The taxonomic boundaries of many Neotropical ant species of the genus Tapinoma are still unclear. Tapinoma atriceps and T. atriceps breviscapum are two morphologically similar taxa which occur sympatrically in the southern Atlantic Forest of Brazil. Some characters such as the scape length and head shape suggest that these taxa may be different species. We used DNA analysis and morphological evidence, including scanning electron microscopy, to evaluate the taxonomic validity of these taxa. We found distinct morphological characteristics that allow separating them as two different species, Tapinoma atriceps and Tapinoma breviscapum status novo , and this decision is supported by the DNA results, where Tapinoma atriceps was recovered as a lineage independent of T. breviscapum .

Even though Colombia has high levels of ant species richness in the Neotropical region, this richness continues to increase. New records of the ant subfamilies Amblyoponinae, Dolichoderinae, Dorylinae, Myrmicinae, and Ponerinae are presented. Two species of Fulakora, two species of Azteca, one species of Cylindromyrmex, 25 species of Myrmicinae belonging to 12 genera (Acanthognathus, Basiceros, Daceton, Eurhopalothrix, Hylomyrma, Mycetomoellerius, Mycetophylax, Mycocepurus, Octostruma, Pheidole, Rogeria, and Talaridris), and one species of Leptogenys are registered for the first time for Colombia. Five species are new records for South America. For each species, the geographical distance of the record closest to the Colombian locality is offered. Several factors, such as access to previously unexplored conserved areas, sampling techniques that cover heterogeneous microhabitats such as leaf litter, and many more taxonomic researches have allowed the knowledge of ant fauna in Colombia to continue growing.

Colombia es un país con alta diversidad de hormigas, sin embargo, nuevos taxones se siguen registrando para el país. Cuarenta y siete nuevos registros se relacionan aquí, todos dentro de la subfamilia Myrmicinae: Uno para los géneros Adelomyrmex, Allomerus, Kempfidris, Megalomyrmex, Octostruma y Tranopelta; dos para Rogeria; cinco para Myrmicocrypta; seis para Procryptocerus; siete para Cephalotes; diez para Pheidole y once para Strumigenys. Tres de esos nuevos registros corresponden a especies invasoras, Pheidole indica, Strumigenys emmae y Strumigenys membranifera. Tres especies se citan por primera vez para América del Sur: Pheidole sicaria, Procryptocerus tortuguero y Strumigenys manis. El género Kempfidris se registra por primera vez para Colombia. Se ofrecen comentarios para todas las especies. La diversidad de hormigas en Colombia comprende 104 géneros y casi 1.100 especies.

The male of the endangered ant Dinoponera lucida Emery is described, providing morphometric measurements, high-resolution images, and a distribution map of the species. This ant inhabits the Brazilian Atlantic forest, an ecosystem strongly impacted by fragmentation. The males show clear morphological differences from the known males of other species of Dinoponera. We briefly discuss the relevance of the male description for the conservation strategies of this ant.

The species of Linepithema Mayr in Colombia are reviewed from collection material. The genus Linepithema comprises 20 species, of which the following are reported in Colombia: L. angulatum (Emery), L. dispertitum (Forel), L. gallardoi (Brèthes), L. humile (Mayr), L. iniquum (Mayr), L. neotropicum Wild, L. piliferum (Mayr), L. tsachila Wild, and a new species, Linepithema hirsutum sp. nov. Linepithema dispertitum is a new record for Colombia and South America. A taxonomic key (English and Spanish) and distribution maps to the species of Linepithema in Colombia are provided.