Aquatic Heteroptera Research Articles

Annotated checklist of aquatic beetles (Coleoptera) and true bugs (Heteroptera) in the Azores Islands: new records and corrections of colonization status.

In comparison with other Macaronesian archipelagos, Azorean freshwater macroinvertebrates are characterized by a smaller list of species at the archipelago regional scale. Although knowledge of the freshwater fauna of the Azores has improved in recent years through the implementation of the "Water Framework Directive", we are still far from having a complete inventory and even further from knowing the precise distribution and biology of each species. The lack of knowledge about Azorean freshwater species is coupled with the vulnerability of their habitats to anthropogenic disturbances and the introduction of non-native species. In contributing to overcome Wallacean and Hutchinsonian biodiversity shortfalls, we here provide expanded knowledge on the distribution and biology of the freshwater species of Coleoptera and Heteroptera in the Azores. We compile data from various fieldwork performed between 2006 and 2014, encompassing four islands in the archipelago. We detected new records of two aquatic Heteroptera species (belonging to the families Corixidae and Notonectidae) and six of aquatic Coleoptera (belonging to the families Dytiscidae, Gyrinidae, Hydrophilidae and Hydraenidae) in these islands, and also a new record (Enochrus fuscipennis) for the Azorean archipelago. We also suggest that the introduced colonization status of three Coleoptera species of the family Hydrophilidae should be reformulated as possibly native, with implications for conservation.

The use of STATICO and COSTATIS, two exploratory three-ways analysis methods: an application to the ecology of aquatic heteroptera in the Medjerda watershed (Tunisia)

This article is intended as a guideline to the use of two exploratory data analysis methods, namely STATICO and COSTATIS. Both techniques have already been used in the field of ecological data analysis, and we present a rapid survey of the ecological literature on three-ways analysis methods. Here, we wish to share some advanced computation and graphical display scripts to help ecologists use these methods. We first recall the main principles of these two methods for the analysis of the relationships between the structures of two series of data tables. In the context of ecology, these two series can be for example (1) a series of species data tables and (2) a series of environmental parameters tables. A detailed, real-size example is presented to show how this strategy can be put in place using the ade4 and adegraphics packages for R. This example relates to the ecology of aquatic Heteroptera in the Medjerda watershed (Tunisia). We show how the outputs of the two methods can be used to interpret the relationships between aquatic Heteroptera species distribution and environmental parameters. Several R scripts to conduct the computations and draw suitable graphical displays are reproduced and explained in the text and in five appendices.

A comparison of methods for sampling aquatic insects (Heteroptera and Coleoptera) of different body sizes, in different habitats using different baits

Although various methods exist for sampling aquatic Heteroptera and Coleoptera in standing water, there are very few comparisons of their performance in different types of habitat. In this study, we evaluated and compared the efficiency and selectivity of three sampling methods: hand netting, bottle traps baited with canned tuna and bottle traps baited with canned cat food. The methods were compared over the period 2010-2012 in two different habitats (temporarily flooded areas and canals) in the Nature Park Kopacki rit, a floodplain on the banks of the River Danube. The results show that the effectiveness of the method differed in the two habitats. Overall, hand netting was the most successful method, mainly in canals. Tuna fish bait was more efficient than the commonly used cat food, especially for large and highly mobile species of Dytiscidae. These findings indicate that knowing the type of habitat and the habitat preferences of aquatic insects and their activity it is possible to predict which of these methods are the best for estimating species richness.

