Current
Impacts of climate change on the microbiome of invasive ant species
How will climate change, especially temperature increases, affect ant species worldwide? To begin addressing this question, we aim to observe the changes in the microbiome of invasive ant species during their development. In collaboration with Dr. Manuela Ramalho from Westchester University.
Microbiome of leaf-cutter ants under a restric diet
How does the specificity of diet incorporated into the fungus garden and manipulated by leaf-cutter ant workers influence the ant microbial community? We aim to understand how the diversity of resources collected by workers benefits or plays a crucial role in high fungus-growing ant colonies. In collaboration with Dr. Amanda de Oliveira from Universidade Estadual Paulista (UNESP).
Behavioral response of leaf-cutter ants to toxic baits
Leaf-cutter ants, as highly socially organized creatures, exhibit specific behavioral responses towards harmful substances. A deeper understanding of these responses could lead to more environmentally-friendly management practices, reducing the need for excessive pesticide use and minimizing environmental damage. Under the supervision of Dr. Odair Correa Bueno and collaboration with Dr. Amanda de Oliveira
Factors that drive ant diversity on carrion
Ants, as diverse insects found worldwide in various terrestrial habitats, contribute to ecosystem services such as pollination, seed dispersal, and nutrient cycling. Yet, their role in decomposition, including the fragmentation of insect bodies, decomposition of dead plant material, and animal dung, remains less explored. Moreover, their involvement in vertebrate tissue decomposition has received limited attention.
To enhance our understanding of the ecological dynamics of ants in carrion decomposition and the drivers of their diversity, we conducted field experiments and reviewed existing literature. Understanding how ants interact with carrion and how their diversity is influenced by different environmental conditions can provide valuable insights for ecological and forensic investigations.
A few important outcomes and results:
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Ant Diversity in Carrion Decomposition: The research collected a substantial dataset of 25,454 individual ants from the Formicidae family, encompassing 7 subfamilies, 38 genera, and 79 species. This extensive sampling effort revealed the presence of approximately 40 ant species previously undocumented in association with decomposing vertebrate matter. This discovery underscores the significance of carrion as a resource for ant diversity.
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Habitat Influence on Species Dominance: We found that habitat plays a crucial role in determining the dominance of certain ant species in carrion decomposition processes. And that different ant species exhibit distinct foraging behaviors in response to carrion. This variation in foraging strategies emphasizes the complexity of ant resource utilization in decomposing organic matter scenarios.
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The findings of this study have important implications for ecological and forensic investigations. Understanding how ants interact with carrion and the factors influencing their diversity can aid in unraveling intricate ecological dynamics. Moreover, these insights can be valuable in forensic contexts, where carrion decomposition timelines are crucial for determining the postmortem interval. Overall, this study enhances our knowledge of ants' role in ecosystem services, including decomposition, and sheds light on their intricate interactions with decomposing organic matter in different environments.
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In prep. Nogueira et al., 2023
Bianca Nogueira
Detection of ingested resource on a carrion-visiting fire-ant
(Hymenoptera: Formicidae)
To investigate the food preferences and distribution patterns within Solenopsis ant colonies, particularly focusing on their behavior related to carrion colonization, we developed a protocol that combines molecular and behavioral techniques to understand how food is selected and distributed among colony members.
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The main results of the study can be summarized as follows:
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1. Importance of Pig Tissue for Larvae: Pig DNA was exclusively found where a higher number of ant larvae was observed. This indicates that pig tissue, being protein-rich, was crucial for the development of the ant immatures. It suggests a specialized distribution of this resource to support the growth of the ant larvae.
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2. Behavioral Insights: The research demonstrated that Solenopsis ants actively engage with available resources and redistribute them within the colony. This behavior sheds light on their foraging and food allocation strategies.
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3. Molecular Techniques for Nutritional Ecology: The study emphasized the potential of molecular techniques in gaining insights into the nutritional ecology of ants. These techniques allow for tracking the origin and distribution of food among colony individuals.
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4. Practical Applications: The developed protocol was deemed effective for studying ecological contexts and was highlighted for its practical relevance, particularly in the field of forensic entomology. Understanding how ants interact with and distribute food resources can have applications in forensic investigations.
Bianca Nogueira
Leaf-cutting ants immune response through mating statuses
Insects possess an innate immune response characterized by defense cells and specific enzymes that have evolved under environmental pressure. Hemocytes, the main mediators of cellular defense, are involved in processes such as phagocytosis and encapsulation. Encapsulation is a defense mechanism in insects where foreign objects or pathogens are surrounded and isolated by layers of immune cells. The immune defenses of founding ants, particularly queens, may be influenced by a trade-off between reproduction and immunity due to their isolated nature during colony initiation. In this study, we aimed to investigate how the reproductive status of leaf-cutting long-lived ant queens, specifically in the species Atta laevigata and Atta sexdens, influences their immune response, particularly their encapsulation.
