Strumigenys diaptyxis

Identification
Bolton (2000) - A member of the Strumigenys emeryi-group. The lack of mesonotal flagellate hairs, reduction of propodeal lamella together with presence of propodeal lacuna, deep ventral spongiform curtain on petiole and form of sculpture combine to make this species easily recognisable.

Longino (Ants of Costa Rica) - Apical fork of mandible with one intercalary tooth; mandible with small preapical tooth very close to apical fork, and a minute denticle near the apical third of mandible length; gaster smooth and shining, with setae stiff, straight, slightly thickened.

This species shares characters with both Strumigenys micretes and Strumigenys nevermanni. It is intermediate in size between micretes and nevermanni. It has gastral pilosity more like nevermanni than micretes. It has a uniformly punctate face, in contrast to the other two species which have more rugose faces.

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica, Nicaragua.

Nomenclature

 *  diaptyxis. Strumigenys diaptyxis Bolton, 2000: 513 (w.) COSTA RICA.

Worker
Holotype. TL 2.8, HL 0.70, HW 0.50, CI 71, ML 0.41, MI 59, SL 0.46, SI 92, PW 0.31, AL 0.72. Mandible with a small preapical tooth close to the apicodorsal tooth; left mandible also with a vestigial denticle proximal to the preapical tooth (implies possibility of variation such as is common elsewhere in the group). Pronotal humeral hair long, fine and flagellate; all other standing hairs simple or weakly spatulate apically. Without flagellate hairs on dorsolateral margin of head, mesonotum, waist segments or first gastral tergite. The two pairs of standing hairs on cephalic dorsum stiff and erect. Dorsum of head reticulate-punctate, without superimposed rugulose sculpture. Pronotal dorsum shagreenate to finely superficially reticulate-punctate, not sharply reticulate-punctate and without longitudinal rugulae. Mesopleuron mostly smooth, metapleuron and side of propodeum smooth anteriorly, feebly punctulate posteriorly. Propodeum with a pair of narrowly triangular spines, lamella immediately below spine narrow, feebly convex in its lower part around the weakly developed propodeal lacuna. Ventral surface of petiole with a spongiform curtain that at maximum is over half the depth of the peduncle. Dorsum of petiole node slightly longer than broad, weakly reticulate-punctate. Disc of postpetiole unsculptured and basigastral costulae shorter than postpetiole disc.

Type Material
Holotype worker, Costa Rica: Provo Alajuela, Rio Penas Blancas, 10°19'N, 84°43'W, 800 m., 26-28.iv.1987, #1618-S, wet forest, workers on vegetation at night (J. Longino).