Brachymyrmex oculatus

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Brachymyrmex oculatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Myrmelachistini
Genus: Brachymyrmex
Species: B. oculatus
Binomial name
Brachymyrmex oculatus
Santschi, 1919

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Specimen Labels

Nothing is known about the biology of Brachymyrmex oculatus.

Identification

Ortiz-Sepulveda et al. (2019) - Brachymyrmex oculatus morphologically resembles B. bruchi and B. patagonicus, because all three species have scapes that surpass the posterior margin of the head, they usually have two erect hairs on the mesonotum, their mesonotum does not bulge dorsally above the pronotum in lateral view, a metanotal groove is absent or narrower than the diameter of the metathoracic spiracles, their gaster has scarce pubescence, and several scattered long erect hairs and their body is brownish. Brachymyrmex oculatus differs from B. bruchi and B. patagonicus, however, by having larger eyes, with a maximal diameter that approximates a third of the length of the head (HL1). They usually have more than 14 ommatidia along their maximal diameter. Whereas B. patagonicus has two erect hairs on the pronotum and B. bruchi usually more than two, the number of erect hairs on the pronotum is variable in B. oculatus.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -31.632389° to -38.15°.

   
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.
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Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.
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Biology

Castes

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • oculatus. Brachymyrmex oculatus Santschi, 1919f: 55 (w.) ARGENTINA (Buenos Aires).
    • Type-material: lectotype worker (by designation of Ortiz-Sepúlveda, et al. 2019: 520), 5 paralectotype workers.
    • Type-locality: lectotype Argentina: Buenos Aires, Sierra de la Ventana (C. Bruch); paralectotypes with same data.
    • Type-depository: NHMB.
    • Quirán, et al. 2004: 283 (m.).
    • Status as species: Santschi, 1923b: 660; Emery, 1925b: 43; Kempf, 1972a: 40; Bolton, 1995b: 82; Quirán, et al. 2004: 282 (redescription); Ortiz-Sepúlveda, et al. 2019: 520 (redescription).
    • Distribution: Argentina.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Ortiz-Sepulveda et al. (2019) - Lectotype and paralectotypes (n = 4). HL1 0.45–0.50; HL2 0.35–0.41; HL3 0.11–0.14; HW 0.48–0.58; SL 0.45–0.50; EL 0.15–0.18; WL 0.53–0.61; PnL 0.15–0.17; PnW 0.30–0.39; ML 0.14–0.20; MW 0.23–0.27; Indices CI 106.67–115.15; SI1 86.84–93.75; SI2 122.22– 133.33; OI1 31.25–34.29; OI2 21.88–27.27.

Head. Slightly longer than wide in full face view; posterior cephalic border flat. Dorsum of the head with sparse appressed 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 surpass the posterior cephalic margin by a length that is shorter than the maximal diameter of the eye; they have appressed hairs. Ocelli absent. Eyes are positioned on the cephalic midline and usually have more than 14 ommatidia along their maximal diameter.

Mesosoma. Dorsum of the mesosoma with sparse appressed hairs, and typically with two erect hairs on the pronotum and two on the mesonotum; sometimes with additional suberect hairs, mainly on pronotum. The mesonotum is not inflated and does not bulge dorsally above the pronotum in lateral view. Metanotal groove absent or narrower than the diameter of the metathoracic spiracles. Metathoracic spiracles in dorsolateral position, not protruding, and touching the 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 scattered appressed hairs. Petiole short and inclined forward.

Gaster. With scattered pubescence and several scattered long erect hairs, mainly at the edges of the segments.

Color and sculpture. Body overall smooth and shiny, with the dorsum of the mesosoma slightly imbricate. Body uniformely brownish.

Type Material

Ortiz-Sepulveda et al. (2019) - Lectotype worker (Naturhistorisches Museum, Basel: USNMENT00758101) and paralectotype workers (NHMB: USNMENT00758101; here designated): six workers [examined]. ARGENTINA: Buenos Aires: Sierra de las Ventanas, Bruch leg.

The specimen at the top of pin NHMB: USNMENT00757132 is here designated as lectotype, whereas the other ants in that pin are paralectotypes.

References

References based on Global Ant Biodiversity Informatics

  • Cuezzo, F. 1998. Formicidae. Chapter 42 in Morrone J.J., and S. Coscaron (dirs) Biodiversidad de artropodos argentinos: una perspectiva biotaxonomica Ediciones Sur, La Plata. Pages 452-462.
  • Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
  • 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
  • Quiran E. M., J. J. Martínez, and A. O. Bachmann. 2004. The Neotropical genus Brachymyrmex Mayr, 1868 (Hymenoptera: Formicidae) in Argentina. Redescription of the type species, B. patagonicus Mayr,1868; B. bruchi Forel, 1912 and B. oculatus Santschi, 1919. Acta Zool. Mex. Nueva Série 20: 273-285.
  • Santschi F. 1925. Fourmis des provinces argentines de Santa Fe, Catamarca, Santa Cruz, Córdoba et Los Andes. Comunicaciones del Museo Nacional de Historia Natural "Bernardino Rivadavia" 2: 149-168.
  • Vittar, F. 2008. Hormigas (Hymenoptera: Formicidae) de la Mesopotamia Argentina. INSUGEO Miscelania 17(2):447-466
  • Vittar, F., and F. Cuezzo. "Hormigas (Hymenoptera: Formicidae) de la provincia de Santa Fe, Argentina." Revista de la Sociedad Entomológica Argentina (versión On-line ISSN 1851-7471) 67, no. 1-2 (2008).