticles, but this species is known only from the queen so the character may not apply in the worker caste. P. gemella, laevipleura and vartana have 3 preapical denticles, set in the distal half of the exposed length. In gemella the basalmost (proximal) denticle is larger than the median. In laevipleura and vartana the median is larger than the proximal. The inner margin of the relatively long mandible of vartana is concave in full-face view, and the basal most denticle arises close to the midlength. On the shorter mandible of laevipleura the inner margin is convex and the basalmost denticle is situated more distally, at the apical third.

Distribution
This taxon was described, and is only known, from Colombia.

Nomenclature

 *  laevipleura. Strumigenys laevipleura Kempf, 1958b: 64, figs. 5-7 (w.) COLOMBIA. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 122. See also: Bolton, 2000: 188.

Worker
Bolton (2000) - TL 2.6-2.7, HL 0.58-0.62, HW 0.47-0.49, CI 79-83, ML 0.33-0.35, MI 55-57, SL 0.34-0.36, SI 69-72 , PW 0.30-0.32, AL 0.65-0.66 (2 measured). Characters of gundlachi-complex. In full-face view inner margins of mandibles shallowly convex proximal of preapical teeth, outer margins concave. Two minute intercalary denticles between apicodorsal and apicoventral teeth, the denticles arising basally from the ventral surface of the apicodorsal tooth. Mandible with 3 preapical denticles, the proximal (basal most) located at the apical third of the mandible length; median denticle the largest, much longer and broader-based than the proximal and slightly longer than the distal most denticle. Apicoscrobal hair long, curved filiform. Cephalic dorsum with two pairs of erect filiform hairs, one pair just in front of highest point of vertex, the other close to occipital margin. Pronotal humeral hair long and filiform, the dorsal alitrunk otherwise with only a single pair of erect simple hairs on the mesonotum. Mesopleuron and metapleuron smooth and shining. Postpetiole disc smooth and shining, without an anterior collar of any form. Basigastral costulae completely absent; first gastral tergite and stemite smooth and shining, standing hairs on tergite simple.

Type Material
Holotype worker and paratype workers, COLOMBIA: Medellin Coll., 3-22-46, SF 20456 Sup, 46-4823 (U.S. Plant Quarantine interception, San Francisco, California, 22.iii.1946, on orchid Miltonia sp.) (USNM) (examined).

Additional References

 * Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria” 99: 1-191.