Pheidole sciophila Wheeler

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 347

Pheidole sciophila Wheeler

Pheidole sciophila Wheeler 1908h: 443. Syn.: Pheidole proserpina Wheeler 1908h: 437, synonymy by Creighton and Gregg 1955: 19. Pheidole sciophila var. semilaevicephala M. R. Smith 1934b: 385, synonymy by Creighton and Gregg 1955: 19.

types Mus. Comp. Zool. Harvard; Amer. Mus. Nat. Hist.

Etymology Gr sciophila , shade-lover, allusion unknown.

Diagnosis An unusual species placed in the fallax group but with other traits in body form, including head form and antenna length that are intermediate to the pilifera group.

Major: head lacking rugoreticulum; bicolorous, reddish brown posteriorly and brownish yellow anteriorly; head in side view elliptical in outline, tapering conspicuously toward the occiput; antennal scape short, its tip in repose reaching halfway between the eye and occipital corner, seen in full face; pronotum weakly bilobous in dorsal-oblique view; mesonotal convexity strongly developed; all of mesosoma and waist foveolate and opaque.

Minor: gaster, clypeus, and frontal triangle smooth and shiny, and all the rest of the body foveolate and opaque; pilosity along dorsal profde of mesosoma mostly comprising evenly spaced pairs of setae.

The species exhibits considerable variation in body form and sculpturing, especially in the major caste, as noted by Creighton and Gregg (1955). The number of hypostomal teeth of the major is 3 or 5.

measurements (mm) Lectotype major: HW 1.04, HL 1.14, SL 0.64, EL 0.12, PW 0.56.

Paralectotype minor: HW 0.48, HL 0.58, SL 0.66, EL 0.08, PW 0.34.

Color Major: body and posterior three-fourths of the head a rich reddish brown, with the gaster a shade darker, and the anterior fourth of the head brownish yellow.

Minor: body plain medium brown, appendages brownish yellow.

range Central Texas to deserts of southern Arizona and California and southward into Chihuahua, Mexico, at 100-1800 m.

Biology Stefan Cover, whose intensive collecting in the southwestern United States has brought him into frequent contact with sciophila , reports as follows (personal communication): "This ant is not commonly collected, in large part because its nests are inconspicuous. Entrances to soil nests are cryptic and they are often located at or near the bases of desert shrubs. They can be deep also: one nest excavated in SE Arizona (elev. 1300 m) in grazed desert penetrated 1.2 m into caliche nearly as hard as a Manhattan sidewalk. Colonies are monogynous and can consist of several hundred ants. P. sciophila appears to be omnivorous; no seeds have been found in many nests excavated in southern Arizona."

Figure Upper: lectotype, major. Some specimens have a weakly developed inner pair of hypostomal teeth in addition to the more conspicuous outer pair shown here. Lower: paralectotype, minor. TEXAS: Austin (William M. Wheeler). Scale bars = 1 mm.