Water Beetle Diversity Research Articles

Water Beetles: Species Diversity and Response to Physico-Chemical Parameters in Different Freshwater Habitats in Samtse, Bhutan

Bhutan is located between the two zoogeographic regions which are assumed to be rich in diversity of water beetles. The study aimed to determine the diversity and distribution pattern of water beetles in different freshwater habitats in Namgaychholing under Samtse district, Bhutan. The study also analysed the association of water beetles with the physico-chemical parameters. The data were collected from four different habitats with sample plot of 3 m × 1 m for a standard time of 1 hour in every plot. A total of 30 species belonging to 7 families were recorded of which Dytiscidae (n=626, RA=51) was the most abundant family and Lacconectus basalis (n=416, RA=34.13) was the most abundant species. The overall Shannon diversity index of the study area was H ′=2.48. Amongst the different habitats, marshy area had the highest Shannon diversity index (H ′=2.45) and stream had the lowest (H ′=1.82). A Kruskal Wallis test on diversity among different habitats showed no significant difference (p<.05). Through a cluster analysis, the species composition between the river and waterlogged showed 100% similarity index. Canonical correspondence analysis showed temperature as a main determining factor affecting the distribution of water beetles. With broad families encompassing the water beetles, similar study on water beetles in different regions of the country is recommended with particular emphasis on different families. Moreover, Bhutan falls in junction of Palearctic and Oriental Zoogeographic regions, which are known to be rich in diversity of water beetles. Hence, study in high-altitude lakes, which are assumed to be rich in diversity of water beetles are recommended despite social beliefs to keep lakes isolated and undisturbed.

Beaver creates early successional hotspots for water beetles

Beavers (Castor spp.) are ecosystem engineers that induce local disturbance and ecological succession, which turns terrestrial into aquatic ecosystems and creates habitat heterogeneity in a landscape. Beavers have been proposed as a tool for biodiversity conservation and ecosystem restoration. So far, most research has compared biodiversity in beaver wetlands and non-beaver wetlands, but few studies have explored how beaver-created succession affects specific taxa. In this study, we investigated how water beetles responded to different successional stages of wetlands in a beaver-disturbed landscape at Evo in southern Finland. We sampled water beetles with 1-L activity traps in 20 ponds, including: 5 new beaver ponds, 5 old beaver ponds, 5 former beaver ponds, and 5 never engineered ponds. We found that beaver wetlands had higher species richness and abundance than non-beaver wetlands, and that new beaver wetlands could support higher species richness (321%) and abundance (671%) of water beetles compared to old beaver wetlands. We think that higher water beetle diversity in new beaver ponds has resulted from habitat amelioration (available lentic water, shallow shores, aquatic vegetation, and low fish abundance) and food source enhancement (an increase of both dead and live prey) created by beaver dams and floods. We conclude that using beavers as a tool, or imitating their way of flooding, can be beneficial in wetland restoration if beaver population densities are monitored to ensure the availability of newly colonizable sites.

Importance of floodplains for water beetle diversity: a crucial habitat for the endangered beetle Graphoderus bilineatus in Southeastern Europe

Natural floodplains are rapidly disappearing ecosystems worldwide, primarily due to changing hydrology. Continental Croatia harbours some of the largest remaining and best preserved natural riverine floodplains in Europe. To establish conservation priorities, we surveyed water beetle assemblages in three large floodplains situated in the Danube, Drava, and Sava basins (Ramsar sites Kopacki rit and Lonjsko polje, and Spacva riparian forest), with special focus on the red-listed beetle Graphoderus bilineatus. The main aim of our study was to investigate the key environmental factors driving variation of water beetle assemblage structure and occurrences of G. bilineatus. Environmental variables describing habitat types and various habitat characteristics were measured and/or estimated for each sampling site. A total of 4.339 water beetle specimens belonging to 98 species were recorded. G. bilineatus was recorded at two out of the three investigated floodplains at 14 out of 30 sampling sites. We found significant differences in water beetle assemblages among the three localities based on the total species dataset, accompanied by different environmental background and vegetation composition. The density of riparian vegetation, permanent water durability, shading, type of bank, and plant communities best explained the distribution of the water beetle species. Based on the regression model, human impact and shading have significant effects on the abundance of G. bilineatus. Sites with G. bilineatus presence have significantly higher species richness compared to the sites without the species. Co-existence analysis indicates various types of associations between G. bilineatus and other water beetle species.

