Environmental thresholds of semiaquatic bugs (Heteroptera, Gerromorpha) as an indicator of environmental change in Amazon streams.

Freshwater ecosystems under the influence of human activities are subject to multiple environmental stressors that lead to biodiversity loss and habitat modification. In recent years, various organisms have been used as bioindicators to detect environmental changes by their ability to perceive changes in community attributes. A good example is the semiaquatic bugs (Hemiptera, infra order Gerromorpha) that act as predators and are sensitive to subtle changes in environmental conditions.

Effects of a Habitat Integrity Gradient on the Diversity of Odonates in the Legal Amazonia Zone of the Brazilian State of Maranhão.

The diverse ecosystems of the Amazon biome play a vital role in the maintenance of biodiversity and delivering essential ecosystem services at both local and global levels. Small-bodied generalist insects, such as those from the order Odonata, contribute significantly to these services and are recognized as sensitive bioindicators of environmental quality. The present study evaluated the diversity and distribution of adult odonates in the Legal Amazonia zone of the Brazilian state of Maranhão, to identify the key environmental drivers shaping local odonate communities.

Beta diversity of macrophyte life forms: Responses to local, spatial, and land use variables in Amazon aquatic environments.

Aquatic macrophytes encompass a highly diverse group of plants with different strategies, niche requirements, and dispersion capacities. Therefore, macrophyte life forms can respond distinctly to environmental factors. We analyzed whether emergent/amphibious, floating-leaves/rooted submerged, and free-floating/free-submerged macrophytes respond differently to local, spatial, and land use variables in ponds and streams of the Amazon.

Efficiency in using genera and families of heteroptera for stream biomonitoring in the Cerrado Biome, Eastern Maranhão, Brazil.

Heteroptera are aquatic insects sensitive to environmental impacts that are frequently used in biomonitoring programs. Resolving families and genera provides consistent responses and can be a useful alternative to accelerate monitoring results and simplify protocols. Our objective was to evaluate which taxonomic levels may be more effective in assessing environmental impacts by testing the following hypotheses: (i) higher taxa of Heteroptera (family and genus) will present congruence with lower taxa (species); (ii) the environmental integrity of the stream will affect the composition of the family, genera and species and will create change points in the abundance and frequency of each taxon.

Amazon streams impacted by bauxite mining present distinct local contributions to the beta diversity of aquatic insects, fish, and macrophytes.

Integrating the physicochemical characteristics of aquatic environments with their biotas is essential for the conservation and monitoring of biodiversity, given the sensitivity of both the biotic and the abiotic components to environmental changes linked to water quality and human activities. In the present study, we evaluate how the contributions of different taxa to beta diversity, through local and species effects, can indicate the priority sites for conservation and ecological restoration in an Amazon region impacted by bauxite mining. We also investigate how environmental conditions at local and landscape scales influence the beta diversity of the aquatic biota.

Assessment of the dark diversity's ability to predict the absence of Zygoptera (Odonata) species sensitive to anthropogenic disturbance in human-altered Amazonian ecosystems.

Estimates of dark diversity, species that belong to a given species pool but are not present locally, can help to understand how environmental conditions influence species distribution. However, it remains uncertain whether dark diversity can predict the absence of indicator species in preserved environments after environmental changes. We explored the sensitivity of dark diversity (the set of species absent from a particular area), in detecting the absence of Zygoptera (Odonata) indicative of preserved forest environments in altered habitats, and the influence of sample coverage on the detected patterns.

Dark diversity of Odonata in Amazonian streams.

The biological diversity of a region may not be fully sampled due to the low abundance or rarity of species, or the absence of species determined by their niche specificity. Investigating these species is essential for understanding the unrealized ecological potential in different habitats, identifying gaps in local and regional communities, and gaining a better understanding of the impacts of environmental changes. Therefore, to expand knowledge about the diversity of Odonata in Eastern Amazonia considering the absent species, we tested the hypotheses that: 1) Environmental variables will influence dark diversity, with greater explanation by canopy cover where sites with lower canopy cover will have higher dark diversity values, and; 2) Functional traits associated with better species dispersal will be correlated with low dark diversity of Odonata, such as larger and wider wings for example.

The loss of riparian vegetation along streams causes morphological divergences in functional traits of semiaquatic insects (Heteropteran: Gerromorpha) in the eastern Amazon.

Understanding the effects of mining activities on Amazonian streams and their impact on aquatic communities is of paramount importance in the current context of resource overexploitation in society. In this study, we assessed the significance of the environment and interspecific interactions on the organization patterns of semiaquatic insect species in a mineral extraction region in the eastern Amazon. We utilized the morpho functional characteristics of 22 species from the suborder Gerromorpha (Heteropteran), considering both the abundance and sexual dimorphism of these species.

