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Pheidole littoralis Cole Pheidole sitarches littoralis Cole 1952b: 443. Raised to species level by Naves 1985: 64. Types Amer. Mus. Nat. Hist.; Nat. Mus. Nat. Hist. U.S.; Mus. Comp. Zool. Harvard. Etymology L littoralis, of the shore, referring to the habitat at the type locality. diagnosis A member of the " pilifera complex" of the larger pilifera group, comprising calens, californica, carrolli, cavigenis, clementensis, creightoni, hoplitica, littoralis, micula, pilifera, polymorpha, rugulosa, senex, soritis, tepicana, torosa, which complex is characterized by the following traits. Major: dorsal head surface extensively sculptured; occipital lobes horizontally rugulose (or, in carrolli smooth, in littoralis foveate, and in micula and soritis carinulate; postpetiole from above diamond-shaped, trapezoidal, or spinose. Minor: eye medium-sized to large. P. littoralis is easily distinguished within the complex by the following combination of traits. Major: occiput not rugulose, but covered with conspicuous foveae; anterior and lateral margins of pronotum rugoreticulate; mesonotum longitudinally carinulate; triangular subpostpetiolar process present; postpetiole from above diamond-shaped. Minor: most of head, mesosoma, and waist foveolate and opaque. Measurements (mm) Paratype major: HW 1.40, HL 1.52, SL 0.56, EL 0.20, PW 0.58. Paratype minor: HW 0.58, HL 0.50, SL 0.42, EL 0.12, PW 0.28. color Major: gaster plain medium to dark brown; remainder of body, and appendages, reddish brown. Minor: most of body light brown, with dark brown gaster and brownish yellow appendages. Range Apparently limited to central Florida. biology Naves (1985) and Stefan Cover (unpublished) found littoralis very common nesting in white-sand scrub at the Archbold Field Station near Lake Placid, Florida, and close to colonies of adrianoi and metallescens. The excavations are relatively very deep, beneath crescentic crater mounds, and the colonies small. A granary chamber filled with seeds is always found 10 to 20 cm beneath the surface. Figure Upper: paratype, major. Lower: paratype, minor. FLORIDA: Lido Beach, Sarasota. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 581

Pheidole humeralis Wheeler Pheidole humeralis Wheeler 1908h: 456. Types Mus. Comp. Zool. Harvard. Etymology L humeralis, of the shoulder, alluding to the elevated humerus of the major. Diagnosis Similar in some traits to furtiva, mera, and tysoni, differing as follows. Major: reddish yellow, with pale brown spot on vertex; head elongate, its posterior ventral profile flat; humeri strongly developed and subangulate, in dorsal view overhanging the rest of the pronotum beneath them and in dorsal-oblique view extending more than 4X higher above the metanotal groove than the mesonotal convexity; propodeal spines robust, as long as half the propodeal basal face preceding them; postpetiole from above oval. Minor: posterior half of head and all of pronotum smooth and shiny; in dorsal-oblique view, humerus subangulate and promesonotal profile behind it flat before dropping to metanotal groove; occiput broad, its margin strongly concave. Measurements (mm) Holotype major: HW 1.02, HL 1.28, SL 0.52, EL 0.12, PW 0.60. Paratype minor: HW 0.50, HL 0.52, SL 0.46, EL 0.08, PW 0.32. Color Major: body and appendages medium reddish yellow except for pale brown spot on vertex and yellowish brown gaster. Minor: body medium brown, appendages yellowish brown. Range Known only from the type locality and western Texas (Moody and Francke 1982). biology P. humeralis is evidently a rare species. During their intensive collecting in western Texas, Moody and Francke (1982) found the species only once, four colonies in Kinney County at 220 meters nesting in open clayey soil. Figure Upper: lectotype, major. Lower: paralectotype, minor. TEXAS: Corsicana, Navarro Co., near Dallas-Ft. Worth (Mary Cooper). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 438

Pheidole colimana new species TYPES Mus. Comp. Zool. Harvard. Etymology Named after the geographical origin of the type colony. Diagnosis Major: distinguished in the diligens group by small size, slender body form, and especially by a smooth and shiny pronotum and weak foveolation and feebly shiny to subopaque intercarinular spaces on the head. Minor: in particular head foveolate and propodeum dentate, as opposed to head smooth and shining and propodeum rounded in cataractae. Major and minor: propodeal spines reduced to denticles. Close to cataractae, with differences in the propodeal spine and cephalic sculpturing as illustrated. Measurements (mm) Holotype major: HW 0.92, HL 0.94, SL 0.72, EL 0.14, PW 0.44. Paratype minor: HW 0.44, HL 0.54, SL 0.70, EL 0.12, PW 0.30. Color Major: gaster light to medium brown; rest of body and appendages brownish yellow. Minor: concolorous dark yellow. range Known only from the type locality. Biology Unknown. Figure Holotype, major. (Minor not figured.) COLOMBIA: Mun. Buenaventura (Bajo Calima), Valle (William L. Brown and Richard B. Root). Scale bar = 1 mm. I-1, Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA, USA :Harvard University Press on page 175

Pheidole specularis new species Types Mus. Comp. Zool. Harvard. Etymology L specularis, of a mirror, alluding to the shiny gaster. diagnosis Similar to chalca, daphne, floridana, nebulosa, quercicola, and stomachosa, differing as follows. Major: mostly reddish yellow; head in full-face view subrectangular; posterior dorsal profile of head flat, not convex; premesonotal profile raised, semicircular; humeri from above subangular, extending beyond rest of pronotum below and only moderately prominent, along with mesonotal convexity in dorsal-oblique view; propodeal spines robust, more than half as long as the propodeal basal face anterior to them; all of mesosoma and most of dorsal surface of head foveolate and opaque; gaster completely smooth. Minor: head subrectangular in side view; occiput broad and slightly concave; propodeal spines robust and half as long as propodeal basal face; all of head, mesosoma, and gaster foveolate and opaque; gaster completely smooth and shiny. Measurements (mm) Holotype major: HW 0.82, HL 0.88, SL 0.40, EL 0.10, PW 0.44. Paratype minor: HW 0.44, HL 0.46, SL 0.36, EL 0.10, PW 0.30. Color Major: all of body and appendages medium reddish yellow except for gaster, which is brownish yellow. Minor: body and mandibles medium reddish yellow, rest of appendages clear medium yellow. Range Atlantic slope to 1200 m and Pacific lowlands, Costa Rica (j. T. Longino 1997). biology The species occurs in both lowland and montane rainforest, where the colonies nest both in dead wood on the forest floor and in live plant cavities and under epiphytes; workers have been observed attending extrafloral nectarines (Longino 1997). Figure Upper: holotype, major. Lower: paratype, minor. COSTA RICA: Arboretum, La Selva Biological Station, near Puerto Viejo, Heredia (Stefan Cover). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 510

Pheidole tenerescens Wheeler Pheidole tenerescens Wheeler 1922e: 7. Types Mus. Comp. Zool. Harvard. etymology Presumably from L tener, soft, alluding to the relatively feeble sculpture. Diagnosis As represented by the major, a small, yellow member of the flavens group with prominent, rounded humerus that rises well above the mesonotum in dorsal-oblique view; a nearly perfectly semicircular outline of promesonotum in side view; a deep, circular metanotal groove with vertical anterior propodeal face in dorsal-oblique view; short pilosity; and mostly smooth, shiny body. Similar to nitidicollis, but lacking a mesonotal convexity in side view, with shorter cephalic carinulae, smaller propodeal spiracle and spine, and yellow as opposed to medium brown gaster. See also the less similar arhuaca, flavifrons, minutula, and other species listed as close to arhuaca (q.v.). Measurements (mm) Holotype major: HW 0.74, HL 0.80, SL 0.34, EL 0.10, PW 0.40. Color Major: concolorous yellow. range Known only from the holotype major. biology Collected by sweeping vegetation (Roland Thaxter). FIGURE Unique holotype, major. TRINIDAD: Port of Spain (Roland Thaxter). Scale bar = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 520

Pheidole riveti Santschi Pheidole riveti Santschi 191 li: 278. Types Naturhist. Mus. Basel. Etymology Named after the collector, P. Rivet. Diagnosis Similar in various ways to the species listed in the heading above, distinguished as follows. Major: propodeal spine reduced to obtuse angle in side view, right angle in dorsal-oblique view; postpetiolar node in side view suppressed, in dorsal view narrow and bell-shaped; occipital margin smooth; carinulae originating on frontal lobes spread laterally as they approach occipital margin; propodeal dorsum and margins of promesonotal dorsum transversely carinulate. Minor: head "tiger-striped" with semicircular carinulae, as depicted; propodeal dorsum transversely carinulate; occiput narrow but lacks nuchal collar; postpetiolar node in side view suppressed and entire postpetiole cylindrical. Measurements (mm) Lectotype major: HW 1.12, HL 1.16, SL (scapes missing), EL 0.14, PW 0.54. Paralectotype minor: HW 0.62, HL 0.76, SL 0.76, EL 0.14, PW 0.40. Color Major: concolorous light brown. Minor: concolorous medium brown. Range Known only from the type locality. Biology Unknown. figure Upper: lectotype, major. Lower: paralectotype, minor. ECUADOR: El Angel, near Tulcan, north-central Ecuador, 3000 m (P. Rivet). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA, USA :Harvard University Press on page 224

