Biodiversity Of Aquatic Insects Research Articles

Aquatic insect biodiversity, water quality variables, and microplastics in the living weir freshwater ecosystem

Most Thai rivers have not yet reached "good" ecological status. Furthermore, the scientific community is deeply concerned about the existence and abundance of microplastics (MPs) in freshwater. The live weirs' river health status was assessed using water quality and a variety of aquatic insect species. The research was conducted along Khlong-La, which was compared in the absence (R1, R2) and presence of living weirs (LWs) (M71, M62, M4, and M2). In 2023, aquatic insects and water samples were gathered during two months: January (rainy season) and July (dry season). The results revealed that the six sampling sites had similar physical and chemical properties, with the exception of total dissolved solids, which varied significantly. A total of 658 aquatic insects from 25 families and 6 orders were identified. The Hydropsychidae dominated the aquatic insect fauna at the LWs locations, followed by Chironomidae, Naucoridae, and Caenidae. Ten genera were discovered at the reference site (R1), whereas 16, 21, 24, and 19 were discovered at LWs (M71, M62, M4, M2), and 16 at the reference site (R2). The results of CCA ordination revealed that the most important factors influencing aquatic insect diversity were dissolved oxygen, water temperature, pH, electrical conductivity, and ammonia nitrogen. This study suggests that because of their significant responses to environmental factors, the species richness of aquatic insects may indicate the conservation value of habitats. The BMWPTHAI score was 41, 51, 57, 58, 73, 54, and the ASPTTHAI score was 5.12, 5.10, 5.18, 5.27, 4.86, and 5.40, respectively. Shannon-Weiner diversity index (Hʼ) values were 2.059, 2.461, 2.839, 2.777, and 2.587, respectively. The results showed that the water quality was average. The physicochemical data, as well as the BMWP and ASPT, revealed that the water at the living well was slightly polluted. Furthermore, larger MPs (>500 µm) were found in the largest concentrations, in the shape of fibers, and primarily in the color violet.

Biodiversity of aquatic insects flourished in the rain water collected from Kosti and Rabak cities, White Nile State, Sudan

Biodiversity including description of status of ecosystems and populations to the best to our knowledge and major threats for better biodiversity conservation. The aim of this study was to evaluate the biodiversity of aquatic insect population in the rain water collected from White Nile State. The samples of the rain water were collected during (March and October 2022) from Kosti and Rabak Cities, White Nile State, Sudan, in clean disposable plastic bottles from random sites. Anopheles, Culex and Aedes mosquito’s larvae were identified and counted, in addition to their aquatic predators (mayfly, dragon fly and water beetles), while algae and snails were just checked for their presence within this sites. The results at Kosti city during March 2022, showed the dominance of Anopheles (37 larvae) over Culex (14 larvae), while mayfly were the more abundant predators (16 naiads), followed by water beetle (6 beetles). In Rabak city, Culex (44 larvae) was the most dominant in addition to water beetles (12 beetles). During October 2022, Anopheles (78 larvae), Culex (34 larvae) and mayfly were the dominant organisms. In Rabak city, Culex (50 larvae) was the most dominant genus, while Aedes larvae were not noticed throughout this study. Mayfly and dragon fly naiads, and water beetles were not noticed in all Rabak site

Aquatic Insects as Bioindicators of Water Quality in the Achenkovil River, Kerala, India.

The origin of the Achenkovil River, the Devarmalai of Western Ghats, is within the Konni reserve forest of Pathanamthitta district, flowing through Pathanamthitta, Kollam, and merging with the Pamba river in the Alappuzha district. This study included the spatial variation of aquatic insect fauna with respect to water quality. The bottom water samples and insect fauna were collected bimonthly using a Niskin sampler and D-frame nets for a period of one year (February 2019 to January 2020). The study yielded 10736 insect fauna under 8 orders, 21 families, 35 genera, and 36 species. How the quality of the water affects biodiversity of aquatic insects was examined using multivariate statistical techniques (PCA and CCA) and Pearson's correlation coefficient. The findings showed that the upstream portion of the river has a remarkable diversity and quantity of aquatic insect species. The major insect group in the collected sample was ephemeroptera. There were no pollution-sensitive taxa in the middle stream or downstream portions of the river, which suggests that the water quality was declining. The middle stream and downstream sections of the river did not contain any pollution-sensitive taxa, indicating deteriorating water quality. Human-caused factors like washing, cleaning cars, and washing cattle and disposal of garbage are common in these regions. Because most aquatic insects are sensitive to environmental fluctuations, they can be used as an efficient tool in biomonitoring studies.

