Daniel Castro

A new genus and species of soldierless termite, Ekueitermes alerosinus gen. et sp. nov ., is described from Colombia based on morphological and molecular evidence. The diagnostic characters for the new taxon are a mixed segment with a short, non-inflated mesenteric tongue, a very short and tubular P1, a well-differentiated tubular enteric valve seating, and an enteric valve armature with six cushions armed with 7–17 sclerotised spines arranged in a palmate shape and polygonal scales. Furthermore, Bayesian inference and maximum-likelihood phylogenetic analysis using concatenated COI and 16S genes, including other Neotropical Apicotermitinae genera described to date, supports the new genus as a distinct terminal and the sister group to Disjunctitermes insularis .

Hunter ants are among top invertebrate predators in tropical forests and play a key role in regulating invertebrate populations. This study documents new records of Ectatomminae and Ponerinae ants in the Colombian Amazon Basin. We provide the first country record of the genus and species Corrieopone nouragues, as well as new country records for ten other species: Alfaria simulans, Poneracantha mediatrix, Odontomachus allolabis, O. chicomendesi, O. davidsoni, O. ruginodis (sensu França et al. 2024), O. spissus, Pachycondyla procidua, Typhlomyrmex meire, and Simopelta anomma. Taxonomic notes are included for five species: Holcoponera auricula, H. dichotoma, Typhlomyrmex major, Odontomachus bauri, and O. ruginodis. An updated modified key is provided for species of Typhlomyrmex, along with the first photographs of the types of H. auricula and H. dichotoma, as well as the description of the queen of O. mormo.

Cohabitation between ants and termites is a widespread yet understudied ecological interaction in tropical forests. This study explores the patterns of termite–ant cohabitation networks across different forest coverages in the Colombian Amazon, focusing on taxonomic composition, nesting substrates, and ant functional guilds. A total of 413 specimens were collected from 283 cohabitation networks, identifying 197 interacting species (110 ants and 87 termites). The network exhibited moderate connectance (C = 0.279) and high modularity (Q = 0.602), indicating that only a subset of potential interactions occurred, with distinct species groups forming stronger intragroup connections. Ant genera such as Pheidole, Camponotus, Crematogaster, Acropyga, and the species Pseudoponera stigma played central roles, interacting with multiple termite genera, while termite genera like Nasutitermes, Heterotermes, and Araujotermes emerged as key nodes due to their nesting habits and high abundance. Cohabitation patterns varied across forest types, with primary forests supporting more complex networks than secondary forests, underscoring the importance of habitat conservation in maintaining biodiversity. Wood-based nests supported the highest diversity of cohabiting ants, and generalist ants—particularly Pseudoponera stigma and species of Pheidole—were frequent connectors across modules. These findings provide new insights into the ecological mechanisms underlying termite–ant cohabitation and emphasize the importance of preserving structurally complex habitats to maintain these interactions.

Understanding the recovery of soil macroarthropod communities during natural regrowth is crucial to demonstrate complete soil restoration. This is because these organisms can play a key role in shaping soil structure and community dynamics, making them essential to understanding these processes. This study investigates the recovery of soil macroarthropod diversity, density, and biomass across different stages of natural regrowth, focusing on the taxonomic groups and feeding guilds dynamics. Macroarthropod communities were analyzed along a chronosequence (young-age, middle-age, and old-growth) including their vertical distribution (litter, 0–10 cm, 10–20 cm, and 20–30 cm). A total of 20 plots and 100 Tropical Soil Biology and Fertility Programme (TSBF) soil monoliths were sampled. Results revealed an increase in total macroarthropod diversity, biomass, and density with regrowth, but these patterns do not occur in the same way for all macroarthropod groups, emphasizing the complexity of ecological succession. Termites were key ecosystem engineers, shaping community composition at each regrowth stage. Predators and decomposers also exhibited significant changes in response to regrowth, reflecting their sensitivity to ecological disturbances. In contrast, ants and some herbivores showed higher densities and biomass in pastures and early regrowth stages, with notable shifts in species composition over time. Vertical distribution of macroarthropods revealed higher activity at the 0–10 cm depth, with similarities in the composition in litter and 10–20 cm soil depth, highlighting soil microarthropod importance in soil mineralization and humification. These findings underscore the critical role of ecosystem engineers in soil restoration and highlight the need for the conservation of soil biology to enhance soil health.