Pheidole durionei Santschi, new status Pheidole wolfringi st. durionei Santschi 1923d: 51. Types Naturhist. Mus. Basel. Etymology Eponymous. Diagnosis A member of the " jujuyensis complex" of the larger fallax group, comprising araneoides, cuevasi, durionei, jujuyensis, kugleri, leonina, leptina, lucretii, lupus, paraensis, punctithorax, tijucana, wallacei, and wolfringi. P. durionei is distinguished as follows. Major: antennal scape exceeding occipital corner by 2X its own maximum width; carinulae on dorsal surface of head reaching almost all the way to the occiput, which is foveolate and opaque; rugoreticulum on head stretches on each side from eye to antennal fossa and anteriorly almost to the anterior border of the head; margins of pronotal dorsum foveolate; propodeal spines equilaterally triangular; postpetiole from above diamond-shaped, with angular lateral margins. Minor: propodeal spines reduced to barely discernible denticles; region mesad to and forward from eyes foveolate; occiput narrowed, with nuchal collar. Measurements (mm) Lectotype major: HW 1.20, HL 1.34, SL 1.22, EL 0.24, PW 0.60. Paralectotype minor: HW 0.52, HL 0.74, SL 1.08, EL 0.16, PW 0.40. color Major: body and appendages light reddish brown except for gaster, which is plain medium brown. Minor: concolorous brownish yellow. Range Known only from the type locality. Biology Unknown. figure Upper: lectotype, major. Lower: paralectotype, minor. ARGENTINA: Tanti Viejo, Cordoba. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 288

Pheidole olsoni new species Types Mus. Comp. Zool. Harvard. Etymology Named after the collector David Olson. Diagnosis Known only from the major, easily distinguished by its very small size, elongated head, bicolorous body, protuberant frontal lobe in side view, small propodeal spine, cornulate postpetiole, and unusual pattern of the rugulae mesad to the eye, which travel downward (anteriorly) from the eye obliquely mesad to meet the circular carinulae of the antennal fossae. Similar to browni, casta, mera, prolixa, and protensa, but easily separated by the above listed traits. measurements (mm) Holotype major: HW 0.54, HL 0.74, SL 0.30, EL 0.08, PW 0.30. color Major: head, dorsum of alitrunk, petiolar node, and all of postpetiole medium brown; rest of body and all of appendages medium yellow. range Known from the type locality and from El Volcan, Chiriqui, Panama, 1280 m (L. Hare). biology The holotype was collected in rainforest at a tuna bait; the Chiriqui, Panama, specimens were found in a log. Males were present in the latter colony on 18 August. figure Holotype, major. COSTA RICA: Refugio de Eladio, Penas Blancas Valley, Alajuela, 780 m (David Olson). Scale bar = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 478

Pheidole pepo new species types Mus. Comp. Zool. Harvard. Etymology Gr pepo, melon, alluding to the unusual head shape of the major. diagnosis A large, yellow member of the tristis group, similar to rotundiceps, sphaerica, and subsphaerica, easily distinguished by the following traits. Major: head greatly swollen; clypeus and mandibles reduced proportionate to the head; outline of head in full-face view almost completely devoid of pilosity; in side view, profiles of both anterior dorsal half and anterior ventral half of head capsule densely pilose, but profiles of posterior dorsal and ventral halves bare of pilosity; propodeal spines long and acute. Minor: body slender; occiput narrowed, with nuchal collar; propodeal spines long and slender, i.e., needle-like. Measurements (mm) Holotype major: HW 1.78, HL 1.66, SL 1.02, EL 0.22, PW 0.84. Paratype minor: HW 0.64, HL 0.80, SL 1.06, EL 0.16, PW 0.44. Color Major: head and appendages medium yellow; mesosoma, waist, and gaster yellowish brown. Minor: concolorous dark yellow. range Known only from the type locality. biology Collected in spiny bamboo (Guadua) forest. Figure Upper: holotype, major. Lower: paratype, minor. COLOMBIA: Finca Los Guaduales, 10 km southwest of San Jose del Palmar, Rio Torito, Choco, 800 m (Charles Kugler). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 730

Pheidole oxyops Forel Pheidole oxyops Forel 1908h: 377. Syn.: Pheidole genalis Borgmeier 1929: 199, synonymy by Kempf 1964e: 58; Pheidole oxyops subsp. regia Forel 1908h: 378, synonymy by Kempf 1964e: 58. Types Mus. Hist. Nat. Geneve; Mus. Comp. Zool. Harvard. Etymology Gr oxyops, sharp-eyed or sharp-faced, allusion uncertain. diagnosis A large (major Head Width 1.90 mm), reddish brown member of the diligens group easily distinguished as follows. Major: head in side view elliptical, tapering equally toward the occiput and clypeus on opposite ends; antennal scape reaches much less than half the distance from eye to occipital corner; in dorsal-oblique view, the two lobes of the pronotum and mesonotal convexity present a profile of three equally spaced convexities, and the propodeal dorsum has a small convexity just anterior to the spine; in side view propodeal spine short, thin, and vertical to propodeal dorsal face; postpetiole from above conulate; no rugoreticulum present anywhere; anterior and parts of lateral margins of pronotum carinulate. Minor: a neck and nuchal collar present; propodeal spine reduced almost to a denticle. Measurements (mm) Syntype major: HW 1.92, HL 2.12, SL 1.06, EL 0.30, PW 0.80. Syntype minor: HW 0.74, HL 1.02, SL 1.24, EL 0.22, PW 0.54. Color Major and minor: concolorous light brown. Range Kempf (1972b) and I have recorded oxyops, in addition to the type series from Paraguay, from Salta, northern Argentina, and Goias, Mato Grosso, Minas Gerais, and Sao Paulo in southeastern and central Brazil. Biology P. oxyops occurs in cerrado (savanna) and the edges of semideciduous forest. In the region of San Antonio de Posse, Sao Paulo, Fernandes et al. (1994) found the species abundant along the forest edge and in cotton fields. In the latter it was very effective in removing adult boll weevils (Anthonomus grandis) from the ground, accounting in one study period for 90% of the predation due to ants, where predation by ants as a whole destroyed 20% of the weevils. Fernandes et al. use the name P. oliveirai, which I erroneously supplied from an early draft of the manuscript of my monograph; the specimens supplied me and hence the name I erected in manuscript fall under oxyops. Figure Upper: syntype, major. Lower: syntype, minor. PARAGUAY: San Bernadino (Fiebring). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA, USA :Harvard University Press on page 212

Pheidole arboricola new species Types INBio. etymology L arboricola, tree-dwelling, alluding to the arboricolous nests of the species. Diagnosis A very small species, close to amazonica, mackayi, minutula, and especially quercicola, distinguished in the major from these species by its subangulate (as opposed to lobate) humerus in dorsal-oblique view, rounded lateral borders of the postpetiole, and bicolorous head. Measurements (mm) Holotype major: HW 0.76, HL 0.84, SL 0.40, EL 0.06, PW 0.40. Paratype minor: HW 0.42, HL 0.46, SL 0.40, EL 0.06, PW 0.26. color Major: head capsule anterior to eyes, along with a fuzzy circular spot in the middle of the capsule dorsum, light brown. Waist and gaster also light brown; rest of body and appendages dark yellow. Minor: body medium brown, tarsi yellow, rest of appendages light brown. Range Atlantic lowlands of Costa Rica, up to 500 meters elevation. Biology John T. Longino (1997) reports arboricola as a resident of moist mature and second-growth forest, nesting in the hollow branches and under the dead bark variously of Bauhinia, Cecropia, Stryphnodendron, and other trees. Figure Upper: holotype, major. Lower: paratype, minor. COSTA RICA: La Selva Biological Station, near Puerto Viejo (J. T. Longino). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 372

Pheidole scabriventris new species Types Mus. Comp. Zool. Harvard. Etymology L scabriventris, rough belly (gaster), referring to the shagreening of the first gastral tergite. diagnosis Similar to mixteca, oaxacana, and trageri of Mexico, differing as follows. Major: brown, with bluish reflections on first gastral tergite; humerus in dorsal-oblique view raised and subangulate; head quadrate; postpetiolar node from above diamond-shaped; all of anterior half of dorsal head surface carinulate, including clypeus; all of dorsal head surface and of mesosoma foveolate and opaque; anterior two-thirds of central strip of first gastral tergite shagreened and with faint bluish reflections. Minor: humerus in dorsal-oblique view low and subangulate; postpetiolar node suppressed; pilosity sparse, on mesosomal dorsum consisting of widely and evenly spaced pairs of setae; all of head and mesosoma foveolate and opaque. Measurements (mm) Holotype major: HW 0.92, HL 0.92, SL 0.50, EL 0.14, PW 0.44. Paratype minor: HW 0.44, HL 0.52, SL 0.46, EL 0.08, PW 0.30. Color Major: body, mandibles, and most of antennae medium brown; legs brownish yellow. Minor: body and most of appendages medium brown; tarsi brownish yellow. Range Known from the type locality, and from Estacion Biologica Los Tuxtlas, Veracruz. Biology The Los Tuxtlas series was taken from ground litter in rainforest (P. S. Ward) and the holotype series from tropical evergreen forest (S. and J. Peck). Figure Upper: holotype, major. Lower: paratype, minor. MEXICO: 3.2 km west of Fortin, on Highway 150, Veracruz (Stewart B. and Jarmila Kukalova-Peck). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 503

