Pheidole risii

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 740

Pheidole risii Forel

Pheidole risii Forel 1892a: 38. Raised to species level in this monograph: rugatula , trachyderma .

Types Mus. Hist. Nat. Geneve; Mus. Comp. Zool. Harvard.

Etymology Named after the collector, Fr. Ris.

diagnosis Similar in various traits to aper , bambusarum , brevicona , dyctiota , laeviventris , lutzi , rugatula , senilis , sigillata , trachyderma , and traini , differing as follows.

Major: shallow antennal scrobes; pilosity along dorsal profile of head dense, with uniform short hairs about as long as Eye Length along the posterior half and much longer hairs along the anterior half; occipital cleft deep; occipital lobes smooth and subangulate; pronotum sparsely carinulate, mostly smooth; propodeal spine very stout, equilaterally triangular; postpetiolar node very broad, 2X broader than petiolar node, and spinose.

Minor: occiput, humeri, and propodeal dorsum rugoreticulate; almost all of head and mesosoma foveolate; occiput broad, concave, and lacking nuchal collar.

Measurements (mm) Syntype major: HW 0.96, HL 1.02, SL 0.44, EL 0.12, PW 0.54. Syntype minor: HW 0.66, HL 0.66, SL 0.62, EL 0.12, PW 0.44. color Major: body reddish yellow except for gaster, which is yellowish brown. Minor: concolorous dark yellow.

Range In addition to the type locality, risii has been recorded from Sao Paulo, Brazil (Kempf 1972b).

Biology Unknown.

Figure Upper: syntype, major. Lower: syntype, minor. ARGENTINA: Buenos Aires (Fr. Ris). Scale bars = 1 mm.