Factors Influencing the Cycles of Foraging Activity and Inactivity in Colonies of the Leaf-Cutting Ant Atta sexdens (Linnaeus) in Eucalyptus Plantations Jessica Josefa Sanches, Vincent Fourcassié, Júlia Vanessa de Sousa Barbosa, Caroline Silva de Abreu, Ronald Zanetti Journal of Applied Entomology, 2025 Foraging in leafcutter ants alternates between periods of inactivity and activity that extend over several days or weeks. Many factors could influence this alternation, with a preponderance of environmental factors, such as temperature, humidity, and rain. Moreover, ant colony size and the management practices used for their control could also modify the cycles of activity/inactivity. We surveyed the foraging activity of the nests of the leaf‐cutting ant Atta sexdens (Linnaeus) in Eucalyptus plantations and evaluated the relative importance on foraging activity of temperature, past possible immediate experience in foraging, and use of machinery. Twenty transects with an average of 6 colonies in each were selected. Each nest was checked for foraging activity once in different months of the year and we investigated whether foraging inactivity was influenced by nest size, temperature, number of favourable hours for foraging on the day preceding the evaluation, and the use of agricultural machinery. The management practices of A. sexdens nests in Eucalyptus plantations had no influence on the occurrence of foraging inactivity, contrary to nest size and possible past immediate experience in foraging. The probability of foraging inactivity decreased by about 23% for each 10 m2 increment in the nest size. A nest was also more likely to be active on a certain day if the conditions for foraging activity had been favourable on the preceding day. Leaf‐cutting ants are one of the main herbivores in Brazil, often reaching pest status in several crops. Our results indicate that the efficiency of their control in Eucalyptus plantations could be increased by implementing control strategies several times a year and by increasing the number of bait applications in areas with a high density of small nests (less than 20 m2), as these areas are more prone to inactivity and thus may lead to increased control failures.
What Can Ground-Dwelling Ants Tell Us About Different Land-Use Systems in the Brazilian Amazon? Elisangela Silva, Cristina Machado Borges, Emília Zoppas Albuquerque, Daniela Faria Florencio, Izaias Fernandes, et al. Forests, 2025 Tropical rainforests are rapidly disappearing due to human activities, particularly land-use changes, resulting in a heterogeneous mosaic of landscapes that substantially contribute to global terrestrial biodiversity loss. We investigated how changes in land-use affect species richness, composition, and functional guilds of ground-dwelling ants within various land-use systems at a local scale in the Amazonian rainforest. Our focus was to respond to the following: (i) How do local species richness and community composition reflect differences among land-use systems? (ii) Are ground-dwelling ants, especially specialists, negatively impacted by intensified land-use changes? We surveyed 55 sites representing five land-use systems: primary forest, secondary forest, forest corridor, selective logging, and Eucalyptus plantation. We registered 150 ant species, and species richness ranged from 43 to 94. Richness varies according to the land-use systems, likely influenced by differences in habitat structural complexity both vertically and horizontally. Ant species composition and guilds distribution also varied among land-use systems studied. Environments characterized by reduced structural complexity or higher disturbed levels, such as Eucalyptus plantations, tend to support lower resource availability, which may lead to decreased species richness. However, the surrounding matrix appears to play a key role in maintaining regional biodiversity, as evidenced by the absence of differences in ground-dwelling ants diversity across all land-use systems studied.
