Hermanella complex on Northern Brazil (Ephemeroptera: Leptophlebiidae): New species and stage descriptions

ABSTRACT The male and female imago stage and a new species of the Hermanella complex are described based on material from Pará State, Northern Brazil: Hydromastodon cf. mikei (Thomas & Boutonnet, 2004) and Paramaka froehlichi sp. nov. The male imago of Hydromastodon cf. mikei can be distinguished from Hydromastodon sallesi by the following combination of characters: (1) body color pattern, especially abdominal terga translucent white with terga I to IV washed with black on posterior margin; (2) compound eyes anteriorly rounded; (3) medial projection of the styliger plate short; and (4) penis lobes close to each other and with posterolateral projection as long as ½ of its length. The male imago of Paramaka froehlichi sp.nov. can be distinguished the from the other species of the genus by the following combination of characters: (1) fore and hind wings with membrane brown; (2) legs uniformly yellowish-white, without distal band; (3) abdominal terga II to VI with marks more expanded laterally, median line absent; (4) medial projection of the styliger plate broad; (5) base of telopenis arising at distal ⅔ of penis lobe; and (6): body size of 6.1 to 7.6 mm.

Environmental and Seasonal Effects on Gerridae Assemblages (Heteroptera: Gerromorpha) from a Stream in Brazilian Savannah.

Our aim here was to assess the seasonal (dry, ebb, and rainy seasons), spatial (upstream, intermediate, and downstream), and environmental effects on the dynamics of Gerridae assemblages (Heteroptera: Gerromorpha) in a Cerrado stream, in central-western Brazil. We sampled the insects on the water line between May 2011 and April 2014 with an 18 cm diameter sieve. We used the scanning method in 100 m of stream in each sampled locality. We sampled 3690 individuals of 19 species. There was a seasonal difference in abundance, which was a result of a lower abundance in the rainy season, but this did not differ between different environments. The estimated species richness was lower upstream and in the rainy season. Species composition was different between the upstream and downstream portions. It was also different among all seasons, with the greatest difference occurring between the rainy and dry seasons. The abiotic factors were responsible for structuring the assemblages in different seasons. The observed differences among seasons in abundance, richness, and species composition have implications for conservation since changes in the structure of the vegetation in the stream edges change the hydrological cycle of streams, and consequently the diversity of the Gerridae assemblages. There was variation in richness and composition between such small distances (upstream and downstream). This shows how sensitive this system can be, and how important elements of the stream's trophic, with the Gerromorpha, can be easily altered.

The impacts of plastics on aquatic insects.

Environmental contamination by plastics and its negative effect on biodiversity have been well-documented in several types of organisms, especially in marine environments. Therefore, it is necessary to assess the impacts of plastic on other organisms such as aquatic insects, which predominantly inhabit freshwaters. It is widely known that these organisms are sensitive to environmental change, especially by contamination. Therefore, this study aimed at testing the hypothesis that aquatic insects are impacted by plastic contamination. We made a systematic search for international papers related to plastics and aquatic insects in databases such as Google Scholar, Web of Science, and Scopus. We obtained 1217 studies of which 40 discussed the impacts of contamination by plastics on aquatic insects. We identified two main impacts: the first one is caused by the use of black macroplastic to protect crops from contact with the soil in agriculture. These black macroplastics attract tons of adult aquatic insects (terrestrial stage) that mistake the plastic surface for water because they select oviposition sites through phototaxis or polarotaxis. The second one comes from water contamination that can originate from the inadequate disposal of plastics, which harms young aquatic insects (aquatic phase) when they feed, reproduce, and construct shelters. Our results show the negative impacts of plastics on both larvae and adult aquatic insects. Despite the large knowledge gap regarding the impacts of plastic on aquatic insects, the evidence above is sufficient to consider these organisms important in global discussions regarding the impacts of plastic on biodiversity.

Protected areas are not effective for the conservation of freshwater insects in Brazil.

