Octostruma batesi

Longino, John T, 2013, A revision of the ant genus Octostruma Forel 1912 (Hymenoptera, Formicidae), Zootaxa 3699, pp. 1-61 : 22

Octostruma batesi (Emery, 1894)

(Figs 1E, 3D, 42)

Rhopalothrix batesi Emery 1894: 218, pl. 1, fig. 11. Holotype worker: Brazil, Amazonas [MCSN] (AntWeb image examined, CASENT0904968). Combination in Octostruma : Brown 1949: 92. See also Brown & Kempf, 1960: 201, fig. 19.

Geographic range. Brazil (Amazonas), Ecuador, Bolivia.

Comments. The holotype of O. batesi closely matches three MCZC collections I have examined, two from the Andean foothills in Ecuador and one from the Andean foothills in Bolivia. The type is slightly larger than any of the other specimens. Brown and Kempf (1960) examined the holotype and provided measurements HW 0.71, HL 0.64, WL 0.78, CI 111. Measurements of the holotype using the AntWeb image were smaller: HW 0.65, HL 0.59, CI 110. Measurements for one worker each from the three MCZC collections are HW 0.53-0.60, HL 0.50-0.55, CI 107-111.

Octostruma batesi is very similar to the widespread O. betschi of the Amazonian lowlands, the latter differing in the presence of appressed spatulate setae on the scape and a somewhat more concave face. Octostruma batesi, O. betschi , and O. stenognatha are all similar in size and head shape and possibly form a clade. Although geographic coverage is poor, the known specimens form an allopatric or parapatric replacement series in South America. However, the provenance of the holotype of O. batesi is uncertain. The type locality, in the original publication and on the specimen, is simply "Amazonas."