Impacts of oil palm plantations on changes in environmental heterogeneity and Heteroptera (Gerromorpha and Nepomorpha) diversity

This study evaluates the effects of oil palm plantations on environmental heterogeneity and diversity (α and β) of aquatic Heteroptera (semi-aquatic and aquatic species) in Amazon streams. We assessed eight streams located in forested areas and 12 in oil palm plantations. As expected, oil palm areas had lower environmental heterogeneity, despite the presence of riparian vegetation. Heteropteran communities differed in forest and oil palm areas, however, only semi-aquatic bugs were affected by environmental variables. Streams in oil palm plantations had lower α-diversity and distinct community structures when compared to forest sites. Oil palm plantation did not affect the β-diversity of semi-aquatic bugs, however, there was increased β-diversity of aquatic bugs in these areas. These results reflect the impacts of environmental heterogeneity generated by plantations next to riparian vegetation, inducing local diversity loss. Effects on β-diversity differed among groups of Heteroptera, mainly due to the differences in the life histories of each group. Semi-aquatic bugs seem to undergo environmental filtering, while aquatic bugs can be structured by limiting similarity. Thus, the management and land conservation strategies adopted to preserve ecosystems within oil palm plantations were insufficient for the protection of aquatic heteropteran communities. In summary, such conservation policies should account for the particularities of different groups of the aquatic ecosystem; especially for aquatic fauna, which are usually overlooked in conservation policies for the Brazilian Amazon.

Waterbugs (Heteroptera: Nepomorpha and Gerromorpha) as sources of essential n‐3 polyunsaturated fatty acids in Central Siberian ecoregions

Summary Aquatic systems are considered to be a main source of essential long‐chain n‐3 polyunsaturated fatty acids (PUFA), which are preferentially synthesized by microalgae and transferred along food chains to terrestrial consumers. Emerging aquatic insects comprise a significant part of this transfer of the essential PUFA from water to land. Quantitative data on PUFA content and composition are available mainly for rheophilic insects while taxa that are characteristic of wetlands and stagnant water bodies, such as aquatic Heteroptera, remain relatively unstudied. We investigated the role of various waterbug taxa (Heteroptera: Nepomorpha and Gerromorpha) inhabiting different ecoregions in temperate Central Siberia (Russia) as potential sources of PUFA. The ecoregions were steppe, forest‐steppe, hemiboreal forest and montane coniferous forest. Although these waterbugs insects are aquatic in both larval and adult stages, they can disperse through the landscape and transfer essential PUFAs from water to land so making them potentially available to terrestrial consumers. Species of Naucoridae, Notonectidae and Corixidae were generally dominant in all ecoregions, attaining maximum biomass in the steppe. We showed that habitat or ecoregion played a major role in the variability of fatty acid composition of Notonectidae and Gerridae but not Corixidae. In contrast, the biochemical composition of the only naucoridae, Ilyocoris cimicoides, was largely affected by life stage. Both the dominant families and species within them differed with respect to their mass‐specific contents of essential long‐chain PUFA of the n‐3 family, namely eicosapentaenoic and docosahexaenoic acids. Corixid species had the highest content of these two essential PUFAs among the waterbug studies, and relative to literature reports for other aquatic insects. Corixids thus appear to be a potentially important vector for transfer of the essential biochemical compounds from water to land, especially in steppe ecoregions with numerous ephemeral water bodies.

The Effect of Dredging of a Small Lowland River on Aquatic Heteroptera

Rehabilitation of river beds is sometimes necessary, particularly when a substantial amount of bottom sediment causes unnaturally slow water flow. However, it is difficult to predict whether such procedures will negatively affect biodiversity and species composition of organisms inhabiting these sites. The effects of such procedures were analysed in the Krąpiel river in northwestern Poland. It was postulated that dredging would not reduce Heteroptera diversity, but would alter the habitat significantly and create lotic habitats for rheophilous species. It was also postulated that conditions would become less favourable for taxa preferring a bottom with accumulated mud and abundant vegetation. According to our results, dredging did not significantly affect species diversity of Heteroptera, but did cause an increase in abundances of several species. Dredging increased the number of available habitats, which were mainly inhabited by abundant pioneer species. Aquarius najas, Aphelocheirus aestivalis, Plea min...

