Gêneros das diferentes famílias de Ephemeroptera apresentam grande variação na ocorrência entre habitats e dentro destes. Sendo assim, o objetivo do presente trabalho é fazer a comparação da distribuição dos gêneros de efemerópteros em diferentes mesohabitats e, na família Leptophlebiidae, relacionar tal distribuição com exploração de itens alimentares. As coletas foram realizadas na Estação Biológica de Boracéia ? MZUSP. Leptophlebiidae foi a família de maior abundância (54%), seguida pelos Baetidae (44%). Em Leptophlebiidae, Farrodes carioca, Massartella brieni e Miroculis sp. foram os mais comuns, particularmente no mesohabitat remanso. Em Baetidae, o gênero Americabaetis foi o mais numeroso, principalmente no mesohabitat de rápido. As análises de conteúdo estomacal nas ninfas de Leptophlebiidae revelaram, em todos os gêneros, que o item alimentar vegetal superior alóctone foi o mais abundante, seguido de partículas minerais. / Genera in the various Ephemeroptera families show much variation in their occurrences among and within habitats. The aim of the present work is to compare the distribution of mayfly genera in different mesohabitats and, in the Leptophlebiidae, relate their distribution with the exploitation of food resources. Samplings were made in the Boracéia Biological Station (23°39\'S, 45°53\'W). The family Leptophlebiidae was the most abundant (54%) followed by the Baetidae (44%). Within the Leptophlebiidae, Farrodes carioca, Massartella brieni and Miroculis sp. were the most common, especially in pools. Americabaetis was the most numerous baetid, particularly in rapids. The analyses of the gut contents showed, for all genera, that the food item \'allochthonous higher plants\' was the most common, followed by mineral particles.

Gêneros das diferentes famílias de Ephemeroptera apresentam grande variação na ocorrência entre habitats e dentro destes. Sendo assim, o objetivo do presente trabalho é fazer a comparação da distribuição dos gêneros de efemerópteros em diferentes mesohabitats e, na família Leptophlebiidae, relacionar tal distribuição com exploração de itens alimentares. As coletas foram realizadas na Estação Biológica de Boracéia ? MZUSP. Leptophlebiidae foi a família de maior abundância (54%), seguida pelos Baetidae (44%). Em Leptophlebiidae, Farrodes carioca, Massartella brieni e Miroculis sp. foram os mais comuns, particularmente no mesohabitat remanso. Em Baetidae, o gênero Americabaetis foi o mais numeroso, principalmente no mesohabitat de rápido. As análises de conteúdo estomacal nas ninfas de Leptophlebiidae revelaram, em todos os gêneros, que o item alimentar vegetal superior alóctone foi o mais abundante, seguido de partículas minerais. / Genera in the various Ephemeroptera families show much variation in their occurrences among and within habitats. The aim of the present work is to compare the distribution of mayfly genera in different mesohabitats and, in the Leptophlebiidae, relate their distribution with the exploitation of food resources. Samplings were made in the Boracéia Biological Station (23°39\'S, 45°53\'W). The family Leptophlebiidae was the most abundant (54%) followed by the Baetidae (44%). Within the Leptophlebiidae, Farrodes carioca, Massartella brieni and Miroculis sp. were the most common, especially in pools. Americabaetis was the most numerous baetid, particularly in rapids. The analyses of the gut contents showed, for all genera, that the food item \'allochthonous higher plants\' was the most common, followed by mineral particles.

A cladistic analysis of the world genera of the mayfly family Leptohyphidae is presented. Analyses of a matrix of 58 ingroup and 9 outgroup species and 119 morphological characters strongly supports the monophyly of Leptohyphidae and its sister-group relationship with Coryphoridae. Larval and adult taxonomic keys are provided to the 11 recognized extant genera. A synonymical listing, differential diagnosis, list of proposed synapomorphies, diagnostic illustrations, and notes on distribution and included species are given for each genus. The following new synonyms of genus Tricorythodes are proposed: Ableptemetes n. syn., Cabecar n. syn., Epiphrades n. syn., Homoleptohyphes n. syn., Macunahyphes n. syn., Tricoryhyphes n. syn. The former genus Asioplax is newly regarded as a subgenus of Tricorythodes. A species-level revision of North and Central American Leptohyphes is presented. A key to the 15 Leptohyphes species known as larvae is provided. In addition, detailed descriptions, diagnosis, and geographic distributions are given for all species of Leptohyphes known from North and Central America. Biogeographic analysis suggests that the family Leptohyphidae originated in South America, and that its North American species are the descendants of one or more ancestral species that crossed northward over the Panamanian land bridge. The results of this research clearly show that the mayfly family Leptohyphidae is a strongly supported monophyletic clade supported by five unique synapomorphies. Currently recognized genera are also strongly supported; however, little support was found for subfamilies. The sister family is clearly Coryphoridae, which is supported by three unique synapomorphies. Biogeographic analysis indicates that Leptohyphidae originated in South American, with at least five independent invasions from South America to North and Central America during the evolution of Leptohyphidae.

