Brachymyrmex iridescens

Nothing is known about the biology of .

Identification
Ortiz-Sepulveda et al. (2019) - Brachymyrmex iridescens morphologically resembles Brachymyrmex santschii, because both have conspicuous, strongly alveolate sculpture on the head and mesosoma. However, they differ from one another because B. iridescens has a metanotal groove that is narrower than the diameter of the metathoracic spiracles, scapes that approximately reach the posterior margin of the head, and a gaster with dense pubescence. B. iridescens is only known from Brazil and Argentina, whereas B. santschii from Costa Rica and Panama.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil.

Nomenclature

 * . Brachymyrmex iridescens Ortiz-Sepúlveda, et al. 2019: 507, fig. 37 (supplementary material fig. S25) (w.) BRAZIL (Santa Catarina, Paraná), ARGENTINA (Misiones).

Worker
Holotype and paratype (n = 2). HL1 0.40–0.43; HL2 0.29–0.30; HL3 0.09; HW 0.35–0.37; SL 0.30–0.34; EL 0.09–0.10; WL 0.39–0.40; PnL 0.13; PnW 0.22–0.25; ML 0.09–0.11; MW 0.13–0.16; Indices CI 85.42–86.67; SI180.95–82.5; SI2 100.00; OI1 23.81–25.00; OI2 23.81–25.00. Additional material (n = 2). HL1 0.37–0.42; HL2 0.26–0.30; HL3 0.07–0.11; HW 0.29– 0.38; SL 0.28–0.30; EL 0.09; WL 0.39–0.42; PnL 0.12–0.13; PnW 0.22–0.22; ML 0.09–0.11; MW 0.13–0.18; Indices CI78.57–89.36; SI1 80.95–93.94; SI2 100.00–106.90; OI1 23.81–30.30; OI2 19.05–25.53.

Description. Head. Slightly longer than wide in full face view; posterior cephalic margin slightly concave or flat. Dorsum of the head with decumbent hairs. Clypeus with a rounded anterior margin and five long, erect hairs of which a single, usually conspicuous hair is near the anterior margin, two hairs are in mediolateral position, and two more near the toruli; other hairs on the clypeus are markedly shorter and appressed or decumbent. Toruli surpassing the posterior clypeal margin in oblique anterodorsal view. The scapes are short and approximately reach the posterior margin of the head; they have decumbent and suberect hairs. Three ocelli are present. Eyes are positioned on the cephalic midline and have 8–9 ommatidia along their maximal diameter.

Mesosoma. With several decumbent hairs, and on the pronotum some suberect hairs. The mesonotum is inflated and bulges dorsally above the pronotum. The metanotal groove is narrower than the diameter of the metathoracic spiracles. Metathoracic spiracles dorsal, slightly protruding, and not touching the mesonotal nor propodeal suture. Dorsum of the propodeum slightly convex and shorter than the propodeal slope. Propodeal spiracles circular, positioned on the posterior propodeal margin at the middle of the propodeal slope. Legs with appressed hairs. Petiole short and inclined forward.

Gaster. With decumbent, dense pubescence and several scattered long erect hairs.

Color and sculpture. Head and thorax finely alveolate, gaster smooth, and shiny. The body is uniformly brownish.

Type Material
Holotype worker (: USNMENT00757758) and paratype workers (MZSP: USNMENT00757757): five workers. BRAZIL: Santa Catharina: Chapecó, July 1960, F. Plaumann 9878.

Etymology
The epithet ‘’iridescens’’ refers to the conspicuous iridescent appearance of this species under stereoscope illumination.

References based on Global Ant Biodiversity Informatics

 * Ortiz-Sepuvelda C. M., B. Van Bocxlaer, A. D. Meneses, and F. Fernandez. 2019. Molecular and morphological recognition of species boundaries in the neglected ant genus Brachymyrmex (Hymenoptera: Formicidae): toward a taxonomic revision. Organisms Diversity & Evolution https://doi.org/10.1007/s13127-019-00406-2