Climatic factors and Euplatypus parallelus populations in teak plantations in the Amazon biome R. J. Oliveira, A. Santos, J. C. Zanuncio, R. Zanetti Brazilian Journal of Biology, 2025 Damage caused by insect pests, such as the ambrosia beetle Euplatypus parallelus (Coleoptera: Curculionidae), is important to forest plantations, like teak. This beetle bores galleries into the trunk of Tectona grandis, where it cultivates symbiotic fungi and staining the wood. However, the effects of climatic factors on its populations are poorly understood. This study aimed to correlate the occurrence of E. parallelus with climatic factors in a 258.09 ha T. grandis plantation, established in October 2014, in São José dos Quatro Marcos (MT), Brazil. Ethanol-baited traps were systematically installed to monitor the pest. Generalized linear mixed models (GLMMs) with negative binomial distribution were used to analyze the relationship between the number of insects collected and environmental variables. Precipitation and temperature were significant and included in the final model, unlike distance from traps to native vegetation, wind speed, relative humidity, and solar radiation. The abundance of E. parallelus increased with rising maximum and medium temperature and precipitation. The results indicate that temperature and precipitation are critical factors for predicting outbreaks of E. parallelus and should therefore be incorporated into monitoring and IPM programs. Including these variables strengthens the identification of critical sampling periods, the strategic placement of traps, and the calibration of action thresholds. It also guides climate-sensitive silvicultural practices and management guidelines, particularly in the context of ongoing climate change
Assessing ant diversity with bioindicators in a deactivated iron mine: implications for environmental monitoring and recovery efforts W. L. P. Silva, D. L. Braga, K. A. Santos, J. Barbosa, A. Santos, et al. Brazilian Journal of Biology, 2025 Mining causes serious environmental damage. Monitoring and restoring mined areas mitigate the impacts caused by mining, and ants are organisms that can be used as bioindicators. Their composition is an excellent method for monitoring environmental conditions. The objective of this study was to describe the diversity of ants in an iron mine that was deactivated ten years ago and to verify the ecological variables that explain this diversity. Ants were collected with pitfall epigeic traps with fish and honey in a mining area in the process of environmental recovery after ten years, and three habitats neighbors of the mine: Brazilian Cerrado, Atlantic Forest, and Campo Rupestre. Environmental variables related to vegetation structure were collected to explain the difference in species composition of all habitats. We collected 84 morphospecies of ants belonging to 23 genera and seven subfamilies. Species richness did vary among the area regeneration with grassy and Campo Rupestre. The composition of ants differed between habitats. The mining area regeneration with grassy was characterized by general species and adapted to disturbed environments. We recommend that the recovery plans must focus on reintroducing native plant species, recovering the vertical structure of the vegetation, and on continuous, long-term monitoring to adjust strategies over time.
Colony identity clues for Syntermes grandis (Blattodea: Termitidae) individuals using near-infrared spectroscopy and PLS-DA approach Alexandre dos Santos, Isabel Carolina Lima dos Santos, Paula Maria de Souza Mendonça, Juliana Cristina dos Santos, Antonio José Vinha Zanuncio, et al. Environmental Entomology, 2024 Termites are social insects with high species diversity in tropical ecosystems. Multivariate analysis with near-infrared spectroscopy (NIRS) and data interpretation can separate social insects belonging to different colonies of the same species. The objective of this study was to propose the use of discriminant analysis by partial least squares (PLS-DA) combined with NIRS to identify the colonial origin of the Syntermes grandis (Rambur, 1842) (Blattodea: Termitidae) in 2 castes. Six ground S. grandis colonies were identified and mapped; 30 workers and 30 soldier termites in each colony were submitted to spectral measurement with NIRS. PLS-DA applied to the termites’ spectral absorbance was used to detect a spectral pattern per S. grandis colony by caste. PLS-DA regression with NIRS proved to be an approach with 99.9% accuracy for identifying the colonial origin of S. grandis workers and 98.3% for soldiers. The methodology showed the importance of qualitatively characterizing the colonial phenotypic response of this species. NIRS is a high-precision approach to identifying the colony origin of S. grandis workers and soldiers. The PLS-DA can be used to design ecological field studies to identify colony territorial competition and foraging behavior of subterranean termite species.
Isocycloseram: A new active ingredient for leaf-cutting ants control Ronald Zanetti, Jessica J. Sanches, Andrea V. A. Wenzel, Khalid Haddi, Henrique Ferreira, et al. Plos One, 2024 Leaf-cutting ants are the most important pests in several cropping systems in the Neotropics. Granulated baits containing active ingredients, considered hazardous by the Stockholm Convention, are the usual method to control these ants. Isocycloseram is a new insecticide molecule with high safety margin for mammals, but without registration for the ants in general. Thus, this study investigated the effectiveness of granulated baits with isocycloseram in leaf-cutting ants control under laboratory and field conditions. Initially, the mortality of Atta sexdens workers, fed with dehydrated citrus pulp paste containing different concentrations of isocycloseram was evaluated in the laboratory for 21 days, for toxicological classification. Subsequently, the loading, devolution, and incorporation of baits with different concentrations of isocycloseram and the mortality of A. sexdens colonies were evaluated in the laboratory. After that, the percentages of loading and devolution of baits, foraging activity, and colony mortality treated with 0.05, 0.1, 0.2, and 0.3% of isocycloseram were evaluated for the species A. sexdens, A. laevigata, and Acromyrmex lundii in field conditions. All concentrations of isocycloseram killed more than 15% of ants in 24 h and more than 90% in 21 days in the laboratory, being classified as a fast-acting and highly effective active ingredient. Baits with 0.001 to 0.03% of isocycloseram were highly loaded and exhibited low rate of devolution. The mortality of A. sexdens colony was higher at concentrations between 0.075 and 0.3%, in the laboratory. Baits containing isocycloseram at concentrations of 0.2 and 0.3% were highly loaded, presented low devolution rates, and were highly efficient in controlling A. sexdens, A. laevigata, and A. lundii in the field, at dosages of 6, 10, and 12 g/m² of nest. This is the first report of the use of isocycloseram against leaf-cutting ants, contributing to the development of efficient and toxicologically safer ant baits.
