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1.
Proc Biol Sci ; 291(2026): 20241214, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38981524

RESUMO

Obligatory ant-plant symbioses often appear to be single evolutionary shifts within particular ant lineages; however, convergence can be revealed once natural history observations are complemented with molecular phylogenetics. Here, we describe a remarkable example of convergent evolution in an ant-plant symbiotic system. Exclusively arboreal, Myrmelachista species can be generalized opportunists nesting in several plant species or obligately symbiotic, live-stem nesters of a narrow set of plant species. Instances of specialization within Myrmelachista are known from northern South America and throughout Middle America. In Middle America, a diverse radiation of specialists occupies understory treelets of lowland rainforests. The morphological and behavioural uniformity of specialists suggests that they form a monophyletic assemblage, diversifying after a single origin of specialization. Using ultraconserved element phylogenomics and ancestral state reconstructions, we show that shifts from opportunistic to obligately symbiotic evolved independently in South and Middle America. Furthermore, our analyses support a remarkable case of convergence within the Middle American radiation, with two independently evolved specialist clades, arising nearly simultaneously from putative opportunistic ancestors during the late Pliocene. This repeated evolution of a complex phenotype suggests similar mechanisms behind trait shifts from opportunists to specialists, generating further questions about the selective forces driving specialization.


Assuntos
Formigas , Evolução Biológica , Filogenia , Simbiose , Formigas/fisiologia , Formigas/genética , Animais , América do Sul , América Central , Mirmecófitas
2.
Naturwissenschaften ; 111(4): 39, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39008082

RESUMO

Coastal dunes are unique habitats, threatened by human activities. In biogeographical terms, coastal dunes are habitat islands, being discrete and distinct patches of similar habitat among themselves, separated from each other by a different type of habitat. Furthermore, coastal dunes harbor endemic species, adapted to living solely in the habitats found on specific dune systems. For example, the honeypot ant Myrmecocystus baja is endemic and restricted to coastal dunes of Mexico's Baja California Pacific coast. This ecological and biogeographical scenario led to the questions whether their geographical isolation is reflected in their genetic diversity and structuring, and how their demographic history is related with the formation of the dune system habitats. To answer these questions, population genetic, isolation-with-migration, and phylogeographical analyses were carried out, based on mitochondrial and five nuclear intronic markers. Minimal gene flow was detected only between two of the dune systems sampled; otherwise, the M. baja populations were found to be isolated and genetically structured, and their divergence generally pre-dated the modern-day dune systems. It is therefore highly likely that these ants were already present in paleodunes and that each of the populations was established from founder populations as the dunes formed. These findings highlight the importance of coastal dunes for species such as the honeypot ant from Baja California, in promoting genetic differentiation.


Assuntos
Formigas , Ecossistema , Variação Genética , Animais , Formigas/genética , Formigas/classificação , México , DNA Mitocondrial/genética , Fluxo Gênico , Filogeografia
3.
Mol Phylogenet Evol ; 198: 108142, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38964594

RESUMO

Assigning a query individual animal or plant to its derived population is a prime task in diverse applications related to organismal genealogy. Such endeavors have conventionally relied on short DNA sequences under a phylogenetic framework. These methods naturally show constraints when the inferred population sources are ambiguously phylogenetically structured, a scenario demanding substantially more informative genetic signals. Recent advances in cost-effective production of whole-genome sequences and artificial intelligence have created an unprecedented opportunity to trace the population origin for essentially any given individual, as long as the genome reference data are comprehensive and standardized. Here, we developed a convolutional neural network method to identify population origins using genomic SNPs. Three empirical datasets (an Asian honeybee, a red fire ant, and a chicken datasets) and two simulated populations are used for the proof of concepts. The performance tests indicate that our method can accurately identify the genealogy origin of query individuals, with success rates ranging from  93 % to 100 %. We further showed that the accuracy of the model can be significantly increased by refining the informative sites through FST filtering. Our method is robust to configurations related to batch sizes and epochs, whereas model learning benefits from the setting of a proper preset learning rate. Moreover, we explained the importance score of key sites for algorithm interpretability and credibility, which has been largely ignored. We anticipate that by coupling genomics and deep learning, our method will see broad potential in conservation and management applications that involve natural resources, invasive pests and weeds, and illegal trades of wildlife products.


