Pheidole clydei Gregg

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 539-540

Pheidole clydei Gregg

Pheidole (Ceratopheidole) clydei Gregg 1950: 89.

Types Mus. Comp. Zool. Harvard; holotype minor may be at the Field Museum, Chicago.

Etymology Eponymous.

Diagnosis A member of the granulata group (4-segmented club), close to grundmanni and distinguished as follows. Major (no comparison available with grundmanni ): hypostoma with only 2 teeth; all of dorsal surface of head longitudinally carinulate; dorsal promesonotal profile in side view smoothly semicircular; petiolar node in side view tapering to a blunt point; postpetiolar node from above conulate.

Minor: propodeal spine needle-like, as long as half the length of the basal propodeal face anterior to it; petiolar node depressed, and petiole as a whole cylindrical; occiput narrow in full-face view, and shallowly concave; the cephalic foveolation is variable, and can occasionally cover the entire upper surface of the head, in which case the carinulae of the head may extend posteriorly between the eye and the antennal insertions; sides of pronotum foveolate and opaque. In habitus and number of hypostomal teeth, this species is evidently a derivative of the pilifera group.

Measurements (mm) Major: HW 1.20, HL 1.32, SL 0.72, EL 0.20, PW 0.62. Syntype minor: HW 0.50, HL 0.66, SL 0.78, EL 0.14, PW 0.34.

Color Major: head and mesosoma concolorous reddish yellow; waist, gaster, and appendages contrasting light reddish brown. Minor: body and legs concolorous light brown, mandibles and antennae brownish yellow.

range Recorded from New Mexico, Arizona, Nevada, and southern California.

Biology This species utilizes an unusual nest site: rock crevices. Gregg (1953b) found a colony nesting in crevices between a boulder and thin laminae split from its surface, with no contact with the soil. Creighton (1965a) found nests on top of large boulders 4.5 meters high and 6-9 meters across, while G. E. Wheeler and J. N. Wheeler (1973e) encountered them in very narrow horizontal cracks in the almost solid rock walls of California's Deep Canyon. At the last locality, according to Wheeler and Wheeler, "The minors did the foraging, bringing home arthropods or fragments thereof, never seeds. The majors did not leave the nests except to assist minors by carving large pieces of foraged food into smaller bits. But their chief duty appeared to be guard duty: a group of them stood just inside the entrance, where they savagely attacked any object thrust into the nest entrance. The minors, by contrast, were not aggressive, which suggests they are scavengers, not predators." Recent discoveries made by Stefan Cover in Arizona indicate that clydei is a member of a small guild of rock-crevice-inhabiting Pheidole that includes P. portalensis n. sp. Several other members of this guild recently found remain undescribed at present. Like these species, P. clydei is only occasionally found in soil or under rocks some distance from rock-crevice habitats.

figure Upper: major. Lower: minor. CALIFORNIA: Split Mountain, Anza State Park, near Palm Springs, 150 m (W. S. Creighton). (Type locality: Carizozo, vicinity of the lava beds of the Tularosa Basin, New Mexico; C. P. Stroud). Scale bars = 1 mm.