Strumigenys dipsas

Identification
Bolton (2000) - Within the group six species, Strumigenys benulia, Strumigenys daithma, dipsas, Strumigenys lacunosa, Strumigenys paraposta and Strumigenys pliocera have the following four characters in combination.

1 Inner margin of mandible without a cuticular lamella.

2 Preapical tooth or denticle present on mandible.

3 Dorsal (outer) surfaces of middle and hind tibiae and basi tarsi with freely projecting long hairs.

4 Katepisternum not completely sculptured, with at least a smooth shining area and sometimes entirely smooth.

Four of these species (benulia, daithma, lacunosa, paraposta) have the hind femur bearing a conspicuous row of fine suberect to erect hairs on its dorsal surface. Of these lacunosa has the lateral spongiform lobe of the petiole large. In dorsal view the lateral lobes project strongly on each side of the node, broadest posteriorly and narrowing anteriorly, extending as far forward as the anteriormost point of the node. In the other three species the lobes are much more restricted and do not approach the anterior end of the node. S. paraposta has transverse costulate sculpture on the front coxae and sculptured metapleuron and side of propodeum, both of which are absent in the last two species, benulia and diathma. These two are easily separated by the very different sculpture of their dorsal alitrunks and the other characters given in the key.

The other two species lack a row of erect hairs on the dorsal surface of the hind femur. Of these pliocera has its pronotum punctate dorsally, and has 3 long hairs projecting laterally from the upper scrobe margin, the posteriormost of which is the apicoscrobal hair. S. dipsas on the other hand has its pronotum longitudinally rugulose dorsally, and has only the apicoscrobal hair on the upper scrobe margin.

Distribution based on Regional Taxon Lists
Oriental Region: Thailand.

Nomenclature

 *  dipsas. Strumigenys dipsas Bolton, 2000: 757 (w.q.) THAILAND.

Worker
Holotype. TL 3.0, HL 0.80, HW 0.57, CI 71, ML 0.37, MI 46, SL 0.42, SI 74, PW 0.34, AL 0.87. Mandible with a small preapical tooth. Apicoscrobal hair present; without laterally projecting hairs on upper scrobe margin anterior to this. Cephalic dorsum with a pair of erect fine hairs that straddle the midline close to the occipital margin; usually also with a shorter erect hair on lateral margin of occipital lobe but without erect hairs at highest point of vertex. Dorsum of head densely reticulate-rugulose, tops of rugulae and spaces between rugular meshes finely punctulate. Promesonotal dorsum rugulose, predominantly longitudinally so; similar sculpture present on propodeal dorsum but much weaker, finer and less conspicuous. Side of pronotum longitudinally rugulose; katepisternum smooth; metapleuron with some punctate sculpture anteriorly but most of its surface, and that of side of propodeum, longitudinally rugulose. Anterior coxae with weak transverse rugulae. Pronotal humeral hair long and fine, flagellate or looped apically (apparently fragile, broken off at about its midlength in half the paratypes). Pronotal dorsum with 1-2 pairs of erect fine hairs, mesonotum with 3-4 similar pairs. First gastral tergite with long fine filiform to flagellate hairs. Dorsal surface of hind femur without standing hairs, but 1-2 may be present on ventral surface; dorsal (outer) surfaces of hind tibia and basitarsus each with 1-2 long erect freely projecting filiform or flagellate hairs. Propodeal teeth short, triangular and acute. Petiole in profile claviform.

Paratypes. TL 3.0-3.2, HL 0.80-0.86, HW 0.57-0.60, CI 69-73, ML 0.37-0.40, MI 45-49, SL 0.42-0.44, SI 73-76, PW 0.30-0.35, AL 0.87-0.90 (5 measured).

Type Material
Holotype worker, Thailand: Doi Inthanon, 7.xi.1985, no. 15 (Lobl & Burckhardt).

Paratypes. 10 workers and 4 queens with same data as holotype; 6 workers with same data but no. 14; 4 workers and 1 queen with same data but 1650 m., no. 16 (MHNG,, ).