Assuntos
Aprendizado Profundo , Animais , Abelhas/genética , Abelhas/classificação , Formigas/genética , Formigas/classificação , Genética Populacional , Galinhas/genética , Galinhas/classificação , Polimorfismo de Nucleotídeo Único , Genômica , Filogenia
4.
Braz J Biol ; 84: e284085, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38958299

RESUMO

The current study evaluates the antibacterial activity of Camponotus compressus (Hymenoptera: Formicidae) body crude extracts. The increasing antibiotic resistance of bacteria has prompted the world to turn its attention towards insects in the search for new sources of antibacterial compounds. The body crude extract obtained with different solvents were tested against both Gram positive (Staphylococcus aureus, Bacillus subtilis) and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae). Standard disc diffusion method was used to perform the activity. The extracts of C. compressus were investigated for their effectiveness against all resistant pathogenic bacteria. Staphylococcus aureus was found to be the most susceptible, exhibiting a high average growth inhibition, while Bacillus subtilis showed a lower average growth inhibition zone. Our findings regarding the inhibitory effect of C. compressus extracts show the presence of a broad-spectrum antibacterial compound. This will be helpful in the search for novel natural antibiotics against robust pathogenic bacterial strains.


Assuntos
Antibacterianos , Formigas , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Testes de Sensibilidade Microbiana , Animais , Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Formigas/efeitos dos fármacos , Misturas Complexas/farmacologia
5.
Nat Commun ; 15(1): 5641, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38969636

RESUMO

On a global scale, biodiversity is geographically structured into regions of biotic similarity. Delineating these regions has been mostly targeted for tetrapods and plants, but those for hyperdiverse groups such as insects are relatively unknown. Insects may have higher biogeographic congruence with plants than tetrapods due to their tight ecological and evolutionary links with the former, but it remains untested. Here, we develop a global regionalization for a major and widespread insect group, ants, based on the most comprehensive distributional and phylogenetic information to date, and examine its similarity to regionalizations for tetrapods and vascular plants. Our ant regionalization supports the newly proposed Madagascan and Sino-Japanese realms based on tetrapod delineations, and it recovers clusters observed in plants but not in tetrapods, such as the Holarctic and Indo-Pacific realms. Quantitative comparison suggests strong associations among different groups-plants showed a higher congruence with ants than with tetrapods. These results underscore the wide congruence of diverse distribution patterns across the tree of life and the similarities shared by insects and plants that are not captured by tetrapod groups. Our analysis highlights the importance of developing global biogeographic maps for insect groups to obtain a more comprehensive geographic picture of life on Earth.


Assuntos
Formigas , Biodiversidade , Filogenia , Filogeografia , Plantas , Animais , Formigas/fisiologia , Plantas/classificação , Evolução Biológica
6.
BMC Genom Data ; 25(1): 70, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009995

RESUMO

OBJECTIVES: Ants are ecologically dominant insects in most terrestrial ecosystems, with more than 14,000 extant species in about 340 genera recorded to date. However, genomic resources are still scarce for most species, especially for species endemic in East or Southeast Asia, limiting the study of phylogeny, speciation and adaptation of this evolutionarily successful animal lineage. Here, we assemble and annotate the genomes of Odontoponera transversa and Camponotus friedae, two ant species with a natural distribution in China, to facilitate future study of ant evolution. DATA DESCRIPTION: We obtained a total of 16 Gb and 51 Gb PacBio HiFi data for O. transversa and C. friedae, respectively, which were assembled into the draft genomes of 339 Mb for O. transversa and 233 Mb for C. friedae. Genome assessments by multiple metrics showed good completeness and high accuracy of the two assemblies. Gene annotations assisted by RNA-seq data yielded a comparable number of protein-coding genes in the two genomes (10,892 for O. transversa and 11,296 for C. friedae), while repeat annotations revealed a remarkable difference of repeat content between these two ant species (149.4 Mb for O. transversa versus 49.7 Mb for C. friedae). Besides, complete mitochondrial genomes for the two species were assembled and annotated.