DR. John T. Polhemus, 1929–2013: Summary of Collecting Expeditions, Scientific Publications, and Taxonomic Names Proposed

Abstract. The current paper summarizes the scientific career of Dr. John T. Polhemus, 1929–2013. It begins with a compendium of his extensive field work devoted to the collection of aquatic Heteroptera, cross-referenced to his associated field collection numbers in order to allow future workers to more accurately associate samples and localities. This is followed by a list of his 288 peer-reviewed publications, the taxonomic names proposed within them, comprising 474 species, 54 genera, and 5 tribes, and the holotype repositories for the specieslevel taxa.

Detection of the IS2404 insertion sequence and ketoreductase produced by Mycobacterium ulcerans in the aquatic Heteroptera in the health districts of Dabou and Tiassalé in Côte d'Ivoire

Buruli ulcer (BU) disease, caused by Mycobacterium ulcerans, is a major public health problem in Côte d'Ivoire. Until now, the mode of BU transmission was unknown, but recent studies implicate aquatic Heteroptera in the chain of transmission. This study was launched in Côte d'Ivoire to search for specific genetic markers for M. ulcerans in these bugs, including the insertion sequence IS2404 and ketoreductase (Kr), both involved in the synthesis of mycolactone, a toxin produced by these mycobacteria. Samples of aquatic Heteroptera were collected monthly with deep nets from ponds near villages in the health districts of Dabou and Tiassalé. After identification and enumeration of the bugs, batches of the same taxon underwent real-time PCR to search for the IS2404 target and Kr. Saliva of 69 specimens of Diplonychus sp randomly selected in the samples was also analyzed by PCR. In all, 283 single-taxon batches were created. Thus, PCR identified 26 batches belonging to the families of Belostomatidae, Naucoridae, Corixidae, Ranatridae, and Nepidae as positive for both targets. The IS2404 insertion sequence and Kr were present in 6 of the 69 samples analyzed in the saliva of Diplonychus sp. These aquatic Heteroptera suspected of infection by M. ulcerans might release it into the environment because of their ability to fly. They might thus be the source of human contamination.

Histological and Ultrastructural Analysis of Spermatogenesis in Gelastocoris flavus flavus (Heteroptera: Nepomorpha)

Studies on the ultrastructural aspects of spermatogenesis and, specifically, the structure of sperm in aquatic Heteroptera are scarce. Therefore, the objective of this study was to analyse of the histology and ultrastructure of spermatogenesis. Semi-fine sections of the testicles of adult male Gelastocoris flavus flavus were stained with toluidine blue or impregnated with silver ions, and ultra-fine sections were analysed by transmission electron microscopy. The ultrastructural features observed during spermatogenesis of the species showed the presence of several small mitochondria uniformly distributed in the cytoplasm of cells in prophase I. These mitochondria then came together to form fewer, larger structures, which converged and formed the mitochondrial complex. Later, this mitochondrial complex was divided into two structures, termed mitochondrial derivatives, which were arranged bilaterally to the axoneme. The axoneme showed a flagellar pattern of 9+9+2. A vesicle was observed that originated in the early stages of spermiogenesis and was composed of many argyrophilic granules that united to form a single structure. This vesicle contained some highly stained structures in its interior. Thus, this paper describes histological and ultrastructural characteristics during spermatogenesis, contributing to the reproductive knowledge of these aquatic Heteroptera

Aquatic Heteroptera of Great Rivers of the Ukrainian Steppe Zone and Seasonal Changes of Abundance and Biomass

Abstract Aquatic Heteroptera of Great Rivers of the Ukrainian Steppe Zone and Seasonal Changes of Abundance and Biomass. Grandova, M. A. - Aquatic Heteroptera are one of the important components of water biocoenoses. During the study of the great rivers of the Ukrainian continental steppe zone 34 species were found, among them Sigara mayri (Fieber, 1860), a new species for Ukraine. Cymatia bonsdorffi i (C. R. Sahlberg, 1819) and Hydrometra stagnorum (Linnaeus, 1758) are recorded in the Ukrainian continental steppe zone for the first time. During the whole year the aquatic Heteroptera taxocenoses of all the concerned objects create the indivisible complex, which basis is formed by inhabitants of inundated reservoirs. Th e highest abundance is observed in the reed bed lakes in the middle of July, aft er the hatching of the second generation nymphs of the polyvoltine species, the maximum of biomass is observed in October in the reed bed lakes, where Nepomorpha gather for overwintering.

