Pseudomyrmex malignus

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Pseudomyrmex malignus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Pseudomyrmecinae
Genus: Pseudomyrmex
Species: P. malignus
Binomial name
Pseudomyrmex malignus
(Wheeler, W.M., 1921)

Pseudomyrmex malignus casent0902888 p 1 high.jpg

Pseudomyrmex malignus casent0902888 d 1 high.jpg

Specimen Labels


An inhabitant of the eastern Amazon basin.


Ward (1999) - The workers and queens of this species can be distinguished from all other members of the viduus group by the combination of well separated frontal carinae (MFC >> basal scape width), laterally angulate median clypeal lobe, and the absence of erect hairs from the posterior margin and upper sides of the head (full-face view). The short dorsal face of the propodeum and shiny integument are also characteristic.


Distribution based on Regional Taxon Lists

Neotropical Region: French Guiana, Guyana (type locality), Suriname, Trinidad and Tobago.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


Ward (1999) - This is a Tachigali-inhabiting species, less frequently encountered than Pseudomyrmex concolor or Pseudomyrmex penetrator, but broadly sympatric with them in eastern Hylaea (Humboldt's term for the rainforests of the Amazon basin). Wheeler (1921a, 1942) presented observations on the biology of this species and P. concolor in Guyana, where the host tree was T. paniculata. A collection from Salto Salas, Venezuela was made from Tachigali rusbyi Harms; for other localities the plant (if mentioned) is identified only as Tachigali sp.



The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • cholerica. Pseudomyrma maligna var. cholerica Wheeler, W.M. 1921f: 146 (w.) GUYANA. Combination in Pseudomyrmex: Kempf, 1961a: 400. Junior synonym of malignus: Ward, 1989: 440.
  • crucians. Pseudomyrma maligna var. crucians Wheeler, W.M. 1921f: 147 (w.) GUYANA. Combination in Pseudomyrmex: Kempf, 1961a: 400. Junior synonym of malignus: Ward, 1989: 440.
  • malignus. Pseudomyrma maligna Wheeler, W.M. 1921f: 143, fig. 14 (w.q.m.) GUYANA. Wheeler, G.C. & Wheeler, J. 1990a: 464 (l.). Combination in Pseudomyrmex: Kempf, 1961a: 400. Senior synonym of auripes, cholerica, crucians: Ward, 1989: 440. See also: Ward, 1999b: 496.
  • auripes. Pseudomyrma auripes Wheeler, W.M. 1922c: 5 (q.) TRINIDAD. Combination in Pseudomyrmex: Kempf, 1961a: 400. Junior synonym of malignus: Ward, 1989: 440.

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 0.91–1.18, HW 0.84–1.11, MFC 0.117–0.154, LHT 0.57–0.82, CI 0.90–0.96, REL 0.32–0.38, REL2 0.35–0.43, FCI 0.12–0.17, SI 0.39–0.41, FLI 1.14–1.42, FI 0.40–0.44, PLI 0.86–1.05, PWI 0.84–1.08, PPWI 1.48–1.84.

Similar to Pseudomyrmex concolor (q.v.) except as follows. Median clypeal lobe laterally angulate and its anteromedial surface not deflected ventrally. Head slightly broader, on average, and the frontal carinae tending to be slightly more separated (compare FCI). Metanotal groove less deeply impressed in some workers. Dorsal face of propodeum shorter than the declivitous face (PDI 0.83–0.99). Petiole generally shorter and broader than that of P. concolor but the relevant indices overlap (compare PLI and PWI); least overlap with PWI2 (0.65–0.69, compared to 0.58–0.66 in P. concolor). Anteroventral petiolar process well developed and often conspicuously recurved. Mandible smooth and shining, with scattered punctulae, striolae weak and confined to apical portion. Punctulae on upper two thirds of head finer (most with diameter < 0.010 mm) and better separated, and the head correspondingly shinier. Mesosomal punctulae also tending to be finer and less dense. Standing pilosity less dense; erect hairs usually absent from the sides of the head (at most one or two may be present below the eyes), and absent from the posterior margin of the head (frontal view); pilosity sparser on the mesosoma dorsum and external faces of tibiae (MSC 6–35, HTC 1–6). Appressed pubescence less well developed, the appressed hairs separated by more than their lengths on abdominal tergite V and parts of abdominal tergite IV. Body colour more variable, ranging from orangebrown to dark brown; head and terminal segments of gaster usually medium to dark-brown, one or more of the remaining parts of body (from the pronotum to the fourth abdominal segment) may be concolorous or a contrastingly lighter orange-brown.

Type Material

Ward (1999):

Syntype workers, males, queens, Kartabo, Guyana (W. M. Wheeler) (Museum of Comparative Zoology, Museu de Zoologia da Universidade de Sao Paulo) [Examined].

Pseudomyrma maligna var. cholerica Wheeler, 1921b:146. Syntype workers, Kartabo, Guyana (W. M. Wheeler) (MCZC) [Examined].

Pseudomyrma maligna var. crucians Wheeler, 1921b:147. Syntype workers, Kartabo, Guyana (W. M. Wheeler) (MCZC) [Examined].

Pseudomyrma auripes Wheeler, 1922:5. Holotype queen, Trinidad (W. M. Wheeler) (MCZC) [Examined].


  • Kempf, W. W. 1961a. Estudos sôbre Pseudomyrmex. III. (Hymenoptera: Formicidae). Stud. Entomol. 4: 369-408 (page 400, Combination in Pseudomyrmex)
  • Ward, P. S. 1989a. Systematic studies on pseudomyrmecine ants: revision of the Pseudomyrmex oculatus and P. subtilissimus species groups, with taxonomic comments on other species. Quaest. Entomol. 25: 393-468 (page 440, Senior synonym of auripes, cholerica and crucians)
  • 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 496, see also)
  • Wheeler, G. C.; Wheeler, J. 1990a [1989]. Notes on ant larvae. Trans. Am. Entomol. Soc. 115: 457-473 (page 464, larva described)
  • Wheeler, W. M. 1921f. The Tachigalia ants. Zoologica (N. Y.) 3: 137-168 (page 143, fig. 14 worker, queen, male described)