Pheidole rudigenis

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Pheidole rudigenis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Pheidole
Species: P. rudigenis
Binomial name
Pheidole rudigenis
Emery, 1906

Pheidole rudigenis casent0178049 profile 1.jpg

Pheidole rudigenis casent0178049 dorsal 1.jpg

Specimen labels


The Itaúnas series was collected by R. Paiva inside a nest of a giant ponerine ant, ‘’Dinoponera’’ sp.; the relationship, if any, is unknown. (Wilson 2003)


See the description in the nomenclature section.

Keys including this Species


In addition to the types, I have seen a series from Itaúnas, Espirito Santo, southeastern Brazil. The holotype of synonymous Pheidole bucolica is from Monte Alegre, Pará, in Amazonian Brazil, an anomalous record for the species. (Wilson 2003)

Latitudinal Distribution Pattern

Latitudinal Range: 25.68015° to -28.4°.

Tropical South

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina (type locality), Brazil, Paraguay.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.





Images from AntWeb

Pheidole rudigenis casent0178050 head 1.jpgPheidole rudigenis casent0178050 profile 1.jpgPheidole rudigenis casent0178050 dorsal 1.jpgPheidole rudigenis casent0178050 label 1.jpg
Worker. Specimen code casent0178050. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by ALWC, Alex L. Wild Collection.


Images from AntWeb

Pheidole rudigenis casent0178049 head 2.jpg
Worker (major/soldier). Specimen code casent0178049. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by ALWC, Alex L. Wild Collection.


The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • rudigenis. Pheidole flavens subsp. rudigenis Emery, 1906c: 155 (s.) ARGENTINA. Raised to species and senior synonym of bucolica: Wilson, 2003: 498.
  • bucolica. Pheidole bucolica Santschi, 1929d: 289, figs. 19-21 (s.) BRAZIL. Junior synonym of rudigenis: Wilson, 2003: 498.

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


DIAGNOSIS From Wilson (2003): Similar to Pheidole exigua, Pheidole glomericeps, Pheidole moffetti, Pheidole nana and Pheidole styrax, differing as follows.

Major: shallow antennal scrobes present; occipital lobes and humeri rugoreticulate; dorsal surfaces of head and pronotum otherwise carinulate; dorsal promesonotal profile elevated, strongly convex, mesonotal convexity subangulate; propodeal spines half the length of the propodeal dorsal face; postpetiolar node from above diamond-shaped.

Minor: space between eye and antennal fossa, as well as anterior third of promesonotal dorsum, rugoreticulate; entire head and mesosoma foveolate and opaque; propodeal spines half as long as propodeal basal face; occiput broad and convex.

The holotype of Pheidole bucolica, placed in provisional synonymy, differs from the rudigenis lectotype in its oval postpetiole, as depicted, and more strongly rugulose genae; given its distant origin, in Pará, it may be a distinct species.

MEASUREMENTS (mm) Lectotype major: HW 1.04, HL 1.02, SL 0.56, EL 0.14, PW 0.50. Paralectotype minor: HW 0.54, HL 0.60, SL 0.52, EL 0.08, PW 0.36.

COLOR Major: head, mesosoma, and waist light reddish brown; gaster and antennae medium brownish yellow; legs light brownish yellow.

Minor: head and mesosoma medium yellowish brown; waist, gaster, and appendages light yellowish brown.

Pheidole rudigenis Wilson 2003.jpg

Figure. Upper: lectotype, major (second, lower outline of postpetiole dorsum is of synonymous bucolica holotype). Lower: paralectotype, minor. Scale bars = 1 mm.

Type Material

ARGENTINA: San Pedro, Misiones. (Wilson 2003) - as reported in Wilson (2003)


L rudigenis, rough cheek, referring to sculpturing of head. (Wilson 2003)


References based on Global Ant Biodiversity Informatics

  • Bruch C. 1914. Catálogo sistemático de los formícidos argentinos. Revista del Museo de La Plata 19: 211-234.
  • Cuezzo, F. 1998. Formicidae. Chapter 42 in Morrone J.J., and S. Coscaron (dirs) Biodiversidad de artropodos argentinos: una perspectiva biotaxonomica Ediciones Sur, La Plata. Pages 452-462.
  • Emery C. 1906. Studi sulle formiche della fauna neotropica. XXVI. Bullettino della Società Entomologica Italiana 37: 107-194.
  • Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
  • Santschi F. 1933. Fourmis de la République Argentine en particulier du territoire de Misiones. Anales de la Sociedad Cientifica Argentina. 116: 105-124.
  • Vittar, F. 2008. Hormigas (Hymenoptera: Formicidae) de la Mesopotamia Argentina. INSUGEO Miscelania 17(2):447-466
  • Wild, A. L. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.