Strumigenys adiastola

Identification
Bolton (2000) - This small species is defined within the ebbae-complex by the form of its mandible and dentition, presence of a distinct preocular impression and sparse pilosity. The closest related species appears to be Strumigenys vindala, but the jagged upper scrobe margins and distally inclined preapical tooth of the latter will differentiate the two.

Distribution based on Regional Taxon Lists
Oriental Region: Thailand.

Nomenclature

 *  adiastola. Strumigenys adiastola Bolton, 2000: 836 (w.) THAILAND.

Worker
Holotype. TL 2.1, HL 0.61, HW 0.51, CI 84, ML 0.24, MI 39, SL 0.32, SI 63, PW 0.27, AL 0.56. With characters of ebbae-complex. Preapical tooth short-conical and straight, very close to apicodorsal tooth; length of preapical tooth less than half width of mandible at point where it arises. Inner margin of mandible straight to extremely weakly convex proximal of preapical tooth, not sinuate. Outer margin of mandible approximately straight from base to about level of preapical tooth. Ventrolateral margin of head with a broad, shallow preocular concavity. Upper scrobe margins broadly divergent posteriorly from frontal lobes, convex; eye not visible in full-face view. Edge of upper scrobe margin not jagged, without a series of sharply defined triangular peaks or tubercles. Small hairs that fringe upper scrobe margin slender and narrowly spatulate. Scape somewhat dorsoventrally flattened and with a sharp leading edge that is broadly convex. Posterior vertex of head without a transverse depression. Dorsum of head in profile with short erect hairs along occipital margin, 1-2 on dorsum of occipital lobe and a single pair just anterior to highest point of vertex; without erect hairs anterior to this. Pronotum with a single pair of short standing hairs, close to anterodorsal margin. Mesonotum with a single pair of short erect hairs. Katepisternum, metapleuron and side of propodeum smooth. Bullae of femoral glands absent from middle and hind legs. Propodeal lamella well developed on declivity, with its posterior (free) margin shallowly convex. Disc of postpetiole smooth. Standing hairs on first gastral tergite simple.

Paratypes. TL 2.0-2.1, HL 0.60-0.61, HW 0.49-0.51, CI 82-84, ML 0.23-0.24, MI 38-40, SL 0.29-0.31, SI 59-61, PW 0.25-0.27, AL 0.55-0.57 (3 measured).

Type Material
Holotype worker, Thailand: Kaeng Krachan N. P., 17.xi.1985, #24 (Burckhardt & Lobl). Paratypes. 1 worker with same data as holotype; 5 workers with same data but 19.xi.1985, #26 (MHN, ).