Assuntos
Formigas , Genoma de Inseto , Animais , Formigas/genética , Formigas/classificação , Genoma de Inseto/genética , Anotação de Sequência Molecular , Filogenia , Genômica/métodos
7.
Sci Rep ; 14(1): 12801, 2024 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834710

RESUMO

We use complex systems science to explore the emergent behavioral patterns that typify eusocial species, using collective ant foraging as a paradigmatic example. Our particular aim is to provide a methodology to quantify how the collective orchestration of foraging provides functional advantages to ant colonies. For this, we combine (i) a purpose-built experimental arena replicating ant foraging across realistic spatial and temporal scales, and (ii) a set of analytical tools, grounded in information theory and spin-glass approaches, to explore the resulting data. This combined approach yields computational replicas of the colonies; these are high-dimensional models that store the experimental foraging patterns through a training process, and are then able to generate statistically similar patterns, in an analogous way to machine learning tools. These in silico models are then used to explore the colony performance under different resource availability scenarios. Our findings highlight how replicas of the colonies trained under constant and predictable experimental food conditions exhibit heightened foraging efficiencies, manifested in reduced times for food discovery and gathering, and accelerated transmission of information under similar conditions. However, these same replicas demonstrate a lack of resilience when faced with new foraging conditions. Conversely, replicas of colonies trained under fluctuating and uncertain food conditions reveal lower efficiencies at specific environments but increased resilience to shifts in food location.


Assuntos
Formigas , Comportamento Alimentar , Animais , Formigas/fisiologia , Comportamento Alimentar/fisiologia , Simulação por Computador , Análise Espaço-Temporal , Comportamento Social , Comportamento Animal/fisiologia , Modelos Biológicos
8.
Proc Biol Sci ; 291(2024): 20240494, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38864332

RESUMO

Social organization, dispersal and fecundity coevolve, but whether they are genetically linked remains little known. Supergenes are prime candidates for coupling adaptive traits and mediating sex-specific trade-offs. Here, we test whether a supergene that controls social structure in Formica selysi also influences dispersal-related traits and fecundity within each sex. In this ant species, single-queen colonies contain only the ancestral supergene haplotype M and produce MM queens and M males, while multi-queen colonies contain the derived haplotype P and produce MP queens, PP queens and P males. By combining multiple experiments, we show that the M haplotype induces phenotypes with higher dispersal potential and higher fecundity in both sexes. Specifically, MM queens, MP queens and M males are more aerodynamic and more fecund than PP queens and P males, respectively. Differences between MP and PP queens from the same colonies reveal a direct genetic effect of the supergene on dispersal-related traits and fecundity. The derived haplotype P, associated with multi-queen colonies, produces queens and males with reduced dispersal abilities and lower fecundity. More broadly, similarities between the Formica and Solenopsis systems reveal that supergenes play a major role in linking behavioural, morphological and physiological traits associated with intraspecific social polymorphisms.