Pheidole termitobia Forel Pheidole termitobia Forel 19011: 390. Types Mus. Hist. Nat. Geneve. Etymology Gr L termitobia, living with termites. diagnosis A member of the flavens group, similar to species listed above in heading, and distinguished from them and other species of the group as follows. Major: reddish yellow; occiput and sides of head rugoreticulate; vertex, frontal lobes, and genae carinulate; antennal scrobes present; all of head, mesosoma, and waist foveolate and opaque; humeri rugoreticulate, and anterior margin of pronotum transversely carinulate; propodeal spines strongly developed; postpetiole from above oval. Minor: reddish yellow; all of head and mesosoma foveolate and opaque; carinulae of head reach eye level; humeri subangulate. Measurements (mm) Lectotype major: HW 0.84, HL 0.84, SL 0.52, EL 0.10, PW 0.42. Paralectotype minor: HW 0.42, HL 0.46, SL 0.42, EL 0.06, PW 0.32. Color Major and minor: light reddish yellow, appendages clear yellow. Range Known only from the type locality. Biology Forel records the types, transmitted to him by Erich Wasmann, as discovered "chez les termites," with no further details. Figure Upper: lectotype, major. Lower: paralectotype, minor. BRAZIL: Sao Leopoldo, Rio Grande do Sul. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 522

Pheidole punctithorax Borgmeier Pheidole punctithorax Borgmeier 1929: 210. Types Mus. Zool. Univ. Sao Paulo. Etymology l punctithorax, punctate chest, evidently referring to the wholly foveolate mesosomas of both castes. diagnosis A member of the " jujuyensis complex" of the larger fallax group, comprising araneoides, cuevasi, durionei, jujuyensis, kugleri, leonina, leptina, lucretii, lupus, paraensis, punctithorax, tijucana, wallacei, and wolfringi, which complex is characterized by slender body form and exceptionally long scapes and petiolar pedicel; also in the major by a proportionately small head; and in the minor by a strongly developed nuchal collar. P. punctithorax is distinguished as follows. Major: pilosity sparse; occiput narrowed so that its width in full face is much less than that of the clypeus; a loose, large-celled rugoreticulum is limited to the space mesad to the eyes and forward of it; the humerus and petiolar node are subangulate; all of the occiput, mesosoma, and waist are foveolate and opaque; anterior third of first gastral tergite is shagreened and opaque. Minor: all of mesosoma and waist, as well as a strip running from the eye to the occiput, foveolate and opaque; neck only moderately narrowed. Major and minor: reddish brown. Measurements (mm) Holotype major: HW 1.24, HL 1.32, SL (antennae missing), EL 0.22, PW 0.64. Paratype minor not measured. color Major: concolorous medium reddish brown. Minor: gaster light reddish brown, rest of body and appendages medium reddish brown. Range Known only from the type locality. Biology Unknown. figure Upper: holotype, major (antennae missing from specimen). Lower: paratype, minor. BRAZIL: Petropolis, Rio de Janeiro. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 342

Pheidole senex Gregg Pheidole senex Gregg 1952a: 1. Syn.: Pheidole pilifera subsp. anfracta Cole 1952c: 278, synonymy by Cole 1953g: 298. Types Mus. Comp. Zool. Harvard. Etymology L senex, old, senior, possibly alluding to rugulose sculpture of head and mesosoma. diagnosis A member of the " pilifera complex" of the larger pilifera group, comprising calens, californica, carrolli, cavigenis, clementensis, creightoni, hoplitica, littoralis, micula, pilifera, polymorpha, rugulosa, senex, soritis, tepicana, and torosa, which complex is distinguished by the following traits. Major: dorsal head surface extensively sculptured; occipital lobes transversely rugulose (or, in carrolli smooth, in littoralis foveate, and in micula and soritis carinulate), postpetiole from above diamond-shaped, trapezoidal, or spinose. Minor: eye medium-sized to large. P. senex is distinguished within the complex by the following combination of traits. Major: large; mesonotal convexity subangulate in dorsal-oblique view, and descends steeply to metathorax in side view; petiolar node tapers to a point in side view; postpetiole from above spinose; sides of pronotum, mesonotum, and propodeum, longitudinally carinulate; anterior dorsal profde of head flat; cephalic pilosity short and erect. Minor: entire dorsal surface of head except mid-section of clypeus longitudinally carinulate; all of mesosoma foveolate and opaque. Measurements (mm) Paratype major: HW 1.74, HL 1.86, SL 0.78, EL 0.22, PW 0.82. Paratype minor: HW 0.64, HL 0.66, SL 0.68, EL 0.14, PW 0.40. color Major and minor: light yellowish to reddish brown. range West-central Arizona through New Mexico to the Texas Panhandle and southern Colorado; apparently rare. Biology Gregg (1963) reports P. senex from Campo, Colorado, in short grass prairie nesting in clay under rocks at 1300 m. Cole recorded it in New Mexico from 2000 to 2700 m. At Springerville, Arizona, I found a colony under a rock in grassy desert. In the Texas Panhandle, Moody and Francke (1982) found two colonies, one beneath a stone and the other in open soil. Figure Upper: paratype, major. Lower: paratype, minor. COLORADO: 14 km south of Campo, Baca Co., extreme southeastern Colorado (Robert E. Gregg). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 596

Pheidole cavifrons Emery Pheidole cavifrons Emery 1906c: 144. Syn.: Pheidole arciruga Forel 1908h: 381, n. syn. Types Mus. Civ. Stor. Nat. Genova. Etymology l cavifrons, hollow front, evidently referring to the deep antennal scrobes. Diagnosis Closest to longior, somewhat less similar to aberrans and obnixa, distinguished as follows. Major: head markedly elongate (Head Length/Head Width 1.39); concolorous yellow; hypostoma toothless; dorsal posterior half of head flat; frontal lobes in full-face view with lobose anterior margins; carinulae originating on frontal lobes end far short of midpoint between eyes and occiput; mesonotal convexity in side view reduced; propodeal spines strongly developed; promesonotum smooth and shiny. Minor: pronotal dorsum covered by semicircular carinulae. Measurements (mm) Lectotype major: HW 0.76, HL 1.06, SL 0.34, EL 0.06, PW 0.54. Minor: HW 0.46, HL 0.52, SL 0.34, EL 0.04, PW 0.32. color Major: concolorous medium yellow. Minor: concolorous pale yellow. Range Recorded from Buenos Aires, Argentina; Uruguay; and Rio Grande do Sul and Parana, Brazil. biology The type colony of synonymous " arciruga " was collected from a termite mound in Rio Grande do Sul. figure Upper: lectotype, major (La Sierra, Uruguay). Lower: minor (" arciruga " syntype, Rio Grande do Sul, Brazil, compared with cavifrons paralectotype). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 132

Pheidole amata Forel Pheidole amata Forel 190lj: 360. Types Mus. Hist. Nat. Geneve. Etymology L amata, loved passionately, reference unknown. diagnosis Similar in various traits to ambigua, celaena, fera, germaini, peruviana, rutilana, schwarzmaieri, superba, and vomer, differing as follows. Major: mostly reddish yellow; lower pronotal margin, upper half of mesopleuron, and sides of propodeum bearing curved carinulae, those on mesopleuron S-shaped; eye bean-shaped, with concave ventral border; clypeus prominent and long in side view but lacking any process; head subrectangular; occipital cleft deep; humerus in dorsal-oblique view prominent, subangulate; petiolar node thin in side view, and broad, elliptical, and marginally angular seen from above. Minor: propodeal spine absent; occiput narrowed to a neck with nuchal collar; posterior half of mesonotum carinulate. Measurements (mm) Lectotype major: HW 1.54, HL 1.88, SL 0.82, EL 0.28, PW 0.80. Paralectotype minor: HW 0.56, HL 0.74, SL 0.86, EL 0.10, PW 0.40. Color Major: body reddish yellow except for gaster; which is plain medium brown; appendages reddish yellow. Minor: body medium brown, verging to yellow at level of clypeus; appendages medium yellow. Range Known only from the type locality. Biology Forel discovered the type colony of amata in 1896 at the foot of the Sierra Nevada de Santa Marta, nesting in the soil of virgin rainforest. Figure Upper: lectotype, major. Lower: paralectotype, minor. COLOMBIA: Ouriheka, near Rio Frio, Magdalena (Auguste Forel). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 651

