Aquatic Heteroptera Research Articles

A new species of Maculambrysus Reynoso & Sites, 2021 (Hemiptera: Heteroptera: Naucoridae) from an aguaje palm swamp in southeastern Peru.

The neotropical saucer bug genus Maculambrysus Reynoso & Sites is currently represented by five species from Tabasco, Mxico to Par, Brazil. Presented here is the description of a sixth species, Maculambrysus gallicei n.sp., which was collected from rootmats and leafpacks in an aguaje palm swamp in southeastern Peru. It can be distinguished from most congeners by the concolorous dark-brown hemelytra and the mottled orange-brown pronotum, as well as characteristics of the male accessory genitalic process of tergum VI, and female subgenital plate and laterosternites VI. Other aquatic Heteroptera co-occurring with this new species are given.

Biodiversity of aquatic Heteroptera in relation to physico-chemical parameters, the Biological Reserve of Sidi Boughaba and the Merja of Fouarat as a case studies (Gharb Plain, Morocco)

Given their great importance in aquatic ecosystems, the literature on aquatic and semi-aquatic Heteroptera is quite extensive worldwide. However, relatively little literature is available on the taxonomy and distribution of aquatic and semi-aquatic Heteroptera in the Gharb Plain, specifically the two wetland areas classified as Ramsar sites, the Biological Reserve of Sidi oughaba and the Merja of Fouarat. Therefore, the present research aims to study the community of aquatic Heteroptera and the physico-chemical variables of these two wetland areas in the Gharb Plain. Additionally, the research aims to document and authenticate the historical review of aquatic and semi-aquatic Heteroptera in these wetlands. The results obtained show the existence of two groups of Heteroptera species. One group consists of species that are found in several environments due to their broad ecological tolerance. This is the case of, Gerris lacustris (Linnaeus, 1758), G. lateralis (Schummel, 1832), Corixa affinis (Leach, 1817), Notonecta glauca rufescens (Poisson, 1933), Anisops sardia (Herrich-Schaeffer, 1849), Plea leachi (McGregor, Kirk, 1899), Naucoris maculatusconspersus (Stål, 1876), Hydrometra stagnorum (Linnaeus,1758) and Mesovelia vittigera (Horváth, 1895). On the contrary, species conditioned by several physicochemical factors of the environment, Stenoic species, such as Sigara lateralis (Leach, 1817), S. stagnalis (Leach, 1817), Naucoris maculatus angustior (Lethierry, 1877), Nepa rubra rubra (Linné, 1758) and Gerris thoracicus (Schummel, 1832).

DNA barcode-based survey documents underestimated diversity and intricate phylogeographic patterns of aquatic Heteroptera in an endangered Balkan biodiversity hotspot: ancient Lake Skadar basin

Lake Skadar with its surrounding springs, wetlands and larger affluents is among the most diverse freshwater ecosystems in the Mediterranean region and a key biodiversity/endemism hotspot in Europe. It is also highly endangered due to climate change and rapid tourism development in the area. Being abundant, diverse and mostly predatory, true aquatic bugs play an important role in the functioning of freshwater ecosystems and are used as indicators of aquatic habitat quality. Nevertheless, this taxonomic group has been scarcely studied in the area. Our survey provides the first comprehensive DNA barcode library for 24 out of 25 species of aquatic Heteroptera collected in the Skadar Lake basin and adjacent regions. By this, we extend the list of species known from the area by 60%. In the case of three species, Notonecta maculata, Hydrometra stagnorum and Nepa cinerea, we detected multiple highly divergent, and also new BINs indicating possible taxonomic inconsistencies, the potential for (pseudo)cryptic diversity and intricate phylogeographic patterns. We show that presumably well-known hotspots, such as Lake Skadar region, are heavily understudied regarding even the prominent insect taxa and, thus, particularly vulnerable to undocumented biodiversity loss. Finally, we underline the value of simple DNA-barcoding-based surveys for providing reference barcode libraries for effective biomonitoring and signalling taxonomic and biogeographic issues.