Assuntos
Distribuição Animal , Formigas , Fertilidade , Comportamento Social , Animais , Formigas/fisiologia , Formigas/genética , Masculino , Feminino , Haplótipos
9.
Sci Adv ; 10(23): eadk9000, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38848359

RESUMO

Olfaction is essential for complex social behavior in insects. To discriminate complex social cues, ants evolved an expanded number of odorant receptor (Or) genes. Mutations in the obligate odorant co-receptor gene orco lead to the loss of ~80% of the antennal lobe glomeruli in the jumping ant Harpegnathos saltator. However, the cellular mechanism remains unclear. Here, we demonstrate massive apoptosis of odorant receptor neurons (ORNs) in the mid to late stages of pupal development, possibly due to ER stress in the absence of Orco. Further bulk and single-nucleus transcriptome analysis shows that, although most orco-expressing ORNs die in orco mutants, a small proportion of them survive: They express ionotropic receptor (Ir) genes that form IR complexes. In addition, we found that some Or genes are expressed in mechanosensory neurons and nonneuronal cells, possibly due to leaky regulation from nearby non-Or genes. Our findings provide a comprehensive overview of ORN development and Or expression in H. saltator.


Assuntos
Formigas , Neurônios Receptores Olfatórios , Receptores Odorantes , Animais , Neurônios Receptores Olfatórios/metabolismo , Formigas/genética , Formigas/metabolismo , Formigas/fisiologia , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Apoptose , Mutação , Sobrevivência Celular , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Perfilação da Expressão Gênica , Transcriptoma
10.
PLoS One ; 19(6): e0302371, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38857223

RESUMO

Formica is a large genus in the family Formicidae with high diversity in its distribution, morphology, and physiology. To better understand evolutionary characteristics of Formica, the complete mitochondrial genomes (mitogenomes) of two Formica species were determined and a comparative mitogenomic analysis for this genus was performed. The two newly sequenced Formica mitogenomes each included 37 typical mitochondrial genes and a large non-coding region (putative control region), as observed in other Formica mitogenomes. Base composition, gene order, codon usage, and tRNA secondary structure were well conserved among Formica species, whereas diversity in sequence size and structural characteristics was observed in control regions. We also observed several conserved motifs in the intergenic spacer regions. These conserved genomic features may be related to mitochondrial function and their highly conserved physiological constraints, while the diversity of the control regions may be associated with adaptive evolution among heterogenous habitats. A negative AT-skew value on the majority chain was presented in each of Formica mitogenomes, indicating a reversal of strand asymmetry in base composition. Strong codon usage bias was observed in Formica mitogenomes, which was predominantly determined by nucleotide composition. All 13 mitochondrial protein-coding genes of Formica species exhibited molecular signatures of purifying selection, as indicated by the ratio of non-synonymous substitutions to synonymous substitutions being less than 1 for each protein-coding gene. Phylogenetic analyses based on mitogenomic data obtained fairly consistent phylogenetic relationships, except for two Formica species that had unstable phylogenetic positions, indicating mitogenomic data are useful for constructing phylogenies of ants. Beyond characterizing two additional Formica mitogenomes, this study also provided some key evolutionary insights into Formica.


Assuntos
Formigas , Evolução Molecular , Genoma Mitocondrial , Filogenia , Animais , Formigas/genética , Uso do Códon , RNA de Transferência/genética , Composição de Bases
11.
J Insect Sci ; 24(3)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38913609

RESUMO

With their unique colony structure, competition between ants (Hymenoptera: Formicidae) can be particularly intense, with colonies potentially willing to sacrifice large number of individuals to obtain resources or territory under the right circumstances. In this review, we cover circumstances in which ant competition escalates into combat, battle strategies and tactics, and analysis methods for these battles. The trends for when colonies choose to fight can vary greatly dependent on the species and situation, which we review in detail. Because of their large group sizes, ant conflicts can follow different patterns than many other species, with a variety of specialist adaptations and battle strategies, such as specialized worker classes and the need to rapidly recruit large number of compatriots. These same large group sizes also can make ant fighting amenable to mathematical analysis, particularly in the context of Lanchester's laws that consider how total numbers influence the outcome of a confrontation. Yet, dynamic behavior can often disrupt idealized mathematical predictions in real-world scenarios, even though these can still shed light on the explanations for such behavior. We also systematically cover the literature on battles between groups of ants, presenting several other interesting studies on species with unique colony organization, such as army ants and leafcutter ants.