Pheidole clementensis Gregg Pheidole clementensis Gregg 1969b: 93. Types Natural History Museum of Los Angeles County; Mus. Comp. Zool. Harvard; Amer. Mus. Nat. Hist. Etymology Referring to the type locality. Diagnosis A member of the " pilifera complex" of the larger pilifera group; for a characterization of the complex, see under pilifera. P. clementensis is distinguished within the complex by the following combination of traits. Major: side of head densely rugoreticulate; occiput extensively rugulose; pronotum smooth and shiny, propodeal spine moderately large, acute; postpetiole from above trapezoidal; humerus in dorsal-oblique view low and smooth and shiny. Closest to californica, from which it differs by its larger size (HW in clementensis about 1.1 mm, in californica major about 0.90 mm) and proportionately smaller eye (major EL/HW 0.13 in clementensis versus 0.20 in californica). Measurements (mm) Paratype major: HW 1.08, HL 1.18, SL 0.54, EL 0.14, PW 0.54. Paratype minor: HW 0.54, HL 0.56, SL 0.52, EL 0.12, PW 0.30. Color Major: head dark yellow, with at least occasionally a pair of medium brown spots on vertex, falling on either side of the cephalic midline; rest of body light yellowish brown. Minor: body concolorous dark brown, appendages yellow. Range San Clemente Island and parts of mainland California (Philip S. Ward, personal communication). biology Roy Snelling (in Gregg 1969b) reports that P. clementensis is one of the commonest ants on San Clemente Island (especially on the seaward side), where it nests under stones. The minor workers are nocturnal, starting to forage shortly before sundown. They are evidently mostly or entirely granivorous, preferring the seeds of Cassus cretica but also gathering grass seeds and those of a small legume, probably a species of Lotus. The majors form an unusually high percentage of the worker population. Figure Upper: paratype, major. Lower: paratype, minor. CALIFORNIA: Pyramid Head, San Clemente Island, San Diego County. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 572

Pheidole furtiva new species Types Mus. Comp. Zool. Harvard. etymology L furtiva, hidden, concealed, alluding to the nest site. diagnosis Similar in various traits to chalca, floridana, daphne, nebulosa, quercicola, specularis, stomachosa, and tysoni, but easily distinguished as follows. Major: dark yellow; head elongate, subrectangular; eyes very small; from above, humeri angulate and overhanging rest of pronotum, and in dorsal-oblique view are bilobate; mesonotal convexity in dorsal-oblique view angulate; propodeal spiracles large; propodeal spines robust, directed backward; angular subpostpetiolar process present in side view; postpetiole from above broad and spinose; small patch of rugoreticulum present behind each antennal fossa. Minor: head mostly carinulate and foveolate, with a rugoreticulum behind each eye; anterior and lateral margins of pronotal dorsum rugulose and rugoreticulate, and all of mesosoma foveolate. Measurements (mm) Holotype major: HW 0.90, HL 1.08, SL 0.56, EL 0.06, PW 0.46. Paratype minor: HW 0.54, HL 0.60, SL 0.52, EL 0.04, PW 0.32. Color Major: body dark yellow, appendages medium yellow. Minor: concolorous medium yellow. range Known only from several Arizona collections made by Stefan Cover in the Chiricahua Mts., 1550-1650 m; Pajarito Mts., Santa Cruz Co., 1110 m; and Patagonia Mts., 1420 m. Biology The type colony was found nesting in soil beneath a pat of dried cow dung in a grassy, grazed meadow with scattered juniper (Stefan Cover). Other colonies were found by Cover beneath a rock in a grassy juniper flat, in a cryptic soil nest on a rocky hillside covered by acacia-opuntia scrub, and under a rock in an overgrazed, grassy creek valley. Figure Upper: holotype, major. Lower: paratype, minor. ARIZONA: 6.9 km west-northwest of junction FSR42 and FSR42B, Cochise Co., 1650 m (Stefan Cover). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 425

Pheidole rosula new species Types Mus. Comp. Zool. Harvard. Etymology L rosula, little rose, alluding to similarity with P. rosae. Diagnosis Similar in various characters to species listed in heading above, especially rosae, and distinguished as follows. Major: reddish yellow; frontal lobes extended forward as low but still conspicuous lobes, in side view; shallow antennal scrobes present, with surfaces smooth except for scattered foveae; postpetiole spinose; rugoreticulum on each side of head extends from eye to antennal fossa, posterior to eye for about an Eye Length distance, and anterior almost to the anterior genal border; carinulae extend to occiput, which is smooth; anterior half of pronotal dorsum carinulate; pilosity dense and long, with some hairs longer than Eye Length. Minor: most of head and mesosoma variably foveolate; frontal lobes carinulate; humerus in dorsal-oblique view denticulate; propodeal spines reduced to denticles. Measurements (mm) Holotype major: HW 1.22, HL 1.28, SL 0.54, EL 0.16, PW 0.72. Paratype minor: HW 0.62, HL 0.64, SL 0.54, EL 0.12, PW 0.40. color Major: body and mandibles reddish yellow, appendages plain dark yellow. Minor: concolorous light reddish yellow. Range Known only from the type locality. Biology Unknown. Figure Upper: holotype, major. Lower: paratype, minor. ARGENTINA: Palermo, Buenos Aires (R. Thaxter). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 743

Pheidole cerebrosior Wheeler Pheidole vinelandica subsp. cerebrosior Wheeler 1915b: 405. Raised to species level by Creighton 1950a: 175. types Amer. Mus. Nat. Hist.; Mus. Comp. Zool. Harvard. Etymology Unknown. Diagnosis A member of the " bicarinata complex" of the larger pilifera group; for a characterization of the complex, see under bicarinata. P. cerebrosior is distinguished within the complex by the following combination of traits. Major: postpetiole seen from above very wide and conulate; propodeal spines well-developed and backward-directed; pronotal humeri with short irregular carinulae. Minor: mesosoma! pilosity comprises rows of evenly spaced pairs of erect hairs. Measurements (mm) Lectotype major: HW 1.12, HL 1.32, SL 0.60, EL 0.14, PW 0.58. Paralectotype minor: HW 0.46, HL 0.56, SL 0.44, EL 0.12, PW 0.28. Color Major: body light reddish yellow, except for the gaster, which is a slightly contrasting yellowish brown. Minor: concolorous plain yellow. Range Arizona and New Mexico, 550 to 1680 m; southern California, 950 m; Baja California, 640 m; Chihuahua, 1500 m (Creighton and Gregg 1955); numerous records by Stefan Cover (collection notes) and extreme southern Nevada (G. C. and J. Wheeler 1986g). biology Creighton and Gregg (1955) report that the preferred habitat of cerebrosior is evergreen-oak-woodland in mountain canyons, with open desert less frequently occupied. The colonies are always small, and contain no more than 3 or 4 majors. Stefan Cover (unpublished specimen data) found numerous colonies in open Ephedra, mesquite, and mesquite-acacia desert, as well as riverine cottonwood forest, nesting variously under rocks beneath cow dung, and in open soil with multiple small crater nests. He found seed chambers in some nests and observed workers feeding on a dead beetle. A winged queen has been collected on 1 July. In Nevada, G. C. and Jeanette N. Wheeler (1986g) found a single colony under a half-buried stone in yucca-larrea desert. Figure Upper: lectotype, major. Lower: paralectotype, minor. ARIZONA: Tucson. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 569

Pheidole fariasana new species Types Mus. Comp. Zool. Harvard. Etymology Named after the type locality. diagnosis A member of the crassicornis group distinguished by the following combination of traits. Major: medium to dark brown; rugoreticulum of head limited to small patches immediately mesad to each eye; posterior half of head capsule smooth and shiny; anterior strip of pronotal dorsum transversely carinulate, remainder of promesonotal dorsum smooth and shiny; postpetiole from above diamond-shaped; pilosity dense and long, especially on gaster. Minor: dark brown with brownish yellow tarsi, posterior half of head capsule smooth and shiny; anterior strip of pronotal dorsum transversely carinulate, rest of pronotum smooth and shiny; occiput broad. Measurements (mm) Holotype major: HW 1.00, HL 1.04, SL 0.82, EL 0.18, PW 0.54. Paratype minor: HW 0.60, HL 0.68, SL 0.80, EL 0.14, PW 0.40. Color Major: head, lower half of pronotum, and appendages medium brown; remainder of body dark brown. Minor: body dark, almost blackish brown; tarsi brownish yellow; rest of appendages light to medium brown. range Known only from the type locality. Biology Unknown. Figure Upper: holotype, major. Lower: paratype, minor. MEXICO: 1.5 km east of Gomez Farias, Tamaulipas, 425 m (Robert J. Hamton). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 155

Pheidole hierax new species Types Mus. Comp. Zool. Harvard. etymology Gr hierax, hawk. Diagnosis Close to pugnax, and also somewhat less similar to the species listed in the heading, distinguished as follows. Major: dark yellow; rugoreticulum absent on head; all of posterior dorsal surface of head foveolate and opaque, but posterior lateral surface smooth and shiny; carinulae along midline of head extends halfway between eye level and occiput; transverse carinulae present on anterior edge bf pronotal dorsum; all of mesosoma and waist foveolate; all of central strip of first gastral tergite shagreened; pronotal dorsum in dorsal-oblique view subangulate, not bilobous; a few long, sparse hairs present on dorsal surface of head, but mesosoma almost completely bare; propodeal spiracle elliptical. Minor: head, mesosoma, and waist completely foveolate and almost bare of pilosity; anterior half of first gastral tergite shagreened; anterior propodeal face drops precipitously to metanotum in dorsal-oblique view. Measurements (mm) Holotype major: HW 1.04, HL 1.04, SL 0.68, EL 0.18, PW 0.58. Paratype minor: HW 0.54, HL 0.60, SL 0.68, EL 0.12, PW 0.38. color Major and minor: dark yellow. Range Known only from the type locality. Biology Unknown. Figure Upper: holotype, major. Lower: paratype, minor. PANAMA: Barro Colorado Island (Diana E. Wheeler). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA, USA :Harvard University Press on page 194