Stenonema, Stenacron, and Maccaffertium are three closely related genera of mayflies commonly found across North America. There are currently 22 described species in Maccaffertium, 7 described species in Stenacron, and 1 described species in Stenonema. Their primarily aquatic life history, and sensitivity to aquatic pollutant make these organisms ideal water quality indicators. However, there is little morphological variation within these genera leading to difficulties in identifications. The classifications of many of the species within these genera have been changed multiple times and still little is known about the relationships with in these genera. In an attempt to resolve the phylogenetic relationships of Stenonema, Stenacron, and Maccaffertium, two Mitochondrial genes (Cytochrome oxidase subunit 1 (cox1), and 16s ribosomal RNA (rrnl)) and two Nuclear genes (Wingless (Wg), and Histone H3) were sequenced from 60 individuals from the three genera, and ten individuals from three outgroup genera (Pseudiron, Epeorus, and Heptagenia). Maximum likelihood and Bayesian analysis were conducted on single-gene and concatenated multi-gene data sets, and species tree methods were utilized to resolve the phylogenetic relationships. Molecular analysis resolve Maccaffertium as paraphyletic, with Stenonema femoratum being resolved within Maccaffertium, as sister to M. mexicanum integrum. Stenacron in most cases was also resolved within Maccaffertium, as a close relative of M. lenati. In order to achieve monophyly, Stenonema needs to be expanded to include Maccaffertium and Stenacron, and four subgenera should be erected to name the well supported clades; Stenonema, Maccaffertium, Stenacron, and Lewisa.

El presente estudio fue realizado con el objetivo de conocer la composición y distribución espacial y temporal de la comunidad de Ephemeroptera, Plecoptera, Trichoptera y Coleoptera (EPTC) en una quebrada de primer orden, Chanchamayo, Perú. Se realizaron colectas bimensuales desde marzo del 2013 a enero del 2014 en cuatro microhábitats lóticos: piedra, grava, musgo y hojas retenidas en la corriente. Fueron colectados un total de 7825 individuos agrupados en 51 géneros distribuidas en 27 familias de EPTC. La mayor riqueza y abundancia fue registrada en las hojas retenidas en la corriente y durante los meses de julio y setiembre (menor caudal). Las pruebas no paramétricas de Kruskall-Wallis para la riqueza, abundancia y estructura comunitaria (diversidad de Shannon-Wiener y equidad de Pielou) determinaron diferencias significativas (p<0.05) a nivel espacial y temporal; en tanto que el análisis de similitud (ANOSIM) y de agrupamiento utilizando el método no paramétrico de escalamiento multidimensional (nMDS) determinaron diferencias significativas a nivel espacial pero no a nivel temporal. La variación espacial estuvo explicada por la heterogeneidad del hábitat; y la variación temporal se explicó principalmente por la hidrología del ecosistema. El factor espacial predominó sobre el temporal para determinar la estructura de la comunidad de EPTC. Además el análisis de similitud porcentual (SIMPER) permitió identificar las especies que más influyeron en la estructura comunitaria de EPTC. La quebrada Pichita fue calificada como de referencia por el “Riparian, Chanel and Enviromental Inventory” (RCE) y el Protocolo de la Calidad Ecológica de los Ríos Andinos (CERA).

The current thesis reviews a cross-section of studies dealing with several problems of systematics of the mayfly (Ephemeroptera) family Baetidae. It is based on classic morphological characters as well as molecular-based methods in order to solve specific taxonomic problems and reconstruct phylogenetic relationships within the selected taxa.

Dispersal of aquatic insects is difficult to measure with traditional direct trapping methodologies. However, genetic markers are an ideal surrogate to indirectly infer dispersal and gene flow. For this research, a portion of the cytochrome oxidase I gene was used to evaluate gene flow and dispersal of Epeorus pleuralis located in the northern Appalachian headwater streams of the Allegheny, Genesee, and Susquehanna watersheds. A total of 536 basepairs from 16 individual insects were used for analysis. Thirteen haplotypes were discovered, two of which were shared between the Allegheny and Genesee streams. Although no shared haplotypes were found in the Susquehanna, analysis of molecular variance results suggest that there is not a significant genetic difference between the three populations and attributes the majority of variation to within population differences.

