Pheidole embolopyx

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Pheidole embolopyx
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Pheidole
Species: P. embolopyx
Binomial name
Pheidole embolopyx
Brown, 1968

MCZ-ENT00031612 Pheidole embolopyx hal.jpg

MCZ-ENT00031612 Pheidole embolopyx had.jpg

Type Label

Pheidole embolopyx inhabits rainforest, nesting in pieces of rotting wood buried in litter. Mature colonies contain up to several hundred workers and a single nest queen. Winged queens have been found in March near Manaus. The queens do not use their truncated abdomens to block galleries and nest entrances, as expected (Wilson and Hölldobler 1985). Instead, it is likely that they assume a turtle-like crouching position when threatened, bringing into play the truncated abdomen, flanges on the pronotum, and gelatinous secretions on the front of the head. Wilson and Hölldobler also report the origin of an odor-trail pheromone in the poison gland and an alarm pheromone in the pygidial gland. (Wilson 2003)

At a Glance • Phragmotic  



See the description in the nomenclature section.

Keys including this Species


In addition to two localities around Manaus, embolopyx has been recorded from Diamantino, Mato Grosso; from near Puerto Maldonado, Madre de Dios, Peru; and Yasuni National Park in Ecuador. (Wilson 2003)

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality), Ecuador, Peru.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


Life History Traits

  • Mean colony size: 300 (Wilson & Holldobler, 1985; Beckers et al., 1989)
  • Foraging behaviour: mass recruiter (Wilson & Holldobler, 1985; Beckers et al., 1989)



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

  • embolopyx. Pheidole embolopyx Brown, 1968a: 332, figs. 1-7 (s.w.q.) BRAZIL. See also: Wilson, 2003: 189.

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


From Wilson (2003): A unique species of Pheidole, distinguished in the queen by the posteriorly flattened gastral tergites, hence truncated shape of the gaster overall, and the flattened rear surface covered by peculiar short, hooked hairs.

Major: head bicolored with broad dark yellow to light reddish brown arcs over most of the dorsal surface and on the genae and the rest medium brown, as depicted; tip of antennal scape touching head margin two-thirds from level of eye to level of occiput; most of dorsal surface of head foveolate; anterior half of pronotal dorsum transversely carinulate; anterior half of central strip of first gastral tergite shagreened; propodeal spines thick, triangular; postpetiole from above oval.

Minor: head narrowed, with nuchal collar; propodeal spines reduced; margins of pronotal dorsum foveolate; anterior fourth of central strip of first gastral tergite shagreened.

MEASUREMENTS (mm) Paratype major: HW 0.94, HL 1.00, SL 0.74, EL 0.14, PW 0.44. Paratype minor: HW 0.44, HL 0.56, SL 0.72, EL 0.12, PW 0.32.

COLOR Major: head bicolored, as described in Diagnosis above; body light to dark yellow; appendages light brown to brownish yellow.

Minor: concolorous light brown, appendages dark yellow.

Pheidole embolopyx Wilson 2003.jpg

Figure. Upper: paratype, major. Lower: paratype, minor. A figure of a paratype queen is also shown (from Brown 1968b). Scale bars = 1 mm.

Holotype Specimen Labels

Type Material

BRAZIL: Ig. Marianil, Rio Branco Rd., 24 km northeast of Manaus. Museum of Comparative Zoology - as reported in Wilson (2003)


Gr embolopyx, stopper box, referring to the truncate abdomen of the queen. (Wilson 2003)


References based on Global Ant Biodiversity Informatics

  • De Souza Holanda P. M. 2016. Efeitos da variacao do lencol: freatico em assembleias de formigas (Hymenoptera: Formicidae) que vivem na serapilheira na reserva Adolpho Ducke, Manaus, Am. Master's Thesis Universidade Federal do Amazonas, 48 pages.
  • Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
  • Franco W., N. Ladino, J. H. C. Delabie, A. Dejean, J. Orivel, M. Fichaux, S. Groc, M. Leponce, and R. M. Feitosa. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674(5): 509-543.
  • Vasconcelos H. L., J. M. S. Vilhena, W. E. Magnusson, and A. L. K. M. Albernaz. 2006. Long-term effects of forest fragmentation on Amazonian ant communities. Journal of Biogeography 33: 1348-1356.
  • Vasconcelos, H.L., J.M.S. Vilhena, W.E. Magnusson and A.L.K.M. Albernaz. 2006. Long-term effects of forest fragmentation on Amazonian ant communities. Journal of Biogeography 33:1348-1356