Effects of Different Types of Agricultural Land Use on the Occurrence of Common Aquatic Bugs (Nepomorpha, Heteroptera) in Habitats with Slow Flowing Water in Bulgaria, Southeast Europe

Agricultural activities can have a significant impact on aquatic organisms, including aquatic insects. Most of the aquatic Heteroptera are known as moderately tolerant to low oxygen and high nutrient concentrations. Nevertheless, the complex effects of agriculture (source of both pesticides and nutrient loads) on this group are still unclear. Therefore, the relationship between six agricultural land use classes and the occurrence of common aquatic bugs in Bulgaria was studied. In order to avoid detection bias, presence-only models were applied; Maxent algorithm was used. According to the results, land use practices connected to arable land (annual crops) have stronger influence on the occurrence of the selected aquatic Heteroptera species than those connected to perennial crops (vineyards and fruit trees). Higher sensitivity to the effects of agriculture was indicated for species preferring microhabitats without macrophyte vegetation, Aphelocheirus aestivalis (Fabricius, 1794) and Micronecta griseola Horváth, 1899, compared to species preferring macrophyte dominated sites, Nepa cinerea Linnaeus, 1758, Ilyocoris cimicoides (Linnaeus, 1758) and Sigara striata (Linnaeus, 1758).

Corrections and comments on MARTINS-SILVA (2022) “Checklist of Aquatic Heteroptera genera (Insecta: Hemiptera) from Brazilian Savanna (Cerrado Biome), with family and genera identification key”

Recently, Martins-Silva (2022) published the article entitled “Checklist of Aquatic Heteroptera genera (Insecta: Hemiptera) from Brazilian Savanna (Cerrado Biome), with family and genera identification key”. The paper provides information on which genera of aquatic Heteroptera would occur in the Cerrado biome and an identification key to families and genera, based on specimens deposited in the Aquatic Invertebrates Collection of the University of Brasília, Brazil. However, it presents many problems, including misidentifications, lack of care with references, scientific names and taxonomic authorities, and poor grammar, syntax and spelling. Here, we express our concern about this paper and provide identification corrections for specimens figured in it whenever possible.

Aquatic and Semiaquatic Heteroptera (Hemiptera: Insecta) Distribution in Streams on the Cerrado–Amazon Ecotone in Headwaters of Xingu River

The modification of landscapes surrounding water bodies leads to changes in limnological characteristics and decreased aquatic biodiversity, such as fish and macroinvertebrates. Aquatic insects are sensitive to changes in aquatic ecosystems and quickly respond to those changes. The aim of this paper was to evaluate the relationship between the compositions of aquatic and semi-aquatic Heteroptera with environmental variables along an environmental gradient in streams at the headwaters of the Xingu River, Brazil. We collected samples from 12 streams belonging to the Suiá-Miçú river basin and tributaries of the Xingu River, in September (dry season), 2008. The Suiá-Miçú river is one of the tributaries on the right bank of the Xingu River, and it is located in the ecotone between the Cerrado and the Amazon rainforest in the area characterized as the “arc of deforestation’’. Insects were sampled in fixed 100 m transections and divided into 20 segments of 5 meters each. To assess the habitat integrity in each stream, the habitat integrity index (HII) was applied. The following environmental variables were measured: electrical conductivity, turbidity, depth, and the normalized difference vegetation index (NDVI). The ordering of species composition was performed with the principal coordinate analysis (PCoA), and the relationship between environmental variables and composition was performed using a Mantel test. Of the 263 individuals collected, distributed in 8 families, there were 20 genera, of these, 12 were from Nepomorpha and 8 from Gerromorpha. The most abundant genera were Limnocoris (n = 121) and Rhagovelia (n = 32). Naucoridae was the most diverse family. Together, the environmental variables explained ~50% of the species distribution (r = 0.49; p = 0.001). These results reinforce the efficacy of aquatic Heteroptera to monitor environmental conditions. Here, in particular, the responses of this group to variations in landscape metrics, environmental integrity, and water variables together demonstrate that it can be useful to indicate the quality of habitat in streams.

Unravelling the environmental correlates influencing the seasonal biodiversity of aquatic Heteropteran assemblages in northern Africa