Zygoptera / Anisoptera (Insecta: Odonata) ratio as a tool to assess anthropogenic changes in Brazilian Cerrado streams.

Aquatic ecosystems are among the most affected by anthropogenic impacts, and the rapid detection and measurement of these impacts are of great importance for the maintenance of such environments. The order of aquatic insects Odonata has emerged as an important bioindicator of environmental quality due to its sensitivity to environmental changes and its ecophysiological requirements, which make them closely associated with habitat conditions. The aim of this study was to test whether the Zygoptera/Anisoptera ratio can be used as an effective tool to assess anthropogenic changes in Cerrado streams.

Behavioral Diversity Among Odonata Larvae Increases in Water with Greater Turbidity Under Captivity Conditions.

Various factors, including environmental variables, influence the behavior of aquatic insects. However, our understanding of insect behavior and their relationships with these variables remains limited. One important variable is water turbidity, which may be exacerbated by soil erosion, directly impacting visibility in the water and potentially affecting the organism's behaviors.

Variations in the Odonata Assemblages: How Do the Dry Season and Water Bodies Influence Them?

Diverse abiotic and biotic factors drive the ecological variation of communities across spatial and temporal dimensions. Within the Amazonian landscape, various freshwater environments exhibit distinct physicochemical characteristics. Thus, our study delved into the fluctuations of Odonata assemblages amidst distinct water bodies within Amazonia, encompassing two distinct climatic seasons.

Do Methodological Differences in Experiments with Stream Shredders Imply Variability in Outputs? A Microcosm Approach.

Experiments are useful scientific tools for testing hypotheses by manipulating variables of interest while controlling for other factors that can bias or confuse the results and their interpretation. To ensures accuracy and reproducibility, experiments must have transparent and repeatable methodologies. Due to the importance of shredder invertebrates in organic matter processing, carbon cycling, and nutrient cycling, we tested experimentally the effect of different methodological approaches in microcosm experiments on the consumption and survival of shredders.

Main drivers of dragonflies and damselflies (Insecta; Odonata) metacommunities in streams inside protected areas in the Brazilian Amazon.

The evaluation of environmental and spatial influence in freshwater systems is crucial for the conservation of aquatic diversity. So, we evaluated communities of Odonata in streams inside and outside sustainable use areas in the Brazilian western Amazon. We predicted that these streams would differ regarding habitat integrity and species α and β diversity.

Trichoptera Life Stages Present Distinct Responses to Environmental Conditions in Amazonian Streams.

Biological communities have their biodiversity patterns affected by environmental, spatial, and biogeographic factors that vary from taxa to taxa, and often between life stages. This is especially true when there are differences in the habitat the species use in each of them. Individuals of the insect order Trichoptera are mostly aquatic in their larval stage and terrestrial in their adult stage, which may result in different behaviors and environmental requirements.

Ecological succession of blow flies (Diptera: Calliphoridae) in the decomposition of pig carcasses in Cerrado areas of Brazil.

This research aims to describe the process of ecological succession by associating the decomposition stages of pig carcasses with flies from the Calliphoridae family (Diptera). For this, 6 pig carcasses were exposed in Maranhão's Cerrado, utilizing metal cages with sawdust trays to catch immature specimens and "suspended traps" to capture adults. Adults of the Hemilucilia benoisti Séguy, and Hemilucilia townsendi Shannon species were only associated with the swelling stage.

Pervasive gaps in Amazonian ecological research.

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases.

Amazonian Odonata Trait Bank.

Discussion regarding the gaps of knowledge on Odonata is common in the literature. Such gaps are even greater when dealing with basic biological data for biodiverse environments like the Amazon Rainforest. Therefore, studies that address, classify, and standardize functional traits allow the elaboration of a wide range of ecological and evolutionary hypotheses.

A new Epipleoneura Williamson, 1915 (Zygoptera, Coenagrionidae) from northern Brazil and notes on E. venezuelensis Rácenis, 1955.

Epipleoneura lencionii sp. nov. is erected based on specimens from Acre State (holotype: 10º7'38.

Psaironeura jeronimoi (Odonata: Zygoptera: Coenagrionidae) sp. nov. from the Brazilian Amazon rainforest, with a key for species of tenuissima group, and discussion on the significance of the genital ligula to the taxonomy of the group.

Psaironeura jeronimoi sp. nov. is described based on seven males (Holotype: ♂ (LABECO, N° 10002717), BRAZIL, Amazonas, Alto Maués Ecological Station, (-5.

Human land-uses homogenize stream assemblages and reduce animal biomass production.

Human land-use change is a major threat to natural ecosystems worldwide. Nonetheless, the effects of human land-uses on the structure of plant and animal assemblages and their functional characteristics need to be better understood. Furthermore, the pathways by which human land uses affect ecosystem functions, such as biomass production, still need to be clarified.