Strumigenys retothra

Known from a few rainforest collections, one from a tree trunk and the other from a rotten log.

Identification
Bolton (2000) - A member of the Strumigenys loriae-group. In the type-series the postpetiole disc is smooth, but the non-paratypic series from near Wau has fine punctulate sculpture on the disc. However, this series retains the other diagnostic features listed above.

For notes on broader relationships within the group see under Strumigenys kyroma. Whether retothra shows polymorphism similar to that seen in Strumigenys loriae cannot be confirmed as only few workers are known; all are large and about the same size. If they represent the upper end of the size range of retothra workers then the species differs from all its close relatives (kyroma, loriae, Strumigenys festigona) by its lack of standing hairs on the pronotum, except for the humeral pair, and lack of a well developed projection on the side of the head in front of the preocular impression, at least in individuals within the same size range (HW ca 1.00-1.30).

Distribution based on Regional Taxon Lists
Indo-Australian Region: New Guinea.

Nomenclature

 *  retothra. Strumigenys retothra Bolton, 2000: 865 (w.) NEW GUINEA.

Worker
Holotype. TL 4.4, HL 1.32, HW 1.20, CI 91, ML 0.60, MI 45, SL 0.80, SI 67, PW 0.46, AL 1.20. Closely related to Strumigenys kyroma; answering the description of that species except as follows.

1 Preapical tooth on mandible short and blunt, inclined toward the apicodorsal tooth.

2 In full-face view side of head in front of preocular impression merely forms a broadly rounded low blunt tumulus.

3 Pronotum without a pair of standing hairs on its dorsum close to the anterior margin (i.e. the humeral hairs are the only ones present on the pronotum).

4 Bulla of femoral gland on hind leg minute or invisible, much smaller than the conspicuous bulla of the hind tibial gland.

5 Head, alitrunk, waist segments and gaster uniformly dark brown to blackish brown. Legs dull brownish yellow, much lighter than body and strongly contrasting with it.

Paratype. TL 4.3, HL 1.32, HW 1.17, CI 89, ML 0.58, MI 44, SL 0.80, SI 68, PW 0.48, AL 1.20.

Type Material
Holotype worker, Papua New Guinea: 6 km. 5 Telefomin, 5.11°S, 141.38°E, 4.vii.1980, 1500 m., on tree trunk, gully rainforest, #4672 (P. S. Ward). Paratype. 1 worker with same data as holotype.