Assuntos
Formigas , Formigas/fisiologia , Animais , Comportamento Competitivo , Comportamento Social , Comportamento Animal
12.
BMC Ecol Evol ; 24(1): 82, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38872087

RESUMO

BACKGROUND: Tandem running is a recruitment method found in some species of ants where one ant follows another ant to reach a destination having maintained a physical contact with its antennae, throughout the journey. It is considered that the exchange of information regarding the destination among the nestmates happened during the process of tandem running. We examined the impact of restricting antennal movement on tandem running by using Diacamma indicum, a tandem-running ponerine ant by following 480 tandem runs across 9 treatment colonies and comparing it with 10 control relocating colonies. RESULT: Though all the 19 colonies relocated successfully, treatment colonies took significantly longer time to do so. Restricted antennal movement did not influence the ability to become tandem leaders, initiate tandem runs or the work organization significantly. However, antennae-restricted ants performed fewer tandem runs and took significantly longer time. Followers with single or both antennae-restriction performed significantly higher number of interruptions and the alignment between the leader and follower was impacted as antenna-restricted followers subtended a greater angle and walked more to the side of the leader as compared to the control followers. CONCLUSION: This study showed unhindered movement of the followers' antennae is important for tandem-running ants. In the next step, to gain a comprehensive understanding of this recruitment method, it is essential to individually delineate different sensory modalities.


Assuntos
Formigas , Antenas de Artrópodes , Animais , Formigas/fisiologia , Antenas de Artrópodes/fisiologia , Corrida/fisiologia , Movimento/fisiologia , Comportamento Social , Comportamento de Retorno ao Território Vital/fisiologia
13.
Food Res Int ; 190: 114574, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945565

RESUMO

Sensory lexicons provide an important tool for describing the sensory properties of emerging, unfamiliar foods such as edible insects. This study sought to establish and validate a sensory lexicon for the description and differentiation of edible insects commercially available in Australia and prepared using common preservation and cooking methods (freeze-drying, hot-air drying, roasting, sautéing and deep-frying). Five species were evaluated, including house crickets (Acheta domesticus), yellow mealworm larvae (Tenebrio molitor), king mealworm larvae (Zophobas morio), tyrant ants (Iridomyrmex spp.) and green tree ants (Oecophylla smaragdina). Following generic descriptive sensory analysis methods, a trained panel (n=8) developed a sensory lexicon of 29 aroma and flavour descriptors, and 16 texture descriptors. Vocabulary were then categorised and ordered to generate a sensory wheel. Due to a lack of cross-over in sensory attributes between species, sub-categories of species-specific vocabulary were also generated for each insect. The lexicon enabled sensory profiling of commercially available edible insect samples which revealed large variation in aroma, flavour, and texture attributes due to both species and preparation method. This work provides a platform for development of a globally relevant edible insect sensory lexicon. International collaboration will enable expansion of the lexicon for use with other insect species and preparation methods, insect-derived ingredients (such as insect powder, defatted insect powder and textured insect protein) and in different cultural settings. As the industry grows, the applicability of vocabulary for differentiating within species and between competitive products should also be assessed.


Assuntos
Insetos Comestíveis , Gryllidae , Odorantes , Paladar , Tenebrio , Animais , Insetos Comestíveis/química , Austrália , Odorantes/análise , Humanos , Culinária/métodos , Formigas/classificação , Larva , Adulto , Feminino , Masculino , Especificidade da Espécie , Pessoa de Meia-Idade
15.
Sci Adv ; 10(24): eadp3623, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38875342

RESUMO

Advanced social behavior, or eusociality, has been evolutionarily profound, allowing colonies of ants, termites, social wasps, and bees to dominate competitively over solitary species throughout the Cenozoic. Advanced sociality requires not just nestmate cooperation and specialization but refined coordination and communication. Here, we provide independent evidence that 100-million-year-old Cretaceous ants in amber were social, based on chemosensory adaptations. Previous studies inferred fossil ant sociality from individual ants preserved adjacent to others. We analyzed several fossil ants for their antennal sensilla, using original rotation imaging of amber microinclusions, and found an array of antennal sensilla, specifically for alarm pheromone detection and nestmate recognition, sharing distinctive features with extant ants. Although Cretaceous ants were stem groups, the fossilized sensilla confirm hypotheses of their complex sociality.


