Water Beetles Research Articles

First confirmed species record of Hydroscaphidae from Peru: description of a new species of Yara Reichardt and Hinton, and key to species(Coleoptera: Hydroscaphidae).

The Hydroscaphidae ("skiff beetles") is a family of minute aquatic beetles within the suborder Myxophaga comprising four genera: Hydroscapha Le Conte, 1874; Scaphydra Reichardt, 1973; Yara Reichardt Hinton, 1976 and Confossa Short et al., 2015. All genera are found within the Neotropical region, with the exception of Hydroscapha, which is widespread. Representatives of this family have been reported for Venezuela, Brazil, Panama (Short etal. 2015) and Nicaragua (Raudez et al. 2019).

Macrophytes promote aquatic insect conservation in artificial ponds

Abstract Farmland ponds promote regional aquatic biodiversity; however, optimally managing these ponds requires knowledge on how the biodiversity differs between ponds across catchments with different land uses. This study investigated the response of macrophytes, both those in the pond and on the bank, as well as dragonfly and water beetle species richness, diversity and composition in artificial ponds, to numerous environmental variables in catchments dominated by three land uses: protected areas (as reference sites), sugarcane‐dominated and forestry‐dominated landscapes, across two seasons. There was a strong association between insect species richness and vegetation cover, particularly sedges (Cyperus spp.) in spring and bulrushes (Typha capensis) in summer. There was also a positive response between insect species richness and sedges up to 70% cover, and bulrushes up to 40% cover, after which there was a decrease. Furthermore, the protected area ponds contained more rare and specialist insect species. Pond size was not a major variable for biodiversity overall. Although there was generally little congruence in composition among the three taxa, dragonflies were a good surrogate for water beetles and floating macrophytes. Well‐vegetated ponds, both in the water and along the margin, are the most suited to promoting biodiversity, as long as the vegetation is not too dense, and not dominated by one plant species. Artificial ponds in production landscapes have great potential for conserving aquatic species, irrespective of land use, as long as there is management for macrophyte density and heterogeneity.

Estado actual de la colección de coleópteros acuáticos en el Museo Entomológico Francisco Luis Gallego, Universidad Nacional de Colombia, Sede Medellín (MEFLG)

El museo entomológico "Francisco Luis Gallego"de la Universidad Nacional de Colombia, sede Medellín (MEFLG), comenzó en 1937 con una colección de insectos de importancia agrícola. Actualmente, el Museo cuenta con una amplia colección que incluye varios órdenes de insectos con relevancia económica, médica, forense y ecológica. La misión del Museo es liderar las actividades de investigación y difundir los conocimientos obtenidos en estudios de colecciones biológicas. Para hacer un diagnóstico de la colección de escarabajos acuáticos en MEFLG y comparar el índice de la salud de la colección (ISC), se llevó a cabo un proceso de curaduría. Se evaluaron 431 especímenes conservados en seco y 170 especímenes conservados en líquido. Antes del proceso de curaduría, el ISC fue bajo (32,9%) y las prioridades de gestión de la colección y el perfil de la colección mostraron un alto valor en el nivel dos. Después del proceso de curaduría y revisión taxonómica, el ISC mejoró y mostró un alto valor en el nivel tres, ya que el material se encuentra accesible a los investigadores.

Role of cuticle hydrocarbons composition in the salinity tolerance of aquatic beetles

Salinity tolerance has enabled the colonization of inland saline waters and promoted species diversification in some lineages of aquatic insects. However, the mechanisms behind this tolerance, particularly the role of cuticle hydrocarbons (CHCs), are not well-known. We characterized the CHC profile of eight species of two water beetle genera (Nebrioporus, Adephaga: Dytiscidae and Enochrus, Polyphaga: Hydrophilidae), which span the fresh-hypersaline gradient, to: i) determine the interspecific variation of CHC composition in relation to species’ salinity tolerance; ii) explore plastic adjustments in CHC profiles in response to salinity changes at the intraspecific level in saline-tolerant species. CHC profiles were highly species-specific, more complex and diverse in composition, and characterized by longer-chain-length compounds in the species with higher salinity tolerance within each genus. Higher salinity tolerance in the Enochrus species was also associated with an increase in the relative abundance of branched alkanes, and with a lower proportion of n-alkanes and unsaturated compounds. These CHC characteristics are related with improved waterproofing capacity and suggest that reducing cuticle permeability was one of the key mechanisms to adapt to saline waters. Similar CHC composition patterns were found at the intraspecific level between populations from lower and higher salinity sites within saline-tolerant species of each genus. These saline species also displayed an extraordinary ability to adjust CHC profiles to changing salinity conditions in the laboratory in a relatively short time, which reflects great plasticity and a high potential to deal with daily and seasonal environmental fluctuations in the highly dynamic saline habitats.