Pheidole rhytifera new species Types Mus. Comp. Zool. Harvard. Etymology L rhytifera, bearing a horn, referring to the profile of the frontal lobe. Diagnosis Similar to the species listed in the heading above, differing in the following combination of traits. Major: shallow antennal scrobes present; frontal lobe in side view angulate and turning upward; postpetiole sharply cornulate; posterior half of head and all the rest of the body smooth and shiny. Minor: occiput narrowed, with nuchal collar; humerus with tooth in dorsal-oblique view; propodeal spine reduced and erect; entire body and head smooth and shiny. Measurements (mm) Holotype major: HW 1.34, HL 1.44, SL 0.60, EL 0.10, PW 0.76. Paratype minor: HW 0.58, HL 0.60, SL 0.66, EL 0.12, PW 0.36. Color Major and minor: light brown. Range Known only from the type locality. Biology Unknown. Figure Upper: holotype, major. Lower: paratype, minor. VENEZUELA: Rancho Grande, Parque Nacional Pittier, 1000-1200 m (J. D. Weintraub). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 739

Pheidole kukrana new species Types Mus. Comp. Zool. Harvard. Etymology Named after the type locality. diagnosis A member of the fallax group close to caribbaea and obscurior, possibly synonymous with the latter, and somewhat less similar to cardinalis, mantilla, and rubiceps, distinguished as follows. Major: dark brown; antennal scape just attaining the occipital corner; humerus angulate in dorsal-oblique view; occiput in frontal view and ventral half of head in side view smooth and shiny; all of pronotum covered by transverse, "wraparound" carinulae; rugoreticulum on head extends on each side from eye to antennal fossa, posteriorly to halfway between eye and occipital comer, and anteriorly to halfway between eye and anterior border of head. Dorsal and lateral surfaces of head coated with dense, long, subdecumbent yellowish hairs. Minor: occiput drawn into neck, with nuchal collar; propodeal spines reduced to denticles; anterior strip of pronotal dorsum foveolate and opaque. Measurements (mm) Holotype major: HW 1.06, HL 1.16, SL 0.98, EL 0.20, PW 0.56. Paratype minor: HW 0.52, HL 0.66, SL 0.96, EL 0.14, PW 0.36. Color Major: body dark brown, appendages medium brown. Minor: body medium brown, appendages light to yellowish brown. Range Known from the type locality, from both the Atlantic and Pacific lowlands of Costa Rica (J. T. Longino), and from Venezuela (4 km northeast of Biscucuy, Portuguesa, 670 m; W. L. Brown and J. Lattke). biology In Costa Rica, kukrana is very adaptable, occurring in seasonal dry forest, and mature and secondary lowland rainforest, and nesting opportunistically in small cavities both on the ground and in the canopy; it occasionally builds carton walls (Longino 1997). Figure Upper: holotype, major. Lower: paratype, minor. NICARAGUA: Kukra River (Ivette Perfecto). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 310

Pheidole guerrerana new species Types Mus. Comp. Zool. Harvard. Etymology Named after the Mexican state of origin. Diagnosis A member of the crassicornis group distinguished by the following combination of traits. Major: rugoreticulum mesad to the eyes very extensive, reaching from near the posterior clypeal border to midway between the eye and occiput; pilosity very dense and long, especially on the dorsal surfaces of the head and on the gastral tergites; anterior strip of pronotal dorsum transversely carinulate; postpetiole from above diamond-shaped. Minor: pilosity extremely long over most of the body; humerus subangulate in dorsal-oblique view; occiput narrowed, with rudiment of a nuchal collar. Measurements (mm) Holotype major: HW 1.28, HL 1.42, SL 1.02, EL 0.24, PW 0.66. Paratype minor: HW 0.58, HL 0.74, SL 0.94, EL 0.20, PW 0.42. Color Major: head indistinctly bicolorous, with capsule anterior to eye level yellow and remainder yellowish brown; mesosoma and appendages yellowish brown; waist and gaster plain light brown. Minor: indistinctly bicolorous, with head capsule posterior to anterior margin of eye as well as gaster and postpetiolar dorsum light brown; remainder of body dark yellow to brownish yellow. Range Known only from the type locality. Biology The nest of the type colony was beneath a rock in a forest clearing. A winged queen was present on 31 July. Figure Upper: holotype, major. Lower: paratype, minor. MEXICO: at road 3.5 km below Omilteme, Guerrero, 2000 m (Cornell University Field Party). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 156

Pheidole tarchon new species Types Mus. Comp. Zool. Harvard. Etymology Named after Tarchon, founder of Tarquinii and the Etruscan dodecapolis. Diagnosis Similar to tetrica and victima, distinguished as follows. Major: brownish yellow; head covered by carinulae, except for occiput, the frontal triangle, strip behind the frontal triangle, and midclypeus; dorsal profile of promesonotum flat, dropping steeply to metanotum through a posterior face; head quadrate, Head Width equaling Head Length, antennal scape long, its tip touching the side of the head in full-face view two-thirds from eye to occipital corner; petiolar node in side view thick, with broad, semicircular apex; postpetiole from above bell-shaped; anterior fringe of pronotal dorsum carinulate, and mesosoma otherwise completely smooth and shiny. Minor: promesonotal profile in side view flat; body almost completely smooth and shiny; antennal scape long; occiput moderately narrowed in full-face view but lacking nuchal collar. measurements (mm) Holotype major: HW 1.22, HL 1.22, SL 0.82, EL 0.18, PW 0.52. Paratype minor: HW 0.68, HL 0.72, SL 0.66, EL 0.14, PW 0.40. color Major and minor: concolorous brownish yellow. Range Known only from the type locality. Biology The type colony was collected in alder woods in a ravine; a winged queen was in the nest on 30 January. Figure Upper: holotype, major. Lower: paratype, minor. ARGENTINA: 3 km northeast of Tafi del Valle, Tucuman, about 2200 m (W. L. Brown). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 517

Pheidole dwyeri Gregg Pheidole dwyeri Gregg 1969b: 97. Types Natural History Museum of Los Angeles County; Mus. Comp. Zool. Harvard; Amer. Mus. Nat. Hist. Etymology Named after Richard F. Dwyer, who sponsored the Snelling collecting tour of Las Tres Marias. diagnosis A very distinctive species in the small group of Pheidole that possess 4-segmented antennal clubs. Major: very large; head disproportionately large, with Head Width more than 2.5X Pronotal Width; head tapered strongly toward occiput in side view; in full-face view, occiput deeply and subangularly concave; median ocellus present; small patch of rugoreticulum present laterad to each antennal fossa. Minor: propodeal spine of medium length; occiput in full-face view broad and weakly concave. Measurements (mm) Paratype major: HW 2.56, HL 2.58, SL 1.24, EL 0.24, PW 1.00. Paratype minor: HW 0.66, HL 0.74, SL 0.76, EL 0.12, PW 0.42. color Major and minor: concolorous medium reddish brown. Range Known only from the type locality. Biology Unknown. Figure Upper: paratype, major. Lower: paratype, minor. MEXICO: Isla Maria Cleofas, Las Tres Marias, Nayarit (Roy R. Snelling). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 541

Pheidole diana Forel 1908c: 51. Types Mus. Hist. Nat. Geneve. etymology No allusion given; presumably after Diana, the Roman goddess of nature, fertility and conception, and the Moon. diagnosis A medium-sized member of the diligens group, and inhabitant of high montane forests, similar to alfaroi, laelaps, riveti, seligmanni, and tepuicola, somewhat less so to laticornis and strigosa, and distinguished from these and other Pheidole species by the following combination of traits. Major: sculpturing confined to carinulae on margins of frontal lobes, anterior third of the head capsule, and entire surface of the propodeum, with the rest of the body smooth and shiny; propodeal spines reduced to denticles; postpetiole from above diamond-shaped. Minor: sculpturing confined to circular carinulae of antennal fossae and transverse carinulae of dorsal propodeal surface, with the rest of the body smooth and shiny; propodeal spines absent; basal and declivitous faces of propodeum meet in an obtuse angle; nuchal collar absent. Measurements (mm) Lectotype major: HW 1.40, HL 1.44, SL 0.90, EL 0.22, PW 0.72. Paralectotype minor: HW 0.66, HL 0.76, SL 0.72, EL 0.12, PW 0.44. Color Major: appendages and most of body medium reddish yellow; gaster a slightly darker shade of plain light brown. Minor: body concolorous plain light brown; appendages a slightly contrasting lighter shade. Range Upper elevations of Cordillera Central and Cordillera de Tilaran, Costa Rica, including the Braulio Carrillo National Park, Penas Blancas Valley, and Monteverde (Longino 1997). biology An arboreal species that nests under epiphyte mats in the canopy of cloud forest and montane wet forest; some colonies are very large (Longino 1997). Figure Upper: lectotype, major. Lower: paralectotype, minor. COSTA RJCA: Las Palmas, near Bajo la Hondura, Braulio Carrillo National Park. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA, USA :Harvard University Press on page 187