Heteropteran communities form a key component of aquatic ecosystems but have not been widely studied compared to other freshwater faunal groups. This research examined the environmental parameters influencing the diversity, seasonal distribution and structure of aquatic Heteroptera assemblages in the Mediterranean region of Tunisia, northern Africa. Heteropterans were most abundant during spring and summer, coinciding with the emergence of several species and the most favorable environmental conditions for benthic aquatic fauna. Three-way multivariate analyses (combining community composition data from all sites and seasons) highlighted the longitudinal spatial organization of Heteropteran communities. Headwater regions were dominated by halophobic sensitive taxa, and lowland sites were characterized by high salinity resistant taxa (halophilic taxa). The longitudinal organization was driven by gradients of mineralization (salinity and electrical conductivity) and oxygen (DO, COD and BOD) concentrations. Taxonomic composition differed between river catchments, with significantly higher diversity (taxa richness) in the streams with adjacent riparian forest cover. These sites were characterized by the presence of endemic species, such as Velia africana and Velia eckerleini, and rare species, Notonecta meridionalis, and Aquarius najas. Results recorded highlight the importance of aquatic vegetation and water quality in driving the seasonal and spatial variability of Heteropterans, and provide important information to inform the management and conservation of freshwater biodiversity in Northern Africa.

Checklist of Aquatic Heteroptera genera (Insecta: Hemiptera) from Brazilian Savanna (Cerrado Biome), with family and genera identification key

Insects of the order Hemiptera (Heteroptera) are considered the largest group of insects with incomplete metamorphosis. Representatives of the Gerromorpha and Nepomorpha infraorders are found in the Brazilian Savanna (Cerrado Biome). This manuscript provides information about the occurrence and distribution of families and genera that occur in the states of the Cerrado Biome, deposited in the UnB Aquatic Invertebrate Collection (CIAq-UnB). The collection started in 1995 and have aquatic specimens of Cerrado Biome. An identification key is also presented for the families and genera that occur in this region.

Species Composition of Aquatic (Nepomorpha) and Semiaquatic (Gerromorpha) Heteroptera (Insecta: Hemiptera) in Kaeng Krachan National Park, Phetchaburi Province, Thailand

The species composition of aquatic (Nepomorpha) and semiaquatic (Gerromorpha) Heteroptera were examined from protected and unprotected study sites in three streams associated with Kaeng Krachan National Park. At each stream, both quantitative and qualitative sampling methods were used during seven collecting events (November 2018 to June 2020). A total of 11 families, representing 33 genera and 60 species, were collected in this study, with more Nepomorpha families but higher species richness in Gerromorpha. The species richness of both protected and unprotected sampling sites were lowest during the fifth sampling event. Nevertheless, there was no significant difference in richness between protected and unprotected sampling sites for any sampling event based on a paired t-test analysis. Based on an nMDS analysis, the patterns of species composition of aquatic and semiaquatic heteropterans were unclear among protected and unprotected sampling sites. The use of aquatic and semiaquatic Heteroptera as bioindicators for habitat quality is still uncertain. Additional physiochemical characters of the water and physical characters of the stream may lead to a clearer picture of the relationship between aquatic and semiaquatic Heteroptera and stream habitat quality.

The Aquatic Heteroptera (Hemiptera) of Marshes in the Florida Everglades

The Everglades is a large subtropical wetland that has been modified heavily by humans and now is undergoing restoration. Aquatic and semiaquatic Heteroptera (Hemiptera) in the infraorders Gerromorpha and Nepomorpha were collected in the Florida Everglades using standardized 1-m2 throw-traps. Sampling efforts were conducted in marshes distributed from southern Everglades National Park, north throughout the Water Conservation Areas to Loxahatchee National Wildlife Refuge. In total, 12,833 individuals were identified representing 17 species in 13 genera and 8 families (Belostomatidae, Corixidae, Gerridae, Mesoveliidae, Naucoridae, Nepidae, Veliidae). The naucorid Pelocoris femoratus (Palisot de Beauvois) (Hemiptera: Naucoridae) was by far the most abundant species, whereas 2 other species, Belostoma lutarium (Stål) (Hemiptera: Belostomatidae) and Neogerris hesione Kirkaldy (Hemiptera: Gerridae), were widespread but less abundant. Two species, Abedus immaculatus (Say) (Hemiptera: Belostomatidae) and Pelocoris balius La Rivers (Hemiptera: Naucoridae) had localized distributions, whereas all other species were collected rarely. We discuss the abundance and distribution of species recorded, along with unique traits and the biology of the aquatic Heteroptera in the Everglades and implications for the restoration of the Everglades.