Effects of chemical pretreatment and intra- and inter-specimen variability on \u03b418O of aquatic insect remains

Oxygen isotope (δ18O) measurements on the exoskeletons of aquatic insects can be used to reconstruct changes in the δ18O of ambient water and, indirectly, to infer the climate and environmental conditions at the time of tissue synthesis. Prior to stable isotope analysis, it is often necessary to chemically pretreat insect remains to remove allochthonous organic and inorganic compounds without altering the δ18O signature. We tested the effectiveness and impact of duration of exposure to a buffered 2 M ammonium chloride (NH4Cl) solution for removing carbonates at neutral pH from chironomid head capsules, water beetle sclerites and marine crab remains prior to stable isotope analysis. Immersion in NH4Cl for 24 h efficiently removed the effect of carbonates with no long-term effects of prolonged exposure observed. Furthermore, we assessed the variability in δ18O values within and between individual sclerites (exoskeleton parts) of both modern and fossil water beetle remains. Both modern and fossil specimens had similar intra-sclerite variability in δ18O values (~ 2‰ range). In contrast, modern specimens had much smaller inter-sclerite variability (< 0.9‰ range) compared with fossil specimens from the same sample (up to 10‰ range). The high inter-sclerite variability observed in fossil material likely results from the nature of fossil material: a mix of sclerites from a 1–2–L sample bin, originating from different individuals that may have existed at different times and under different environmental conditions. We therefore recommend that material to be analysed for stable isotopes be sampled at high temporal resolution to reduce uncertainties in paleotemperature estimates derived from water beetle δ18O records.

Ecological factors affecting aquatic beetle species (Insecta: Coleoptera)

Aquatic Coleoptera play an important role in freshwater ecosystems and are considered as a suitable bioindicator. Despite being widely distributed in Iran, there are few studies in which aquatic Coleoptera are used to assess ecological quality and environmental conditions. With abundant water resources, Chaharmahal & Bakhtiari province, Iran, provides an excellent opportunity to explore the influence of environmental features on aquatic beetles. This research was aimed were to investigate community structure and to determine the dominant factors controlling aquatic beetles in the Borujen and Lordegan (as two main towns of the province). Using standard sampling tools (a small net and soft paintbrush), sampling was done seasonally for one year (between Sep. 2017 to July 2018) at six stations, also at each station ecological factors such as water temperature, water pH, water electrical conductivity and air temperature were measured by means of appropriated instruments. A total of 12 species belonging to 11 genera and 4 families were identified. The greatest number of species identified were found in the family Dytiscidae and the least number in the family Hydrophilidae. Two species of Agabus namely, Agabus conspersus and Agabus bipustulatus were the most abundant insects. Linear regression analysis showed that water temperature with correlation coefficient of 1.685 was the most effective factor in the distribution of aquatic Coleoptera and the air temperature with a correlation coefficient of 0.39 was the least important factor. In addition, canonical correspondence analysis (CCA) disclosed that water pH, water electrical conductivity (EC), water temperature (WT) and air temperature (AT) had an impact on the distribution of aquatic beetles. Our results suggest that water quality plays a key role in species richness of aquatic beetles, and that therefore they could be considered as an indicator organism of freshwater ecosystem health.