Patterns of Aquatic Insect Biodiversity in the Highly Urbanized Bronx River, NY

Aquatic insects are important components of stream food webs and are greatly impacted by anthropogenic disturbances, including urbanization. Successful restoration of urban rivers is contingent on the growth of aquatic insect populations from colonizers from local, less-disturbed streams. However, rivers in highly urbanized watersheds may not have nearby source populations, and therefore must rely only on individuals already surviving in the river. At the regional level, urbanization is a homogenizing process, but the impacts could be heterogeneous at the local level. Therefore, some sites within highly urban rivers might support higher local biodiversity and provide source populations for restoration projects focused on other sites in the river. In this study, we collected aquatic insects from sites within the Bronx River, a highly urbanized river in the New York City metropolitan area, NY, in the summers of 2021 and 2022. We found that while taxonomic richness was similar among sites, insect abundance and dominant taxa, particularly members of Hydropsychidae (Trichoptera), varied significantly among sites. These findings suggest sites within the Bronx River are not homogenous and that some sites within the river harbor larger populations of aquatic insects and may be integral to the success of future conservation projects. This pattern of within-river heterogeneity may exist in other urban rivers and deserves consideration in determining conservation goals and the planning of stream-restoration projects.

Distributional Trends and Species Richness of Maryland, USA, Stoneflies (Insecta: Plecoptera), with an Emphasis on the Appalachian Region

Faunistic studies of regional biodiversity of aquatic insects are increasing in importance as declines are noted globally. Federal and state government conservation attempts for rare and threatened species are predicated upon the initial research of specialized taxonomists and trained field biologists. The reporting of aquatic insect occurrence data provides a baseline for conservation agencies to compare water quality monitoring studies. Updated field work, literature reviews, and database queries for stoneflies from the mid-Atlantic United States of America state of Maryland necessitated an assessment of species diversity for the state. Seven new state records and one new literature record are presented, bringing the total number of species to 122. Chao1 estimates of species richness are presented for diversity hotspots and the state as a whole, indicating that increased sampling is still necessary to fully understand diversity patterns. Accompanying are assessments of elevation trends and adult presence patterns within nine families. Collections are predominantly restricted to the Appalachian region. Herein, we direct future efforts to focus on understudied regions. An outline of distribution knowledge for species is presented to inform upcoming State Wildlife Action Plans.

A new molecular phylogeny for the Tanypodinae (Diptera: Chironomidae) places the Australian diversity in a global context

The non-biting midge subfamily Tanypodinae (Diptera: Chironomidae) is species-rich, ecologically diverse, and near-globally distributed. Within the subfamily, aspects of generic and species-level taxonomy remain poorly understood, in particular the validity of assignment of Australian and New Zealand taxa to genera erected for northern hemisphere (Holarctic) fauna. Here, we place the austral diversity within this global context by extensive geographical and taxonomic sampling in concert with a multilocus phylogenetic approach. We incorporated sequence data for mitochondrial COI, and nuclear 28S and CAD, and conducted Bayesian and maximum likelihood phylogenetic inferences and Bayesian divergence time estimation. The resolved phylogeny supported many associations of Australian taxa with their proposed Holarctic congeners, with the exception of Apsectrotanypus Fittkau, and validates several taxa as endemic. Three of four New Zealand sampled taxa had their sister groups in Australia; New Zealand Monopelopia Fittkau was sister to a German congener. This included the first record of Procladius Kieffer from New Zealand. Most nodes connecting austral and Holarctic taxa clustered around the Cretaceous-Tertiary boundary (60–80 mya), whereas New Zealand-Australia nodes were generally slightly younger (53–57 mya). Together, these data contribute substantially to our understanding of the taxonomy, systematics and biogeography of the Australian Tanypodinae and more broadly to knowledge of Australia’s aquatic insect biodiversity.

