The Galápagos ant fauna has long been understudied, with the last taxonomic summary being published almost a century ago. Here, a comprehensive and updated overview of the known ant species of the Galápagos Islands is provided with updated species distributions. The list is based on an extensive review of literature, the identification of more than 382,000 specimens deposited in different entomological collections, and recent expeditions to the islands. The ant fauna is composed of five subfamilies (Dolichoderinae, Dorylinae, Formicinae, Myrmicinae, and Ponerinae), 22 genera, 50 species, and 25 subspecies, although three species (Crematogaster crinosa Mayr, 1862, Camponotus senex (Smith, 1858), and Solenopsis saevissima (Smith, 1855)) are considered dubious records. Finally, an illustrated identification key of the species found in the archipelago is presented.

The ants of the genus Rhopalothrix are diverse in the Neotropical region, with 14 of the 16 described species. Based on museum material and recent fieldwork, Rhopalothrix ants in Colombia were reviewed. Morphological analysis of the workers allowed delimitation of six species, including two new species, Rhopalothrix mandibularis Guerrero & Grajales, sp. nov. and Rhopalothrix mariaemirae Tocora, Fiorentino & Fernández, sp. nov. A new combination Rhopalothrix amaticomb. nov. is proposed for Eurhopalothrix amati. A worker-based taxonomic key, high-definition images of the workers, and a distribution map of all Rhopalothrix species present in Colombia are provided.

The classification of ants (Hymenoptera: Formicidae) has progressed in waves since the first 17 species were described by Linnaeus in the 1758 edition of Systema Naturae. Since then, over 18,000 species-rank names have accumulated for the global myrmecofauna, of which ~14,260 living and ~810 fossil species are valid. Here, we provide a synopsis of ant biodiversity and review the history and classification of the family, while highlighting the massive growth of the field in the new millennium. We observe that major transformation has occurred for ant classification due to advances in DNA sequencing technologies, model-based hypothesis testing, and imaging technologies. We therefore provide a revised and illustrated list of diagnostic character states for the higher clades of Formicidae, recognizing that vastly more work is to be done. To facilitate discussion and the systematic accumulation of evolutionary knowledge for the early evolution of the ants, we suggest an informal nomenclatural system for the higher clades of ants, based on names currently in use and a set of names that have been democratically selected by the authors. To guide future work on ant systematics, we summarize currently available databases and present perspectives on regions in need of biodiversity exploration, challenges facing the field, and the future of ant taxonomy.

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.

La presente publicación es el resultado de la ejecución del Convenio de Colaboración 5211740 celebrado entre la Universidad Pedagógica y Tecnológica de Colombia y la Empresa Colombiana de Petróleos, Ecopetrol S. A., en el Proyecto 6, el cual tuvo como objetivo principal ejecutar acciones de restauración ecológica de 105 ha en el DRMI Rabanal (Ventaquemada, Boyacá) y en el municipio de Sabanalarga (Casanare). Lo anterior, como medida de compensación ambiental en el marco de la ejecución del Proyecto del Poliducto Andino. Es muy importante para Ecopetrol S.A., demostrar que los proyectos de infraestructura son ejecutados con un sello de responsabilidad social y ambiental, en los que siempre se ha procurado mitigar al máximo el impacto sobre los ecosistemas. Se debe tener en cuenta que sobre los sitios de estudio se han venido desarrollando procesos históricos de impactos de tipo antropogénico como talas, quemas, minería, ganadería extensiva y la ampliación de la frontera agrícola, que afectan directamente la diversidad de especies en la zona. Por lo anterior, el presente trabajo pretende mostrar la riqueza de fauna y flora de los ecosistemas de alta montaña, páramo y piedemonte llanero, y destacar la provisión de servicios ecosistémicos que estos sitios ofrecen. Esta iniciativa quiere dar a conocer, lo importante que es cuidar y preservar los bosques, ya que son el hogar de una amplia gama de plantas y animales que cumplen un rol en el desarrollo de una serie de procesos como el ciclaje de nutrientes, el ciclo del agua y la regulación hídrica. La fauna y la flora son el tema principal, se muestran las plantas vasculares y no vasculares, además de insectos, reptiles y anfibios más representativos de los ecosistemas alto andino de páramo, así como del piedemonte llanero, haciendo énfasis en los municipios de Ventaquemada (Boyacá) y Sabanalarga (Casanare). Este material bibliográfico pretende convertirse en una herramienta útil no solo para la comunidad académica, sino también para la comunidad en general y sobre todo para los habitantes de las localidades de influencia del proyecto, con el fin último de conocer algunas de las especies, de una manera fácil y didáctica. Se debe resaltar la labor y el trabajo que ha venido haciendo el grupo de investigación Sistemática Biológica (SisBio) de la Universidad Pedagógica y Tecnológica de Colombia, ya que sus integrantes catalogaron y realizaron inventarios completos en las diferentes localidades, además del montaje y preparación de especímenes que reposan en colección de referencia, la cual se convertirá también en una herramienta y punto de partida para futuros estudios. El personal profesional y técnico que realizó sus aportes a este libro está comprometido con entregar un producto de calidad y con el que buscan demostrar que los proyectos de investigación también deben involucrar a la comunidad campesina, ya que con ellos y su conocimiento empírico el aporte cobra un significado importante.

Ant-plant symbioses are classic examples of mutualism in which ant "bodyguards" defend myrmecophytic plants against enemies in exchange for nest sites and often food. We used RNA-Seq to profile the transcriptomes of Allomerus octoarticulatus ant workers, which aggressively defend the Amazonian plant Cordia nodosa against herbivores, but to varying degrees. Field behavioral assays with herbivores in the Peruvian Amazon showed striking variation among colonies in the relative zeal with which A. octoarticulatus workers defend their host plant. Highly effective and ineffective bodyguards differed in their gene expression profiles, which revealed viral infections significantly associated with ant bodyguarding behavior. Transcripts from eight new positive-sense single-stranded RNA viruses were differentially expressed between colonies with high- or low-quality bodyguards. Colonies of high- and low-quality bodyguards were infected by distinct viruses, including viruses clustering phylogenetically with viruses known to cause aggression or reduced locomotion, respectively, in bees. Gene expression, including of immunity-related genes, also differed between broodcare workers and bodyguard ants, suggesting bodyguarding is a distinct worker task. Ant colony health and viral infections may influence ant cooperation with plants in ant-plant mutualisms.