Pheidole caltrop new species Types Mus. Comp. Zool. Harvard. Etymology ML caltrop, a four-pointed weapon placed on the ground to impede movement. Diagnosis A unique member of the fallax group characterized as follows. Major: yellow; occiput, genae, and promesonotal dorsum rugoreticulate; large "sharkfin" protrusion on humerus extends beyond the boundaries of the rest of the pronotum when viewed from above; dorsum of postpetiolar node carinulate. Minor: large "sharkfin" angle protrudes from humerus; all of body except gaster foveolate and opaque; very thin nuchal collar present. Measurements (mm) Holotype major: HW 1.22, HL 1.18, SL 0.64, EL 0.14, PW 0.62. Paratype minor: HW 0.60, HL 0.66, SL 0.66, EL 0.10, PW 0.42. color Major: concolorous dark yellow. Minor: concolorous medium yellow. range Known only from the type locality. biology "From large thorns hollowed out on living tree" (A. E. Emerson, collection note 13 April 1935). figure Upper: holotype, major. Lower: paratype, minor. PANAMA: Barro Colorado Island (Alfred E. Emerson). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 270

Pheidole ectatommoides new species Types Mus. Comp. Zool. Harvard. Etymology L ectatommoides, referring to the distinctive sculpturing of the minor especially, reminiscent of ectatommoid ponerine ants. diagnosis A highly distinctive species with some resemblance to arietans, glyphoderma, and triumbonata, but instantly recognizable by the unique pattern of sculpturing, especially on the minor worker, as illustrated. Measurements (mm) Holotype major: HW 1.98, HL 2.12, SL 0.90, EL 0.24, PW 0.86. Paratype minor: HW 0.74, HL 0.80, SL 0.84, EL 0.20, PW 0.50. color Major: head, mesosoma, and waist light reddish brown; appendages and gaster reddish yellow. Minor: head and mesosoma reddish yellow; waist, gaster, and appendages plain medium yellow. Range Recorded from Costa Rica, Panama, Colombia, and Ecuador. J. T. Longino (1997) found the species in Costa Rica on the Atlantic slope. Biology Longino (1997) discovered workers foraging at night on the ground and on a fallen branch in a forest. At several localities across the range, caches of seeds have been found in the nests. Figure Upper: holotype, major. Lower: paratype, minor. COSTA RICA: Rio Toro Amarillo, near Guapiles (William L. Brown). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 683

Pheidole aripoensis new species Types Mus. Comp. Zool. Harvard. etymology Named in reference to the type locality. Diagnosis Recognizable within the punctatissima group by the uniquely concave posterior dorsal profile of the major's head, combined with the double convexity of the major's pronotum (hence triple convexity of the promesonotum), concave occipital border of the minor, and well-developed propodeal spines, relatively sparse pilosity, and yellow color of both castes. Other traits in body form and sculpturing are illustrated. Measurements (mm) Holotype major: HW 0.92, HL 0.92, SL 0.64, EL 0.14, PW 0.42. Paratype minor: HW 0.44, HL 0.50, SL 0.60, EL 0.10, PW 0.26. color Major: yellow, with head and mesosoma possessing a slightly dark, "orange" tinge. Minor: concolorous yellow. Range Known only from the type locality. Biology Unknown. Figure Upper: holotype, major. Lower: paratype, minor. TRINIDAD: Aripo Ridge, Arima Valley, 600-700 m (Stefan Cover and Mark W. Moffett). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 610

Pheidole bakeri Forel Pheidole bakeri Forel 1912c: 82. Types Mus. Hist. Nat. Geneve; Mus. Comp. Zool. Harvard. Etymology Eponymous. Diagnosis Most similar to androsana of the Bahamas, from which it differs principally by the smooth and shiny posterior half of the major's head capsule and carinulate mesopleuron, as well as by its longer propodeal spines. Measurements (mm) Syntype major: HW 1.60, HL 1.90, SL (not measured), EL 0.22, PW 0.80. Syntype minor: HW 0.60, HL 0.64, SL 0.62, EL 0.12, PW 0.40. Color Major: concolorous medium yellow with a slight reddish tinge, hence light "orange." Minor: concolorous medium yellow. Range Known only from Cuba (Havana and San Bias, Pinar del Rio). Biology Unknown. Figure Upper: syntype, major (damaged specimen; outline of antenna drawn from specimen collected at San Bias, Pinar del Rio). Lower: syntype, minor. CUBA: Havana. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 660

Pheidole huacana new species Types Mus. Comp. Zool. Harvard. Etymology L huacana, from huaca, belonging to Inca spirits of the land. Diagnosis A member of the fallax group, close to galba and oliveirai, distinguished as follows. Major: yellow; nadir of occipital mid-cleft seen in full-face view very deep, reached by carinulae that start on the vertex and run along the mid line of the head; rugoreticulum on each side of head runs from the eye to and into the circular carinulae around the antennal fossa; the rugoreticulum leads at the level of the posterior margin of the eye to weak rugulae that proceed obliquely toward the lateral head margin; frontal lobes mostly covered by rugulae; propodeal spines well-developed, often nearly vertical as shown; postpetiolar node from above transversely carinulate. Minor: propodeal spines well-developed; occiput narrowed, with nuchal crest. Propodeal spines directed strongly upwards. Measurements (mm) Holotype major: HW 1.88, HL 2.08, SL 1.10, EL 0.24, PW 0.92. Paratype minor: HW 0.76, HL 0.94, SL 1.18, EL 0.18, PW 0.54. color Major: concolorous reddish yellow ("orange"). Minor: concolorous medium yellow. Range Known only from the type locality. biology Unknown. Figure Upper: holotype, major. Lower: paratype, minor. PERU: Quincemil, Cuzco, 750 m (L. Pena). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 300

Pheidole gaigei Forel Pheidole gaigei Forel 1914c: 616. Types Mus. Hist. Nat. Geneve; Mus. Comp. Zool. Harvard. Etymology Eponymous. diagnosis A member of the tristis group, similar to balzani, godmani, grandinodus, huilana, obrima, and, less so, to species listed with them, distinguished as follows. Major: postpetiole from above bell-shaped, 2X broader than petiole; postpetiole with prominent ventral, forward-projecting subangular process; anterior third of pronotal dorsum and all of mesopleuron carinulate; carinulae on dorsal surface of head reach midway between eye and occipital border. Minor: occiput very broad, lacking nuchal collar; propodeal spines reduced to denticles; margins all around of pronotal dorsum, as well as lower half of mesopleuron, carinulate. Measurements (mm) Syntype major: HW 1.28, HL 1.38, SL 0.72, EL 0.08, PW 0.62. Syntype minor: HW 0.64, HL 0.72, SL 0.66, EL 0.12, PW 0.44. Color Major: concolorous light reddish yellow. Minor: concolorous brownish yellow. Range Known only from the type locality. Biology Unknown. Figure Upper: syntype, major. Lower: syntype, minor. COLOMBIA: Mt. San Lorenzo, Sierra Nevada de Santa Marta, 1700 m. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 692

Pheidole tisiphone Wheeler Pheidole tisiphone Wheeler 191 lk: 203. Combination inpheidole (Elasmopheidole) by Emery 1915g: 190. types Nat. Mus. Nat. Hist. U. S. etymology Tisiphone, Avenger of Murders, one of the Furies of Greek mythology. Diagnosis A large member of the scrobifera group, with a bizarre major instantly recognizable by shield-shaped head in full-face view, with the frontal lobes expanded laterally to touch the lateral margins of the head at the level of the eyes and behind it and extended anteriorly almost to touch the anterior clypeal border; by the very dense, long hairs covering the entire head, with those around the region of the eye curving posteriorly; and by the deep, narrow antennal scrobes. The mesonotum is rugoreticulate in the Guatemalan specimen, and mostly carinulate in the unique holotype, but otherwise the two specimens are very close. measurements (mm) Holotype major: HW 1.80, HL 2.16, SL 0.76, EL 0.20, PW 1.00. color Major: body light reddish brown, appendages light reddish to yellowish brown. range Known only from the two major workers noted above, from Oaxaca, Mexico, and Guatemala. biology Unknown. figure Major. GUATEMALA: San Jose (E. S. Ross, in Mus. Comp. Zool. Harvard). Compared with unique holotype major, Almoloya, Oaxaca, Mexico, collected by Frederick Knab, in Nat. Mus. Nat. Hist U. S. Scale bar = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 632

Pheidole paiute Gregg Pheidole bicarinata subsp. paiute Gregg 1959: 17. Raised to species level by G. C and J. Wheeler 1973e: 75. Types Mus. Comp. Zool. Harvard. Etymology Named after one of the Amerindian peoples of the southwestern United States. diagnosis A member of the " bicarinata complex" of the larger pilifera group; for a characterization of the complex, see under bicarinata. P. paiute is distinguished within the complex by the following combination of traits. Major: propodeal spine in side view equilaterally triangular; humerus with a very low denticle in dorsal-oblique view; postpetiolar node laterally angular; sculpturing of head consists of carinulae confined entirely to the part anterior to the level of the posterior margin of the eyes. Minor: some of the hairs on the promesonotal dorsum are very long; propodeal spines in side view equilaterally triangular. Measurements (mm) Paratype major: HW 1.04, HL 1.14, SL 0.54, EL 0.18, PW 0.46. Paratype minor: HW 0.50, HL 0.56, SL 0.48, EL 0.12, PW 0.30. color Major: concolorous dark yellow. Minor: body brownish yellow, appendages brownish yellow to clear yellow. Range Deserts of Nevada and southern California. Biology In Nevada, George C. and Jeanette N. Wheeler (1986g) encountered paiute at 1040-2100 m in cottonwood groves, a triplex scrubland, pinyon-juniper woodland, and in disturbed habitats, nesting mostly under stones but also in open soil, where colonies built craters about 25 mm across. At Deep Canyon, near Palm Springs, California, the same authors found the species in larrea-palo verde scrub and desert, nesting in the soil; in one nest excavated, they found a cache of Oenothera clavaeformis seeds. Figure Upper: paratype, major. Lower: paratype, minor. NEVADA: Goldfield, Esmeraldo Co., Mojave Desert (William S. Creighton). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 588

