Navegando por Assunto "Insetos - populações"

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Acesso aberto (Open Access)
Desenvolvimento colonial em abelhas nativas sem ferrão Amazônicas (Apidae: Meliponini): tamanho populacional, nutrição e alocação fenotípica
(Universidade Federal do Pará, 2019-11) LEÃO, Kamila Leão; MENEZES, Cristiano; http://lattes.cnpq.br/9845970576214577; CONTRERA, Felipe Andrés Léon; http://lattes.cnpq.br/0888006271965925; https://orcid.org/0000-0002-7078-5048
Meliponines or stingless bees comprise a diverse and abundant group of eusocial bees, which live in perennial colonies and have a wide range of behavioral characteristics. The general objective of this thesis is to understand population dynamics and developmental patterns of Amazonian stingless bee species. In Section I, we evaluated the population size and several biological characteristics of colonies (e.g. worker external activity, queen egg-laying rate) of five stingless bee species in order to understand how colony characteristics relate to population size. We found an average adult population of 1,046.00 in Melipona flavolineata, Friese, 1900, 592.75 in Melipona fasciculata, Smith, 1854, 7,404.00 in Scaptotrigona aff. postica (Latreille, 1807), 2,425.33 in Frieseomelitta longipes (Smith, 1854) and 404.75 in Plebeia minima (Gribodo, 1893). External activity was the variable that best explained population size. In Section II we investigate the longevity of stingless bee workers fed soy-based diets. Our objective was to compare the effect of a semi-artificial soybean diet versus a natural diet on the longevity of adult workers of two stingless bee species (Melipona flavolineata Friese, 1900 e Scaptotrigona aff. postica (Latreille, 1807)). We found a higher longevity in workers that consumed only pollen compared to those that consumed the soybean diet for both species studied. Finally, In Section III we evaluated the phenotypic allocation in stingless bees. In this work we investigate phenotypic allocation as a response to climatic and environmental variation, using the stingless bee Melipona fasciculata Smith, 1854 as a model species. Our results reveal that phenotypic allocation in M. fasciculata was strongly associated with seasonal variation and not the quality of the environment (local). The production of virgin queens was influenced by season and year (being higher in the dry season), but not by location. Male production was explained by season and local environmental variables and season and study year influenced the percentage of workers produced, showing differences between years. We believe that this thesis contributes to our understanding of the natural history of Amazonian stingless bees and the development of regional meliponicultural practices.
Acesso aberto (Open Access)
Efeitos de perturbações antrópicas sobre os fatores ambientais e espaciais na estruturação de metacomunidades de insetos aquáticos na Amazônia Oriental
(Universidade Federal do Pará, 2022-07) OLIVEIRA, Stéfany Vitória Santos; FARIA, Ana Paula Justino de; http://lattes.cnpq.br/6041546003155327; https://orcid.org/0000-0003-2729-5358; SANTOS, Raphael Ligeiro Barroso; http://lattes.cnpq.br/7227882802366966; https://orcid.org/0000-0001-9717-5461
Anthropogenic pressures resulting from changes in land use have great potential to impact the dynamics of aquatic insect metacommunities, once they alter the environmental quality of streams, and may impose barriers to dispersal. The objective of this study is to evaluate the structuring of aquatic insect assemblages (Ephemeroptera, Plecoptera and Trichoptera orders - EPT) in Amazonian streams under natural conditions (control streams) and under disturbance by human activities (altered streams) is influenced by characteristics of fluvial habitats and by the spatial structure. Our hypotheses is that in control streams, habitat characteristics are the main structuring factor of EPT assemblages, and that in altered streams, habitat characteristics related to human disturbances and spatial structure are the main assemblage structuring factors. A total of 74 streams were sampled in the Capim River basin, Pará, Brazil, wich 38 are control streams and 36 are altered streams. In each of them, environmental variables associated with water chemistry, channel hydromorphology, sediment types, riparian vegetation and insect shelter were measured, in addition to the proportion of land uses and EPT assemblages. Our results showed that several environmental characteristics of the streams were affected by human activities. Environmental factors had a greater influence on the structuring of EPT assemblages than the other factors evaluated, both in the control and altered streams. The influence of the spatial factor was weak. The assemblages of altered streams were structured both by environmental variables affected by disturbances and by variables subject to natural variation, demonstrating that the assemblages in these environments are not governed only by environmental changes. Our study demonstrates the importance of the species sorting process in metacommunities of Amazonian streams, and the role of disturbance in this process.
