In an previous 72-hr mercury bioassay with the larval caddisfly Nectopsyche albida, electrophoretically detectable esterase activity was absent in exposed individuals that succumbed to mercury toxicity, while nine other enzymes remained active hours after death. Esterase activity also persisted in unexposed individuals (Benton and Guttman, 1992a.b). To test the effects of mercury exposure duration on esterase activity, additional larval N. albida were exposed under conditions identical to those in the earlier bioassay, and esterase activity in live individuals was tested electrophoretically every 12 hr. To test the effects of mercury concentration on esterase activity, unexposed N. albida larvae were electrophoresed, and the esterase-specific stain was spiked with various concentrations of mercury. Electrophoretic banding patterns were then densitometrically quantified to identity changes in esterase activity with exposure duration and mercury concentration. Results suggest that: inorganic mercury inhibited esterase activity in N. albida, inhibition increased with exposure duration, and inhibition increased with mercury concentration.

Drift moves aquatic insects downstream, risking depopulation of upstream reaches. However, the necessity and exist­ence of an upstream flight to compensate for drift has not been undisputed. I analysed a sample of approximately 70 000 Trichoptera from a stream in northern Sweden collected during one season in 1974. The overall flight direction was upstream. Females had a stronger upstream flight than males and species varied in both flight direction and strength of the preference. Flight direction was not affected by wind or trap type. Upstream flight varied during the season and with different larval behaviours. Upstream flight increased with the size of the imago and with the abun­dance in flight. A colonisation cycle might be in effect but even though upstream flight occurs, it might not be neces­sary to sustain populations in upstream reaches.

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).

Drift moves aquatic insects downstream, risking depopulation of upstream reaches. However, the necessity and exist-ence of an upstream flight to compensate for drift has not been undisputed. I analysed a sample of approximately 70 000 Trichoptera from a stream in northern Sweden collected during one season in 1974. The overall flight direction was upstream. Females had a stronger upstream flight than males and species varied in both flight direction and strength of the preference. Flight direction was not affected by wind or trap type. Upstream flight varied during the season and with different larval behaviours. Upstream flight increased with the size of the imago and with the abun-dance in flight. A colonisation cycle might be in effect but even though upstream flight occurs, it might not be neces-sary to sustain populations in upstream reaches.

Caddisflies (Insecta, Trichoptera) is one of the most important group of benthic components in temperate freshwater ecosystems. They are sensitive to changes of physical and chemical parameters in water bodies, so often used to assess the ecological status of the water body. The main objective of this work was to investigate the caddisfly fauna, diversity, species distribution and rarity in Lithuania, to evaluate the influence of environmental factors on the distribution and abundance of caddisflies in different habitats of Lithuanian rivers. The results obtained supplement the knowledge of the fauna, diversity and distribution of caddisflies and other benthic invertebrate animals of Lithuanian rivers. The determined patterns of caddisfly distribution and abundance are important in optimizing biodiversity conservation measures. The results are important for improvement of methods for biotic assessment of ecological status of Lithuanian rivers. For the first time 22 new species of caddisfly were discovered and the checklist of Lithuanian caddisfly was updated. The relation between Lithuanian caddisfly distribution and abundance was determined. Seasonal flight periods for caddisfly adults and the factors influenting the flight dynamics were estimated. The environmental factors influencing the distribution and abundance of caddisfly taxa (families, genera, species) in Lithuanian rivers were detected. The significance of caddisflies in the communities of benthic invertebrates of... [to full text] / Apsiuvos (Insecta, Trichoptera) yra vienas svarbiausių vidutinio klimato gėlavandenių ekosistemų bentoso komponentų. Būdamos jautrios vandens telkinių fizinių ir cheminių parametrų pokyčiams, dažnai naudojamos vandens telkinių ekologinės būklės bioindikacijai. Gauti darbo rezultatai papildo žinias apie apsiuvų ir kitų bentoso bestuburių fauną, įvairovę, paplitimą ir gausumą Lietuvos upėse. Nustatyti apsiuvų paplitimo ir gausumo dėsningumai yra svarbūs optimizuojant bioįvairovės apsaugos priemones. Darbo rezultatai svarbūs tobulinant Lietuvos upių ekologinės būklės biotinio vertinimo metodus. Pirmą kartą buvo rastos 22 naujos apsiuvų rūšys ir atnaujintas Lietuvos apsiuvų faunos sąrašas. Nustatyta priklausomybė tarp Lietuvos apsiuvų paplitimo ir gausumo. Nustatyti apsiuvų suaugėlių sezoninio skraidymo tipai ir veiksniai kurie turi įtakos skraidymo dinamikai. Išaiškinti aplinkos veiksniai, kurie daro įtaką apsiuvų taksonų (šeimų, genčių, rūšių) paplitimui ir gausumui Lietuvos upėse. Įvertinta apsiuvų reikšmė skirtingų Lietuvos upių bentoso bestuburių bendrijų sudėtyje. Patikslintos apsiuvų taksonų bioindikacinės ypatybės Lietuvos sąlygomis ir pateiktos tekančių vandenų ekologinės būklės vertinimo rekomendacijos.