Aquatic insect communities in headwater streams of Ciliwung River watershed, West Java, Indonesia

Abstract. Wakhid, Rauf A, Krisanti M, Sumertajaya IM, Maryana N. 2021. Aquatic insect communities in headwater streams of Ciliwung River watershed, West Java, Indonesia. Biodiversitas 22: 30-41. Ciliwung is one of the major rivers flowing from Cisarua (Bogor) to Jakarta. This study was conducted to assess and compare aquatic insect biodiversity and community structure in various headwater streams with respect to different land-use types. Ten stream reaches of the first and second orders representing three different land-use types in the surrounding area (forest, tea plantation, village) were selected. At each stream reach, the aquatic insects were collected using a D-net (0.4 mm mesh). Physico-chemical properties of water were directly measured in the field. Samples were collected every two months from April until December 2018. A total of 26531 aquatic insect specimens belonging to 75 species/morphospecies, 46 families, and 10 orders were recorded. The order Trichoptera was the most abundant comprising 51.28% of the total collected insects, followed by Diptera (30.5%), Ephemeroptera (7.52%), and Plecoptera (6.25%). The highest proportion of functional feeding group was filtering-collectors (61.34%), followed by shredders (16.29%), gathering-collectors (15.32%), and predators (6.94%). Abundance of Diptera and Plecoptera was significantly higher in forest streams, while Ephemeroptera in plantation streams, and Trichoptera in village streams. The peak population of Diptera, Ephemeroptera, and Trichoptera occurred in June (dry period), while Plecoptera in December (wet period). The forest streams exhibited the highest species richness and diversity. Analysis of similarity (ANOSIM) showed a low dissimilarity among streams of the three land uses (Global R=0.217; P<0.001). The non-metric multidimensional scaling (NMDS) analysis showed that forest streams somewhat separated from plantation and village streams. The study provided important information on aquatic insect biodiversity, and indicated the need for forest area preservation in the headwater streams of Ciliwung River watershed.

Differences in land use modify Odonata assemblages in the Cerrado-Caatinga ecotone

Abstract: Aim The present study tested the hypothesis that the composition of the odonate assemblages in environments with greater habitat integrity is significantly different from that of areas with reduced habitat integrity. Methods The samples were collected between April 2017 and November 2017 in eight streams in Caxias, in the Brazilian state of Maranhão. The habitat integrity index was used to quantify habitat integrity. The odonate specimens were collected by the fixed area scanning method. Results The habitat integrity index ranged from 0.265 to 0.915 at the different localities. A total of 229 specimens were collected, representing 19 odonate species. Species composition varied among streams that presented different degrees of conservation, with some species being typical of specific habitats. However, this variation had no effect on the number of taxa or the abundance of odonates, which may reflect the local substitution of extinct specialist species by generalists. Conclusions Evidence indicates that the reduction of habitat integrity is an important predictor of changes in the biodiversity of aquatic insects in streams such as those of the Cerrado-Caatinga ecotone.

Biodiversity of aquatic insects in relation to physico-chemical parameters of Shekh Turab stream

Ecological integrity and their properties of any aquatic environment are important to monitor its stability and any change to the ecological system. The current work was undertaken to study the community of aquatic insects and physio-chemical variables of the Shekh Turab stream in periods extended for two months, one in July and the other in November 2017. The aquatic insects’ samples collected from five sites with three replications/site. The physio-chemical parameters of water were water temperature, air temperature (˚C), pH, electrical conductivity EC (μS.cm-1), total dissolved solid TDS (mg.l-1), dissolved oxygen DO (mg.l-1), BOD5 (mg.l-1), alkalinity (mg CaCO3.l-1), bicarbonate HCO3 (mg.l-1), total hardness (mgCaCO3.l-1), calcium (mg Ca2+.l-1), magnesium (mg Mg2+.l-1), nitrate (mg NO3-N.l-1), chloride (mg.l-1), sodium (mg.l-1), potassium(mg.l-1) and sulfate (mg SO4.l-1). The correlation between physio-chemical parameters and different biological taxa were statistically tested. The correlation analysis showed significant relationship. In phylum Arthropoda, a total of 5 insect species belonging to 2 orders; Ephemeroptera and Diptera depicted the Shesk Turab stream macroinvertebrates. Depending on Shannon-Weiner index, species diversity varied from 0.365 to 0.755 at site 4 and 2 respectively.

Water quality parameters and aquatic insect diversity in Aahoo stream, southwestern Nigeria