Metal pollution from Acid Mine Drainage (AMD) is one of the most serious environmental challenges associated with mining operations as well as a potential threat to biological life. Effects of AMD from mining regions are site-specific and depend on several biotic and abiotic factors in the recipient waters. The aim of this thesis was to assess the effects of metals (As, Cd, Cr, Cu, Ni, Pb, U, Zn) on mayfly (Ephemeroptera) larvae presence in recipient waters in Norr- and Västerbotten counties, Sweden. To fulfil this aim I used data from recipient surveys that has sampled benthic fauna with the kick-net method and collected water samples for chemical analysis. Regression analyses were performed to determine the relationships between dissolved and bioavailable concentrations of Cu, Ni, Pb and Zn. Additional regression analyses were performed to assess the relationships between the dissolved concentration of each metal and number of mayfly species as. Lastly, a regression analysis was performed for number of mayfly species and water pH. Results revealed that the number of mayfly taxa decreased exponentially as metal concentrations increased. There was also a correlation between number of mayfly taxa and pH, with the highest number of species in the pH interval 6,7 – 7,7. The ability to draw any definitive conclusions about the effects of metal pollution on mayflies in this geographical area are complicated by water pH, which for some sites is quite low. Further studies may be needed to determine how much of the effect can be attributed to high metal concentrations and how much is a consequence of low water pH.

As fases imaturas dos insetos das Ordens Ephemeroptera, Plecoptera e Trichoptera (EPT) são consideradas membros sensíveis da comunidade macrobentônica dos ecossistemas lóticos. Portanto, são freqüentemente utilizados como indicadores de perturbações ambientais como a poluição. Foram adotados oito pontos de amostragem ao longo dos rios Atibainha, Cachoeira e Atibaia, na bacia do rio Piracicaba, São Paulo. Nestes locais foram determinadas as qualidades e toxicidades da água e do sedimento, bem como a composição do EPT em seis diferentes habitats, nas estações seca e chuvosa. Os resultados mostraram um gradiente de poluição ao longo dos rios que foi acompanhado pelo índice EPT nos níveis de gênero e família. Não foi possível selecionar grupos de táxons como indicadores de condições ambientais degradadas e preservadas, pois a maioria dos gêneros ocorrentes é tolerante à poluição. Recomenda-se o uso do índice EPT no nível de família nos programas de biomonitoramento regionais. / Immature insects of the Orders Ephemeroptera, Plecoptera and Trichoptera (EPT) are considered sensible members of the macrobenthic community in lotic ecosystems. Accordingly, they are often used as indicators of environmental disturbances as pollution. Eight sampling sites were established along the rivers Atibainha, Cachoeira and Atibaia of Piracicaba river basin, São Paulo, Brazil, where water and sediment quality, toxicity, as well as EPT composition in six different habitats, were determined in dry and wet seasons. The results showed a pollution gradient along the water stream matched with EPT index at genus and family levels. It was not possible to select groups of taxa as indicators of degraded and preserved environmental conditions because most of genera occurring are tolerant to pollution. It is recommended the use of EPT index in family level in stream biomonitoring programs for regional purposes.

As fases imaturas dos insetos das Ordens Ephemeroptera, Plecoptera e Trichoptera (EPT) são consideradas membros sensíveis da comunidade macrobentônica dos ecossistemas lóticos. Portanto, são freqüentemente utilizados como indicadores de perturbações ambientais como a poluição. Foram adotados oito pontos de amostragem ao longo dos rios Atibainha, Cachoeira e Atibaia, na bacia do rio Piracicaba, São Paulo. Nestes locais foram determinadas as qualidades e toxicidades da água e do sedimento, bem como a composição do EPT em seis diferentes habitats, nas estações seca e chuvosa. Os resultados mostraram um gradiente de poluição ao longo dos rios que foi acompanhado pelo índice EPT nos níveis de gênero e família. Não foi possível selecionar grupos de táxons como indicadores de condições ambientais degradadas e preservadas, pois a maioria dos gêneros ocorrentes é tolerante à poluição. Recomenda-se o uso do índice EPT no nível de família nos programas de biomonitoramento regionais. / Immature insects of the Orders Ephemeroptera, Plecoptera and Trichoptera (EPT) are considered sensible members of the macrobenthic community in lotic ecosystems. Accordingly, they are often used as indicators of environmental disturbances as pollution. Eight sampling sites were established along the rivers Atibainha, Cachoeira and Atibaia of Piracicaba river basin, São Paulo, Brazil, where water and sediment quality, toxicity, as well as EPT composition in six different habitats, were determined in dry and wet seasons. The results showed a pollution gradient along the water stream matched with EPT index at genus and family levels. It was not possible to select groups of taxa as indicators of degraded and preserved environmental conditions because most of genera occurring are tolerant to pollution. It is recommended the use of EPT index in family level in stream biomonitoring programs for regional purposes.