Long‐term monitoring reveals decreasing water beetle diversity, loss of specialists and community shifts over the past 28 years

Abstract Lentic freshwater organisms are influenced by a multitude of factors, including geomorphology, hydrology, anthropogenic impacts and climate change. Organisms that depend on patchy resources such as water beetles may also be sensitive to anthropogenic habitat degradation, like pollution, eutrophication, water level or management alteration. To assess composition and ecological trends in the water beetle communities of Central Europe, we sampled water beetles (Dytiscidae, Haliplidae, Noteridae) in 33 water bodies in Southern Germany from 1991 to 2018. We used manual, time‐standardised capture during three periods: between 1991 and 1995, 2007 and 2008, and 2017 and 2018. During the 28‐year survey period, we captured a total of 81 species. We found annual declines in both species number (ca −1%) and abundance (ca −2%). Also, community composition showed significant changes over time. The significant impact of pH on the community composition suggests that the recorded changes through time partly reflect natural succession processes. However, a pronounced decline of beetle species belonging to the moor‐related beetle associations indicated that Central European water beetles are also threatened by non‐successional factors, including desiccation, increased nitrogen input and/or mineralisation, and the loss of specific habitats. This trend to physiographical homogenisation resulted in corresponding community composition shifts. To effectively protect endangered species, conservation strategies need to be aimed at regularly creating new water bodies with mineralic bottom substratum, and maintenance of moor water bodies that represent late successional stages.

Aquatic beetles (Insecta: Coleoptera) of selected Natura 2000 protected sites in eastern Slovakia – a new record for Slovakia and new distribution records

Abstract Results of faunistic research of aquatic Coleoptera in seven Natura 2000 Sites of Community Importance are presented in this paper. Altogether, 50 species were recorded. One species, Helochares (Helochares) punctatus Sharp, 1869, is recorded as new to the fauna of Slovakia. Three very rare species in Slovakia (Dryops similaris Bollow 1936, Limnius intermedius Fairmaire, 1881, and Hydraena excisa Kiesenwetter, 1849) were found at new sites. First faunistic records on aquatic Coleoptera from two important protected sites are presented. Furthermore, data on the occurrence of several species and on the water beetle diversity of partial river basins of Slovakia were considerably extended.

The role of protected areas in representing aquatic biodiversity: a test using α, β and γ diversity of water beetles from the Segura River Basin (SE Spain)

