Pheidole bergi Mayr

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 269

Pheidole bergi Mayr

Pheidole bergi Mayr 1887: 593, 605. Syn.: Pheidole bergi subsp. subparallela Emery 1906c: 145, n. syn.; Pheidole bergi st. pulliventris Santschi 1929d: 288, n. syn.; Pheidole goetschi Santschi 1939e: 314, placed as bergi goetschi by Kusnezov 1952d: 67, n. syn. Raised to species level in this monograph: alienata .

types Naturhist. Mus. Wien; Mus. Comp. Zool. Harvard.

Etymology Eponymous.

diagnosis A medium-sized reddish brown (major) or brownish yellow (minor) member of the fallax group distinguished as follows.

Major: head subquadrate; propodeal spine moderately long and suberect; postpetiolar node from above roughly trapezoidal; mesonotal convexity prominent and symmetrical in shape in both side and dorsal-oblique views; rugoreticulum extends as a broad band from the eye to the circular carinulae of the antennal fossa; frontal lobes completely covered by longitudinal carinulae; carinulae mesad to the eye reach halfway between the eye and the occipital border.

Minor: occiput narrow, with nuchal collar; humerus smoothly rounded in dorsal-oblique view. Similar to aenescens , alienata , chrysops , cordiceps , dentata , dione , eidmanni , midas , and nitidula , differing in many details as described and illustrated. measurements (mm) Syntype major: HW 1.94 (Cafayate, Argentina, major has HW 1.54), HL 2.08, SL 1.12, EL 0.32, PW 0.96. Minor (Cafayate): HW 0.56, HL 0.80, SL 1.10, EL 0.16, PW 0.38.

Color Major: body mostly light reddish brown; terminal gastral segments medium reddish brown. Minor: concolorous brownish yellow.

range Uruguay, and widespread through Argentina, from Jujuy and Santa Fe in the north to Rio Negro in the south.

biology Bruch (1916) describes bergi as an abundant, widespread species in Argentina. It builds conspicuous soil nests, each with a single entrance hole 2-3 cm in diameter, often surrounded by a crater or partially by a semicircle of excavated soil as much as 25 cm in diameter. A single gallery descends to a succession of 5 to 10 roughly ellipsoidal chambers, each spaced about equally apart, and reaching a depth of 40-60 cm. The colonies are aggressive, with a high proportion of majors, and exclusively insectivorous. They readily attack other colonies of their own and other ant species.

figure Upper: major (compared with syntype major, and the left profde of the head belongs to the syntype). Lower: minor. ARGENTINA: Cafayate, Salta. (Type locality: Buenos Aires, Argentina.) Scale bars = 1 mm.