BackgroundThe role of water in the maintenance of an aquatic ecosystem is indispensable. In this study, aquatic insect biodiversity and the physico-chemical parameters of Aahoo stream, in southwestern Nigeria, were investigated from March to August 2017. Seven physico-chemical parameters were examined in six study sites.ResultsThere were significant effects (p < 0.0001) of flow rate (F5, 12 = 2221.9), electrical conductivity (F5, 12 = 276.3), air temperature (F5, 12 = 110.3), water temperature (F5, 12 = 55.5) and pH (F5, 12 = 31.45) on the quantity of aquatic insects at the study sites in Aahoo stream. Dissolved oxygen (F2, 12 = 7.82) also had a significant impact (p = 0.002) on the quantity of aquatic insects at the stream. Three aquatic insect orders, Diptera (most dominant), Odonata (median dominant) and Hemiptera (least dominant)], nine families and 12 genera were found occurring in the stream. Chironomus sp. (Chronomidae, 55.29%), Brachithemis sp. and Orthetrum sp. (Libellulidae, 21.84%) which are usually associated with polluted water showed the highest occurrence in the stream. Low values of diversity indices were observed across the six study sites, which suggest that the six sites were in unstable conditions. Site 5 has the richest (Simpson 1-D 0.77, Shannon H 1.81, Margalef 1.91) and best taxa distribution (Equitability J: 0.73), while site 3 was the poorest (Simpson 1-D 0.52 and Shannon H 1.31) and the least in taxa distribution (Equitability J 0.55).ConclusionThis study has provided information on the assemblage and copiousness of various aquatic insects as well as the physico-chemical parameters of Aahoo stream. It could therefore be concluded that the stream could be somewhat polluted and unsafe for human consumption without being properly treated.

Relative importance of Conservation Reserve Programs to aquatic insect biodiversity in an agricultural watershed in the Midwest, USA

The Conservation Reserve Program (CRP) and the Conservation Reserve Enhancement Program (CREP) in the USA offer farmers government financial incentives to take erosive agricultural lands out of production. Many conservation practices are used along streams to improve habitat for stream biota. However, the ecological benefits of these programs to streams are yet to be demonstrated. This study investigates the responses of communities of three sensitive aquatic insect orders (Ephemeroptera, Plecoptera, and Trichoptera or EPT) to CRP and CREP practices in the Kaskaskia River basin, a predominantly agricultural watershed in Illinois, USA. A total of 10,373 EPT specimens were examined from 84 sites across the basin during 2013–2015. Nine environmental variables were used to account for variance in EPT taxonomic diversity, and sets of best regression models were selected based on Akaike information criterion (AICc). AICc importance values and hierarchical variance partitioning revealed three important variables associated with EPT taxa richness: link (number of first order tributaries), soil permeability, and urban land. Two important variables were associated with Shannon and Simpson diversity measures: link and dissolved oxygen. The percentage of CRP/CREP land in the watershed was less important, suggesting that this mosaic of conservation practices as currently implemented in the basin may not affect EPT taxonomic diversity.

Is there a relationship between socio-economic factors and biodiversity in urban ponds? A study in the city of Stockholm

Urban small water bodies, such as ponds, are essential elements of human socio-economic landscapes. Ponds also provide important habitats for species that would otherwise not survive in the urban environment. Knowledge on the biodiversity of urban ponds and the relationship between their ecological value and factors linked to urbanization and socio-economic status is crucial for decisions on where and how to establish and manage ponds in cities to deliver maximum biodiversity benefits. Our study investigates if the pattern of urban-pond biodiversity can be related to different socio-economic factors, such as level of wealth, education or percentage of buildings of different types. Because of lack of previous studies investigating that, our study is of exploratory character and many different variables are used. We found that the biodiversity of aquatic insects was significantly negatively associated with urbanisation variables such as amount of buildings and number of residents living around ponds. This relationship did not differ depending on the spatial scale of our investigation. In contrast, we did not find a significant relationship with variables representing socio-economic status, such as education level and wealth of people. This latter result suggests that the socio-economic status of residents does not lead to any particular effect in terms of the management and function of ponds that would affect biodiversity. However, there is a need for a finer-scale investigation of the different potential mechanism in which residents in areas with differing socio-economic status could indirectly influence ponds.

Unravelling the correlates of species richness and ecological uniqueness in a metacommunity of urban pond insects

City ponds have the potential to harbour a rich biodiversity of aquatic insects despite being located in an urban landscape. However, our current knowledge on the correlates of pond biodiversity is limited and even less is known about the factors that influence the ecological uniqueness of urban ponds. The multiple environmental gradients, at different spatial scales, that may affect biodiversity and ecological uniqueness of urban ponds can thus be seen both as an opportunity and as a challenge for a study. In this study, we aimed to fill this gap by focusing on aquatic insect assemblages in 51 ponds in the Swedish city of Stockholm, using a metacommunity perspective. We found that species richness was primarily determined by the density of aquatic insects, water depth and proportion of buildings around the pond. The uniqueness of ponds was estimated as local contributions to beta diversity (LCBD), and it was primarily related to the proportion of arable land and industry around the ponds. With regard to the metacommunity we found two interesting patterns. First, there was a negative relationship between richness and LCBD. Second, biodiversity was spatially independent, suggesting that spatially-patterned dispersal did not structure species richness or LCBD. These last two patterns are important when considering conservation efforts of biodiversity in city ponds. We hence suggest that the conservation of insect biodiversity in urban pond should consider the surroundings of the ponds, and that high-richness ponds are not necessarily those that require most attention because they are not ecologically the most unique.

