Pheidole bergi

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. (Wilson 2003)

Identification
See the description in the nomenclature section.

Distribution
Uruguay, and widespread through Argentina, from Jujuy and Santa Fé in the north to Rio Negro in the south. (Wilson 2003)

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

Worker
Minor

Nomenclature

 *  bergi. Pheidole bergi Mayr, 1887: 593 (s.), 605 (w.) ARGENTINA. Senior synonym of goetschi, pulliventris, subparallela: Wilson, 2003: 269.
 * subparallela. Pheidole bergi subsp. subparallela Emery, 1906c: 145 (s.w.) URUGUAY. Junior synonym of bergi: Wilson, 2003: 269.
 * pulliventris. Pheidole bergi st. pulliventris Santschi, 1929d: 288 (s.) BRAZIL. Junior synonym of bergi: Wilson, 2003: 269.
 * goetschi. Pheidole goetschi Santschi, 1939e: 314, figs. 1, 2 (s.w.) ARGENTINA. Subspecies of bergi: Kusnezov, 1952b: 67 (in key). Junior synonym of bergi: Wilson, 2003: 269.

Description
From Wilson (2003): 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 Pheidole aenescens, Pheidole alienata, Pheidole chrysops, Pheidole cordiceps, Pheidole dentata, Pheidole dione, Pheidole eidmanni, Pheidole midas and Pheidole 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.



'''Figure. Upper: major (compared with syntype major, and the left profile of the head belongs to the syntype). Lower: minor. ARGENTINA: Cafayate, Salta. Scale bars = 1 mm.'''

Type Material
Buenos Aires, Argentina. and  - as reported in Wilson (2003)

Etymology
Eponymous. (Wilson 2003)