espanolLas redes de areas protegidas representan una de las principales estrategias para reducir la perdida de biodiversidad. Sin embargo, muchas de estas areas han sido disenadas considerando unicamente grupos carismaticos mayoritariamente terrestres, como los vertebrados y las plantas. Por lo tanto, existe un escaso conocimiento sobre la capacidad de las areas protegidas para representar la biodiversidad acuatica. Este trabajo analiza la idoneidad de las redes nacionales y europeas de areas protegidas (Espacios Naturales Protegidos y Red Natura 2000) para representar dicha biodiversidad. Para ello, estudiamos los diferentes componentes de la diversidad (α, β y γ) utilizando los coleopteros acuaticos de la cuenca del rio Segura como indicadores de la biodiversidad total de macroinvertebrados. Nuestros resultados no muestran diferencias significativas en la diversidad α entre areas protegidas y no protegidas. Del mismo modo, no encontramos diferencias significativas en los componentes de la diversidad β (reemplazamiento y anidamiento, i.e., diferencias en la riqueza entre localidades sin que tenga lugar recambio de especies) entre areas protegidas y no protegidas. El reemplazamiento de especies contribuyo mas que el anidamiento en los cambios observados en la diversidad β total. Finalmente, encontramos que las dos redes de areas protegidas mostraron una diversidad γ mayor, en comparacion con un numero equivalente de localidades seleccionadas al azar. Por lo tanto, las redes de areas protegidas de la cuenca del rio Segura parecen presentar actualmente algunas lagunas a la hora de abarcar los diferentes componentes de la biodiversidad. Por ultimo, discutimos las implicaciones de estos resultados en la gestion y conservacion de los rios, proporcionando algunas directrices para futuras investigaciones EnglishNetworks of protected areas represent one of the main strategies to reduce the rapid loss of biodiversity. However, most of these protected areas have been designed by considering only charismatic groups of vertebrates and plants, most linked to terrestrial environments. Thus, little is known about how well protected areas perform in representing aquatic biodiversity. This study analyses the suitability of national and European protected area networks (Natural Protected Areas and Natura 2000) in representing such biodiversity. For this purpose, we studied the different components of diversity (α, β and γ) using water beetles from the Segura River Basin as surrogates of overall macroinvertebrate biodiversity. Our results revealed no significant differences in α-diversity between protected and non-protected areas. Similarly, we did not find significant differences in β-diversity components (species replacement and nestedness, i.e., differences in among-site richness without species replacement) between protected and non-protected areas. The species replacement contributed more than nestedness to explain overall β-diversity changes. Finally, we found that the γ-diversity component was significantly higher in both protected areas, when compared to an equivalent number of randomly selected locations. Thus, the protected area networks from the Segura River Basin currently seem to have gaps in embracing the different aquatic biodiversity components. These results for river management and biodiversity conservation are discussed, providing some guidelines for future research.

How well do protected area networks support taxonomic and functional diversity in non-target taxa? The case of Iberian freshwaters

Protected area networks represent one of the mainstays of global conservation polices and are therefore central to current efforts to maintain biodiversity. However, a major limitation of most conservation strategies is their bias towards particular taxonomic groups and ecosystems, meaning that many taxa and habitats are often only incidentally protected as a by-product of inclusion within reserves. Here we investigate how effectively protected area networks, not specifically designated for freshwaters, support aquatic biodiversity in the Iberian Peninsula (Spain and Portugal), using data for water beetles, surrogates of overall macroinvertebrate diversity in these habitats. We explore the behaviour of different measures (α, β and γ) of both taxonomic and functional diversity at different spatial scales. Overall our findings highlight the contrasting performance of reserve systems in the maintenance of either taxonomic or functional diversity, as well as the importance of spatial scale. Iberian reserves perform relatively well in supporting taxonomic diversity of water beetles at the peninsular scale, but the same protected areas poorly represent functional diversity. Such a mismatch cautions against the use of any one diversity component as a surrogate for others, and emphasizes the importance of adopting an integrative approach to biodiversity conservation in aquatic ecosystems. Furthermore, our results often show contrasting patterns at smaller spatial scales, highlighting the need to consider the influence of scale when evaluating the effectiveness of protected area networks.

Integrated constructed wetlands: hotspots for freshwater coleopteran diversity in the landscape of Ireland

Constructed ponds are small water bodies that have an enormous biodiversity potential. The creation of this habitat can be seen as a valuable ecological enhancement tool, as ponds can host a great number of species. Integrated constructed wetlands (ICWs) are a type of surface-flow constructed wetland formed by interconnected ponds that integrate their water treatment capabilities with other functions such as biodiversity enhancement, carbon sequestration and landscape fit, by virtue of mimicking natural wetlands. ICWs have been shown to have the potential to enhance freshwater macroinvertebrate diversity in Ireland, especially Coleoptera diversity, in agricultural areas due to their unique design adaptability. A total of 67 water beetle taxa were found to inhabit the 15 studied ponds in the Annestown River catchment, Co. Waterford. Furthermore, when the taxa that have the potential to inhabit ICW ponds in Ireland were included a total of 82 water beetle taxa was obtained, which represents 26% of the known Irish aquatic lentic coleopteran fauna and includes several species of conservation interest. If the potential of these small water bodies to support water beetle diversity and that of other aquatic macroinvertebrates is to be maximised, particular attention should be paid to enhancing the range of mesohabitats within the ICW system.

