Palestra de Abertura – 50 anos de Psicologia Experimental e a contribuição do Prof. Walter Hugo Cunha para a Mirmecologia


Fantastic wasps and how to study them: Behavior, Physiology and Evolution

Social insects exemplify a major evolutionary transition, in which organisms went to live in societies. I use Vespidae wasps to study the evolution towards advanced sociality and the mechanisms that can help to stabilize and resolve internal conflicts. In this talk I will show how those fascinating insects can be studied integrating behavioural ecology, reproductive physiology, chemical and comparative analyses.


Advances in reproductive biology of stingless bees

The reproductive biology of stingless bees is poorly understood, especially when compared to other groups of social bees with great ecological and economic importance. However, research on this topic has grown over the past few years, mostly driven by technological advances in molecular biology. Here, we aimed to review several recent developments in the research of stingless bee reproduction, including the mating systems of stingless bees, reproductive strategies of queens, inbreeding and diploid male production, as well as conflicts over male production. We also briefly explore topics that have not substantially advanced, highlighting the gaps that need to be further investigated. Understanding the reproductive biology of stingless bees can aid conservation efforts for these important pollinators and improve management practices that promote their sustainable economic use.


The use of OMICs to understand behavioural traits in social insects

Social insects present some unique and puzzling behavioural traits related to their work, reproductive and environmental adaptations.Our understanding of many of these behaviours are restricted at the molecular level due to the difficult of applying classical genetic and molecular techniques to a wide range of species. Recently new sequencing technologies have allowed studies of non-model and model organisms in a deep and non-directional way, which is promising for evolutionary studies of complex traits. Particularly, understanding transcriptomic regulation and genomic patterns connected to certain characteristics is a powerful approach to look for shared and derivate genetic pathways among different species. Therefore the combined use of these recent OMIC approaches allow us to look at behavioural adaptations through a fresh and more comprehensive evolutionary perspective.


The evolutionary history of the fungus-farming ant genus cyphomyrmex and its fungal cultivars

Evolutionary innovations allow species to access new ecological niches. The cultivation of fungi for food opened an entirely new nutritional niche to the ancestor of fungus-farming ants. Among the fungus-farming (“attine”) ants, “yeast agriculture” is practiced solely by a subset of species in the genus Cyphomyrmex and remains perhaps the least understood of thefive ant agricultural systems. The “yeasts” cultivated by attine ants are not true yeasts, however, but rather an agaricaceous fungus that grows as a unicellular morph when it is associated with the ants. Because yeast gardens consist of masses of yellowish clumped and encapsulated nodules, it has been suggested that the yeast morph may have emerged as an evolutionary strategy for resisting fungal pathogens. Interestingly, the yeast fungi are known to occur apart from the ants in a free-living, mycelium-producing, mushroom-forming form and cultures in axenic, nutrient-rich medium revert to a mycelial phase similar to fungi grown by other species of fungus-farming ants. Understanding the relationships of both the yeast-cultivating Cyphomyrmex ant species and their fungi is critical for understanding the key evolutionary event in which a typical, mycelium-farming ancestor began cultivating a yeast-morph fungus. Thus, reconstructing the sequence of evolutionary events that produced this transition requires explicit phylogenies for both symbionts. With the advent of methods for sampling the genome, we can now properly delimit species boundaries for both symbionts. Genome-scale sequencing of ultraconserved elements (UCEs) has proven decisive for reconstructing fungus-farming ant and fungal phylogenies. Our study constitutes the first molecular phylogeny of the Cyphomyrmex rimosus group. Our dataset is composed of UCE data from 171 ant taxa in the rimosus group and 31 ant-associated fungal samples. Preliminary results indicate that UCEs are effective for: (i) delimiting ant species and identifying cryptic species in groups or complexes that have challenged morphology and (ii) delimiting ant-cultivated fungal species and clades, for which only a handful of markers were available previously.


Unraveling diversity patterns and endemism in Malagasy ants: a phylogenomic approach.

