Brachymyrmex pilipes

The specimen from São Paulo at Ubatuba, Parque Estadual da Serra do Mar, Núcleo Santa Virgínia [USNM ENT 00757823] was collected in an area of relatively well-preserved mature forest with some remnants of primary forest where selective logging took place until 1970 (Magrini et al. 2011). Habitat information is lacking for the other specimens. (Ortiz & Fernández, 2014)

Identification
This species can be differentiated from most of the Brachymyrmex by the following: presence of tumuliform metathoracic spiracles (see key for image of this character); worker caste dimorphic; toruli touching the posterior clypeal margin, but never surpassing it (best observed in anterodorsal oblique view); and long thick hairs in a row near anterior clypeal margin. These traits are shared with Brachymyrmex micromegas, but B. pilipes differs by the fine, longitudinal striations on most of the mesosoma, and the gaster color often is darker than the body color. (Ortiz & Fernández, 2014).

Key to Brachymyrmex with tumuliform metathoracic spiracles

Distribution
Brazil: states of Paraná, Santa Catharina, São Paulo and Rio de Janeiro.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Castes
This species has major and minor workers, which is unusual for the genus.

Nomenclature

 *  pilipes. Brachymyrmex pilipes Mayr, 1887: 524 (q.m.) BRAZIL. Santschi, 1929d: 310 (w.). Combination in Brachymyrmex (Bryscha): Santschi, 1923b: 674.

Worker
Ortiz & Fernández (2014) - Minor Measurements (mm) (n=8) HL1 0.62 – 1.21; HL2 0.50 – 0.74; HL3 0.33 – 0.39; HW 0.60 – 1.07; SL 0.57 – 1.17; EL 0.12 – 0.22; WL 0.97 – 1.42; PnL 0.40 – 0.55; PnW 0.64 – 0.76; ML 0.20 – 0.33; MW 0.33 – 0.37; Indices CI 88 – 97; SI195 – 109; SI2114 – 158; OI 18 – 20.

Head slightly longer than wide, almost squared, slightly narrowing anteriorly. Posterior cephalic border slightly concave. Clypeus large, with rounded anterior margin. Toruli touching the posterior clypeal margin, but never surpassing it (best observed in anterodorsal oblique view). Scapes long, surpassing the posterior margin of the head. Ocelli present. Eyes well developed, located at the midline of the head, with 10–11 ommatidia at their maximum diameter. Mesonotum conspicuously convex. Metanotal groove deep and wide. Metathoracic spiracles fully dorsal, tumuliform, bulging out of the metanotal groove in lateral view. Propodeum strongly convex, unarmed. Propodeal spiracle near to posteriopropodeal margin. Petiole scale rounded and not inclined forward.

Head and gaster smooth and shiny. Mesosoma with very fine, dense longitudinal and oblique striations. Most of mandibular surface with longitudinal rugulae (best observed in anterodorsal oblique view). Entire body, including antennae, legs, and palps with conspicuous erect and suberect pilosity that are larger on dorsum. Long thick hairs in a row near to the anterior clypeal margin. Most of clypeal surface with many erect hairs, which are shorter than the thick hairs. Body light brown, gaster dark brown, hairs lighter.

Major Measurements (mm) (n=2) HL1 1.44 – 1.46; HL2 0.92 – 0.94; HL3 0.37 – 0.39; HW 1.35; SL 1.17; EL 0.20 – 0.21; WL 1.60 – 1.83; PnL 0.59; PnW 0.88; ML 0.39; MW 0.49. Indices CI 92; SI1 104.34; SI2 58 – 68; OI 17.39.

Head bigger than that of the minor worker, squared with posterior corners angulate and posterior cephalic border slightly concave. Clypeus large, with rounded anterior margin. Toruli touching the posterior clypeal margin, never surpassing it. Scapes long, surpassing the posterior margin of the head. Ocelli present. Eyes well developed, located at mid line of head, with 11 ommatidia at their maximum diameter.

Mesonotum conspicuously convex. Metanotal groove present. Metathoracic spiracles fully dorsal, tumuliform, bulging out of the metanotal groove in lateral view. Propodeum strongly convex, unarmed. Propodeal spiracle near posteriopropodeal margin. Petiolar scale rounded and inclined forward.

Head and gaster smooth and shiny. Mesosoma with very fine, dense longitudinal and oblique striations. Entire body, including antennae, legs, and palps with conspicuous erect and suberect pilosity that is longer on the dorsum. Long hairs in a row near anterior clypeal margin. Most of clypeal surface with abundant erect hairs, which are shorter than the thick hairs. Body light brown, gaster dark brown, hairs lighter colored.

Queen
Ortiz & Fernández (2014) - Lectotype measurement (mm) (n=1) HL1 1.61; HL2 0.42; HW 1.88; SL 1.54; EL 0.47; WL 4.04; PnL 2.21; PnW 2.19; ML 0.97; MW 1.59. Indices CI 116.17; SI1 82.27; OI 25.31.

Same as worker except for standard queen modifications and the following: abundant erect hairs and dense pubescence on entire body. There is a row of thick hairs near the anterior margin of clypeus, similar to the workers and abundant pubescence on the body. Body dark brown.

Male
Ortiz & Fernández (2014) - Paralectotype measurements (mm) (n=1) HL 0.31; EL 0.16; WL 0.88.

Scapes surpassing the posterior margin of the head, few erect hairs, and sparse pubescence on the body; some sparse long hairs on the tibiae. Head brown, mesosoma and gaster yellow. Penis valves longer than parameres in situ.