Water beetles (Insecta: Coleoptera) of some peatlands in the North Caucasus

Water beetles (Insecta: Coleoptera) of some peatlands in the North Caucasus

Environmental Cues Induce Dispersal and Burial in Crawling Water Beetle, Haliplus punctatus (Coleoptera: Haliplidae)

Aquatic insects are known to modify their behavior in response to environmental conditions, but manipulative experiments are necessary to distinguish which environmental cues trigger which behaviors. Understanding these responses is particularly important for arid-land aquatic taxa because ongoing climate change is predicted to make the current extreme abiotic environment even more extreme. Here we conducted a manipulative experiment to determine the behavioral responses of a widespread and common crawling water beetle, Haliplus punctatus (Coleoptera: Haliplidae), to three environmental cues, temperature, conductivity, and water level, and recorded two behaviors, dispersal and burial. We found that increasing water temperature caused animals to bury less and disperse more, but that neither conductivity nor water level affected beetle behaviors. These responses to temperature may have widespread consequences for natural populations.

Bats in a changing landscape: Linking occupancy and traits of a diverse montane bat community to fire regime.

Wildfires are increasing in incidence and severity across coniferous forests of the western United States, leading to changes in forest structure and wildlife habitats. Knowledge of how species respond to fire‐driven habitat changes in these landscapes is limited and generally disconnected from our understanding of adaptations that underpin responses to fire.We aimed to investigate drivers of occupancy of a diverse bat community in a fire‐altered landscape, while identifying functional traits that underpinned these relationships.We recorded bats acoustically at 83 sites (n = 249 recording nights) across the Plumas National Forest in the northern Sierra Nevada over 3 summers (2015–2017). We investigated relationships between fire regime, physiographic variables, forest structure and probability of bat occupancy for nine frequently detected species. We used fourth‐corner regression and RLQ analysis to identify ecomorphological traits driving species–environment relationships across 17 bat species. Traits included body mass; call frequency, bandwidth, and duration; and foraging strategy based on vegetation structure (open, edge, or clutter).Relationships between bat traits and fire regime were underpinned by adaptations to diverse forest structure. Bats with traits adapting them to foraging in open habitats, including emitting longer duration and narrow bandwidth calls, were associated with higher severity and more frequent fires, whereas bats with traits consistent with clutter tolerance were negatively associated with fire frequency and burn severity. Relationships between edge‐adapted bat species and fire were variable and may be influenced by prey preference or habitat configuration at a landscape scale.Predicted increases in fire frequency and severity in western US coniferous forests are likely to shift dominance in the bat community to open‐adapted species and those able to exploit postfire resource pulses (aquatic insects, beetles, and snags). Managing for pyrodiversity within the western United States is likely important for maintaining bat community diversity, as well as diversity of other biotic communities.

Taxonomical and bionomical notes on the Sicilian endemic water beetle Ochthebius (Cobalius) biltoni (Coleoptera: Hydraenidae)

Ochthebius (Cobalius) biltoni Jäch &amp; Delgado, 2017 is the most recently described species of Italian water beetles of the family Hydraenidae (Jäch &amp; Delgado 2017). Most of the new hydraenid species recently discovered from southern Europe were found in two quite different aquatic habitats, as small streams in mountain areas, and hypersaline coastal habitats. These aquatic ecosystems evidently represent a not still exhausted source of unknown biodiversity in Europe (Jäch 1989, 1997; Audisio et al. 1996, 2010; Trizzino et al. 2011, 2013a, 2013b; Sabatelli et al. 2016; Jäch &amp; Delgado 2017). Ochthebius (Cobalius) biltoni was described on a male collected (2012) along a rocky shore of Cefalù (NW Sicily), and on a few specimens collected in marine rock pools of the SW Sicily (Jäch &amp; Delgado 2017). Several vain attempts were made (2014-2017) to collect again this species at the type locality, suggesting that O. biltoni represents an exceedingly rare and elusive taxon. The present note is aimed to add information on the poorly known biology and taxonomy of this species, basing on material and data collected during recent expeditions to Sicily. Taxonomy. Ochthebius (Cobalius) biltoni represents the smallest (1.4- 1.6 mm long) Mediterranean species of the subgenus Cobalius, and it is also characterized by a series of specific traits (Fig. 1) not evidenced by Jäch &amp; Delgado (2017): the convex posterior portion of elytra, more convex and more abruptly sloping posteriad than in all other Cobalius; the series of large sharp projections along the outer elytral sides; the nearly cylindrical, narrow, and strongly pointed distad last maxillary palpomeres. The male genitalia of this species are not markedly distinguished from other species of Cobalius (Fig. 2 in Jäch &amp; Delgado 2017). The apical lobe is dilated distad, recalling the condition presented by O. (Cobalius) celatus Jäch, 1989. Genetically, Ochthebius (C.) biltoni, recently analyzed by our research team, is confirmed to occupy an isolated position, external to most other known members of its subgenus. An upcoming paper (Sabatelli et al. unp. data) is aimed at summarizing the genetic relationships among Cobalius. Ecology. All specimens of O. biltoni from SW Sicily were found in small (15-40 cm wide) and shallow (2-5 cm depth) marine rockpools with a yellowish- brown bottom layer of Diatoms, placed along wide rocky calcareous platforms surrounding the littoral road between Mazara del Vallo and Sciacca, about 2 m above the sea level (Fig. 2). In the same localities, larger and deeper rock pools resulted to be only inhabited by other widespread sympatric species of Ochthebius. Amog these, O. quadricollis and O. subinteger were collected in company of O. biltoni. Our observations allow us to hypothesize that adults and larvae of this species are present throughout the year, even if they are more active in Autumn and Spring. Conservation. Ochthebius (Cobalius) biltoni is an exceedingly rare taxon, exhibiting selective habitat preferences. Despite the poor available data, it is likely that this species represents a taxon with a small and ecologically fragmented geographic range, and poor connectivity between the different populations. Most marine rock pools areas where the species could potentially be present at least in the past in Sicily have been, and continue to be, exposed to severe anthropogenic pressures, including the increasing impact of coastal urbanization, and the frequent use of marine rock pools as trash wastes by tourists. This species therefore matches most criteria necessary for being considered in the IUCN risk Category EN [IUCN criteria B2 (a,b,c); see IUCN, 2013].

