Strumigenys xenognatha

Bolton (2000) - The single specimen of this species was found together with workers that comprise the type-series of Strumigenys laevipleura. Kempf (1958a) speculated on the circumstances of this. He noted that the differences between the queen and its apparently associated workers were greater than in any other known species of the group, and suggested that the series may have been mixed or that the queen was a social parasite. Whatever, he decided that the queen merited description as a separate taxon but admitted that it could represent the genuine queen of laevipleura. I can do nothing to resolve the problem as no further material of either has been discovered, and so retain xenognatha as a species.

Distribution based on Regional Taxon Lists
Neotropical Region: Colombia.

Nomenclature

 *  xenognatha. Strumigenys xenognatha Kempf, 1958b: 64, fig. 4 (q.) COLOMBIA. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 130. See also: Bolton, 2000: 196.

Queen
Bolton (2000) - TL 3.25, HL 0.65, HW 0.51, CI 79, ML 0.41, MI 63, AL 0.84 (measurements from Kempf, 1958a). As laevipleura but differing as follows.

1 Mandibles relatively longer, MI 63 (as opposed to MI 56-57 in laevipleura).

2 Inner margin of mandible concave in vicinity of preapical teeth but markedly convex distally.

3 Preapical dentition restricted to 2 denticles, in the apical third of the length, the proximal denticle longer and stouter than the distal.

4 Scape almost linear, lacking a noticable subbasal bend.

In addition, the specialised projecting hairs are stiff and simple, those at the humeri long. Hairs on the first gastral tergite are simple, stiff and quite numerous, short straight and bristly. Basigastral costulae are faint and extremely short; only 4 - 5 can be discerned and they are shorter than the thickness of the pospetiolar spongiform collar.

Type Material
Holotype queen, COLOMBIA: Medellin Col., 3-22-46, SF 20456 Sup, 46-4823 (U. S. Plant Quarantine interception, San Francisco, California, 22.iii.1946, on orchid Miltonia sp.) (examined).

Additional References

 * Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria” 99: 1-191.