Acesso aberto (Open Access)
Urhai gen. nov., um novo gênero para Edessinae (Hemiptera: Heteroptera: Pentatomidae)
(Universidade Federal do Pará, 2025-03) FERREIRA, Adiney Ferreira; FERNANDES, José Antônio Marin; http://lattes.cnpq.br/6743352818723245; https://orcid.org/0000-0001-7450-5296
Edessinae is the second most diverse subfamily of Pentatomidae, with approximately 500 described species distributed in 17 genera. This taxon is considered monophyletic, supported by molecular evidence and morphological characteristics. Among the genera, Edessa stands out for harboring more than 300 species, but it faces taxonomic challenges, including problems of nomenclature and classification, and is often considered a "species repository". This work aims to describe a new genus with three species previously allocated to Edessa and five new species. For the study, 94 specimens from national and foreign institutions were analyzed. Urhai gen. nov. is easily recognized by the morphology of the body, mainly presenting the head with median punctuations forming two vertical stripes on the clypeus, antennal articles I–III with small dark circular spots, pronotum with developed humeral angle; flattened and punctuated dorsoventrally; distal margin laminar; posterior angle spiniform, posterior margin of the pronotum covering the anterior part of the scutellum, metasternal process flattened; anterior arms of the bifurcation reaching or nearly reaching the limit of the propleura; distal margin generally straight. Diagnoses, species identification key and distribution maps were presented. This study is of great importance in understanding the diversity of Edessinae.
Acesso aberto (Open Access)
Variação temporal de Ephemeroptera, Plecoptera e Trichoptera (EPT) com base em sua especificidade ambiental em riachos impactados pela mineração na Amazônia Oriental
(Universidade Federal do Pará, 2022-03) PÉREZ, Juan Mateo Rivera; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029; https://orcid.org/0000-0002-6188-4386; FEITOZA, Yulie Shimano; http://lattes.cnpq.br/7380463661182614; https://orcid.org/0000-0003-2931-4719
Knowing aquatic diversity and understanding how different species are distributed in time and space has become one of the main focuses of research in ecology in recent decades. This is mainly due to the rapid environmental changes caused by human activities. In this scenario, aquatic insects of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) are used to monitor environmental conditions because they are sensitive to these changes. The intensity of the response depends directly on the breadth of the niche of each taxon given the variability and changes in the habitat. With the general objective of investigating the effects of iron mining based on the environmental specificity of EPT in streams of the Carajás National Forest in Pará, over six years, this dissertation is divided into two chapters. In the first, we classified EPT taxa into generalists and specialists and evaluated whether the estimated abundance and richness of these groups vary according to the level of alteration of the streams impacted by mining activities. In the second, we evaluated the spatial and temporal variation of the beta diversity of generalist and specialist EPT. In both studies, EPT data sampled annually in 24 streams over six years were used in streams conserved and impacted by mining in the Carajás Flona. A total of 49,922 individuals distributed in 59 genera were collected, of which 31 were classified as specialists and 28 as habitat generalists. In the first chapter, we verified that there was a negative effect of mining on the estimated wealth and a positive effect on the abundance of specialist genera. On the other hand, the abundance and estimated wealth of generalists were negatively influenced by the mining effect. In the second chapter, no differences were found in gender composition or heterogeneity between treatments. However, over time, both generalists and specialists changed their composition. Mining affects the communities of EPT generalists and specialists, in particular, specialists from sites impacted by mining that showed an increase in their abundances, possibly due to the expansion of habitat made available by the process of habitat homogenization. For generalists, gender loss was the main component in temporal beta diversity, while specialists showed gender gains and losses. Therefore, mining has affected communities of both generalist and specialist groups over the years, despite their habitat specificity, presenting different patterns of environmental changes.