Tropical dry forests (TDF) are amongst the most important tropical biomes globally, recognised for their remarkable biodiversity. This biome features a favourable climate and high soil fertility, which has facilitated the development and expansion of human societies. However, continuous and extensive human intervention has led to habitat loss and fragmentation, disrupting the assemblages of biological communities. Within these communities, ants (Hymenoptera, Formicidae) represent one of the predominant groups and their high sensitivity to habitat transformation makes them a useful model for monitoring the effects of land-use changes and assessing ecosystem quality. The objective of this research was to compare ant diversity between two habitat types, tropical dry forest fragments and the surrounding matrices in the Cauca River Valley region. Ants were collected from 2021 to 2022 using six collection methods: arboreal baiting, epigeal baiting, hypogeal baiting, pitfall traps, mini-Winkler extractors and manual capture. A substantial portion of the data generated from this research is available in two datasets associated with two Colombian entomological collections. The first dataset (1574 ant records) is housed at the Centro de Colecciones Biológicas de la Universidad de Magdalena (CBUMAG) and the second (546 records) at the Museo de Entomología de la Universidad del Valle (MUSENUV).<br> Five ant species were registered for the first time in Colombia: Leptogenys montuosa Lattke, 2011, Neoponera rugosula Emery, 1902, Neoponera zuparkoi Mackay & Mackay, 2010, Pheidole traini Wilson, 2003 and Wasmannia sulcaticeps Emery, 1894. Additionally, the distributions of 45 ant species native to two Departments in the Cauca River Valley geographic region (VGRC) have been expanded. Of these, 31 species extended their distribution into the Valle del Cauca Department: Azteca alfari Emery, 1893, Forelius damiani Guerrero & Fernández, 2008, Eciton mexicanum Roger, 1863, Neivamyrmex emersoni (Wheeler, 1921), Holcoponera moelleri Forel, 1912, Brachymyrmex musculus Forel, 1899, Cephalotes porrasi (Wheeler, 1942), Cephalotes targionii (Emery, 1894), Cephalotes umbraculatus (Fabricius, 1804), Crematogaster montezumia Smith, 1858, Crematogaster obscurata Emery, 1895, Nesomyrmex pittieri (Forel, 1899), Octostruma batesi (Emery, 1894), Octostruma excertirugis Longino, 2013, Octostruma obtusidens Longino, 2013, Pheidole bilimeki Mayr, 1870, Pheidole boliviana Wilson, 2003, Pheidole colobopsis Mann, 1916, Pheidole gauthieri Forel, 1901, Pheidole hasticeps Wilson, 2003, Pheidole simonsi Wilson, 2003, Pheidole subarmata Mayr, 1884, Pheidole vallifica Forel, 1901, Solenopsis azteca Forel, 1893, Solenopsis brevicornis Emery, 1888, Strumigenys grytava (Bolton, 2000), Strumigenys marginiventris Santschi, 1931, Strumigenys wheeleriana Baroni Urbani, 2007, Temnothorax subditivus (Wheeler, 1903), Hypoponera opacior (Forel, 1893), Leptogenys pubiceps Emery, 1890 and Pseudomyrmex longior (Forel, 1904). Ten species extended their distribution into the Cauca Department: Azteca velox Forel, 1899, Brachymyrmex minutus Forel, 1893, Crematogaster evallans Forel, 1907, Megalomyrmex drifti Kempf, 1961, Pheidole fimbriata Roger, 1863, Pheidole longiscapa Forel, 1901, Pheidole radoszkowskii Mayr, 1884 and Rogeria scandens (Mann, 1922); and four species extended their distribution into both Departments: Brachymyrmex cordemoyi Forel, 1895, Pheidole sculptior Forel, 1893, Hypoponera fiebrigi antoniensis (Forel, 1912) and Hypoponera parva (Forel, 1909). Finally, three exotic species were registered for the first time in the VGRC, extending their distributions within Colombia: Strumigenys emmae (Emery, 1890) in the Valle del Cauca Department and Cardiocondyla emeryi Forel, 1881 and Cardiocondyla wroughtonii (Forel, 1890) in the Cauca Department.
