Pheidole susannae

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 351

Pheidole susannae Forel

Pheidole susannae Forel 1886b: xliii. Syn.: Pheidole susannae r. atricolor Forel 190lj: 356, n. syn. Raised to species level in this monograph: obscurior .

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

Etymology Eponymous, no attribution given.

diagnosis A member of the fallax group, most similar to haskinsorum , lattkei , obscurior , petrensis , and distinguished as follows. Major: in both side and frontal views, head tapered conspicuously toward occiput; occipital cleft deep, antennal scape failing to reach the occipital corner by about 2X the maximum scape width; pilosity fringing side and frontal profiles posterior to eye level subrecumbent; rugoreticulum extensive all around the eye; anterior half of first gastral tergite shagreened and opaque; humerus in dorsal-oblique view low and smoothly rounded.

Minor: pronotum entirely smooth; occiput moderately narrowed, with nuchal crest; propodeal spines reduced to denticles.

A highly variable species that may in time prove to be a complex of sibling species.

measurements (mm) Lectotype major: HW 1.30, HL 1.44, SL 1.06, EL 0.20, PW 0.60.

Paralectotype minor: HW 0.54, HL 0.82, SL 1.12, EL 0.14, PW 0.40.

Color Major: body reddish yellow, gaster a slightly contrasting light reddish brown.

Minor: concolorous medium yellow. Other series vary from reddish yellow to dark brown.

range Ranging from Veracruz, Mexico, south to Colombia, Venezuela, and Trinidad. I have also verified a record from Cayo Congo, Puerto Rico (J. A. Torres). Kempf (1972b) cites the species from Rio Grande do Sul, a doubtful record I have not been able to check.

Biology This widespread species is also very adaptable in habitat and nest site. In Colombia colonies have been found variously in forests and pastures. In Costa Rica, Longino (1997) reports susannae nesting under the bark and into an abandoned termite nest at the base of a large tree and in cracks in the floor of a housing unit near the La Selva Biological Station forest. I found it nesting behind a concrete curb inside a San Jose, Costa Rica, city park, foraging during the day. On Barro Colorado Island, Panama, I observed a nuptial flight in progress in tropical evergreen forest at 1600 hrs; males were emerging in the company of minors and majors from a crevice in the trunk of a tree 1-2 m from the ground.

figure Upper: lectotype, major. Lower: paralectotype, minor. GUATEMALA: Retalhuleu, Pacific slope. Scale bars = 1 mm.