Pseudomyrmex eculeus

A Tachigali inhabitant with aggressive workers.

Identification
Ward (1999) - Related to Pseudomyrmex pictus and Pseudomyrmex ferox. All three are characterized by having broad worker heads (CI [0.91), short petioles with a subtriangular profile, long legs, and large queens (queen HW >1.30). P. eculeus can be distinguished from P. ferox by its longer legs, more slender worker profemur, and the position of the worker propodeal spiracle close to the flattened dorsal face; and from P. pictus by its much darker body color, shape of the propodeum, and smaller size.

Distribution based on Regional Taxon Lists
Neotropical Region: Ecuador, Peru.

Nomenclature

 *  eculeus. Pseudomyrmex eculeus Ward, 1999b: 518, figs. 42, 51, 60 (w.q.) ECUADOR.

Worker
Measurements (n=9). HL 1.16–1.30, HW 1.13–1.25, MFC 0.030–0.054, LHT 0.97–1.11, CI 0.94–0.99, REL 0.61–0.65, REL2 0.63–0.67, FCI 0.03–0.05, FI 0.39–0.42, PLI 1.04–1.14, PWI 0.83–0.93.

A member of the sericeus group. Palp formula: mostly 6,4, but some individuals apparently 5,3. Frontal carinae relatively well separated; head broad, with strongly convex sides; posterior margin of head straight or (less commonly) slightly concave, in frontal view. Profemur very slender (see FI values); legs long (LHT/HL 0.82–0.88). Dorsal face of propodeum flat, submarginate laterally, subequal in length to declivitous face, and rounding into it; propodeal spiracle close to the basal (dorsal) face of propodeum. Petiole short, high, subtriangular in profile, with a single convex anterodorsal face, which rounds gently into the steep posterior face. Anteroventral process prominent, subrectangular, with a blunt posteroventral angle. Standing pilosity sparse but more common than is usual for the species group. Long, golden, paired (and often curved) setae usually present on pronotum (1–2 pairs), mesonotum (0–1 pairs), on propodeum at the junction of the dorsal and declivitous faces (0–1 pairs), petiole (1–2 pairs) and postpetiole (1–2 pairs); these setae sometimes unpaired, or accompanied by one or two additional shorter setae. Black or very dark blackish-brown, with appendages and frontoclypeal complex contrastingly orange-brown; funiculus and parts of middle and hind legs infuscated.

Type Material
Holotype worker. ECUADOR, Napo: Jatun Sacha, 1°04’S, 77°36’W, 450 m, 13.ix.1992, ex Tachigali, B. L. Fisher #458. HW 1.16, HL 1.19, EL 0.76, LHT 1.03, PL 0.43, PH 0.45.

Paratypes. Same data as holotype: series of workers, 1 queen; same locality, ex Tachigali, M. Asanza# 86: four workers; same locality, 400 m, ex Tachigali, P. S. Ward# 11384: four dealate queens (,, MCZC, , , , , , ).

References based on Global Ant Biodiversity Informatics

 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * Rasmussen C., and G. Lamas. 2011. Catalog of entomological types in the Museo de Historia Natural (MUSM), Universidad Nacional Mayor de San Marcos, Lima, Peru: Hymenoptera. Rev. peru. entomol. 46(2): 51-58.