New Records ofMartarega,Graptocorixa, andAbedus(Heteroptera: Notonectidae, Corixidae, Belostomatidae) From Northwestern Mexico and Arizona, Including the First Record ofGraptocorixa emburyiIn the United States

Abstract While distributions of aquatic insects are fairly well known in the southwestern United States, relatively few surveys have been conducted in northwestern Mexico. We report new collections of species of aquatic Heteroptera in the region, which extend the known range of several species by hundreds of kilometers, including the first record of Graptocorixa emburyi in the United States, and help show that disjunct distributions of other species are more continuous than previously thought.

Aquatic Heteroptera (Nepomorpha, Gerromorpha) in small intermittent rivers of Ukraine steppe zone

Small intermittent rivers are some of the most widespread types of water currents in the steppe zone. In the ecosystems of the intermittent rivers we have found 28 species of water bugs that compose the majority of the described fauna in the south Ukraine. Our study added two new species to the faunistic list of this zone (Sigara fossarum, Hydrometra gracilenta), and finally confirmed the presence of Micronecta scholtzi in Ukraine. We also studied the seasonal changes of biotopic distribution and quantitative characteristics of aquatic Heteroptera. It was shown thatfor water bugs the ecosystem of the small intermittent rivers consists of three closely connected components: the riverbed, the flooded areas and the extra inundated constant basins. During the droughty period when the riverbed is dry, the extra inundated basins (including artificial ones – sandy pits) serve as refugia. The wintering of many species takes place there, especially when the riverbed is not filled before the cold period. However, the reproduction of most species takes place in the riverbed and associated flooded areas. Thus, this work is a confirmation and development of the concept for “a uniform architectonic complex of a river valley”.

Gerris Lacustris (Linaeus 1758) and Gerris Costae (Herrich-Schäffer 1850) Species - Habitat Relations on Mountainous Tributaries of Vişeu River (Maramureş, Romania)

ABSTRACTSemi aquatic Heteroptera species from some mountainous tributaries of the Vişeu River were collected and their relations with habitat variables were investigated. Only two species, Gerris lacustris and Gerris costae were found, either one or both species, in almost half of the investigated sampling stations. Correlation analysis between samplings and habitat conditions showed that Gerris lacustris prefers small deep ponds or river banks with steep slopes and is easily adaptable to habitat changes, while Gerris costae is mostly found in large marshes with low, stagnant water and high amounts of vegetation. Both species are relatively tolerant to human impact in their habitat, Gerris lacustris more so. The two species are negatively correlated to each other, as an expression of competition between them. Principal Component Analysis resulted in two dominant factors explaining almost 60% of the habitat variation, and their graphic representation proved the observed correlations.

Nepomorpha, Gerromorpha and Leptopodomorpha (Hemiptera: Heteroptera) of the Tuscan Archipelago (Italy).

This paper provides the first checklists for Nepomorpha (12 spp.), Gerromorpha (10 spp.) and Leptopodomopha (5 spp.) of the Tuscan Archipelago; summarizing and updating the knowledge for this area. The presence of the family Micronec- tidae is recorded for the first time in the Archipelago, as well as six species: Nepomorpha - Micronecta scholtzi (Fieber, 1860), Sigara selecta (Fieber, 1848), S. stagnalis (Leach, 1817), S. lateralis (Leach, 1817); Gerromorpha - Gerris asper (Fieber, 1860); Leptopodomorpha - Saldula palustris (Douglas, 1874); increasing the numbers of aquatic Heteroptera sensu lato from 21 to 27 species. The three infraorders are present in only four of the seven major islands of the Tuscan Archipelago (Capraia, Elba, Montecristo and Giglio). The Isle of Elba has been scarcely investigated until now: ten species are newly recorded for this island (doubling the number to 20 spp.), whilst another species has been first recorded for Giglio Island. The most remarkable finding is Gerris asper (Fieber, 1860) on Elba, a species inhabiting marshy areas that is very rare to Italy. Notonecta glauca Linnaeus, 1758 is excluded from the fauna of the Tuscan Archipelago.