Interspecific insect relationships on Terminalia argentea (Myrtales: Combretaceae) trees in the Cerrado biome Germano Leão Demolin Leite, David Lopes Teixeira, Carlos Alberto Domingues da Silva, Pedro Guilherme Lemes, Wagner de Souza Tavares, et al. Environmental Entomology, 2024 Terminalia argentea Mart. (Combretaceae), native to Brazil, is used in habitat restoration programs. Arthropods are bioindicators because their populations reflect changes in the environment. We evaluated the recovery of a degraded area by using ecological indices and analyzing arthropod interactions on T. argentea plants. The richness and diversity of sap-sucking Hemiptera and the abundance of tending ants and Sternorrhyncha predators increased with the number of T. argentea leaves. The correlation of the abundance of tending ants and Sternorrhyncha predators was positive with that of the sap-sucking Hemiptera, and the abundance of Sternorrhyncha predators was negative with that of tending ants and sap-sucking Hemiptera. The positive correlation between the abundance, richness, and diversity of insect groups and numbers of T. argentea leaves is an example of the bottom-up regulation mechanism, with the population dynamics of the lower trophic levels dictating those of higher trophic levels. The contribution of T. argentea, a host plant of many arthropods, to the recovery of ecological relationships between organisms in degraded ecosystems is important.
Macrofauna A Handbook of Tropical Soil Biology Sampling and Characterization of Below Ground Biodiversity, 2012
Sampling strategy and design to evaluate below-ground biodiversity A Handbook of Tropical Soil Biology Sampling and Characterization of Below Ground Biodiversity, 2012
Economic damage level for leaf-cutting ants in function of the productivity index of eucalyptus plantations in an atlantic forest region: Pest management Neotropical Entomology, 2011
Subterranean termites (Insecta: Isoptera) sampled in sandy and sandy-clay soils at minas gerais Cerrado, Brazil Sociobiology, 2011
Dispersion of seeds of tree species by the leaf-cutting ant acromyrmex subterraneus molestans (hymenoptera: Formicidae) in viçosa, Minas Gerais State, Brazil Sociobiology, 2010
Occurrence of Atta laevigata (Hymenoptera: Formicidae) in the South of Espírito Santo State, Brazil. Recently introduced or endangered species? Sociobiology, 2010
Transects to estimate the number of leaf-cutting ant nests (Hymenoptera: Formicidae) in Eucalyptus urophylla plantations Sociobiology, 2005
Spatial distribution and sampling methodology of heartwood termite (Isoptera: Rhinotermitidae) attacks in Eucalyptus spp. plantations in the Brazilian Savannah Sociobiology, 2005
Estimation of wood volume losses by heartwood termites (Insecta: Isoptera) in Eucalyptus plantations in the Brazilian Savannah Sociobiology, 2005
Preference of leaf-cutting ants by eucalypts seedlings sprayed or immersed in pyroligneous extract solutions in different concentrations Scientia Forestalis Forest Sciences, 2005
Species of soil inhabiting termites (Insecta: Isoptera) collected in Eucalyptus plantations in the State of Minas Gerais, Brazil Sociobiology, 2004
Sampling methods for monitoring the number and area of colonies of leaf-cutting ants (Hymenoptera: Formicidae) in Eucalyptus plantations in Brazil Sociobiology, 2004
Level of economic damage for leaf-cutting ants (Hymenoptera: Formicidae) in Eucalyptus plantations in Brazil Sociobiology, 2003
Ant (hymenoptera: formicidae) diversity in eucalyptus (myrtaceae) plantations and cerrado litter in Minas Gerais, Brazil Neotropical Entomology, 2002
Effect of Eucalyptus species and soil type on infestation levels of heartwood termites (Insecta: Isoptera) in reforested areas of Brazil Sociobiology, 2002
Spatial distribution of nests of the leaf cutting ant Atta sexdens rubropilosa (Hymenoptera: Formicidae) in plantations of Eucalyptus urophylla in Brazil Sociobiology, 2002
Búsqueda de alimento y marcación de trillo por larvas de Brassolis sophorae (Lepidoptera: Nymphalidae) en condiciones naturales Revista De Biologia Tropical, 1999