Assuntos
Comunicação Animal , Formigas , Comportamento Social , Animais , Formigas/fisiologia , Feromônios/metabolismo , Fósseis , Comportamento Animal/fisiologia , Evolução Biológica , Sensilas/fisiologia
16.
PeerJ ; 12: e17375, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38915387

RESUMO

Elevational gradients constitute excellent systems for understanding the mechanisms that generate and maintain global biodiversity patterns. Climatic gradients associated with elevation show strong influence on species distribution in mountains. The study of mountains covered by the same habitat type is an ideal scenario to compare alternatives to the energy hypotheses. Our aim was to investigate how changes in climatic conditions along the elevational gradient drive α- and ß-diversity of four taxa in a mountain system located within a grassland biome. We sampled ants, spiders, birds and plants, and measured climatic variables at six elevational bands (with 10 sampling sites each) established between 470 and 1,000 masl on a mountain from the Ventania Mountain System, Argentina. Species richness per site and ß-diversity (turnover and nestedness) between the lowest band and upper sites were estimated. For most taxa, species richness declined at high elevations and energy, through temperature, was the major driver of species richness for ants, plants and birds, prevailing over productivity and water availability. The major ß-diversity component was turnover for plants, spiders and birds, and nestedness for ants. The unique environmental conditions of the upper bands could favour the occurrence of specialist and endemic species.


Assuntos
Altitude , Formigas , Biodiversidade , Aves , Pradaria , Aranhas , Animais , Formigas/fisiologia , Formigas/classificação , Aves/fisiologia , Argentina , Aranhas/fisiologia , Aranhas/classificação , Plantas/classificação , Clima , Ecossistema
17.
Naturwissenschaften ; 111(4): 35, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916816

RESUMO

Whether in ant-aphid mutualism the ants exert evolutionary selection pressure on aphid morphology has not yet been fully tested. Here, we tested whether the long proboscises of Stomaphis yanonis (Aphididae Lachninae) aphids confer an advantage in preventing predation by the tending ants. Specifically, we tested the hypothesis that aphids with a shorter proboscis would excrete less honeydew, making them more likely to be preyed upon by ants. Our results showed that aphid individuals with a shorter proboscis took up less phloem sap and excreted less honeydew than individuals with a longer proboscis. In addition, among aphids with a similar body size, those with a shorter proboscis were more susceptible to predation by ants than those with a longer proboscis. These results suggest that predation by tending ants, by exerting selection pressure on aphid proboscis morphology, has caused the aphids to evolve longer proboscises.


Assuntos
Formigas , Afídeos , Comportamento Predatório , Animais , Afídeos/fisiologia , Formigas/fisiologia , Comportamento Predatório/fisiologia , Simbiose/fisiologia
18.
Math Biosci Eng ; 21(4): 5536-5555, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38872547