A new species of Limnephilidae (Insecta: Trichoptera) from the Western Alps (Insecta: Trichoptera).

A new species of the alpine caddisfly genus Consorophylax (Trichoptera, Limnephilidae, Stenophylacini) and the female of the recently described C. vinconi Graf & Malicky 2015 are described. The new species C. lepontiorumsp. nov. is a microendemic of the South-Western Alps and differs from its congeners in the shape of the superior and inferior appendages and the unique setation of the aedeagus, absent in all other Consorophylax species. The female of C. vinconi is characterized by the unique formation of the anal tube. Potential effects of alpine orogenesis, phenology and climatic oscillation on speciation of aquatic insects inhabiting high-altitude habitats are discussed. The description of C. lepontiorumsp. nov. accentuates the significance of the Western Alps as harbours of aquatic insect biodiversity, and demonstrates the necessity of faunal and taxonomic studies in Europe - a supposedly well-explored region.

Trends in species diversity of lotic stoneflies (Plecoptera) in the Czech Republic over five decades

Abstract An unusual data set of Plecoptera, very sensitive aquatic insects, allow diversity changes to be estimated for 175 streams in the Czech Republic between two periods, 1955–1960 and 2006–2011. Substantial overall declines in Plecoptera biodiversity were found. Three‐quarters of the species studied declined in their frequency of occurrence, 48% of which were estimated have undergone a reduction of &gt;30%. Overall, streams either at lowland or submontane altitude, particularly large rivers, lost the most species. A significant decrease in local species biodiversity was found in streams up to 700 m a.s.l., especially in small rivers. The taxonomic dissimilarity between contemporary and previous assemblages increased from montane to lowland altitudes (from ˜30 to ˜70%) and was the same in streams of different size (˜50%). Partitioning of dissimilarity showed that the overall change in dissimilarity was primarily driven by changes in species richness; however, species replacement was not negligible. The results demonstrated that aquatic insect biodiversity (Plecoptera in particular) is substantially declining in Europe, probably to a similar or greater extent than terrestrial insects, with potential implications for biodiversity of running waters. Plecoptera showed a complex response to habitat change, including loss of pollution‐sensitive species and habitat‐specialists as well as common species, which, in some cases, counterbalanced their losses by concurrent colonisation of new sites.

Effects of environmental factors on the species composition of aquatic insects in irrigation ponds

AbstractAlthough irrigation ponds contribute to the conservation of aquatic biodiversity, they have experienced declines in recent years. We therefore examined the relationships between various environmental factors and the community composition of aquatic insects, specifically insect predators, in irrigation ponds to gain knowledge that would aid in the conservation and restoration of biodiversity. We selected Odonata, Hemiptera and Coleoptera as target taxonomic groups and conducted censuses of these groups in 21 ponds in Shiga, central Japan. In total, we collected 30 and 10 species (or species groups) of Odonata and Hemiptera, respectively, and 17 species of Coleoptera. A partial canonical correspondence analysis revealed that the following four environmental factors significantly affected the species composition of aquatic insect communities: the number of emergent plant species, percent concrete revetment, presence of litter and peripheral length. Among these variables, the number of emergent plant species was the most potent factor, perhaps because emergent plants serve as sites for oviposition and emergence, and provide refugia for aquatic insects (odonate nymphs in particular). In contrast, some species specifically inhabited sites poor in emergent plants. This study shows that reductions in concrete revetments are necessary for the conservation of biodiversity. This would lead to increases in the number of aquatic plant species, which provide habitats and oviposition sites for many aquatic insects. Furthermore, to enrich the local biodiversity of aquatic insects, groups of irrigation ponds with different environments are needed.