Apsiuvos (Insecta, Trichoptera) yra vienas svarbiausių vidutinio klimato gėlavandenių ekosistemų bentoso komponentų. Būdamos jautrios vandens telkinių fizinių ir cheminių parametrų pokyčiams, dažnai naudojamos vandens telkinių ekologinės būklės bioindikacijai. Gauti darbo rezultatai papildo žinias apie apsiuvų ir kitų bentoso bestuburių fauną, įvairovę, paplitimą ir gausumą Lietuvos upėse. Nustatyti apsiuvų paplitimo ir gausumo dėsningumai yra svarbūs optimizuojant bioįvairovės apsaugos priemones. Darbo rezultatai svarbūs tobulinant Lietuvos upių ekologinės būklės biotinio vertinimo metodus. Pirmą kartą buvo rastos 22 naujos apsiuvų rūšys ir atnaujintas Lietuvos apsiuvų faunos sąrašas. Nustatyta priklausomybė tarp Lietuvos apsiuvų paplitimo ir gausumo. Nustatyti apsiuvų suaugėlių sezoninio skraidymo tipai ir veiksniai kurie turi įtakos skraidymo dinamikai. Išaiškinti aplinkos veiksniai, kurie daro įtaką apsiuvų taksonų (šeimų, genčių, rūšių) paplitimui ir gausumui Lietuvos upėse. Įvertinta apsiuvų reikšmė skirtingų Lietuvos upių bentoso bestuburių bendrijų sudėtyje. Patikslintos apsiuvų taksonų bioindikacinės ypatybės Lietuvos sąlygomis ir pateiktos tekančių vandenų ekologinės būklės vertinimo rekomendacijos. / Caddisflies (Insecta, Trichoptera) is one of the most important group of benthic components in temperate freshwater ecosystems. They are sensitive to changes of physical and chemical parameters in water bodies, so often used to assess the ecological status of the water body. The main objective of this work was to investigate the caddisfly fauna, diversity, species distribution and rarity in Lithuania, to evaluate the influence of environmental factors on the distribution and abundance of caddisflies in different habitats of Lithuanian rivers. The results obtained supplement the knowledge of the fauna, diversity and distribution of caddisflies and other benthic invertebrate animals of Lithuanian rivers. The determined patterns of caddisfly distribution and abundance are important in optimizing biodiversity conservation measures. The results are important for improvement of methods for biotic assessment of ecological status of Lithuanian rivers. For the first time 22 new species of caddisfly were discovered and the checklist of Lithuanian caddisfly was updated. The relation between Lithuanian caddisfly distribution and abundance was determined. Seasonal flight periods for caddisfly adults and the factors influenting the flight dynamics were estimated. The environmental factors influencing the distribution and abundance of caddisfly taxa (families, genera, species) in Lithuanian rivers were detected. The significance of caddisflies in the communities of benthic invertebrates of... [to full text]

Freshwater ecosystems in south-western Australia have been extensively altered over the last two centuries as a result of human activities. The effect this has had on aquatic fauna, particularly invertebrates, is largely unknown because of inadequate knowledge of the pre-existing fauna. Future changes in the composition of aquatic fauna will also go undetected unless current distributions of existing species are well documented. This thesis addresses the problem by investigating the current distributions and conservation status of aquatic insects in south-western Australia from three orders: Odonata, Plecoptera and Trichoptera. Extensive distributional data was collected by identifying larval specimens from a large number of samples collected throughout the south-west as part of an Australia-wide macroinvertebrate bioassessment project. In addition, a database created from a species-level biological study of the wheatbelt region of Western Australia was utilised, and previously published records of occurrence for species within the south-west were compiled. These results were then used to assess the conservation status of each species using the IUCN red list criteria. Environmental parameters measured at time of sampling were also examined using logistic regression to determine which factors are important in influencing the distributions of aquatic insects in south-western Australia. The conservation value of sites based on Odonata, Plecoptera and Trichoptera compositions was also determined and the degree of protection provided for sites of high conservation value investigated.The high rainfall forested region of the south-west was found to be important for a large number of species, including the majority of those found to be rare and/or restricted. Overall, 37% of species were found to be threatened, with the Trichoptera containing both the greatest number and highest proportion of threatened species. Logistic regression results generally agreed with the distributions obtained for each species, with rainfall and other parameters indicative of streams in the headwaters of forested catchments being positively associated with species found to be restricted to the high rainfall region. Two parameters known to be affected by human disturbance in the south-west, conductivity and nutrient concentrations, were found to be important in determining the occurrence of many species and this could have important consequences for aquatic insect conservation. Widespread species occurring within the low rainfall region of the south-west did not show as many significant relationships to measured environmental parameters, possibly due to their greater ecological tolerances and adaptations which allow them to persist in a low rainfall environment. The implications of results are discussed, and recommendations for the conservation and management of aquatic insects in south-western Australia are given.

Artificial light is an important and necessary part of our urban environment, but has become a threat to biodiversity. It can have substantial direct and indirect effects on populations of all kinds of organisms. While light attraction in bats and moths has been well studied other organisms such as Trichoptera have been largely neglected, despite Trichoptera being one of the most abundant insect orders in freshwater systems. The light attraction of Trichoptera was studied through seasonal data from three different locations in Sweden. The data was examined through meta- and regression analyses to compare catches in light traps and passive traps. The use of relative abundances excluded bias from the species with large populations, and the difference in individuals caught between passive traps and light traps. The results indicated that artificial light could affect Trichoptera populations. Unlike moths, female Trichoptera were more attracted to light than males and attraction to light varied between species. In both cases, size dimorphism could explain the variation. Day-, evening- and night-active species were all attracted to light, but the latter more so. Research has shown that a false flight activity can occur in day-active Trichoptera when a lamp is lit during night, which could explain the capture of day- and evening-active species in a light trap. In all, artificial light could alter Trichoptera populations, changing sex ratios and species composition. This impact should be considered when erecting light sources near waterways.

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.