Pseudomyrmex laevifrons

Most collections consist of scattered foragers on low vegetation and on recent treefalls. I have collected seven nest series, all from dead twigs of woody plants: two from vines, three from Melastomataceae trees, and two from unidentified plants. (Ward 2017)

Identification
Ward (2017) - Workers of this species can be recognized by their small size (HW 0.47–0.55), shiny puncticulate head, angulate propodeum, and the presence of a single pair of erect setae on the pronotal humeri, petiole and postpetiole. Pseudomyrmex obtusus and Pseudomyrmex parvulus have a more densely sculptured head and less standing pilosity (lacking at least on the petiole). Differences between Pseudomyrmex laevifrons and the closely similar Pseudomyrmex micans are discussed under the latter species.

Distribution
Ward (2017) - This species is distributed from Nicaragua to Bolivia and central Brazil, and has been recorded from tropical moist forest, rainforest, second-growth rainforest, and rainforest edge.

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Brazil, Costa Rica.

Nomenclature

 * laeviceps. Pseudomyrma laeviceps Smith, F. 1877b: 63 (w.) BRAZIL. [Misspelled as leviceps by Dalla Torre, 1893: 57.] Combination in Pseudomyrmex: Kusnezov, 1964: 83. [Junior primary homonym of laeviceps Smith, F. 1859a: 145, above.]. Replacement name: laevifrons Ward, 1989: 440.
 *  laevifrons. Pseudomyrmex laevifrons Ward, 1989: 440. Replacement name for laeviceps Smith, F. 1877b: 63, above. [Junior primary homonym of laeviceps Smith, F. 1859a: 145.]

Pseudomyrma laeviceps

Holotype worker in. With two labels, “Aru 21” and “Aru.”

Description
Small species (HL 0.65–0.75, HW 0.47–0.55) with elongate head and eyes (CI 0.69–0.78, REL 0.57–0.64, REL2 0.79–0.87); masticatory margin of mandible with 5 teeth; palp formula 4,3; juncture between dorsal and declivitous faces of propodeum usually notably angulate, sometimes producing slight tubercles laterally; anterodorsal face of petiole usually ascending relatively steeply (Fig. 5b). Head smooth and shiny with scattered fine punctulae; pronotum similar centrally, but remainder of mesosoma becoming sublucid, with coriarious-imbricate sculpture on most surfaces including mesopleuron, metapleuron and propodeum; petiole, postpetiole and gaster with moderately dense pubescence. Standing pilosity sparse (MSC 2); paired erect setae present on pronotal humeri, petiole and postpetiole. Dark brown, mandibles, frontoclypeal complex and tarsi lighter; pronotum, petiole and postpetiole often a contrastingly lighter medium- to yellowish-brown.

Ward (2017) - (n = 16). HL 0.65–0.75, HW 0.47–0.55, MFC 0.005–0.010, LHT 0.36–0.41, CI 0.69– 0.78, REL 0.57–0.64, REL2 0.79–0.87, FCI 0.010–0.019, FI 0.50–0.56, PLI 0.66–0.80, PWI 0.54–0.66.

Type Material
Ward (1989) - Two syntype workers, Para. Brazil [Examined]. One syntype worker here designated LECTOTYPE.

References based on Global Ant Biodiversity Informatics

 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Fernández F., E. E. Palacio, W. P. Mackay, and E. S. MacKay. 1996. Introducción al estudio de las hormigas (Hymenoptera: Formicidae) de Colombia. Pp. 349-412 in: Andrade M. G., G. Amat García, and F. Fernández. (eds.) 1996. Insectos de Colombia. Estudios escogidos. Bogotá: Academia Colombiana de Ciencias Exactas, Físicas y Naturales, 541 pp
 * 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).
 * Smith F. 1863. Catalogue of hymenopterous insects collected by Mr. A. R. Wallace in the islands of Mysol, Ceram, Waigiou, Bouru and Timor. Journal and Proceedings of the Linnean Society of London. Zoology 7: 6-48.