Cohabitation between ants and termites is a widespread yet understudied ecological interaction in tropical forests. This study explores the patterns of termite-ant cohabitation networks across different forest coverages in the Colombian Amazon, focusing on taxonomic composition, nesting substrates, and ant functional guilds. A total of 413 specimens were collected from 283 cohabitation networks, identifying 197 interacting species (110 ants and 87 termites). The network exhibited low connectance (C = 0.112) and moderate modularity (Q = 0.334), indicating that only a subset of potential interactions occurred, with distinct species groups forming stronger intragroup connections. Ant genera such as Pheidole, Camponotus, Crematogaster, Acropyga and the species Pseudoponera sitgma played central roles, interacting with multiple termite genera, while termite genera like Nasutitermes, Heterotermes, and Anoplotermes emerged as key nodes due to their nesting habits and high abundance. Cohabitation patterns varied across forest types, with primary forests supporting more complex networks than secondary forests, underscoring the importance of habitat conservation in maintaining biodiversity. These findings provide new insights into the ecological mechanisms underlying termite-ant cohabitation and emphasize the importance of preserving structurally complex habitats to maintaining these interactions.

Understanding the recovery of soil macroarthropod communities during natural regrowth is crucial for effective soil restoration. This study investigates the recovery of soil macroarthropod diversity, density, and biomass across different stages of natural regrowth, focusing on both: taxonomic and functional dynamics of groups. Macroarthropod communities were analyzed in a chronosequence from pastures to various stages of natural regrowth (young-age, middle-age, and old-growth). A total of 20 plots and 100 TSBF monoliths at four different soil depth layers were sampled. As expected, results revealed a significant increase in the total macroarthropod diversity, biomass, and density with regrowth, but these do not occur in similar way for all macroarthropod groups or do not occur at all for some groups, emphasizing the complexity of ecological succession. Termites emerged as key ecosystem engineers shaping community composition at each regrowth stage. Predators and decomposers also exhibited significant changes in response to regrowth, reflecting sensitivity to ecological disturbances. In contrast, ants and some herbivores showed higher densities and biomass in pastures and early regrowth stages, with notable shifts in species composition over the time. Vertical distribution of macroarthropod revealed a higher activity at 0-10 cm depth. Macroarthropod composition of litter and at 10-20 cm soil depth was similar, highlighting important macroarthropod activity in the litter and topsoil were mineralization and humification occurs. These findings highlight the critical role of ecosystem engineers in soil restoration and highlight the need for targeted conservation and management strategies to enhance soil health in tropical ecosystems. Including the monitoring of edaphic communities helps to understand the stage of restoration in which the soil is and serves as a support tool for soil restoration

Typhlomyrmex Mayr is a genus of small and cryptic ants of the subfamily Ectatomminae. Here, we provide taxonomic notes on the ants of the genus Typhlomyrmex Mayr from Colombia, along with the description of Typhlomyrmex encantosp. nov. based on the worker caste, and the re-description / description of the worker caste of T. clavicornis Emery and T. prolatus Brown. Finally, we offer a key for the known species of Typhlomyrmex, and distribution maps for the three species this study focuses on.

The neotropical Apicotermitinae is a common and widespread clade of mostly soil-feeding soldierless termites. With few exceptions, species of this group were originally assigned to the genus Anoplotermes Müller, 1873. The application of internal worker morphology coupled with genetic sequencing has recently shed light on the true diversity of this subfamily. Herein, Anoplotermes susanae Scheffrahn, Carrijo & Castro, sp. nov. and four new species in four new genera are described: Hirsutitermes kanzakii Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov., Krecekitermes daironi Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov., Mangolditermes curveileum Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov., and Ourissotermes giblinorum Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov. Worker descriptions are based mainly on worker gut morphology, including the enteric valve, while imagoes were described based on external characters. A Bayesian phylogenetic tree of New World Apicotermitinae was constructed using the complete mitogenome to infer genera relationships and corroborate the taxonomic decisions. Distribution maps and a dichotomic key to the known Neotropical Apicotermitinae genera are provided.

Successional processes in abandoned pastures in the Amazon region have been well-documented for the floristic component; however, soil succession has been poorly studied. This study assessed the physical, chemical and biological responses of soils in the Amazon region during the natural succession process in two main landscapes of the Colombian Amazon. Soil data on soil physico–chemical (bulk density, macroaggregates, pH and minerals) and biological (soil macrofauna) composition were evaluated along chronosequence with four successional stages: (i) degraded pastures, (ii) young (10–20-year-old), (iii) middle-age (25–40-year-old) and (iv) mature forests, in two different landscapes (hill and mountain). Individual soil variables and a synthetic indicator of soil quality (GISQ) were evaluated as tools for natural succession monitoring. The results corroborated the negative impact that cattle ranching has on Amazon soils. After 10 years of natural succession, the physico–chemical and biological soil components were widely restored. Less soil compaction and organic carbon occurred in older successional stages. Soil macrofauna richness and density increased along the chronosequence, with an evident association between the macrofauna composition and the macroaggregates in the soil. None of the individual soil properties or the GISQ indicator discriminated among natural succession stages; therefore, new soil quality indicators should be developed to monitor soil quality restoration in natural successions.