Pheidole ambigua, Wilson, E. O., 2003

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 652

Pheidole ambigua new species

Types Mus. Comp. Zool. Harvard.

etymology L ambigua , uncertain, doubtful.

diagnosis A medium-sized member of the tristis group, similar to amata , celaena , fera , germaini , peruviana , rutilana , schwarzmaieri , vomer , and possibly the same as bruchi of Argentina, on the basis of resemblance of the minor (major syntypes of bruchi could not be located in the Forel collection at the time of study). The paratype minor of ambigua differs from a syntype minor of bruchi in its more abundant pilosity, lighter color, and foveolate promesonotal dorsum. Otherwise, ambigua is distinguished within the tristis group by the following combination of traits.

Major: anterior two-thirds of dorsum of head carinulate, remainder smooth and shiny; carinulae on rest of body limited to anterior strip of pronotal dorsum; humerus in dorsal-oblique view moderately prominent and lobose; postpetiole from above diamond-shaped. Minor: pilosity sparse; propodeal spines reduced to denticles; promesonotal profile in dorsal-oblique view smoothly convex; occiput narrowed, with a nuchal collar.

Measurements (mm) Holotype major: HW 1.54, HL 1.74, SL 0.78, EL 0.18, PW 0.72.

Paratype minor: HW 0.56, HL 0.62, SL 0.74, EL 0.40, PW 0.36.

color Major: light reddish yellow.

Minor: body light yellowish brown, appendages yellow.

range Known only from the type locality.

Biology Unknown.

figure Upper: holotype, major. Lower: paratype, minor. BRAZIL: Caraguatatuba Reserva Florestal, Sao Paulo (William L. and Doris E. Brown). Scale bars = 1 mm.