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The main results of the study are as follows:
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1. Reproductive Status Influence: The study found that the reproductive status of the ant queens had a significant influence on their encapsulation immune response. Specifically, newly mated queens of A. laevigata exhibited the highest level of encapsulation. This suggests that there is a positive regulation of cell defense in these ants when they are in the early stages of reproduction.
2. No Correlation with Morphological Aspects: The study also investigated whether morphological aspects such as body mass and head width correlated with the immune response. However, the results indicated that there was no significant correlation between these morphological aspects and the encapsulation immune response in these ant species.
3. Practical Implications: The study highlights the importance of understanding the cellular defense mechanisms of leaf-cutting ants. This understanding can have practical applications in improving less-agressive population control methods. Additionally, the research contributes to the broader knowledge of insect immune responses, which can have implications for various fields of biology.
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Bianca Nogueira
Influence of the reproductive status in immune resistance against
entomopathogen fungus in queens of Monomorium pharaonis
Bianca Nogueira
We also investigated the immune resistance of mated and non-mated Monomorium pharaonis queens when exposed to the entomopathogenic fungus Beauveria bassiana.
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1. Differential Survival Rates: The study found significant differences in survival rates between mated and virgin queens of M. pharaonis when exposed to Beauveria bassiana. Mated queens exhibited greater survival compared to virgin queens, suggesting that reproductive status plays a role in their immune resistance.
2. Impact of Spore Concentration: Additionally, the study exposed both mated and virgin queens to different concentrations of Beauveria bassiana spores (10^6 and 10^8). For mated queens, the spore concentration had a significant impact on their survival curves, indicating that the level of pathogen exposure influences their survival.
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3. Implication of Reproductive Status: The results suggest that being mated and potentially engaged in reproduction enhances the immune resistance of M. pharaonis queens when faced with the fungal pathogen. This finding is significant because it implies that reproductive status can be a factor influencing the immune defenses of ant queens, possibly due to the importance of queen longevity in colony success.
Leaf-cutting ants' preference to sub products used in baits
Leaf-cutting ants are eusocial insects that cultivate a mutualistic fungus as their main food source. Their large colonies, consisting of millions of individuals, engage in intense cutting activities, which can cause economic loss to farmers. Chemical control methods using toxic bait have been commonly employed, with citric pulp being the most widely used attractive compound. However, colony workers, after encountering the bait and experiencing its toxicity, start rejecting it, which leads to the ineffective use of insecticides and environmental harm. This research aimed to assess the preference of Atta sexdens and Atta laevigata species for alternative attractive compounds in granulated baits as a means to enable the rotation of bait types and reduce the environmental impact of chemical control methods.
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Here are some of our outcomes:
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​1. Preference for Alternative Attractive Compounds: The study conducted laboratory and field tests using various baits formulated with industrial sub-products as alternative attractive compounds. The results indicated that certain baits were preferred by the leaf-cutting ants. This suggests that these alternative attractive compounds were more appealing to the ants compared to the traditional citric pulp-based baits.
2. Potential for Rotation of Control Methods: The findings of this research have practical implications for the population control of leaf-cutting ants. By identifying alternative attractive compounds like soybean and cashew sub-products, the study suggests that it may be possible to rotate the toxic batis. This rotation can help in managing leaf-cutting ant populations more effectively and reduce the likelihood of bait rejection due to ant aversion.
Bianca Nogueira
Attractiveness of Colocasia esculenta (taro) to leaf-cutting ants
The purpose of this study was to investigate the potential of Colocasia esculenta (taro) as a natural and environmentally friendly insecticide against leaf-cutting ants, specifically Atta sexdens. The study aimed to compare the attractiveness or repellency of taro to leaf-cutting ants when offered alongside Acalypha wilkesiana, a plant known to attract these ants. Additionally, the study aimed to observe and record various ant behaviors in response to taro and Acalypha wilkesiana, including cutting, licking, exploring, holding, antenna movement, and immobility.
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1. Frequency of Behaviors: The study found that the recorded behaviors were less frequent in taro compared to Acalypha wilkesiana. This suggests that the ants were less active or less attracted to taro than to Acalypha wilkesiana.
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2. Proportions of Behaviors: Despite the differences in frequency, the proportions of behaviors were similar for both plants. This means that the types of behaviors exhibited by the ants were comparable between taro and Acalypha wilkesiana.
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3. Preference for Senescent Leaves: Notably, the cutting activities observed in taro were directed towards senescent (aging) leaves. This indicates that the ants may have a preference for certain parts of the taro plant, specifically older leaves. The results suggest that taro may produce or contain substances that are less attractive to leaf-cutting ants. This could have implications for the use of taro as a natural repellent or insecticide.
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4. Need for Further Research: The study concludes that further research is needed to understand the specific properties of volatiles (chemical compounds released into the air) and microorganisms present on Colocasia esculenta (taro) leaves. This additional research can help elucidate the mechanisms behind the observed differences in ant behavior and attractiveness.
Chemical control
Biological control
Cultural control
Volatiles
Endophytic microorganisms communities
Bianca Nogueira
Collaborators, colleagues and supervisors
Dr. Odair Correa Bueno (supervisor)