The conservation status of southern South American aquatic insects in the literature

We provide a comprehensive review of publications regarding the conservation of aquatic and terrestrial insects at a global scale and with an emphasis on southern South America. We reviewed three prominent conservation journals (Conservation Biology, Biodiversity and Conservation, and Biological Conservation) and found that only 5 % of all the works published between 1995 and 2008 focus on the conservation of aquatic insects. The highest percentage of publications on the conservation of aquatic insects comes from Europe (2.3 %), while the lowest percentage comes from South America (0.1 %). To assess the trends of aquatic insect research in southern South America, we conducted a literature search using Zoological Records,Biological Abstracts, and Current Contents. We conclude that there is a gap in research regarding the conservation of freshwater and terrestrial insects, as reflected by the low amount of publications that specifically focus on the description and identification of new insect species and their conservation. In order to help overcome this gap in conservation research, we propose three ideas that could help enhance the research and conservation initiatives regarding these organisms: (1) focus research on understudied regions of the world, such as the Magellanic sub-Antarctic ecoregion, (2) increase the amount of funding available for taxonomic research focused on the description and identification of new aquatic and terrestrial insect species, and (3) increase the amount of public education programs which focus on field experiences and direct encounters with aquatic insect biodiversity and their habitats.

Borders of Biodiversity: Life at the Edge of the World's Large Lakes

The great lakes of the world represent a global heritage of surface freshwater and aquatic biodiversity. Species lists for 14 of the world's largest lakes reveal that 15% of the global biodiversity (the total number of species) of freshwater fishes, 9% of noninsect freshwater invertebrate biodiversity, and 2% of aquatic insect biodiversity live in this handful of lakes. The vast majority (more than 93%) of species inhabit the shallow, nearshore littoral zone, and 72% are completely restricted to the littoral zone, even though littoral habitats are a small fraction of total lake areas. Most fish species exploit benthic resources, which increases food web complexity. Moreover, littoral zones are both more negatively affected by human activity and less intensively studied than offshore waters. Conservation of the remarkable biodiversity and biotic integrity of large lakes will require better integration of littoral zones into our understanding of lake ecosystem functioning and focused efforts to alleviate human impacts along the shoreline.

Biodiversity of Aquatic Insects: Spatial Gradients and Environmental Correlates of Assemblage-Level Measures at Large Scales

Biodiversity embraces multiple facets of the variability of nature, although most research has dealt separately with population-, species- and assemblage-level measures. This review concentrates on aquatic insect biodiversity and the assemblage-level measures, such as species richness, assemblage compositional variation, taxonomic distinctness and functional diversity. Most studies on aquatic insects have considered biodiversity patterns based on surveys of local assemblages along geographical and environmental gradients, while there is a virtual lack of studies that have considered regional grain sizes (i.e. the size of the observational unit). Latitudinal gradients at both regional and local grain are ambiguous in aquatic insects, as different studies have found either higher or lower local diversity in the tropics than in the temperate zone. Other geographical patterns in aquatic insect diversity may also be relatively weak, as suggested by subtle among-ecoregion differences in both local species richness and assemblage composition. An ecological explanation for the absence of strong geographical gradients is that local environmental features may not necessarily vary with geography, and these factors may override the influences of historical and climatic influences on local diversity. Evidence from large-scale studies suggests, however, that not only various local habitat and ecosystem variables, but also those measured at the watershed, regional and geographical scales are needed to account for variation in the species richness and assemblage composition of aquatic insects. Within regional species pools, species richness and assemblage composition in both lotic and lentic ecosystems vary most strongly along gradients in habitat size and acidity. Knowing how α-, β- and γdiversity of aquatic insects vary along geographical and environmental gradients has important implications for the conservation of biodiversity in freshwater ecosystems. Such knowledge is not yet well-developed, and two aspects should be considered in future research. First, further survey research on lotic and lentic ecosystems is necessary for improving our understanding of general biodiversity patterns. Second, given that freshwater ecosystems are facing a severe biodiversity crisis, the implementation of representative networks of freshwater protected areas would certainly benefit from increased understanding of patterns in aquatic insect biodiversity.

Invasive species threats to native aquatic insect biodiversity and conservation measures in Hawai’i and French Polynesia

Impacts of invasive species, and of attempts to control them, on the aquatic invertebrate fauna of Hawaii and French Polynesia are reviewed and discussed, as a foundation for determining conservation need. Aquatic insects are poorly documented in the region, with many species undescribed, so that practical conservation must be pursued with highly incomplete basic taxonomic knowledge. The establishment of at least one dedicated reserve for aquatic invertebrates is recommended for each high island in an archipelago, as an aid to safeguarding local endemic species, and other recommendations include increased monitoring for new alien species (particularly of fish), planning for removal of alien species from selected water bodies where alien species are less likely to recolonize, effective protection of key sites with high biodiversity value, and securing sites for future restoration and translocation or rare and endangered species.