Pheidole erratilis

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Pheidole erratilis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Pheidole
Species: P. erratilis
Binomial name
Pheidole erratilis
Wilson, 2003

Pheidole erratilis inbiocri001282704 p 1 high.jpg

Specimen Label


This species occurs in wet forest habitats, from sea level to 1400m elevation. Nests are in rotten wood or dead sticks on or near the forest floor. Workers are occasionally collected in Winkler or Berlese samples, but have not been collected at baits. In the Osa region, a colony was found in necrotic cavities beneath the bracts of a live Costus inflorescence. (Longino 1997, Longino 2009).


See the description in the nomenclature section.

Keys including this Species


Widespread in wet forest to 800 m in Peñas Blancas and 2000 m in Braulio Carrillo (Longino 1997).

Distribution based on Regional Taxon Lists

Neotropical Region: Costa Rica (type locality), Nicaragua.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb






The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • erratilis. Pheidole erratilis Wilson, 2003: 414, figs. (s.w.) COSTA RICA. Senior synonym of petersoni: Longino, 2009: 31.
  • petersoni. Pheidole petersoni Wilson, 2003: 486, figs. (s.w.) COSTA RICA. Junior synonym of erratilis: Longino, 2009: 31.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.


A relatively large, brown member of the flavens group distinguished by a combination of exceptionally long pilosity and prominent, “sharkfin” shape of the humerus in major and minor, and narrow occiput surmounted by a collar in the minor.

Similar to Pheidole petersoni of Costa Rica but with longer pilosity and absence of rugoreticulum on the mesosoma in both castes, and more extensive cephalic carinulae in the major (but less extensive in the minor).

See also these less similar species: Pheidole angulifera, Pheidole ecuadorana, Pheidole pariana, Pheidole polita (in the tristis group), Pheidole tennantae, Pheidole schmalzi and Pheidole styrax.

MEASUREMENTS (mm) Holotype major: HW 1.06, HL 1.12, SL 0.62, EL 0.12, PW 0.48. Paratype minor: HW 0.56, HL 0.62, SL 0.60, EL 0.14, PW 0.34.

COLOR Major: gaster medium brown, tarsi dark yellow, rest of body and appendages light reddish brown.

Minor: body dark, almost blackish brown, appendages light reddish brown.

Pheidole erratilis Wilson 2003.jpg

Figure. Upper: holotype, major. Lower: paratype, minor. Scale bars = 1 mm.

Type Material

Longino (2009):

Holotype major worker and associated paratype minor worker: Costa Rica, Prov. Alajuela, 3km S Volcan Arenal, 10°26'N 84°42'W, 700m, 17 Feb 1994 (J. Longino) [[[INBC|Instituto Nacional de Biodiversidad]]] (examined).

Pheidole petersoni Holotype major worker and associated paratype minor worker: Costa Rica, Prov. Alajuela, Peñas Blancas, 10.300° N 84.751°W, 940m, 24 Jul 1984 (J. Longino) [[[INBC|Instituto Nacional de Biodiversidad]]] (examined).


L erratilis, wanderer, alluding to the wide range of habitats occupied in Costa Rica.