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Species: Pheidole nigella   Emery, 1894 

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Taxonomic History (provided by Barry Bolton, 2019)

Pheidole fabricator var. nigella Emery, 1894d PDF: 155 (s.w.) BOLIVIA. Neotropic. AntCat AntWiki HOL

Taxonomic history

Raised to species and senior synonym of Pheidole dimidiata: Wilson, 2003A: 728.


  Geographic regions (According to curated Geolocale/Taxon lists):
    Americas: Bolivia, Mexico
  Biogeographic regions (According to curated Bioregion/Taxon lists):


J. Longino, 24 Apr 2014: Wilson's synonymy of P. dimidiata under P. nigella is probably incorrect. The types of P. nigella have major HW around 1.1, the pilosity on the sides of the major head is relatively short and somewhat appressed, and the minor worker has the face and the lateral pronotum smooth and shining. The types of P. dimidiata have major HW 0.87 (based on AntWeb image), the pilosity on the sides of the major head is relatively long and erect, and the minor worker has the face smooth and shining but the lateral pronotum foveolate. Pheidole dimidiata is actually much more similar to Wilson's P. boliviana. The majors of these two appear identical (based on AntWeb images). The minors are also very similar in shape, size, pilosity, and sculpture of the lateral mesosoma. The only difference is face sculpture: P. boliviana has foveolate face, P. dimidiata has mostly smooth and shiny face.

Taxonomic Treatment (provided by Plazi)

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

Pheidole nigella EmeryHNS, new status

Pheidole fabricator var. nigella EmeryHNS 1894d: 155. Syn.: Pheidole dimidiata EmeryHNS 1894d: 160, n. syn. Raised to species level in this monograph: nitidicollisHNS, schmalziHNS.

Types Mus. Civ. Stor. Nat. Genova.

Etymology L nigellaHNS, little dark one.

diagnosis A member of the tristisHNS group similar to balzaniHNS, fabricatorHNS, and tristisHNS, and distinguished from these and other species in the group by the following traits.

Major: small and dark; occiput with very broad, moderately deep median occipital concavity in full-face view; humerus in dorsaloblique view a low, smooth convexity that runs almost indistinguishably into the mesothorax; mesothoracic convexity extremely reduced, barely visible; postpetiolar node oval; weak longitudinal carinulae cover sides of pronotum.

Minor: humerus with low blunt denticle in dorsal-oblique view; pronotum and mesonotum indistinguishable in a single profile; mesonotal convexity absent.

Measurements (mm) Major ( nigellaHNS lectotype): HW 1.06, HL 1.10, SL 0.60, EL 0.14, PW 0.50. Minor: HW 0.54, HL 0.60, SL 0.54, EL 0.10, PW 0.38.

Color Major and minor: body concolorous medium brown, appendages brownish yellow.

Range Known from Bolivia and Peru.

Biology Unknown.

figure Upper: major (syntype of synonymous P. dimidiata EmeryHNS). Lower: minor (syntype of synonymous P. dimidiata EmeryHNS). BOLIVIA: Salinas, Rio Beni, Bolivia; Luigi Balzan. (Type locality of nigellaHNS: also Salinas, Rio Beni, Bolivia; Luigi Balzan.) Scale bars = 1 mm.

Specimen Habitat Summary

Found most commonly in these habitats: 1 times found in lowland wet forest, 1 times found in mature wet forest.

Found most commonly in these microhabitats: 1 times ex dead wood, 1 times at bait.

Collected most commonly using these methods: 1 times Baiting, 1 times search.

Elevations: collected at 160 m

Type specimens: Lectotype of Pheidole dimidiata: casent0904426; Lectotype of Pheidole fabricator nigella: casent0904379; paralectotype of Pheidole dimidiata: casent0904427; paralectotype of Pheidole fabricator nigella: casent0904380

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