Pheidole yaqui

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 607

Pheidole yaqui Creighton and Gregg

Pheidole yaqui Creighton and Gregg 1955: 43.

Types Nat. Mus. Nat. Hist. U. S.

Etymology Named after either the type locality or the Yaqui people of the Sonoran desert.

Diagnosis Close to and possibly a senior synonym of bajaensis , differing as follows.

Major: occiput smooth, not rugulose; postpetiole seen from above ovoid, not literally angulate; margins of pronotal dorsum transversely carinulate.

Minor: humerus in dorsal-oblique view subangulate; occiput narrow, its corners less angulate than in bajaensis . Together, yaqui and bajaensis differ from gilvescens and xerophila in the major's head shape, which is rounded (not flattened) in the dorsal profile of its posterior half, and in the failure of the head to taper toward the occiput; other traits exist in the major and minor as depicted.

Measurements (mm) Paratype major: HW 1.20, HL 1.30, SL 0.62, EL 0.20, PW 0.52. Paratype minor: HW 0.50, HL 0.54, SL 0.44, EL 0.16, PW 0.32. color Major: brownish yellow.

Minor: body and appendages medium yellow except for dorsal surface of head, which is a slightly contrasting shade of light yellowish brown.

Range Known from southern California (100-1050 m) and Baja California (northern half of the peninsula), sea level to 550 m.

Biology The unpublished records of Stefan Cover show that yaqui occurs in southern California from desert at lower elevation to creosote-acacia-juniper scrub in the uplands. The colonies of 50 to 100 workers nest in arid soil, sometimes with a crater of excavated earth and seed chaff. At Deep Canyon, near Palm Springs, California, Wheeler and Wheeler (1973e) found yaqui in desert and in palo verde and agave-ocotillo scrub, in crater soil nests; they uncovered caches of Euphorbia micromera and Oenothera clavaeformis seeds inside the nests.

figure Upper: paratype, major. Lower: paratype, minor. CALIFORNIA: Yaqui Well, Anza Desert State Park (W. S. Creighton). Scale bars = 1 mm.