A new species and immature stages of the skiff beetle genus Yara Reichardt and Hinton (Coleoptera: Myxophaga: Hydroscaphidae) from Nicaragua.

Yara marmontsedu, a new species in the family Hydroscaphidae (Coleoptera: Myxophaga), is described and illustrated. Specimens of Y. marmontsedu were collected at the Pijibay Creek, tributary of the Mico River in Chontales, Nicaragua. The immature stages are described and illustrated for the first time for a species of Yara. This is a contribution to the knowledge of the water beetle fauna of Nicaragua.

Aquatic beetles Cercyon unipunctatus as bioindicators of pollution in Lake Edku and Mariut, Egypt.

The lakes of the North Delta give a rich and imperative territory for marine fish and its regeneration, and have dependably been major areas of fish creation in Egypt, 75% of the production was collected from them. As of late, many difficulties are confronting these lakes and prompt the exhaustion of fish production from them. The aim of the present study is to evaluate different inorganic pollutants in Coleopterons aquatic insect (Cercyon unipunctatus) taken from both Lake Edku and Mariut and also, to estimate their effect on oxidative stress markers and chromosomal aberrations. The average concentrations of heavy metals differ in the two locations. The concentration of (Pb, Cd, Fe, Co, Cu, Zn, and Mn) was significantly higher in water samples of Lake Mariut than those of Lake Edku. Also, the present work, showed the physical and chemical characters of the two lakes water. In the current study, the obtained results showed that there was a significant increase in (Pb, Cd, Fe, Co, Cu, Zn, and Mn) concentrations in C. unipunctatus tissues which were collected from Lake Mariut. The biochemical parameters of oxidative stress have been affected by the pollution in Lake Mariut water. Significant increases in the activity level of aspartate aminotransferase, alanine aminotransferase, and malondialdehyde concentration were recorded, while there were significant decreases in (total protein content, GSH content, and GPx activity). The result of chromosomal aberration test showed that there were different types of aberrations as binucleate cell, lagging chromosome, and abnormal distribution of chromosomes. The obtained data showed that C. unipunctatus highly affected by environmental stressors in water. So we suggest that these beetles could be a suitable monitor for ecotoxicological studies.

Water Beetles as Models in Ecology and Evolution.

Beetles have colonized water many times during their history, with some of these events involving extensive evolutionary radiations and multiple transitions between land and water. With over 13,000 described species, they are one of the most diverse macroinvertebrate groups in most nonmarine aquatic habitats and occur on all continents except Antarctica. A combination of wide geographical and ecological range and relatively accessible taxonomy makes these insects an excellent model system for addressing a variety of questions in ecology and evolution. Work on water beetles has recently made important contributions to fields as diverse as DNA taxonomy, macroecology, historical biogeography, sexual selection, and conservation biology, as well as predicting organismal responses to global change. Aquatic beetles have some of the best resolved phylogenies of any comparably diverse insect group, and this, coupled with recent advances in taxonomic and ecological knowledge, is likely to drive an expansion of studies in the future.

