Pseudomyrmex pictus

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Pseudomyrmex pictus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Pseudomyrmecinae
Genus: Pseudomyrmex
Species: P. pictus
Binomial name
Pseudomyrmex pictus
(Stitz, 1913)

Pseudomyrmex pictus focol1193 p 1 high.jpg

Pseudomyrmex pictus focol1193 d 1 high.jpg

Specimen Labels


P. pictus is typically associated with Tachigali, but the types of heterogyna were reportedly collected from the ‘hairy cauline swelling’ of a Platymiscium species (Wheeler & Mann, 1942a: 173).


Ward (1999) - P. pictus is most easily recognized by its predominantly light (orange-brown) coloration, broad head (worker CI > 0.90, queen CI ≈ 0.86), slender worker profemur (FI 0.36–0.41), and long legs (worker LHT/HL 0.82–0.91, queen LHT/HL ≈ 0.75). The superficially similar Pseudomyrmex rubiginosus, which is also light in colour, has a darker and more elongate head, broader worker profemur, shorter legs, and a more blocky petiole. P. pictus appears to be most closely related to Pseudomyrmex eculeus (see eculeus).


Known from Bolivia, western Brazil, Colombia and Peru.

Distribution based on Regional Taxon Lists

Neotropical Region: Bolivia, Brazil (type locality), Colombia, Peru.

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.

  • pictus. Pseudomyrma picta Stitz, 1913: 209, fig. 2 (w.) BRAZIL. Combination in Pseudomyrmex: Kempf, 1961a: 399. Senior synonym of casta, heterogyna, humboldi: Ward, 1999b: 524. See also: Wheeler, W.M. 1942: 171.
  • casta. Pseudomyrma picta subsp. casta Wheeler, W.M. 1942: 173 (w.) PERU. Combination in Pseudomyrmex: Kempf, 1972a: 222. Junior synonym of pictus: Ward, 1999b: 524.
  • heterogyna. Pseudomyrma picta var. heterogyna Wheeler, W.M. & Mann, in Wheeler, W.M. 1942: 172 (w.q.) BOLIVIA. Combination in Pseudomyrmex: Kusnezov, 1953e: 214. Junior synonym of pictus: Ward, 1999b: 524.
  • humboldi. Pseudomyrma picta var. humboldi Enzmann, E.V. 1944: 75 (diagnosis in key), pl. 3, fig. 21 (w.) BRAZIL. Combination in Pseudomyrmex: Kempf, 1972a: 222. Junior synonym of pictus: Ward, 1999b: 525.

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



Ward (1999) - Measurements (n=10). HL 1.21–1.43, HW 1.19–1.38, MFC 0.038–0.059, LHT 1.02–1.26, CI 0.91–1.03, REL 0.60–0.64, REL2 0.61–0.67, FCI 0.03–0.05, FI 0.36–0.41, PLI 1.00–1.10, PWI 0.80–0.94.

Worker description. A member of the sericeus group. Palp formula variable: 6,4 or 5,4. Frontal carinae relatively well separated; head broad, with strongly convex sides; posterior margin of head straight or slightly concave, in frontal view. Profemur very slender (see FI values); legs long (LHT/HL 0.82–0.91). Dorsal face of Propodeum somewhat convex and rounding gradually into the declivitous face; length of dorsal face subequal to or slightly shorter than that of the declivitous face; propodeal spiracle distant from the basal (dorsal) face of propodeum. Petiole as high as long to slightly higher than long, subtriangular in profile, with a single convex anterodorsal face, which rounds gently into the steep posterior face. Anteroventral process small, subrectangular or subtriangular, usually with a blunt posteroventral angle or tooth. Standing pilosity variable, more common than is usual for the species group. Long, golden, paired (and often curved) setae present on pronotum (1–6 pairs), mesonotum (0–1 pairs), on propodeum at the junction of the basal and declivitous faces (0–1 pairs), petiole (1–3 pairs) and postpetiole (2–3 pairs); these setae sometimes unpaired, or accompanied by one or two additional shorter setae. Body, including appendages, predominantly orange-brown in colour; legs, mesosoma (especially dorsal face of propodeum), petiole, and gaster with variable amounts of darker maculation.

Type Material

Ward (1999) - Syntype workers, Alto Acre, Brazil (Ule) (Berlin Museum für Naturkunde der Humboldt-Universität) [Examined].

Pseudomyrma picta var. heterogyna Wheeler & Mann, 1942a:172. Syntype workers, one dealate queen, Cavinas, Bolivia (W. M. Mann) (Museum of Comparative Zoology) [Examined].

Pseudomyrma picta subsp. casta Wheeler, 1942:173. Syntype workers, La Sombre, Putumayo, Peru ( J. C. Bradley) (MCZC) [Examined].

Pseudomyrma picta var. humboldi Enzmann, 1944:75. Syntype workers, one dealate queen, Cavinas, Bolivia (W. M. Mann) (MCZC) [Examined].


  • Kempf, W. W. 1961a. Estudos sôbre Pseudomyrmex. III. (Hymenoptera: Formicidae). Stud. Entomol. 4: 369-408 (page 399, Combination in Pseudomyrmex)
  • Stitz, H. 1913. Ameisen aus Brasilien, gesammelt von Ule. (Hym.). Dtsch. Entomol. Z. 1913: 207-212 (page 209, fig. 2 worker described)
  • 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 524, Senior synonym of casta, heterogyna and humboldi)
  • Wheeler, W. M. 1942. Studies of Neotropical ant-plants and their ants. Bull. Mus. Comp. Zool. 90: 1-262 (page 171, see also)