Pseudomyrmex deminutus

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Pseudomyrmex deminutus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Pseudomyrmecinae
Genus: Pseudomyrmex
Species: P. deminutus
Binomial name
Pseudomyrmex deminutus
Ward, 1999

The only known collection is from a Tachigali plant in southern Amazonas state, Brazil.


Ward (1999) - There are no other known species in the sericeus species group in which the queen has such an elongate head (CI ≈ 0.66). The small size, relatively short eyes (for the species group), broad profemur and narrow petiole are also distinctive. In petiole shape P. deminutus is perhaps closest to Pseudomyrmex vinneni but the queens of that species are larger (HW 0.96–1.06) with broader heads (CI 0.77–0.81) and longer eyes (REL 0.60–0.63).


Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb



Known only from the queen caste.


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

  • deminutus. Pseudomyrmex deminutus Ward, 1999b: 517, figs. 50, 59, 68 (q.) BRAZIL.

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



Measurements (n=3). HL 1.19–1.21, HW 0.78, MFC 0.015–0.022, LHT 0.67– 0.68, CI 0.65–0.66, REL 0.58–0.59, REL2 0.89–0.90, FCI 0.02–0.03, FI 0.52–0.53, PLI 0.87–0.88, PWI 0.69–0.72.

A species in the sericeus species group of small stature (HW < 0.80, LHT < 0.70). Palp formula 5,4. Frontal carinae closely contiguous; head elongate, with straight sides and concave posterior margin, in frontal view; eyes relatively short in relation to head length (REL < 0.60); profemur very broad (see FI values). Petiole relatively low, long and narrow, not expanded posterolaterally; petiolar node rounded in lateral view, without differentiated anterior and dorsal faces. Anteroventral petiolar process thin and blunt. Standing pilosity sparse, a pair of long, thin, pale setae on the anterior pronotum, posterior pronotum, mesoscutellum, petiole, and postpetiole. Brownish-black, the antennae, frontoclypeal complex, protibia, and tarsi yellow-brown.

Type Material

Holotype alate queen. BRAZIL Amazonas: Rio Juma, near Apui, 400 km E Humaita, Transamazonica Hwy. [7°08’S, 59°57’W], 30.iv.1985, ex Tachigali, F. Rickson B-41-85 (Museum of Comparative Zoology). HW 0.78, HL 1.19, EL 0.70, LHT 0.68, PL 0.52, PH 0.45.

Paratypes. Same data as holotype: two alate queens (Museu de Zoologia da Universidade de Sao Paulo, Philip S. Ward Collection).


  • Ward, P. S. 1999b. Systematics, biogeography and host plant associations of the Pseudomyrmex viduus group (Hymenoptera: Formicidae), Triplaris- and Tachigali-inhabiting ants. Zool. J. Linn. Soc. 126: 451-540 (page 517, figs. 50, 59, 68 queen described)