Biodiversity conservation has faced many challenges, especially the conversion of natural areas that compete with use for agriculture, energy production and mineral extraction. This problem is further aggravated by lack of knowledge of the biodiversity that exists and the geographical distribution of different groups. The objectives of our study were to examine the distributional pattern of Gerromorpha diversity in Brazil, create a map of conservation priority areas, estimate the degree of protection that the current network of protected areas guarantees to this insect group, and identify the size thresholds in geographical distributions that would allow species to be protected. We used species occurrences from the Water Bugs Distributional Database, and we used 19 bioclimatic variables to build models of the potential distributions of species using the MaxEnt program. Using the potential model results, we calculated diversity metrics and overlapped them with the current state and federal "conservation units" (protected areas for biodiversity) in Brazil. Total beta diversity and turnover portions were separated into two faunistic groups, one in northern and the other in southern Brazil. The Amazon has higher beta diversity than what was predicted by the null models. We detected a positive relationship between species distribution area and occurrence in conservation units. Conservation units with less than 250 km2 do not protect Gerromorpha species. Our results reinforce the necessity of formulating new conservation strategies for this group, contemplating species with both restricted and ample distributions, because rare and specialist species are the most harmed by habitat reduction, given that they are more sensitive to environmental disturbance.

Fishway in hydropower dams: a scientometric analysis.

Building dams for hydroelectric use causes several negative effects on the aquatic fauna with special attention to fish communities. In fact, among other impacts, dams act as a barrier for migratory fish, causing discontinuities in rivers and not allowing fish to move to the headwaters to breed and back to the lower portions of rivers, to grow. For more than 300 years, fishways have been used to minimize the impact of dams. Here, we assess the worldwide knowledge about fishways, identifying the temporal and spatial pattern and the situation of Brazil in this global pattern. For this, we conducted scientometric research on the Web of Science repository with the following words: weir, fish, facilities, ladder, pass, dam, fish ladder, fish pass, fishway, hydropower, Petromyzon, and salmon between 1985 and 2019. Initially, we obtained 1282 articles. After a selection, 324 articles aimed to describe fishway efficiency and the relationship with the fish fauna remained. Most of the articles on dams, fishways, and fish are from North America and Europe. Among the articles in South America, most are from Brazil. Nonetheless, information on the topic is incipient in Brazil, since the country has one of the biggest hydropower in the world and 42 scientific articles about fishways published in the international scientific database. Ecology is the area of knowledge with most articles, with continuous growth in the last 10 years. Studies in the field of ecology are strategical, as this field can integrate different areas of knowledge to test the efficiency of fishways in fish conservation and may be able to answer the question: "Are fishways an ecological trap?" Research focusing on this question is important to understand the efficiency of fishways to better evaluate solutions to minimize the negative effects of dams on fish and increase the effectiveness of fishways.

Measuring stream habitat conditions: Can remote sensing substitute for field data?

The ongoing encroachment of agricultural activities into natural areas is a growing problem for the ecological condition of streams. Stream ecological condition is best measured using both biotic and abiotic parameters that reflect different channel, riparian zone and catchment aspects. Multiple physical-chemical measures of water quality have long been widely used to represent the environmental conditions of water bodies. More recently, physical habitat structure, catchment land use and land cover have been employed to better understand water body conditions. Both water quality and physical habitat structure metrics are usually measured in the field and often have strong predictive power to analyze biological assemblage conditions. On the other hand, remote sensing of catchment land use and land cover provide relatively low-cost environmental information at large spatial extents, minimizing the need for fieldwork and reducing analytical time. Given these considerations, our aim in the present study was to evaluate the degree to which stream environmental conditions could be measured reliably via remote sensing. In particular, we assessed whether a remote sensing index (Normalized Difference Vegetation Index) and land use can be used as reliable surrogates for site habitat condition, channel dimensions, and water quality. We found that our remote sensing variables were not sufficient for predicting stream water quality or habitat structure. Therefore, we recommend using remote sensing indicators only when it is impossible to measure water quality and habitat structure in the field directly.

Impact of environmental changes on the behavioral diversity of the Odonata (Insecta) in the Amazon.

The odonates are insects that have a wide range of reproductive, ritualized territorial, and aggressive behaviors. Changes in behavior are the first response of most odonate species to environmental alterations. In this context, the primary objective of the present study was to assess the effects of environmental alterations resulting from shifts in land use on different aspects of the behavioral diversity of adult odonates. Fieldwork was conducted at 92 low-order streams in two different regions of the Brazilian Amazon. To address our main objective, we measured 29 abiotic variables at each stream, together with five morphological and five behavioral traits of the resident odonates. The results indicate a loss of behaviors at sites impacted by anthropogenic changes, as well as variation in some morphological/behavioral traits under specific environmental conditions. We highlight the importance of considering behavioral traits in the development of conservation strategies, given that species with a unique behavioral repertoire may suffer specific types of extinction pressure.