Knitting patterns of biodiversity, range size and body size in aquatic beetle faunas: significant relationships but slightly divergent drivers

1. Ecogeographical rules refer to recurring patterns in nature, including the latitudinal diversity gradient (LDG), Rapoport's rule and Bergmann's rule, amongst others. In the present study, the existence of these rules was examined for diving beetles (Coleoptera: Dytiscidae), a family of aquatic predatory beetles.2. Assemblage‐level data were analysed for diving beetles, focusing on species richness, local contribution to beta diversity (LCBD), mean range size and mean body size across the biogeographical provinces of Northern Europe. First, each of these variables was correlated with latitude, and then variation in each variable was modelled using actual environmental variables in boosted regression tree analysis.3. Species richness was found to decrease with latitude, LCBD increased with latitude, mean range size did not show a significant relationship with latitude, and mean body size decreased with latitude. The latter finding was in contrast to Bergmann's rule. The actual environmental variables best predicting variation in these four response variables varied among the models, although they generally included temperature‐related and land use variables as the most influential ones.4. The results obtained in the present study suggest that diving beetles conformed to the LDG, did not follow Rapoport's rule, and showed a reversed latitudinal gradient in the context of Bergmann's rule. In addition, species‐poor provinces harboured ecologically most unique faunas, suggesting that species richness and LCBD are complementary measures of biodiversity.5. Even though general support was not found for most of the ecogeographical rules examined, the findings of the present study are interesting because they suggest that aquatic ectothermic invertebrates may show patterns different from those originally described for terrestrial endothermic vertebrates.

Factors affecting aquatic beetle communities of Northern Western Ghats of India (Arthropoda: Insecta: Coleoptera)

We studied faunistic and ecological factors influencing distributions of aquatic beetles in the Northern Western Ghats (NWG) of India. In the period 2013–2017, we collected 213 samples from 105 localities within the area and obtained 66 species, the majority of which belong to Dytiscidae. Relative occurrence based on incidence data revealed that dytiscid water beetleLaccophilus inefficiensas the most widespread species. Non-parametric richness estimators Chao2, Jackknife1 and Bootstrap showed that 70–80% of the fauna was covered in the sampling efforts from different types of freshwater habitats. Sample-based rarefaction suggested that more sampling efforts within the region can yield additional species. Canonical correspondence analysis (CCA) revealed that altitude, salinity, hydroperiod and depth influenced the distribution of aquatic beetles. Further, CCA also revealed habitat preference and co-occurrence of various aquatic beetle species. For instance, while co-occurring species under Laccophilinae and Hydroporinae were eurytopic, other co-occurring speciesClypeodytes hemani,Microdytes sabitaeandLacconectus lambaiwere restricted to temporary habitats. Multiple correspondence analysis (MCA) showed a strong association between altitudinal classes and species distribution where many species were restricted within a particular altitudinal gradient. For example,M. sabitae,C. hemani,Hygrotus nilghiricus,L. lambaiandRhantus taprobanicuswith classes 900–1199 and 1200–1499 whileHyphydrus flavicans,Laccophilus ceylonicus,Lacconectus andrewesi,Sternolophus inconspicuusandCanthydrus laetabiliswith the class 300–599. The present work on aquatic beetles is the first attempt to study the influence of environmental factors on species diversity and distribution in the Northern Western Ghats of India.

