Pheidole chalca

Mann (in Wheeler 1914c) found numerous small colonies in oak-pine woodland near Molino Guerrero, an ore mill on the eastern slope of the mountain range east of Pachuca; they were nesting under stones. I found a nest of several chambers about 15 cm below the surface in the dense clay soil of Liquidambar woods adjacent to a meadow at approximately 1700 m on the south slope of Pico Orizaba. Workers were foraging along an adjacent trail. Sexual pupae were in the nest on 23 August. (Wilson 2003)

Identification
From Wilson (2003): A small-medium species, with angulate postpetiole and bicolorous head in the major. Similar to Pheidole chalcoides, but distinguished in the major by the smooth humerus, which is less prominent in dorsal-oblique view; broader, angular-sided postpetiolar node; and yellow occiput; and in the minor by the unarmed humerus and smooth pronotal dorsum.

Also similar but less so to Pheidole arhuaca, Pheidole caulicola, Pheidole mincana, Pheidole sagana, Pheidole schmalzi and Pheidole tragica, differing in details of body shape, and sculpture as illustrated, and color.

COLOR Major: anterior third of head and occiput yellow, remainder of head brown; body yellowish to light brown; appendages light yellow. Minor: brownish yellow.

Distribution
Hidalgo and Veracruz, Mexico. (Wilson 2003)

This taxon was described from Mexico.

Description
A small-medium species, with angulate postpetiole and bicolorous head in the major. Similar to Pheidole chalcoides, but distinguished in the major by the smooth humerus, which is less prominent in dorsal-oblique view; broader, angular-sided postpetiolar node; and yellow occiput; and in the minor by the unarmed humerus and smooth pronotal dorsum.

Also similar but less so to Pheidole arhuaca, Pheidole caulicola, Pheidole mincana, Pheidole sagana, Pheidole schmalzi and Pheidole tragica, differing in details of body shape, and sculpture as illustrated, and color.

MEASUREMENTS (mm) Lectotype major: HW 1.04, HL 1.24, SL 0.54, EL 0.14, PW 0.52. Paralectotype minor: HW 0.52, HL 0.60, SL 0.50, EL 0.12, PW 0.38.

COLOR Major: anterior third of head and occiput yellow, remainder of head brown; body yellowish to light brown; appendages light yellow. Minor: brownish yellow.



'''Figure. Upper: lectotype, major. Lower: paralectotype, minor. Scale bars = 1 mm.'''

Type Locality Information
MEXICO: Molino Guerrero (Guerrero Mill), Hidalgo, 2600–2700 m (W. M. Mann). (Wilson 2003)

Etymology
Presumably from Gr chalkos, copper, alluding to the body color. (Wilson 2003)