Aquatic insects and their environmental predictors: a scientometric study focused on environmental monitoring in lotic environmental.

Since early studies about aquatic ecology, it has been found that changes in environmental conditions alter aquatic insect communities. Based on this, the combined study of environmental conditions and aquatic insect communities has become an important tool to monitor and manage freshwater systems. However, there is no consensus about which environmental predictors and facets of diversity are more useful for environmental monitoring. The objective of this work was to conduct a scientometric analysis to identify the main environmental predictors and biological groups used to monitor and manage lotic freshwater systems. We conducted a scientometric study on the Web of Science platform using the following words: stream, river, aquatic insect, Ephemeroptera, Plecoptera, Trichoptera, Odonata, Heteroptera, Chironomidae, bioindicator, environmental change, anthropic, and land use. Although most of the environmental predictors employed are local, intrinsic of freshwater systems using local environmental and associated landscape variables is a better strategy to predict aquatic insect communities. The facets of diversity most used are composition and richness of species and genera, which are not efficient at measuring the loss of ecosystem services and extinction of phylogenetic lineages. Although very important, these functional and phylogenetic facets are poorly explored for this purpose. Even though tropical regions are the most diverse globally and are experiencing major losses of native vegetation, these ecosystems are the least studied, a knowledge gap that needs addressing to better understand the effect of anthropogenic activities on the diversity of aquatic insects.

The Response of Neotropical Dragonflies (Insecta: Odonata) to Local and Regional Abiotic Factors in Small Streams of the Amazon.

Since the relative role of local and regional abiotic factors on the Odonata diversity in rainforest streams is still poorly understood, we evaluated the effects of these factors on adult Odonata (Insecta) from preserved and altered streams in the Amazonian region. Adult Odonata were sampled in 98 streams in the Eastern Amazon, Pará, Brazil. Six variables were used to measure local environmental factors: habitat integrity index; mean canopy over the channel; and four physical and chemical descriptors of the water. To measure regional environmental factors, six variables were also used: altitude gradient, three bioclimatic variables and two percentage forest variables. In partial redundancy analysis, both abiotic factors (local and regional) were important to explain the variation in the Odonata community. The Odonata community can be influenced by regional and local factors. The relationship between Odonata and the local (e.g., integrity, canopy cover, and physical and chemical descriptors of the water) and regional (e.g., bioclimatic and forest cover variables) environmental variables recorded in this study has important implications for the use of these organisms to monitor small streams of the Eastern Amazon. The scale at which habitat is measured is an important issue in community structuring studies considering the rapid environmental changes. It is of great importance to consider the different scales in studies assessing community structure, once an adequate habitat must meet the ecological needs of all stages of the life of the Odonata.

Elements of metacommunity structure in Amazonian Zygoptera among streams under different spatial scales and environmental conditions.

An important aspect of conservation is to understand the founding elements and characteristics of metacommunities in natural environments, and the consequences of anthropogenic disturbance on these patterns. In natural Amazonian environments, the interfluves of the major rivers play an important role in the formation of areas of endemism through the historical isolation of species and the speciation process. We evaluated elements of metacommunity structure for Zygoptera (Insecta: Odonata) sampled in 93 Amazonian streams distributed in two distinct biogeographic regions (areas of endemism). Of sampled streams, 43 were considered to have experienced negligible anthropogenic impacts, and 50 were considered impacted by anthropogenic activities. Our hypothesis was that preserved ("negligible impact") streams would present a Clementsian pattern, forming clusters of distinct species, reflecting the biogeographic pattern of the two regions, and that anthropogenic streams would present random patterns of metacommunity, due to the loss of more sensitive species and dominance of more tolerant species, which have higher dispersal ability and environmental tolerance. In negligible impact streams, the Clementsian pattern reflected a strong biogeographic pattern, which we discuss considering the areas of endemism of Amazonian rivers. As for communities in human-impacted streams, a biotic homogenization was evident, in which rare species were suppressed and the most common species had become hyper-dominant. Understanding the mechanisms that trigger changes in metacommunities is an important issue for conservation, because they can help create mitigation measures for the impacts of anthropogenic activities on biological communities, and so should be expanded to studies using other taxonomic groups in both tropical and temperate systems, and, wherever possible, at multiple spatial scales.

