Pseudomyrmex tachigaliae

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Pseudomyrmex tachigaliae
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Pseudomyrmecinae
Genus: Pseudomyrmex
Species: P. tachigaliae
Binomial name
Pseudomyrmex tachigaliae
(Forel, 1904)

Pseudomyrmex tachigaliae casent0281899 p 1 high.jpg

Pseudomyrmex tachigaliae casent0281899 d 1 high.jpg

Specimen Labels


The workers aggressively defend their host plant, yet Verhaagh (1988) found tenthredinoid sawfly larvae on Tachigali foliage that were able to thwart attacks by P. tachigaliae workers. Most nest series of P. tachigaliae are labelled as coming from unspecified species of Tachigali. The type series was collected from Tachigali formicarum (Forel, 1904c) and the collection from Cerros Campanquiz, Peru (see below) was taken from Tachigali tessmannii Harms. (Ward 1999)


Ward (1999) - Queens and workers of P. tachigaliae can be recognized by the modified median clypeal lobe. In the worker this is in the form of a tectiform (tent-shaped) lobe with lamellate anterolateral margins that appear subangulate in frontal view. In the queen the clypeal lobe is developed as a striking, tongue-like anterodorsal protrusion. Other characteristic features of the workers and queens of this species are the closely contiguous frontal carinae and correspondingly well-exposed median lobes of the torulus (see worker FCI, FCI2, ASI2 and PFC/ASD values above; queen FCI 0.05–0.08, queen FCI2 0.34–0.51), densely punctulate head sculpture, low petiole (worker PLI < 0.83, queen PLI 0.54–0.68) with the dorsal face broadly convex in lateral profile, scarcity of standing pilosity, and conspicuous appressed pubescence.

Keys including this Species


Western portions of the Amazon basin in Peru and adjacent Brazil.

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality), 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.

  • tachigaliae. Pseudomyrma latinoda r. tachigaliae Forel, 1904e: 686 (w.q.m.) BRAZIL. Combination in Pseudomyrmex: Kempf, 1961a: 400. Raised to species and senior synonym of bradleyi Wheeler (and its junior synonym bradleyi Enzmann): Ward, 1989: 444. See also: Wheeler, W.M. 1942: 170; Ward, 1999b: 501.
  • bradleyi. Pseudomyrma latinoda subsp. bradleyi Wheeler, W.M. 1942: 169 (w.) PERU. Combination in Pseudomyrmex: Kempf, 1961a: 400. Senior synonym of bradleyi Enzmann: Brown, 1949a: 42. Junior synonym of tachigaliae: Ward, 1989: 444.
  • bradleyi. Pseudomyrma bradleyi Enzmann, E.V. 1944: 82, pl. 2, fig. 20 (w.) PERU. [Unresolved junior primary homonym of bradleyi Wheeler, above.] Junior synonym of bradleyi Wheeler: Brown, 1949a: 42.

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=16). HL 0.95–1.18, HW 0.80–1.03, MFC 0.023–0.065, LHT 0.61–0.96, CI 0.81–0.88, REL 0.37–0.40, REL2 0.42–0.48, FCI 0.03–0.07, SI 0.43–0.49, FLI 1.41–1.80, FI 0.41–0.47, PLI 0.72–0.82, PWI 0.71–0.86, PPWI 1.30–1.63.

Relatively small, worker HW < 1.04 (but queen large: HW > 1.44). Basal margin of mandible with one or two very weak mesial teeth; masticatory margin of mandible with six or seven teeth. Palp formula 5,3. Median clypeal lobe tectiform, with a distinctive, inflected, lamellate anterior margin which appears straight or concave in frontal (dorsal) view, and subangulate laterally. Below the lamellate margin of the clypeus is a small tongue-like medial protrusion, visible in anterodorsal view. Frontal carinae not well separated (for the P. viduus group), converging posteriorly, MFC usually less than basal scape width. Median lobe of antennal sclerite more exposed than in other species in the P. viduus group (worker FCI2 0.22–0.45, worker ASI2 0.75–0.87), in particular because of a smaller PFC such that worker PFC/ASD 0.27–0.48 (> 0.50 in all other species) and worker PFC/ ASM 0.33–0.62 (> 0.74 in all other species) and scape tending to be relatively longer (compare SI values). Scape expanded distally to about twice its basal width; funiculus also expanded apically, the terminal segment about 1.8 times the width of the first segment; funicular segments 3–10 conspicuously broader than long. Eye small, only moderately elongate (REL < 0.41, REL2 < 0.49, OI 0.61–0.66). Head longer than broad (CI > 0.80), the sides weakly convex, rounding abruptly into the posterior margin, which is flat or slightly concave, in frontal view. Mesosoma dorsum more or less flattened, and with a moderately incised metanotal groove. Dorsal face of propodeum subequal to, or slightly longer than, the declivitous face (PDI 0.95–1.15), the two meeting at a rounded angle. Petiole relatively low, notably longer than high (PLI < 0.83), with an evenly convex anterodorsal face in lateral profile, rounding into a steeper posterior face. Anteroventral petiolar tooth weakly developed or absent. In dorsal view, the minimum (anterior) width of petiole more than half the maximum width (PWI3 0.51–0.62), and the straight sides of the petiole diverging only moderately. Postpetiole globular, notably broader than long (PPWI > 1.29); ventral protrusion of postpetiolar sternite less prominent than in P. concolor, and anteroventral process less well developed. Mandible with scattered punctulae and variable amounts of fine striolation which dull the reflectance. Head subopaque to sublucid, densely punctulate, the punctures about 0.012–0.018mm in diameter and separated by their diameters or less on most of the head, only small marginal areas immediately above and below the eye being shiny and unsculptured. Mesosoma, petiole, postpetiole and gaster mostly subopaque (the episternum sublucid), with fine corarious-imbricate sculpture, punctulae absent or ill-defined, especially posteriorly. Standing pilosity relatively sparse and short on most of body (MSC 6–26; HTC 0); a few (0–6) short, inconspicuous erect setae visible in outline on either side of the head in frontal view. Appressed pubescence very well developed and conspicuous on most of body, especially dense on the petiole, postpetiole, and abdominal tergites. Body uniformly light yellow-brown to (more commonly) dark-brown in colour, the appendages lighter.

Type Material

Ward (1999) - Syntype workers, queens, Tarapoto, Peru (Ule) (Museo Civico di Storia Naturale, Genoa, Musee d'Histoire Naturelle Genève, Naturhistorisches Museum, Basel) [Examined].

Pseudomyrma latinoda subsp. bradleyi Wheeler, 1942:169. Syntype workers, Perene, Peru (Bradley) (Museum of Comparative Zoology) [Examined].

Pseudomyrma bradleyi Enzmann, 1944:82. Syntype workers, Perene, Peru (Bradley) (MCZC) [Examined].


  • Forel, A. 1904f. In und mit Pflanzen lebende Ameisen aus dem Amazonas-Gebiet und aus Peru, gesammelt von Herrn E. Ule. Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere 20: 677-707 (page 686, worker, queen, male described)
  • 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 444, Raised to species, and senior synonym of bradleyi Wheeler (and its junior synonym bradleyi Enzmann))
  • 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 501, see also)
  • Wheeler, W. M. 1942. Studies of Neotropical ant-plants and their ants. Bull. Mus. Comp. Zool. 90: 1-262 (page 170, see also)