Pheidole sicaria new species Types Mus. Comp. Zool. Harvard. Etymology L sicaria, with dagger, assassin. Diagnosis A member of the diligens group, most similar in habitus to scimitara of Peru, distinguished by the following traits. Major: brown; antennal scape slightly exceeding occipital border; propodeal spine as long as the basal propodeal face; postpetiole from above laterally angulate; head capsule swollen, so that venter is strongly convex, and Head Width exceeds Head Length; humerus subangulate in dorsal-oblique view; anterior third of pronotal dorsum carinulate; head lacking rugoreticulum; anterior third of central strip of first gastral tergite shagreened. Minor: propodeal spine as long as basal propodeal face; occiput narrowed, with nuchal collar. Measurements (mm) Holotype major: HW 1.20, HL 1.16, SL 1.04, EL 0.22, PW 0.60. Paratype minor: HW 0.62, HL 0.72, SL 1.00, EL 0.14, PW 0.42. Color Major: body, mandibles, and scape medium brown; rest of appendages light to yellowish brown. Minor: body light brown, appendages yellowish brown. Range Mid-elevation, Atlantic slope; also upper elevation, to 700 m, Osa Peninsula of Costa Rica (J. T. Longino 1997). Biology Known from mid-elevation rainforest and cloud forest. The types were collected by P. S. Ward on a palm trunk. Longino (1997) found two nests respectively in a clump of aroid roots and in loose dead leaves and fragments of carton lodged on the branch of a small Ocotea tree, whose hollow stems harbored a colony of Myrmelachista. Figure Upper: holotype, major. Lower: paratype, minor. COSTA RICA: Llorona, Corcovado National Park (Philip S. Ward). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA, USA :Harvard University Press on page 232

Pheidole gagates new species Types Mus. Comp. Zool. Harvard. etymology Gr gagates, jet (black), referring to the color of the workers. Diagnosis Distinguished within the diligens group by the following set of traits. Major: body concolorous blackish brown; pilosity extremely sparse, and completely absent from the mesosoma and waist; mesosomal convexity low, especially in dorsal-oblique view; postpetiolar node bell-shaped; patches of rugoreticulum present just mesad to the eyes; carinulae limited to lateral margins of the frontal lobes and sides of head anterior to the posterior margins of the eyes. Minor: body concolorous blackish brown; occiput narrow, with nuchal collar; sculpturing very sparse, limited to circular carinae around the antennal fossae and patches of foveolation as illustrated. See also anima, diligens, mooreorum, nubila, piceonigra, radoszkowskii, stigma, triconstricta, venatrix, and zelata. Measurements (mm) Holotype major: HW 0.92, HL 0.96, SL 0.62, EL 0.16, PW 0.50. Paratype minor: HW 0.46, HL 0.56, SL 0.68, EL 0.12, PW 0.32. Color See description above in Diagnosis. range Known from the type locality and from Yasuni National Park, Puerto Tipugini, Ecuador. Biology At Cuzco Amazonico, Peru, Cover and Tobin found colonies nesting in small rotten tree branches lying in leaf litter on the floor of rainforest. Figure Upper: holotype, major. Lower: paratype, minor. PERU: Cuzco Amazonico, 15 km northeast of Puerto Maldonado, Madre de Dios (Stefan Cover and John E. Tobin). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA, USA :Harvard University Press on page 192

Pheidole dorsata new species Types Mus. Comp. Zool. Harvard. Etymology L dorsata, of a ridge or back of a hill, referring to the peaked pronotum of the major in side view. Diagnosis A member of the tachigaliae group, characterized by 11-segmented antennae, and distinguished within it as follows. Major: in side view, pronotal profile broken by a sharp obtuse angle; rugoreticula present mesad and laterad to eye; all of dorsum of head posterior to eye transversely carinulate except for antennal scrobes, which are smooth; humeri and anterior pronotal margin rugoreticulate; postpetiole from above very broad and narrowly elliptical in shape. Minor: space between eyes and antennal fossae carinulate, foveolate, and opaque; rest of head smooth and shiny; in full-face view, a single, very long curving hair extends from each occipital corner; eye oval and set well forward on the head. Measurements (mm) Holotype major: HW 0.68, HL 0.74, SL 0.30, EL 0.08, PW 0.44. Paratype minor: HW 0.36, HL 0.40, SL 0.28, EL 0.06, PW 0.26. COLOR Major: body light brown, appendages yellowish brown. Minor: body medium brown, appendages brownish yellow. range Known only from the type locality. Biology The type colony was found in a shaded coffee plantation. Figure Upper: holotype, major. Lower: paratype, minor. COLOMBIA: Finca El Recreo, Magdalena, 850 m (Charles Kugler). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 635

Pheidole paraensis new species Types Mus. Comp. Zool. Harvard. Etymology Named after the Brazilian state of origin of the types. diagnosis A member of the " jujuyensis complex" of the larger fallax group, comprising araneoides, cuevasi, durionei, jujuyensis, kugleri, leonina, leptina, lucretii, lupus, paraensis, punctithorax, tijucana, wallacei, and wolfringi. P. paraensis differs as follows. Major: proportionately small-headed; head subrectangular in full-face view; a very loose (large-celled) rugoreticulum stretches on each side of the head from eye to frontal carina and is succeeded posteriorly by widely spaced rugulae that almost attain the occiput; antennal scape reaches about halfway between level of the eye and level of occiput; propodeal spines in side view reduced to right angles. Minor: propodeal spines absent; occiput narrowed, with thin nuchal collar. Measurements (mm) Holotype major: HW 1.50, HL 1.50, SL 1.00, EL 0.22, PW 0.68. Paratype minor: HW 0.46, HL 0.64, SL 0.86, EL 0.14, PW 0.34. color Major: body and mandibles light reddish brown, gaster plain light brown, appendages brownish yellow. Range Known only from the type locality. Biology Unknown. figure Upper: holotype, major. Lower: paratype, minor. BRAZIL: Utinga Tract, near Belem, Para (P. f. Darlington). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 335

Pheidole juniperae new species TYPES Mus. Comp. Zool. Harvard. Etymology Named after the prevailing tree of the type locality habitat. diagnosis Similar in various traits to chalca of Mexico, mera of Texas, and neolongiceps of Cuba, differing as follows. Major: yellow; shallow antennal scrobe present; carinulae originating on frontal lobes travel posteriorly all the way to but not across the occiput, which is smooth and sprinkled with foveae; space between eye and antennal fossa on each side of head rugoreticulate; almost all of mesosoma smooth and shiny; center of promesonotal dorsum in side view flat; postpetiole from above elliptical, with angulate lateral margins. Minor: eye large, Eye Length almost a fourth of Head Width, and nearly as long as distance from eye to anterior clypeal margin; occiput very broad, its margin weakly concave; propodeal spines small, in side view equilaterally triangular. measurements (mm) Holotype major: HW 0.80, HL 0.94, SL 0.42, EL 0.14, PW 0.50. Paratype minor: HW 0.44, HL 0.46, SL 0.38, EL 0.08, PW 0.26. color Major: concolorous medium yellow, with mandibles a slightly darker shade. Minor: concolorous medium yellow. range Known from several collections at the type locality at 1660-1675 m. biology The species was found by Stefan Cover in juniper-oak-pinyon savanna with a grassy understory. The nest openings were cryptic and in most cases surmounted by a minute turret of vegetable fibers. No seeds were found in the nests. figure Upper: holotype, major. Lower: paratype, minor. ARIZONA: 11 km west-northwest of Montezuma Pass, Huachuca Mts., Cochise Co., 1660 m (Stefan Cover). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 440

Pheidole tenuis new species types Mus. Comp. Zool. Harvard. Etymology L tenuis, thin, referring to the body shape. diagnosis A member of the diligens group similar to calimana, cataractae, demeter, machetula, scimitara, and sicaria, distinguished as follows. Major: scape just reaches occipital border; propodeal spines stout, one-fourth as long as basal propodeal face; postpetiolar node laterally angulate; lower mesopleuron and middle of propodeal side with short, broken rugulae; cephalic carinulae do not extend posteriorly beyond eye. Minor: occiput narrowed but lacking nuchal collar; mesonotal convexity in side view very small and subangulate; genae lacking carinulae. Measurements (mm) Holotype major: HW 0.80, HL 0.80, SL 0.84, EL 0.12, PW 0.44. Paratype minor: HW 0.44, HL 0.52, SL 0.62, EL 0.10, PW 0.28. Color Major: head bicolorous, with narrow strip on clypeus and genae yellowish brown, and remainder dark brown; body concolorous dark brown. Minor: body blackish brown, appendages medium brown. Range Known only from the type locality. Biology Collected from a slope covered by spiny bamboo (Guadua). Figure Upper: holotype, major. Lower: paratype, minor. COLOMBIA: Finca Los Guadales, 10 km south of San Jose del Palmar, Rio Torito, Choco, 760 m (Charles Kugler). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA, USA :Harvard University Press on page 238

