Pheidole chalca Wheeler ^HNS

Pheidole chalca Wheeler ^HNS 1914c: 44.

Types Mus. Comp. Zool. Harvard.

Etymology Presumably from Gr chalkos, copper, alluding to the body color.

Diagnosis A small-medium species, with angulate postpetiole and bicolorous head in the major. Similar to chalcoides ^HNS, 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 arhuaca ^HNS, caulicola ^HNS, mincana ^HNS, sagana ^HNS, schmalzi ^HNS, and tragica ^HNS, 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.

Range Hidalgo and Veracruz, Mexico.

biology 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.

Figure Upper: lectotype, major. Lower: paralectotype, minor. MEXICO: Molino Guerrero (Guerrero Mill), Hidalgo, 2600-2700 m (W. M. Mann). Scale bars = 1 mm.