Spatio-temporal distribution and species traits of water beetles along an oligotrophic hydrosystem: a case study

This study presents the first comprehensive investigation of population aspects and ecological traits of water beetles in oligotrophic hydrosystems with tufa formation in southeastern Europe. Diverse lotic habitats (springs, rivers and tufa barriers) were investigated monthly for one year in Plitvice Lakes National Park in Croatia. Elmidae were the most diverse and abundant family, followed by Scirtidae and Hydraenidae. The ecological traits of water beetles were primarily defined by nutrients and water depth.Elmis bosnicaZaitzev, 1908, about which little has been published, was found to be bryophilous and to prefer low water temperatures. Biogeographical analysis revealed the dominance of typical southeastern and Mediterranean species. Species population dynamics could be attributed to differences in flow permanence, current velocity and canopy coverage. Both current velocity and water depth significantly influenced the occurrence of larval stages, while abundance of adults correlated with water depth. Our results highlight tufa barriers as preferred habitats for species of the genusRiolusand the family Scirtidae. The results of this study, many of which are the first to be reported for water beetles, provide a basis for further investigations of these animals and their ecology in oligotrophic hydrosystems with tufa. In particular, our study demonstrates the potential of Elmidae as water quality indicators, which should be considered in future conservation and protection management efforts.

Regulated Coal Mine Wastewater Contaminants Accumulating in an Aquatic Predatory Beetle (&amp;lt;i&amp;gt;Macrogyrus rivularis&amp;lt;/i&amp;gt;): Wollangambe River, Blue Mountains New South Wales Australia

This study investigates contaminants from a single coal mine wastewater discharge released to the Wollangambe River accumulating in an aquatic predatory beetle (Macrogyrus rivularis). The study was undertaken within the Wollangambe River and its surrounding tributaries. The coal mine wastewater discharge is regulated by the New South Wales Environment Protection Authority and the regulation of the pollutants only concentrates on water column concentrations. The majority of the Wollangambe River flows within the World Heritage Greater Blue Mountains National Park and is protected through many layers of legislation from state to federal and international (Threatened Species Conservation Act 2005, Environment Protection and Biodiversity Conservation ACT 1999, United Nations Educational, Scientific and Cultural Organization 2000). Results show that many contaminants are at statistically higher concentrations within the water column, stream sediment and beetles sampled when compared between reference and impacted sample locations. Analysis of Similarity (ANOSIM) found significant differences for contaminants in beetles sampled at impacted sites compared to reference sites with no significant difference recorded between reference sites. Biota and/or Environmental matching (Best) found Manganese, Cobalt, Nickel and Zinc as the factors which have the greatest influence in differences. The implications that contaminants from the regulated wastewater being discharged may be accumulating within aquatic biota is of major concern as the regulation of the wastewater only concentrates on water column pollutants and is not taking into account the greater environmental ramifications of the pollution.

New records of water beetles (Coleoptera, Dytiscidae) from Tuva, Russia

New records of water beetles (Coleoptera, Dytiscidae) from Tuva, Russia

Notes on the crawling water beetles (Coleoptera, Haliplidae) of Kemerovskaya Oblast, Russia

Notes on the crawling water beetles (Coleoptera, Haliplidae) of Kemerovskaya Oblast, Russia

Predicting beta diversity of terrestrial and aquatic beetles using ecogeographical variables: insights from the replacement and richness difference components

AbstractAimWe examined the responses of the beta diversity of aquatic and terrestrial beetles to ecogeographical variables, including climate, land cover and land use, across Northern Europe.LocationNorthern Europe (Denmark, Sweden, Norway and Finland).MethodsInformation on the occurrence of ground beetles and diving beetles across Northern European biogeographical provinces was collated from literature sources. Beta diversity was examined using Jaccard dissimilarity coefficient as well as its replacement and richness difference components. Each of the three dissimilarity matrices (responses) was modelled using various ecogeographical variables (predictors) by generalized dissimilarity modelling (GDM).ResultsThe magnitude of total beta diversity was relatively similar between ground beetles and diving beetles, but the richness difference component contributed more than the replacement component to total beta diversity in ground beetles, whereas the opposite was true for diving beetles. The predictor variables most influential in GDM in accounting for spatial variation in beta diversity varied between the two beetle groups as well as between the replacement and richness difference components. In general, the richness difference component of ground beetles responded strongly to latitude and associated climatic variables, whereas the replacement component of diving beetles varied strongly along the same geographical gradient.Main conclusionsOur findings suggest that the study of the determinants of biodiversity patterns benefits from the partitioning of beta diversity into different components and from comparing terrestrial and aquatic groups. For example, our findings suggest that the strong climatic and land use‐related gradients in beta diversity have important implications for predicting and mitigating the effect of ongoing global change on the composition of regional biotas.