Strumigenys aenigma

The type material was collected from rainforest leaf-litter.

Identification
Bolton (2000) - A member of the rofocala complex in the Strumigenys godeffroyi-group. Three species of the rofocala-complex are indigenous in New Caledonia, Strumigenys aenigma, Strumigenys lamia and Strumigenys chareta. Of these aenigma is the only one to possess erect fine hairs on the dorsal surfaces of the middle and hind femora. The propodeal lamella is also broader in aenigma than in the other two species and has its posterior (free) margin at least straight, usually shallowly convex; in chareta and lamia the lamella is narrow and shallowly concave. Strumigenys chareta has mandibles that average longer than in aenigma (MI 48-52 as opposed to MI 43-46) but chareta usually has a distinct pair of short erect hairs at about the highest point of the vertex and has scapes that average longer (SI 86-93 as opposed to SI 82-85 in aenigma.

Strumigenys lamia has shorter mandibles and scapes (MI 42-46, SI 76-81) than either aenigma or chareta, and tends to have a somewhat broader head (CI 71-76 as opposed to CI 67-72 in the other two). Like aenigma it lacks erect hairs at the highest point of the vertex and like chareta it has a narrow propodeal lamella with a concave posterior (free) margin.

Distribution based on Regional Taxon Lists
Australasian Region: New Caledonia.

Nomenclature

 *  aenigma. Strumigenys aenigma Bolton, 2000: 955 (w.) NEW CALEDONIA.

Worker
Holotype. TL 2.2, HL 0.56, HW 0.39, CI 70, ML 0.26, MI 46, SL 0.32, SI 82, PW 0.24, AL 0.58. With characters of rojocala-complex. Apicoscrobal hair absent. Cephalic dorsum with a single pair of very slender erect hairs, located close to midline near occipital margin, these hairs often hard to distinguish among the narrowly spatulate curved ground-pilosity and frequently lost. Eye small, maximum diameter less than maximum width of scape, with about 4-7 ommatidia in total. Pronotal humeral hair flagellate; pronotal dorsum otherwise without erect hairs. Mesonotum with a single pair of erect fine flagellate hairs. Pronotal dorsum finely reticulate-punctulate and with traces of weak longitudinal rugulae; mesonotal and propodeal dorsa more strongly reticulate-punctate. Dorsal surface of middle and hind femora each with two very slender erect subflagellate hairs (easily dislodged); one just proximal of midlength, the other closer to the trochanter. Propodeal declivity with a broad lamella, its posterior (free) margin straight to shallowly convex. Mesopleuron, metapleuron and side of propodeum smooth and shining. Dorsum of petiole node finely reticulate-punctate; disc of postpetiole smooth. Hairs on first gastral tergite erect and fine, sub flagellate to flagellate.

Paratypes. TL 2.2-2.3, HL 0.56-0.58, HW 0.39, CI 67-70, ML 0.25-0.26, MI 43-46, SL 0.32-0.33, SI 82-85, PW 0.23-0.24, AL 0.58-0.60 (5 measured).

Type Material
Holotype worker, New Caledonia: Sud, Yate, Dolines of Yate, 5.xii.1995, YelS, NC95-169 (Deharveng & Bedos). Paratypes. 5 workers with same data as holotype (BMNH, ).