Aquatic and Semi Aquatic Heteroptera Communities from South-East Transylvanian Small Rivers

AbstractThe paper presents the analysis of the relations between aquatic and semi aquatic Heteroptera from south-east Transylvanian small rivers and habitat characteristics of the sampling sites. Biological material was collected from 23 sampling sites from Hârtibaciu Plateau (8), and Făgaraş (12) and Sibiu (3) Depressions. A large number of species were identified, almost a third (22 out of 69) of the species sampled so far in Romania. Gerris (Gerris) lacustris (Linnaeus, 1758) has the highest relative abundance and frequency, seconded by Nepa cinerea Linnaeus, 1758 and Sigara (Pseudovermicorixa) nigrolineata nigrolineata Fieber, 1848. Community composition is influenced by habitat characteristics, the most important role being held by the presence of aquatic vegetation, favoring G. lacustris and N. cinerea, and the inconstancy of the hydrological regime, favoring S. nigrolineata. Habitat conditions are having a low influence on biodiversity values, although substrate and hydrological heterogeneity and aquatic vegetation seem to be responsible for higher species richness, while mild anthropic impact and a larger site size are resulting in higher species heterogeneity.

The aquatic Heteroptera (Insecta: Hemiptera) of the "Foreste Casentinesi, Monte Falterona e Campigna" National Park (Central Italy)

We provide the first checklist of the aquatic Heteroptera of the “Foreste Casentinesi, M. Falterona e Campigna” National Park, located on the Apennines between Tuscany and Emilia-Romagna. We list 31 species, representing the 28% of the aquatic Hemiptera present in Italy. We summarize data on Gerromorpha (14 spp.), Nepomorpha (13 spp.) and water-dependent Leptopodomorpha (4 spp.) of this protected area, reporting for each species all sampling data.

When do beetles and bugs fly? A unified scheme for describing seasonal flight behaviour of highly dispersing primary aquatic insects

Changes of seasonal dispersal flight were investigated based on a wide spectrum of aquatic Heteroptera and Coleoptera species. We hypothesized that species or groups of species can be characterized by various seasonal patterns of dispersal flight. Dispersal activity was studied in a lowland marsh located in NE Hungary during a 30-week long monitoring period. Insects were attracted to highly polarising horizontal shiny black plastic sheets laid onto the ground. There are no periods of the year (from April till October) when insects are not rising into the air, but species have various seasonal flight activity. Dispersal flight activity of 45 species could be described. These activities assessed based on a seasonal approach and proportional classification. Based on these results, three seasonal patterns and twelve sub-patterns were defined. Comparing the observed patterns with previously reported dispersal activity data, we argue that observations found in the literature fit well with patterns defined here, therefore, to assess the dispersal behaviour, a unified scheme can be established. Owing to this unified scheme, the seasonal dispersal activity of primary aquatic insects observed in different studies becomes highly comparable. This scheme can be a useful tool for assessing dispersal behaviour of insects across other geographic regions.