Taxonomic and numerical resolutions of nepomorpha (insecta: heteroptera) in cerrado streams.

Transformations of natural landscapes and their biodiversity have become increasingly dramatic and intense, creating a demand for rapid and inexpensive methods to assess and monitor ecosystems, especially the most vulnerable ones, such as aquatic systems. The speed with which surveys can collect, identify, and describe ecological patterns is much slower than that of the loss of biodiversity. Thus, there is a tendency for higher-level taxonomic identification to be used, a practice that is justified by factors such as the cost-benefit ratio, and the lack of taxonomists and reliable information on species distributions and diversity. However, most of these studies do not evaluate the degree of representativeness obtained by different taxonomic resolutions. Given this demand, the present study aims to investigate the congruence between species-level and genus-level data for the infraorder Nepomorpha, based on taxonomic and numerical resolutions. We collected specimens of aquatic Nepomorpha from five streams of first to fourth order of magnitude in the Pindaíba River Basin in the Cerrado of the state of Mato Grosso, Brazil, totaling 20 sites. A principal coordinates analysis (PCoA) applied to the data indicated that species-level and genus-level abundances were relatively similar (>80% similarity), although this similarity was reduced when compared with the presence/absence of genera (R = 0.77). The presence/absence ordinations of species and genera were similar to those recorded for their abundances (R = 0.95 and R = 0.74, respectively). The results indicate that analyses at the genus level may be used instead of species, given a loss of information of 11 to 19%, although congruence is higher when using abundance data instead of presence/absence. This analysis confirms that the use of the genus level data is a safe shortcut for environmental monitoring studies, although this approach must be treated with caution when the objectives include conservation actions, and faunal complementarity and/or inventories.

The genus Paravelia Breddin, 1898 (Hemiptera: Heteroptera: Veliidae) in Brazil, with descriptions of eight new species.

Eight new species of Paravelia Breddin, 1898 from Brazil are described and illustrated: P. amapaensis sp. nov. from Amapá State, P. bipunctata sp. nov. from Minas Gerais, Mato Grosso and Mato Grosso do Sul States, P. bilobata sp. nov. and P. polhemusi sp. nov. from Mato Grosso State, P. bahiana sp. nov. from Bahia State, P. lacrymosa sp. nov. from Minas Gerais State, P. micromaculata sp. nov. from Maranhão State, and P. ornata sp. nov. from Amazonas State. The genus is redescribed, with photos of the dorsal view for nineteen species: P. basalis (Spinola), P. biae Spangler, P. boliviana Breddin, P. bullialata Polhemus & Polhemus, P. capillata (Drake& Harris), P. capixaba Moreira, Nessimian & Rúdio, P. conata (Hungerford), P. dilatata Polhemus & Polhemus, P. foveata Polhemus & Polhemus, P. itatiayana (Drake), P. lanemeloi Moreira & Barbosa, P. manausana Polhemus & Polhemus, P. nieseri Moreira & Barbosa, P. platensis (Berg), P. recens (Drake & Harris), P. rotundanotata (Hungerford), P. spinifera Polhemus & Polhemus, P. splendoris (Drake & Harris) and P. williamsi (Hungerford). Three of these species are recorded for the first time from Brazil: P. platensis, P. spinifera and P. williamsi. Also, the macropterous forms of P. capixaba and P. dilatata are described. Lastly, an identification key to the 36 species of Paravelia recorded from Brazil and a checklist of described species are presented.

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network.

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazônia Sustentável, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.

Gerromorpha (Hemiptera: Heteroptera) of eastern Mato Grosso State, Brazil: checklist, new records, and species distribution modeling.

The infraorder Gerromorpha comprises semiaquatic bugs, most of which spend much of their lifetime on the water surface, between floating plants, or on the margins of water bodies. Based on literature and collections made on streams and lakes on municipalities of eastern Mato Grosso, Brazil, a list has been elaborated with 52 species, including several new records. Out of the recorded species, 26 belong to the family Veliidae, 20 to Gerridae, three to Hydrometridae, two to Mesoveliidae, and one to Hebridae. The modeling of the potential geographical distribution is also presented for the 20 species that have been recorded for the first time from the state.