Pheidole strobeli

Identification
Casadei-Ferreira et al. (2020): Pheidole strobeli resembles Pheidole nitidula and Pheidole dione. Majors of P. strobeli have the lateral margin of head with appressed hairs except in the vertexal margin with standing hairs, while P. dione has standing hairs that extend laterally, and P. nitidula has appressed hairs only. Minors of P. strobeli have the vertexal margin of the head strongly rounded, and mesosoma with stiff standing hairs; P. nitidula has the margin slightly rounded; and P. dione has the mesosoma with flexuous standing hairs (Casadei-Ferreira et al., 2020).

Distribution
Casadei-Ferreira et al. (2020): Casadei-Ferreira et al. (2020): Pheidole strobeli and P. nitidula occur sympatrically in the state of Paraná (see Franco & Feitosa (2018) for the records), presenting a diagnosis consistent with the described above. Regarding P. dione, only known from Corrientes and Jujuy in Argentina, it is not possible to confirm its sympatry with P. strobeli in a local scale in Argentina, considering that P. strobeli occurs in La Plata and Alta Gracia (Bruch, 1931) as well as Missiones and Buenos Aires (junior synonym distribution).

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

Nomenclature

 * . Pheidole strobeli Emery, 1906c: 149 (s.w.) ARGENTINA.
 * Goni, Zolessi & Imai, 1983: 365 (k.).
 * Subspecies of cordiceps: Santschi, 1912e: 528; Bruch, 1915: 531.
 * Subspecies of nitidula: Santschi, 1929d: 282; Kempf, 1972a: 197.
 * Junior synonym of nitidula: Wilson, 2003: 328.
 * Senior synonym of daguerrei: Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * Senior synonym of divexa: Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * Senior synonym of misera: Santschi, 1929d: 282; Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * Senior synonym of perversa: Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * Senior synonym of richteri: Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * Status as species: Emery, 1922e: 101; Borgmeier, 1927b: 61; Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * daguerrei. Pheidole nitidula var. daguerrei Santschi, 1931e: 275 (s.w.) ARGENTINA.
 * Junior synonym of nitidula: Wilson, 2003: 328.
 * Junior synonym of strobeli: Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * perversa. Pheidole perversa Forel, 1908c: 373 (s.w.) BRAZIL.
 * Subspecies of strobeli: Emery, 1922e: 101.
 * Subspecies of nitidula: Kempf, 1972a: 197.
 * Junior synonym of nitidula: Wilson, 2003: 328.
 * Junior synonym of strobeli: Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * divexa. Pheidole rufipilis var. divexa Forel, 1908c: 372 (s.w.m.) BRAZIL.
 * Junior synonym of rufipilis: Wilson, 2003: 226.
 * Junior synonym of strobeli: Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * misera. Pheidole strobeli var. misera Santschi, 1916e: 373 (s.w.q.) ARGENTINA.
 * Junior synonym of strobeli: Santschi, 1929d: 282.
 * Junior synonym of strobeli: Casadei-Ferreira, Economo & Feitosa, 2020: 15.
 * richteri. Pheidole perversa subsp. richteri Forel, 1909a: 266 (s.w.q.) ARGENTINA.
 * Forel, 1914d: 273 (m.).
 * Subspecies of strobeli: Santschi, 1916e: 373.
 * Subspecies of nitidula: Santschi, 1929d: 281.
 * Junior synonym of nitidula: Wilson, 2003: 328.
 * Junior synonym of strobeli: Casadei-Ferreira, Economo & Feitosa, 2020: 15.

Taxonomic Notes
Casadei-Ferreira et al. (2020): Based on the head shape and sculpture pattern, this species was considered a subspecies of P. nitidula by Santschi (1929). Later, Wilson (2003) synonymized all the subspecies described for P. nitidula under this name. Pheidole strobeli can be recognized by the distinctly different head pilosity. We revive P. strobeli to species with three of the former subspecies of P. nitidula as its junior synonyms (Pheidole nitidula daguerrei, Pheidole perversa and Pheidole perversa richteri). Forel (1908) described Pheidole rufipilis divexa, a name subsequently synonymized under Pheidole rufipilis by Wilson (2003). The head sculpture in P. rufipilis (reticulate-rugose extending from the frontal lobe) is notably different from that of P. rufipilis divexa (only a few rugulae extending from the frontal lobe). We consider P. rufipilis divexa a junior synonym of P. strobeli by the lack of any important morphological differences.