Pheidole titanis Wheeler

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 602

Pheidole titanis Wheeler

Pheidole titanis Wheeler 1903c: 95.

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

Etymology Gr titanis , of a mythical race of giants.

diagnosis A large member of the pilifera group further characterized by the following traits.

Major: rugoreticular patch just mesad of each frontal carina and posterior to the antennal fossa; the rest of the dorsal surface of the head except for the occiput, central piece of the clypeus, and frontal triangle longitudinally carinulate; median carina present on the clypeus; carinulae cover anterior third and sides of the pronotal dorsum, part of the propodeal dorsum, sides of the petiole, and dorsum of the postpetiolar node; postpetiolar node from above diamond-shaped.

Minor: head subrectangular in full-face view; humerus lobose in dorsal-oblique view; postpetiole bell-shaped from above. measurements (mm) Lectotype major: HW 1.94, HL 2.02, SL 0.98, EL 0.30, PW 1.10. Paralectotype minor: HW 0.92, HL 0.94, SL 0.86, EL 0.24, PW 0.60. Color Major and minor: concolorous light reddish brown.

Range Western Texas, southern Arizona and Jalisco, Mexico.

biology The species occurs in desert scrub and deciduous thorn forest, nesting under stones. As suggested by Creighton and Gregg (1955) and proved by Feener (1988), titanis is primarily a specialized predator on termites. In Jalisco, Feener found the species most often attacking foraging columns of Nasutitermes, only occasionally scavenging for dead arthropods of other kinds. Scouts recruit nestmates until a raiding force of 200-2000 majors and minors are assembled, encircling the termites, whereupon each ant tries to seize individual prey, then returns to the nest along the chemical recruitment trail. Feener has provided a detailed account of both the raiding behavior of titanis and their defensive maneuvers against enemies, especially parasitic phorid flies.

figure Upper: lectotype, major. Lower: paralectotype, minor. TEXAS: Chisos Mts., Brewster Co., southwestern Texas (O. W. Williams). Scale bars = 1 mm.