The first step in preserving biodiversity and its associated ecosystem functions is assessing and quantifying measurable units of this diversity. Two key elements of measuring biodiversity across space and time are species diversity and endemism. In the past, most survey efforts have been focused on using taxonomic species as the units of diversity and endemism, but over the last decade it has become more common practice to assess phylogenetic (or lineage) diversity alongside taxonomic species richness. Measuring arthropod diversity based on either of these units is challenging, given that surveys are often too limited in geographic scope to capture the magnitude and breadth of arthropod species distributions and diversity, and timely identification of collected samples is difficult. Arthropods are thus often excluded from conservation planning decisions. Here we outline the goals of our project MAMI (Malagasy ant microendemism), which aims at a synthesis of survey efforts for ants in Madagascar spanning two decades. We use a phylogenomic approach to investigate regional patterns of phylogenetic diversity, endemism, and community structure across ants in Madagascar based on ~2,200 loci of ultraconserved elements. We present first results from our project using a data set of 32 species of Malagasy acrobat ants (genus Crematogaster), for which we compiled distribution data from approximately 2,400 collection records across 168 well-sampled communities. We analyzed phylogenetic patterns of community structure, diversity and endemism of these ants in Madagascar across eleven different habitat types and along climatic and primary productivity gradients. Our island-wide community analyses will uncover general patterns of species richness, lineage diversity and endemism across ant communities in Madagascar, allowing us to draw broad, widely applicable conclusions about the importance of these patterns for conservation planning.


The evolution and roles of symbionts in fungus-growing termites

Termite-farming of fungi in the genus Termitomyces originated approximately thirty million years ago in a sub-family of higher termites (the Macrotermitinae) in Sub-Saharan Africa. Since then, the association has evolved and diversified to inhabit most of sub-Saharan Africa and large parts of Southeast Asia, becoming the dominant decomposer of plant biomass and playing important roles in nutrient turnover in arid and semi-arid environments. This success has been accomplished through intricate symbiotic association with the plant-biomass degrading Termitomyces fungi and complex gut bacterial communities that complement each other metabolically. This symbiotic association is incredibly efficient in utilizing plant substrates harvested by the termites and appears to avoid contracting diseases. Here, I review our current understanding of how this complex symbiosis accomplishes near-complete degradation of plant material and how the association remarkably manages to avoid specialized diseases of their monoculture fungus crop.


The ecological correlates of spider sociality

Ecological factors can strongly influence group formation and cooperation and may be responsible for species differences in sociality and a variety of group characteristics. Although ecology has long been recognized to shape animal societies, the environmental correlates of sociality across broad geographical scales remain poorly understood for the majority of non-insect social arthropods. Using a database of all known occurrences of New World social spiders of the genus Anelosimus, I explore latitudinal patterns of spider sociality and, focusing on species that occur in Ecuador, elevational patterns. I show that social spiders exhibit dramatic geographic variation in social behaviour. Social species dominate the lowland tropical rainforests but are generally absent from higher latitudes and elevations. The distribution of subsocial species, on the other hand, reach higher latitudes, but within the tropics are restricted to higher elevations. These patterns of sociality are significantly explained by temperature and seasonality, followed by rainfall parameters. The prevalence of social species in the lowland rainforest may be delimited by conditions that promote abundant large prey in this habitat. I finally argue that the absence of subsocial species from these areas may reflect frequent disturbance due to strong rains and conditions associated with greater predation risk.