Pheidole weiseri Santschi, new status Pheidole (Elasmopheidole) aberrans st. weiseri Santschi 1923d: 64. Types Naturhist. Mus. Basel. Etymology Eponymous. Diagnosis A member of the aberrans group, closest to minensis and obscurifrons. Major: light yellow; frontal lobes seen from the side form prominent lobes that only partly overhang the clypeus; seen from above, the lobes are broad, and subangular at their anterior tips, which extend to within an Eye Length of the anterior clypeal border; tips of frontal lobes smooth, which surfaces are succeeded posteriorly by a broad band of carinulae, and this gives way at eye level to a smooth area that extends all the way to the occiput; pronotal profile semicircular; faint carinulae line the lower pronotal margin. Minor: pronotum covered by semicircular carinulae, and mesopleuron by foveolae and longitudinal carinulae. Measurements (mm) Lectotype major: HW 1.42, HL 1.64, SL 0.58, EL 0.18, PW 0.84. Paralectotype minor: HW 0.80, HL 0.80, SL 0.58, EL 0.12, PW 0.48. Color Major: concolorous light reddish yellow. Minor: body light brown, appendages brownish yellow. range Known only from the type locality. Biology Unknown. Figure Upper: lectotype, major. Lower: paralectotype, minor. ARGENTINA: Pucapampa, near Santa Catalina, Jujuy. Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 142

Pheidole lignicola Mayr Pheidole lignicola Mayr 1887: 586. Syn.: Pheidole lignicola var. levocciput Forel 1908h: 370, n.syn. Raised to species level in this monograph: bruchella, victima. Types Naturhist. Mus. Wien. Etymology L lignicola, dwelling in wood. Diagnosis Similar in various traits to the species listed in heading above, distinguished as follows. Major: yellowish brown; occiput and space between eye and antennal fossa on each side rugoreticulate; most of rest of dorsal surface of head carinulate; antennal scape relatively long, its tip touching the sides of the head just posterior to the midpoint between the eye and level of the occipital lobe; mesonotal convexity well defined both anteriorly and posteriorly; humerus, in dorsal-oblique view low and smoothly rounded; propodeal spine moderately long and thin; postpetiole from above narrow and oval; almost all of body except gaster foveolate. Minor: posterior half of venter of head in profile weakly concave; humerus in dorsal-oblique view subangulate; propodeal spine vertical to propodeal basal face; occiput slightly narrowed, its margin weakly concave, and nuchal collar absent. Almost all of head and mesosoma foveolate and opaque. Measurements (mm) Lectotype major: HW 0.88, HL 0.90, SL 0.56, EL 0.10, PW 0.44. Paralectotype minor: HW 0.42, HL 0.52, SL 0.50, EL 0.06, PW 0.30. Color Major: medium yellowish brown. Minor: light yellowish brown. range Recorded from Buenos Aires, Argentina; San Bernardino and Jejuimi, Paraguay; and Sao Paulo and Santa Catarina states, Brazil. biology Unknown. Figure Upper: major, compared with lectotype. Lower: minor, compared with paralectotype. BRAZIL: Caraguatatuba, Sao Paulo (W. L. Brown). (Type locality: Santa Catarina, Brazil.) Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 444

Pheidole obtusopilosa Mayr Pheidole obtusopilosa Mayr 1887: 586. Raised to species level in this monograph: heterothrix. Types Naturhist. Mus. Wien. Etymology L obtusopilosa, blunt-haired, allusion uncertain. Diagnosis Similar to heterothrix, distinguished from it and other Pheidole species by the following combination of traits. Major: entire dorsal surface of head rugoreticulate except for frontal lobes, frontal triangle, clypeus, and anterior genae; humeri rugoreticulate; anterior margin of pronotal dorsum carinulate; all of mesosoma and waist foveolate; postpetiole from above elliptical. Minor: almost all of body except gaster foveolate and opaque; humeri subangulate; propodeal spines moderately long and slender; occipital margin concave; nuchal collar absent. Measurements (mm) Lectotype major: HW 1.16, HL 1.18, SL 0.54, EL 0.14, PW 0.60. Paralectotype minor: HW 0.56, HL 0.58, SL 0.50, EL 0.10, PW 0.36. Color Major: body light reddish brown except for gaster, which is plain medium brown. Range Recorded from Uruguay; and, in Argentina, the northern and central provinces of Buenos Aires, Cordoba, Jujuy, La Pampa, and Tucuman (Kempf 1972b). I have confirmed a series from Sao Paulo. biology A collection of obtusopilosa was made by William L. Brown at the Boraceia Biological Station, near Salesopolis, Sao Paulo, in wet mountain forest at 850 m. Figure Upper: lectotype, major. Lower: paralectotype, minor. URUGUAY (no further locality). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 477

Pheidole skwarrae Wheeler Pheidole skwarrae Wheeler 1934g: 163. Types Mus. Comp. Zool. Harvard. Etymology Named after the collector, Elisabeth Skwarra. Diagnosis A member of the fallax group, closet to vistana and distinguished from it and other fallax group species by the following combination of traits. Major: head elongate, with deep occipital cleft and subangulate occipital lobes in full-face view; antennal scape exceeding the occipital lobe by 2X its own maximum width; entire body, including all of the tergites and sternites of the gaster, foveolate and opaque; space between eye, frontal lobes, and frontal carinae rugoreticulate. Minor: entire body, including at least the anterior two segments of the gaster, foveolate and opaque; nuchal collar well developed; antennal scape very long, extending 2X the distance between its insertion and nuchal collar. Measurements (mm) Lectotype major: HW 1.32, HL 1.60, SL 1.42, EL 0.24, PW 0.64. Paralectotype minor: HW 0.54, HL 0.84, SL 1.20, EL 0.16, PW 0.42. Color Major and minor: body concolorous medium brown, appendages yellowish brown. range Known only from the type locality. Biology The type colony was nesting beneath a stone. figure Upper: lectotype, major. Lower: paralectotype, minor. MEXICO: Cuernavaca, Morelos (Elisabeth Skwarra). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 349

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., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 602

Pheidole lovejoyi new species Types Mus. Comp. Zool. Harvard. etymology Named after Thomas E. Lovejoy, distinguished field biologist and my host at Fazenda Dimona. diagnosis A member of the fallax group, most similar to laniger (but also scan alienata, cardinalis, caribbaea, fallax, jelskii, lattkei, mantilla, obscurior, petrensis, puttemansi, rubiceps, roushae, susannae, tobini), distinguished by the following combination of traits. Major: in full-face view, profde of head posterior to eyes fringed by short, subrecumbent hairs of uniform length; in side view, center of pronotal dorsal profile raised as a low convexity; petiolar peduncle slender, its dorsal border concave in side view; pronotal dorsum partly carinulate; anterior strip of first gastral tergite foveolate and opaque. Minor: nuchal collar present; propodeal spine reduced to obtuse angle. Measurements (mm) Holotype major: HW 1.42, HL 1.50, SL 1.04, EL 0.20, PW 0.66. Paratype minor: HW 0.46, HL 0.64, SL 0.94, EL 0.12, PW 0.34. Color Major: head reddish brown, mesosoma plain medium brown, gaster and appendages plain light brown. Minor: head medium brownish yellow, appendages and rest of head medium brownish yellow. Range Known only from the type locality. Biology In lowland rainforest. Figure Upper: holotype, major. Lower: paratype, minor. BRAZIL: Fazenda Dimona, Smithsonian Institution Field Station, 90 km north of Manaus, Amazonas (E. O. Wilson). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 318

Pheidole bicornis Forel Pheidole bicornis Forel 1899e: 74. Types Mus. Hist. Nat. Geneve. Etymology L bicornis, two-horned, referring to the cornulate extensions of the frontal lobes of the major. diagnosis A member of the transversostriata group and evidently close to the tristis group, easily distinguished by its small size; and in the major by the sharp, upturned horn-like extensions of the frontal lobes and heavy rugoreticulate dorsum of the head, broken in the central posterior region by a ladder-like sequence of parallel transverse carinae. Measurements (mm) Lectotype major: HW 0.86, HL 1.08, SL 0.38, EL 0.12, PW 0.54. Minor (San Vito, Costa Rica): HW 0.48, HL 0.54, SL 0.42, EL 0.08, PW 0.32. Color Major: concolorous light reddish brown. Minor: concolorous yellow. Range Costa Rica, Panama. In Costa Rica the species has been found in both the Atlantic and Pacific lowlands (Longino 1997) and to an elevation of 1270 m (Risch et al. 1977). Biology In Costa Rica at least, P. bicornis is an obligate inhabitant of species of understory rainforest shrubs of the genus Piper. The ants live in cavities of the petioles and stems that they hollow out themselves. The relationship appears to be mutualistic: the workers, which seldom forage on the ground, feed on lipid-rich food bodies developing within the petiolar cavities. For their part the plants evidently benefit from the removal of the eggs and early stages of herbivorous insects (Letourneau 1983), as well as from the clearing of vines and transport of organic material into the plant by the ants during nest construction (Risch et al. 1977). Figure Upper: lectotype, major (Bugaba, Panama). Lower: minor (Finca Loma Linda, near Agua Buena, Puntarenas, Costa Rica, J. Vandermeer). Scale bars = 1 mm., Published as part of Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA :Harvard University Press on page 641