Consistency of fuzzy rules in an ecological context

In this paper, we assess the performance of fuzzy inference systems (FISs) and the consistency of fuzzy rules generated from a meta-analysis exploring diversity–environment relationships, in a system of temporary and fluctuating ponds located in two regions of southern England. The analyses focus on aquatic coleopteran assemblages, which act as excellent surrogates of wider freshwater macroinvertebrate diversity. Evaluated FISs were calibrated using evolutionary algorithms and the consistency of the rules examined using a consistency index specifically developed in this work. The best fit accounted for 76% of observed variability in the Shannon diversity index across ponds in the validation phase, which was 56 points better than the benchmark value established by a generalized additive model (GAM). The analysis of fuzzy rules indicated that the basic dynamics of this system are controlled by 8 rules. Another 10 complementary rules were detected, suggesting that more than a single dimension controlled the dynamics of the system. Therefore, water beetle diversity appears to be driven by a relatively short set of rules which relate diversity and environmental factors in a non-linear manner. These rules can be grouped according to their consistency levels, which reflect differences in coleopteran community composition.

Diversity of Water Beetles in Picos de Europa National Park, Spain: Inventory Completeness and Conservation Assessment

ABSTRACT The diversity of true water beetles (Coleoptera: Gyrinidae, Haliplidae, Dytiscidae, Helophoridae, Hydrochidae, Hydrophilidae, Hydraenidae, Elmidae, and Dryopidae) in Picos de Europa National Park (Cantabrian Mountains, Spain) was examined. Taking into account historic long-term sampling (all collections from 1882 to the present), a total of 117 species are recorded. Species accumulation models and non-parametric estimators were used to estimate the actual species richness of aquatic Coleoptera occurring in Picos de Europa National Park. Estimates were generated by analyzing both the collector's curve from the long-term sampling and the historic cumulative curve of species recorded from the park since 1882. Values of species richness estimated by different methods range from 127 to 170 species (mean = 148 ± 15 SD). Therefore, it seems that the current inventory has reached a reasonably good level of completeness as estimates indicate that about 80% of the water beetle fauna has already been record...

Lazy ecologist's guide to water beetle diversity: Which sampling methods are the best?

Biodiversity surveys of aquatic macroinvertebrates in standing water rely on various methods, but a thorough comparison of the techniques is lacking. This hampers analyses across surveys and impedes development of efficient sampling schemes. We compare the selectivity and efficiency of four methods commonly used to collect aquatic insects – activity traps (ATs), box trap (BT), handnetting (HN) and light trap (LT) – using a large dataset on water beetles in a site with ∼100 species. We propose to use time investment as a natural basis to compare efficiency, since it applies to any method. The results inherently differ from results based on samples or individuals because methods are neither equally demanding nor equally rewarding. Most differences between methods arise from their size selectivity: ATs select for larger species, while HN and BT seem least selective. Attraction to light is taxon-specific and LT yields more depauperate samples than ATs, BT and HN, limiting the use of LT in community studies. To boost the development of cost-effective protocols, we also identify the best designs for rapid bioassesment by simulating short surveys from the data. Combinations of ATs and BT give most species; the results are robust to partitioning of effort between both methods. However, these rapid surveys miss on average more than 40% of all species in our study. Our results therefore emphasize that long-term studies using multiple methods are vital for measuring diversity in species-rich freshwater habitats.