Preliminary Study on Water Quality and Heteropterans Diversity in a Semi-Urban Stream (Central Region of Cameroon)

A study was conducted in the Konglo stream for six months to make an inventory of aquatic heteroptera, following a monthly sampling frequency. Some hydrological and physicochemical parameters such as water width, current velocity, and water flow, water temperature and pH, electrical conductivity, dissolved oxygen, total hardness, phosphates, nitrates, and ammonia were measured according to standard methods. For an inventory of the heteropterans, the multihabitat approach was used during sampling, but only heteropterans representing 3.15 % of total abundance are considered in this study. The hydrological variables were different in each station. The water width and flow were increased from upstream to downstream. The results showed that pH, total hardness, nitrites, phosphates, and ammonia values ​​were weak and no significant differences were observed. Among physicochemical variables, only dissolved oxygen and electrical conductivity were different between upstream and downstream. The conductivity increased from upstream to downstream while the dissolved oxygen was very low downstream. 62 individuals were collected and counted belonging to 11 taxa, the most abundant being Ranatra linearis. The other taxa such as Anisops sp., Aphelocheirus aestivalis, Gerris sp., Gerridae Nd., Hydrometra sp., Ilyocoris cimicoides, Naucoris sp., Nepa sp., Notonectidae Nd., and Velia sp. were poorly represented. High abundance was recorded at the upstream (38 individuals), but the taxonomic richness (3 taxa) and diversity (0.24 bits/ind) remain low, unlike the stations located downstream (7 taxa and 1.82 bits/ind).

Anatomy and histology of the male reproductive tract in creeping water bugs (Heteroptera: Naucoridae)

AbstractCreeping water bugs (Naucoridae) are predatory aquatic insects widely distributed in the Neotropical region. This study describes the structure of the male reproductive tract in two species, Limnocoris porphyros Nieser & Lopez Ruf, 2001 (Limnocorinae) and Pelocoris subflavus Montandon, 1898 (Naucorinae), under light microscopy. Both in L. porphyros and P. subflavus, the reproductive tract of sexually mature males consists of a pair of testes, efferent ducts, deferent ducts, seminal vesicles, two pairs of accessory glands, and an ejaculatory duct. Each testis has seven follicles. Deferent ducts were long with a dilation forming the seminal vesicle. Post‐vesicular deferent ducts were long, coiled, and contained spermatozoa. Characters derived from anatomy and histology of the male reproductive tract in the two species, expand the knowledge on reproductive biology and provide new data that can enhance behavioural research and contribute to understand the evolutionary history of aquatic Heteroptera.

Flight polymorphism drives metacommunity structure of aquatic Heteroptera in tropical rock pools

AbstractRock pool metacommunities are shaped by the dispersal ability of organisms, which together with environmental heterogeneity, determine whether the metacommunity is structured more by environmental or spatial factors. To understand the effect of interspecific differences in dispersal capacity on beta diversity patterns and metacommunity structure, we studied aquatic Heteroptera (an actively dispersing insect group with species exhibiting flight polymorphism) in the rock pools on three outcrops in the Western Ghats, India. We used an abundance‐based gamma diversity partitioning framework to assess the percent contributions of similarity (S) and the decompositions of beta diversity‐abundance difference (D) and abundance replacement (R) to community structure for two mobility groups, that is, flying and flightless species. We compared the variation in beta diversity components “D” and “R” within and between outcrops for both mobility groups. We also studied the effects of the local environment on both mobility groups using redundancy analysis. Percent contributions of “S”, “D” and “R” changed according to the mobility group, with higher nestedness (S+D) in flying species (74.2%) and higher beta diversity (R+D) in flightless species (76.3%). There was a significant variation in overall beta diversity between outcrops for the respective mobility groups, caused by abundance difference for flying species (p = .003) and by abundance replacement for flightless species (p = .003). Flying and flightless species were not associated with different environmental variables. Our study demonstrates that dispersal capacity is responsible for structuring regional diversity, with distinct sources of dissimilarity being associated with each mobility group: Abundance replacements between assemblages imposed by dispersal limitation for flightless species and abundance differences in assemblages of flying species, which might reflect the carrying capacity of the habitats.