Juvenile hormone signaling and the evolution of advanced eusociality in bees

Juvenile hormone (JH) is the ancient gonadotropin of insects but not for advanced eusocial honey bees, where it regulates division of labor. To probe the evolutionary basis of this change, we combined endocrine manipulations, transcriptomics, and behavioral analyses to study JH- regulated processes in a “primitively eusocial” bumble bee, where JH is the major gonadotropin. We show that JH influences behavior such as dominance, aggression and circadian rhythmicity, but not task performance (i.e., division of labor). Our transcriptomic analyses show that in the fat body, more JH-regulated genes were upregulated and enriched for metabolic and biosynthetic pathways. Remarkably, in the brain, most JH-regulated genes were downregulated and enriched for protein turnover pathways, suggesting an encdocrine-mediated tradeoff. Supporting this possibility, brain ribosomal protein gene expression was downregulated in dominant workers, which naturally have high JH titers, but not in hormone-treated honey bees. These findings suggest that the evolution of advanced eusociality was associated with modifications in hormonal signaling supporting extended and extremely high fertility while reducing the ancient costs of high gonadotropin titers to the brain. Thus, our findings link two remarkable physiological traits of advanced eusocial insects: first, they defy the widespread trade-off between reproduction and longevity, second, JH, which is the ancient insect gonadotropin, does not appear to regulate fertility in some social insects such as honey bees and some ants. Our findings suggest that these two traits are linked because high JH titres would have caused a serious cost to queens that are highly fertile over extended periods, and therefore the evolution of eusociality in these lineages was associated with modifications in JH signalling pathways.


A inclusão das pessoas no mundo das formigas: como conectar a comunidade científica com a sociedade

Comumente o conhecimento científico é visto como algo distante da sociedade, seja por ter uma linguagem pouco acessível, por parecer algo muito complexo ou pela sociedade ter pouco acesso a este tipo de informação. Este distanciamento é prejudicial tanto para a ciência quanto para a sociedade de forma geral, uma vez que cientistas deixam de aprender com comunidades tradicionais, que há tempos convivem no seu dia a dia com/na natureza, e a sociedade perde ao não saber quais avanços temos alcançado e como estes podem auxiliar na sua vida. Desta forma, o objetivo desta palestra é apresentar alguns meios de promover essa troca de conhecimentos, além da construção conjunta dos mesmos, utilizando formigas. Serão apresentados diferentes exemplos de alguns grupos de pesquisa no Brasil, com maiores detalhes para os trabalhos desenvolvidos em meu laboratório, que passam pela etnomirmecologia, divulgação científica, ciência cidadã, popularização da ciência e a visão artística sobre as formigas.


Coexistência de espécies de cupins: uma abordagem de ecologia química 

Cupins exercem um papel primordial no funcionamento dos ecossistemas e na manutenção da riqueza de espécies nas regiões tropicais. Este efeito depende fundamentalmente do uso do habitat por estes organismos durante suas atividades de forrageio e nidificação, as quais incluem mudanças físicas e químicas no solo e na paisagem. A extensão na qual os cupins exploram as áreas no entorno de seus ninhos é regulada pelo balanço entre custos e benefícios locais. A disponibilidade de recursos, por exemplo, pode regular as áreas de uso dos cupins e interferir na sobreposição espacial interespecífica; assim como na percepção e aceitação intercolonial. Os mecanismos envolvidos neste processo são mediados por pistas químicas liberadas pelos indivíduos da colônia. A percepção e a aceitação destas pistas químicas também é modulada pela disponibilidade de recursos e interfere na detecção e exploração de sinais entre colônias vizinhas. Em alguns casos, a detecção de sinal heteroespecífico ocorre unilateralmente o que torna a outra espécie imperceptível quimicamente. Desta forma, estes comportamentos podem ser parte de estratégias que permitem a coexistência de espécies tanto localmente (ex. em torno do ninho) ou até mesmo o compartilhamento de um mesmo ninho por diferentes espécies de cupins. Esta palestra tem como objetivo explorar os mecanismos envolvidos na coexistência de diferentes espécies via percepção de pistas químicas e modulação do comportamento.


Dra. Luciana Regina PodgaiskiUniversidade Federal do Rio Grande do Sul

Aliança com o inimigo? Formigas e a invasão da uva-do-japão (Hovenia dulcis) na Mata Atlântica

Dra. Erin Cole – Universidade de Copenhagem

Advances In Reproductive Biology Of Stingless Bees

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