Pheidole fallax Mayr

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press, pp. -1--1: 290

publication ID


persistent identifier

treatment provided by


scientific name

Pheidole fallax Mayr


Pheidole fallax Mayr  HNS 

Pheidole fallax Mayr  HNS  1870b: 984. Syn.: Pheidole fallax r. columbica  HNS  Forel 1886b: xliv, n. syn.; Pheidole jelskii var. fallacior  HNS  Forel 1901j: 356, n. syn.; Pheidole fallax var. britoi  HNS  Forel 1912g: 221, n. syn.; Pheidole fallax var. ovalis  HNS  Forel 1912g: 221, n. syn. Raised to species level in this monograph: infraspecific variants jelskii  HNS  , obscurithorax  HNS  , puttemansi  HNS  .

Types Naturhist. Mus. Wien.

Etymology L fallax  HNS  , deceitful, false; allusion unknown.

diagnosis A member of the fallax  HNS  group, similar to gigas  HNS  , jelskii  HNS  , obscurithorax  HNS  , puttemansi  HNS  , roushae  HNS  , tobini  HNS  , and valens  HNS  , and especially the very abundant and widespread jelskii  HNS  , with which it is easily confused.

Major: posterior half of dorsal surface of head primarily carinulate, with rugoreticulum extensive mesad of the eye most of the way to the occiput; pronotum transversely carinulate; anterior fourth to third of central strip of first gastral tergite shagreened; head tapered toward occiput in side view, as shown.

P. fallax  HNS  differs from P. jelskii  HNS  as follows and as depicted: in major, petiolar node higher and descending to peduncle by a much more concave curve, and scapes shorter (Scape Length/Head Width 0.50-0.59 as opposed to 0.60-0.70 in jelskii  HNS  major); and in minor, occiput much broader and nuchal collar thinner than in jelskii  HNS  .

Measurements (mm) Lectotype major: HW 1.72, HL 1.84, SL 0.90, EL 0.24, PW 0.80. Paralectotype minor: HW 0.60, HL 0.72, SL 0.92, EL 0.18, PW 0.40.

Color Major and minor: body medium reddish brown, with gaster sometimes dark reddish brown.

Range A circum-Caribbean species, which I have verified from the Greater Antilles (Cuba, Jamaica, Puerto Rico), Central America, Colombia, and Venezuela. No certain records exist from the Lesser Antilles, where the closely related jelskii  HNS  abounds.

Biology Because fallax  HNS  has a range enclosed by the more abundant jelskii  HNS  and is so easily confused with it, natural history notes published in the past under the name of either species are generally unreliable.

Figure Upper: major (compared with lectotype); variation in hypostomal teeth shown is with specimens from Puerto Rico (4 teeth) and Cuba (3 teeth). Lower: minor (compared with paralectotype, which shares the long, thin propodeal spine depicted; the very short spine at the top is of a Panama specimen, and the medium-length spine in the middle is of a syntype of the synonymous " var. columbica  HNS  "). CUBA: Soledad, Las Villas. (Type locality: Cuba.) Scale bars = 1 mm.