Structure of aquatic assemblages of Coleoptera and Heteroptera in relation to habitat type and flood dynamic structure

The abundance and taxonomic composition of the aquatic insect fauna were investigated, with focus on adult water bugs, water beetles and water scavenger beetles (Heteroptera: Nepomorpha and Gerromorpha, and Coleoptera: Hydradephaga and Hydrophilidae) in two different freshwater habitats: (1) a periodically flooded area of the Special Zoological Reserve in Kopački rit Nature Park, Croatia; and (2) melioration canals in the wider area of the Nature Park during 2005. Aquatic insects are generally abundant in various water systems, including floodplains that are exposed to water level fluctuations. Our aims were (1) to determine abundance and species richness in relation to habitat type; (2) to determine the influence of high flood peaks and oscillations during high water levels on the diversity of aquatic Coleoptera and Heteroptera in the flooded area; and (3) to identify characteristic species associated with each habitat type. We collected 71 species; 41 were captured at canals and 64 at the flooded area. Diversity of the two habitat types varied depending on the months but there were remarkable differences in species pool and their abundance. Both high and low water levels as well as oscillations during high water levels had major influence on species assemblages at the flooded area. Diversity of aquatic Coleoptera and Heteroptera was higher when the water level decreased after high water level peaks. A total of 11 species fulfilled the criteria for specificity and were sufficiently abundant to be suitable species characteristic for these two habitats. A higher proportion of significant characteristic species was present in the flooded area than in the canals. The presence of two Red List species of water beetles (Graphoderus bilineatus De Geer, 1774 and Berosus geminus Reiche et Saulcy, 1856) and nine significant characteristic species at the flooded area clearly indicates that the contribution of floodplains in maintaining freshwater biodiversity is not only important regionally but also at the international level. Also, our results suggest that the power of high water levels is an important factor that can be used in analyses on aquatic Coleoptera and Heteroptera assemblages, showing the uniqueness of large floodplain areas.

Seven decades of monitoring the aquatic bug fauna of Lake Balaton (Heteroptera: Nepomorpha)

Detailed faunistic data originating from four sampling series of aquatic Heteroptera (Nepomorpha) in the Lake Balaton (the largest shallow lake of Central Europe) between 1928 and 2002 were analysed. A comparative analysis confirmed that the aquatic bug fauna of this great lake can be established with suitable accuracy if it is sampled by different but devoted collectors. So far 26 species of aquatic bugs have been reported from here. The fauna changed considerably during the seven decades. Species lists of the four basins of the lake established during the four sampling periods show characteristic differences. Not only the frequency of four Micronecta species (Micronecta griseola, M. pusilla, M. scholzi, M. minutissima) changed characteristically but there has been a distinct change in the ratio of rare species too. Rare species were present in significantly higher proportion in the period 1928–1930 than in any of the later samplings between 1984 and 2002. All these changes run parallel with the direction of anthropogenic influences.

Spermatogenesis of riffle bugs, Rhagovelia whitei and Rhagovelia sp (Veliidae), and backswimmers Martarega sp (Notonectidae)

We examined the course of spermatogenesis and the meiotic chromosome complements in aquatic species of true bugs, Heteroptera. The chromosome complement of the Veliidae species was 2n = 39 (38A + X0) and 23 (22A + X0) in Rhagovelia whitei and Rhagovelia sp, respectively, and in the species of the Notonectidae (Martarega sp) it was 26 (22A + 2m + XY); all collected from the region of São José do Rio Preto, SP, Brazil. An impressive characteristic of the first analysis was the size of the cells belonging to Martarega sp, which were six times larger than the same cells in Pentatomidae and twice as large as the cells in aquatic Heteroptera (Gerridae). Regarding spermatogenesis, all the species analyzed showed the same pattern: holocentric chromosomes and elongated spermatids with the chromatin distributed evenly along the head. The family Veliidae showed several bodies impregnated with silver nitrate at prophase, while the family Notonectidae displayed only one. The cells of Notonectidae also showed an evident and round body until the end of prophase I and in the family Veliidae the silver-impregnated bodies were disorganized, where the only region visualized was possibly that of the NOR. In metaphase, silver-stained regions were found at the periphery of all chromosomes in Veliidae and at the periphery of some chromosomes in Notonectidae. The spermatids of Veliidae showed a less silver-impregnated vesicle, while Notonectidae showed silver staining only in part of the nuclear membrane. Therefore, families of Heteroptera have some differences and features that can help identify and classify these species.