Strumigenys idiogenes

I know this species from one specimen (the holotype), a worker collected by Bob Matlock, in an intercept trap in an agricultural area near Guapiles. (Longino, Ants of Costa Rica)

Identification
Bolton (2000) - A member of the Strumigenys ludia-group. The holotype is the only known specimen of this species so there is no way of ensuring that the asymmetrical preapical dentition that it possesses is stable. Elsewhere in the Neotropical fauna of this genus are species which show variation in development of preapical dentition (see emeryi group) and it may be that idiogenes is capable of the same variation. Specimens may perhaps be expected which have a preapical tooth on each mandible, or which lack such a tooth on both mandibles.

The presence of flagellate hairs on head and alitrunk easily separates this species from Strumigenys boneti. Apart from differences in preapical dentition idiogenes differs from Strumigenys ludia as the latter lacks erect hairs at highest point of cephalic vertex and does not have a transversely rectangular petiole node in dorsal view; in profile idiogenes lacks the long low claviform petiole characteristic of ludia.

Longino (Ants of Costa Rica) - Apical fork of mandible with one intercalary tooth; right mandible with one acute preapical tooth near apical fork, left mandible without preapical tooth; propodeal spines long, well developed; first gastral tergum mat, finely and densely striatopunctate on anterior third, remainder finely and densely punctate; first gastral tergum with abundant long, stiff, clavate setae, separated by a distance subequal to their length.

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

Nomenclature

 *  idiogenes. Strumigenys idiogenes Bolton, 2000: 527 (w.) COSTA RICA.

Worker
Holotype. TL 3.3, HL 0.78, HW 0.64, CI 85, ML 0.52, MI 67, SL 0.58, SI 91, PW 0.39, AL 0.79. Mandible with asymmetrical preapical dentition; left mandible without trace of preapical dentition, right mandible with a small slender preapical tooth that is located close to the apicodorsal tooth and is slightly smaller than the intercalary tooth (see discussion below). Apicoscrobal hair and pronotal humeral hair long and flagellate. Mesonotum with two pairs of flagellate hairs and a third, posteriormost, standing pair that appear to be elongate-spatulate or weakly remiform, much shorter than the two preceding pairs and resembling the gastral pilosity. The flagellate hairs contrast strongly with the gastral pilosity which is stout and shallowly curved, narrowly remiform or somewhat flattened and spatulate apically. Cephalic dorsum with two pairs of standing hairs; a shorter pair at about the highest point of the vertex and a longer pair close to the occipital margin. Posterior half of cephalic dorsum finely reticulate-rugulose. In dorsal view anterior margin of pronotum bounded by a semi translucent narrow cuticular rim or flange. Promesonotal dorsum irregularly but predominantly longitudinally rugulose, side of pronotum more regularly longitudinally so. Sculpture mostly weak and effaced on katepisternum but metapleuron and side of propodeum reticulate-punctate with a few weak overlying rugulae. Petiole node in dorsal view transversely rectangular, much broader than long; anterolateral angles of node extended into short broad triangular teeth. Dorsum of petiole node and disc of postpetiole with fine rugulae overlying fine reticulate-punctate ground-sculpture. Basigastral costulae fine and dense, the spaces between them and the entire tergite posterior to them finely and densely reticulate-punctulate to reticulate-shagreenate, opaque.

Type Material
Holotype worker, Costa Rica: Provo Limon, 24 km. E Guapiles, 20 m., 10°15'N, 83°35'W, 4.iv.1996, project 5, intercept (R. Matlock).

References based on Global Ant Biodiversity Informatics

 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.