RESUMO

Ant colonies demonstrate a finely tuned alarm response to potential threats, offering a uniquely manageable empirical setting for exploring adaptive information diffusion within groups. To effectively address potential dangers, a social group must swiftly communicate the threat throughout the collective while conserving energy in the event that the threat is unfounded. Through a combination of modeling, simulation, and empirical observations of alarm spread and damping patterns, we identified the behavioral rules governing this adaptive response. Experimental trials involving alarmed ant workers (Pogonomyrmex californicus) released into a tranquil group of nestmates revealed a consistent pattern of rapid alarm propagation followed by a comparatively extended decay period [1]. The experiments in [1] showed that individual ants exhibiting alarm behavior increased their movement speed, with variations in response to alarm stimuli, particularly during the peak of the reaction. We used the data in [1] to investigate whether these observed characteristics alone could account for the swift mobility increase and gradual decay of alarm excitement. Our self-propelled particle model incorporated a switch-like mechanism for ants' response to alarm signals and individual variations in the intensity of speed increased after encountering these signals. This study aligned with the established hypothesis that individual ants possess cognitive abilities to process and disseminate information, contributing to collective cognition within the colony (see [2] and the references therein). The elements examined in this research support this hypothesis by reproducing statistical features of the empirical speed distribution across various parameter values.


Assuntos
Comunicação Animal , Formigas , Simulação por Computador , Modelos Biológicos , Comportamento Social , Animais , Formigas/fisiologia , Comportamento Animal
19.
Biol Lett ; 20(6): 20240102, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38889776

RESUMO

Social insects can sense colony size-even without visual information in a dark environment. How they achieve this is yet largely unknown. We empirically tested a hypothesis on the proximate mechanism using ant colonies. In Diacamma colonies, the monogynous queen is known to increase the effort devoted to queen pheromone transmission behaviour (patrolling) as the colony grows, as if she perceives colony size. The negative feedback hypothesis assumes that, through repeated physical contact with workers, the queen monitors the physiological state (fertility) of workers and increases her patrolling effort when she encounters more fertile workers. Supporting this hypothesis, we found that the queen increased her patrolling effort in response to a higher ratio of fertile workers under the experimental condition of constant colony size. Furthermore, chemical analyses and bioassays suggested that cuticular hydrocarbons have queen pheromone activity and can mediate the observed queen-worker communication of fertility state. Such a self-organizing mechanism of sensing colony size may also operate in other social insects living in small colonies.


Assuntos
Formigas , Feromônios , Comportamento Social , Animais , Formigas/fisiologia , Feminino , Densidade Demográfica , Hidrocarbonetos/metabolismo , Hidrocarbonetos/análise , Fertilidade , Comunicação Animal , Comportamento Animal/fisiologia
20.
Naturwissenschaften ; 111(4): 33, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38904668

RESUMO

Some parasitic fungi can increase fitness by modifying the behavior of their hosts. These behaviors are known as extended phenotypes because they favor parasitic gene propagation. Here, we studied three lineages of Ophiocordyceps, a fungus that infects ants, altering their conduct before death. According to fungal strategy, ants may die in leaf litter, with entwined legs in branches, under the moss mat, or biting plant tissue. It is critical for parasites that the corpses stay at these places because Ophiocordyceps exhibit iteroparity, possibly releasing spores in multiple life cycles. Thus, we assumed substrate cadaver permanence as a fungi reproductive proxy and corpse height as a proxy of cadaver removal. We hypothesize that biting vegetation and dying in higher places may increase the permanence of ant corpses while avoiding possible corpse predation on the forest floor. We monitored over a year more than 4000 zombie ants in approximately 15 km2 of undisturbed tropical forest in central Amazonia. Our results show a longer permanence of corpses with increasing ground height, suggesting that the parasites may have better chances of releasing spores and infecting new hosts at these places. We found that the zombie ants that last longer on the substrate die under the moss mat in tree trunks, not necessarily biting vegetation. The biting behavior appears to be the most derived and complex mechanism among Ophiocordyceps syndromes. Our results put these findings under a new perspective, proposing that seemingly less complex behavioral changes are ecologically equivalent and adaptative for other parasite lineages.


Assuntos
Formigas , Fenótipo , Formigas/fisiologia , Formigas/microbiologia , Formigas/parasitologia , Animais , Hypocreales/fisiologia , Brasil , Comportamento Animal/fisiologia , Interações Hospedeiro-Parasita/fisiologia
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