Pheidole tristis (F. Smith)

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press : 769

Pheidole tristis (F. Smith)

Myrmica tristis F. Smith 1858a: 132, combination to Pheidole by Mayr 1886c: 360. Syn.: Atta rubra F. Smith 1858a: 168, combination to Pheidole by Mayr 1886c: 360 and synonymy by Kempf 1965: 183; Pheidole emeryi Mayr 1887: 589, synonymy by Kempf 1965: 183; Pheidole crassipes Mayr 1887: 590, 600, n. syn.; Pheidole emeryi var. alsia Santschi 1923d: 58, n. syn.

Types Nat. Hist. Mus. London.

Etymology L tristis , sad, allusion unknown.

Diagnosis A medium-sized reddish-yellow (major) or yellowish brown (minor) member of the tristis group whose major has very prominent subangulate pronotal humerus, swollen hind femora, diamond-shaped postpetiolar node with subangulate margins, small rounded subpostpetiolar process, and foveolate and opaque gastral tergite.

Minor: large ovoid postpetiolar node, prominent convex subpostpetiolar process, and foveolate and opaque gastral tergites. Similar to balzani , fabricator , and nigella , and less so to brunnescens , exarata , excubitor , germaini , grandinodus , hispaniolae , grantae , obrima , prattorum , rogeri , sabina , sarpedon , stulta , tristops , unicornis , and zoster , differing in many details of body form, sculpturing, and pilosity, as illustrated, and in color.

measurements (mm) Major (Boraceia Biological Station, Sao Paulo state): HW 1.66, HL 1.76, SL 0.82, EL 0.20, PW 0.84. Holotype minor: HW 0.80, HL 0.84, SL 0.84, EL 0.12, PW 0.52.

Color Major: body and appendages clear light reddish yellow ("orange"), with gaster a shade darker. Minor: concolorous medium yellow brown, in both the Boraceia Biological Station series and holotype minor.

Range Kempf (1972b): southeastern Brazil (Santa Catarina, Sao Paulo, Rio de Janeiro, Parana) and north central Argentina (Misiones).

Biology Unknown.

Figure Upper: major (Boraceia Biological Station, Mun. Salesopolis, Sao Paulo state, Brazil, William L. Brown), associated with minors compared by E. O. Wilson with holotype minor from Tijuca, Rio de Janeiro, Brazil. At the bottom the right hind femur is depicted. Lower: holotype, minor (from Tijuca, Brazil). Scale bars = 1 mm.