Pseudomyrmex vinneni

Nests in Tachigali plants.

Identification
Ward (1999) - P. vinneni can be recognized by its small size (worker HW 0.81–1.03, queen HW 0.96–1.06), elongate eyes (worker REL 0.63–0.68, queen REL 0.60–0.63), and rounded (subtriangular to subglobose) petiolar profile. In addition, in the worker caste, the quadrate head, broad profemur, rounded juncture of the basal and declivitous faces of the propodeum (in lateral view), and scarcity of standing pilosity are characteristic. Pseudomyrmex sericeus has more closely contiguous frontal carinae, a propodeum whose short dorsal face meets the longer declivitous face at an obtuse angle, and a petiole which is subtriangular in lateral profile.

Distribution
Known from Brazil, Colombia, Peru and Venezuela.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil, Colombia, Peru, Venezuela.

Biology
Most of the individuals I have examined were extracted from herbarium specimens of Tachigali by Woody Benson. Specific plant records include Tachigali cavipes (Spruce ex Bentham) Macbride, T. paniculata, T. myrmecophila, T. physophora (Huber) Zarucchi & Herendeen, T. schultesiana Dwyer, T. venusta Dwyer and T. odoratissima (Spruce ex Bentham) Zarucchi & Herendeen. (Ward 1999)

Nomenclature

 *  vinneni. Pseudomyrma sericea var. vinneni Forel, 1906d: 230 (w.) BRAZIL. Combination in Pseudomyrmex: Kempf, 1972a: 223. Raised to species: Ward, 1999b: 526.

Worker
Ward (1999) - Measurements (n=13). HL 0.90–1.17, HW 0.81–1.03, MFC 0.024–0.039, LHT 0.59–0.77, CI 0.87–0.91, REL 0.63–0.68, REL2 0.71–0.75, FCI 0.03–0.04, FI 0.46–0.51, PLI 1.02–1.17, PWI 0.80–0.92.

A member of the sericeus group. Palp formula: 6,4. Frontal carinae moderately well separated; head longer than broad but not strongly so (see CI values), somewhat quadrate, with almost straight sides, and flat to slightly concave posterior margin; eyes elongate. Profemur broad; legs relatively short (LHT/HL 0.63–0.67). Dorsal face of propodeum subequal in length to declivitous face, and rounding gradually into it. Petiole short, high, subtriangular or subglobose in profile, with a single convex anterodorsal face, which rounds gently into the steep posterior face. Anteroventral process varying from slightly to moderately well developed, usually lobe-like and without a posteroventral tooth or angle. Standing pilosity sparse; stout, paired setae on pronotum (1 pair), petiole (1 pair) and postpetiole (1 pair), absent from mesonotum and propodeum, and sometimes small and inconspicuous on the petiole and postpetiole. Dark brown to brownish black, with appendages, frontoclypeal complex and (in some workers) promesonotum a lighter medium-brown to orange-brown.

Type Material
Ward (1999) - Syntype workers, [Barcelos], Rio Negro, Amazonas, Brazil (Ducke) [Examined].

References based on Global Ant Biodiversity Informatics

 * Bezdeckova K., P. Bedecka, and I. Machar. 2015. A checklist of the ants (Hymenoptera: Formicidae) of Peru. Zootaxa 4020 (1): 101–133.
 * Forel A. 1913. Fourmis d'Argentine, du Brésil, du Guatémala & de Cuba reçues de M. M. Bruch, Prof. v. Ihering, Mlle Baez, M. Peper et M. Rovereto. Bulletin de la Société Vaudoise des Sciences Naturelles. 49: 203-250.
 * Franco W., N. Ladino, J. H. C. Delabie, A. Dejean, J. Orivel, M. Fichaux, S. Groc, M. Leponce, and R. M. Feitosa. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674(5): 509-543.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).