A heuristic approach to predicting water beetle diversity in temporary and fluctuating waters

An understanding of the causal mechanisms and processes that shape macroinvertebrate communities at a local scale has important implications for the management and conservation of freshwater biodiversity. Here we compare the performance of linear and non-linear statistics to explore diversity–environment relationships using data from 76 temporary and fluctuating ponds in two regions of southern England. We focus on aquatic beetle assemblages, which have been shown to be excellent surrogates of wider freshwater macroinvertebrate diversity. Ponds in the region contained a rich coleopteran fauna, totaling 68 species, which provided an excellent model system with which to compare the performance of two non-linear procedures (artificial neural networks—ANNs and generalised additive models—GAMs) and one more traditional linear approach (Multiple linear regression—MLR) to modelling diversity–environment relationships. Of all approaches employed, the best fit was obtained using an ANN model with only four input variables (conductivity, turbidity, magnesium concentration and depth). This model accounted for 82% of the observed variability in Shannon diversity index across ponds. In contrast, the best GAM and MLR models only explained 50% and 14% of this variation, respectively. Contribution profile analysis of conductivity, turbidity, magnesium concentration and depth, obtained from the best fit ANN through a hierarchical cluster analysis, allowed the identification of direct and proxy effects in relation to the environmental variables measured in this study. In each case, distinct clusters of ponds were identified in contribution profile analysis, suggesting that ponds across the two regions fall into a number of discrete groups, whose beetle faunas respond in subtly yet significantly different ways to key environmental variables. Aquatic coleopteran diversity in ponds in the two regions appears to be driven at a local scale by changes in relatively few physicochemical gradients, which are related to diversity in a clearly non-linear manner.

Paroster baylyi sp. n., P. ursulae sp. n. (Col. Dytiscidae, Hydroporinae) and the water beetle diversity of pan-gnammas on isolated granite outcrops in the Mallee of south-western Australia

Paroster baylyi sp. n., P. ursulae sp. n. (Col. Dytiscidae, Hydroporinae) and the water beetle diversity of pan-gnammas on isolated granite outcrops in the Mallee of south-western Australia

Paroster baylyi sp. n., P. ursulae sp. n. (Col. Dytiscidae, Hydroporinae) and the water beetle diversity of pan-gnammas on isolated granite outcrops in the Mallee of south-western Australia

Paroster baylyi sp. n. and P. ursulae sp. n. are described from south-western Australia, and compared with the similar P. michaelseni Régimbart, 1908. Their median lobes, parameres, gonocoxae, gonocoxosterna and habitus are illustrated, and details about their unique habitats and water beetle coenoses are given. The two new species are the first dytiscids to be known breeding solely in temporarily water filled rock-holes—so-called “pan-gnammas”—in the Mallee zone of south-western Australia. The total number of described species in the genus Paroster Sharp, 1882 is now 11. Eight aquatic Coleoptera of the families Dytiscidae and Hydrophilidae are recorded from 13 pan-gnammas on four granite outcrops in south-western Australia.

Global diversity of water beetles (Coleoptera) in freshwater

Global diversity of water beetles (Coleoptera) in freshwater

Species richness and succession of aquatic beetles in some kettle‐hole ponds in northern Sweden

Ten closely‐located kettle‐hole ponds in northern Sweden were ordered along a vegetational, successional gradient from the present‐day representation of the six vegetational units distinguished. Different rates of vegetational development caused by differences in depths of basins have made possible the long‐term existence of early successional stages. A fact that has offered the possibility of studying most of the vegetational succession of these habitats.The number of water beetle species inhabiting each pond were correlated to successional stage and area of pond. Mean species numbers decreased from 34 to 14 per pond with increasing maturity of the vegetational succession. This decrease in species richness of water beetles is caused by a decrease in number of habitats or vegetational units present. The increased floral conformity is mainly due to a more stable water‐level caused by lower rates of bottom seepage from the accumulation of organic deposits. Besides the extended zonation of littoral vegetation, a high water‐amplitude is also connected with recurrent nutrient pulses caused by the faster detritus composition during drought periods. Thus the changing water‐levels contribute to a high water beetle diversity through the maintenance of both a high habitat complexity and a high production.A positive correlation between pond size and number of water beetle species were only found if the fen ponds were excluded. From this it is concluded that the area effect is here a good predictor of species richness only within ponds of a similar successional stage.