Anatomy and histology of the male reproductive tract in giant water bugs of the genus Belostoma Latreille, 1807 (Heteroptera, Belostomatidae)

Giant water bugs (Belostomatidae) are widespread in the tropical and subtropical regions and have important ecosystem functions. This study describes the structure of the male reproductive tract in three species of Belostoma Latreille, 1807. The reproductive systems of sexually mature males of B. plebejum, B. stollii and B. testaceopallidum have a pair of globular testes, deferent ducts, seminal vesicles, an ejaculatory duct and an aedeagus. Each testis has five folded follicles, and each follicle is continuous with an efferent duct (0.72 cm in length on average), which opens together in the deferent duct (0.85 cm in length on average). Inside the testis follicles, germ cells develop synchronously in cysts with seven mitotic and two meiotic cycles. The deferent ducts have a dilated portion for the storage of spermatozoa, the seminal vesicles. Accessory glands were absent. The morphological characteristics of the male reproductive tract in these three species of Belostoma and their similarities with other aquatic Heteroptera are discussed.

A comparison of aquatic and semiaquatic Heteroptera (Hemiptera) inhabiting natural habitats and experimental mesocosms at the University of Mississippi Field Station

Aquatic and semiaquatic Heteroptera (Hemiptera) in the infraorders Gerromorpha and Nepomorpha were collected from the University of Mississippi Field Station (UMFS) in north-central Mississippi from May 2014 until August 2019. UMFS encompasses over 200 ponds, springs, wetlands, and streams in the headwaters of the Little Tallahatchie River. We collected insects from mesocosm experiments and natural water bodies in order to survey and document the aquatic and semiaquatic Heteroptera of UMFS. A total of 20,304 individuals were collected representing 43 species in 20 genera and 10 families (Belostomatidae, Corixidae, Gerridae, Hebridae, Hydrometridae, Mesoveliidae, Naucoridae, Nepidae, Notonectidae, Veliidae). We compare mesocosms and natural water bodies in terms of species present and their abundances, and we also provide notes on the abundance, distribution, and habitats of some species, with new state records for three species.

Environmental determinants of species turnover of aquatic Heteroptera in freshwater ecosystems of the Western Ghats, India

Partitioning beta diversity into its two components of spatial turnover and nestedness is a more robust method for checking spatial variability in biological communities than calculating the total beta diversity alone. The relative contribution of spatial turnover and nestedness has been used to test the effects of climatic, environmental, spatial and temporal variables on community composition. In this study, we tested the effects of environmental factors and microhabitat features on total beta diversity and its spatial turnover and nestedness components using a comprehensive dataset of aquatic Heteroptera collected from four types of permanent freshwater habitats (i.e. streams, ponds, rock tanks and reservoirs) in the Western Ghats of India. We observed that communities in all four types of habitats were predominantly shaped by dissimilarity caused due to spatial turnover (>85 %). Each type of habitat showed the presence of one or more species uniquely associated with it, which might contribute to the turnover between communities. The abiotic environment (climatic factors, topological factors, soil characteristics and microhabitat features) as well as assemblage structure differed significantly between habitat types. Communities in each type of habitat were affected by different environmental factors, such as precipitation and temperature patterns for streams, altitude and rocky substrate for rock tanks, and soil characteristics and the presence of aquatic macrophytes for ponds and reservoirs. Assemblages observed in the four types of permanent habitats are thus compositionally distinct due to species replacements between local communities, which in turn are strongly influenced by environmental variables. Similar to previous studies, our results show that spatial turnover largely measures the same phenomenon as total beta diversity on a regional scale.

Vodene stenice u Srbiji

This paper includes a list of 62 species of Heteroptera (Nepomorpha and Gerromorpha), categorized into 12 families: Nepidae (2), Belostomatidae (1), Corixidae (25), Naucoridae (1), Aphelocheiridae (1), Notonectidae (6), Pleidae (1), Mesoveliidae (1), Hebridae (3), Hydrometridae (2), Velidae (9) and Gerridae (10). Two species are new for the fauna of Serbia: Hesperocorixa moesta (Fieber, 1848) and Velia (Plesiovelia) mancinii mancinii Tamanini, 1947.

The Naucoridae (Heteroptera: Nepomorpha) of Belize

ABSTRACTFew regional faunistic treatments of aquatic Heteroptera exist for Mesoamerica. Records given here are the result of three extensive, coincident projects, each generating many specimens of Naucoridae. Thus, presented here is an annotated list of Naucoridae occurring in Belize, with an illustrated taxonomic key and notes on habitat. Three species are new country records, and ten species in four genera are now known from Belize.

From water striders to water bugs: the molecular diversity of aquatic Heteroptera (Gerromorpha, Nepomorpha) of Germany based on DNA barcodes.

With about 5,000 species worldwide, the Heteroptera or true bugs are the most diverse taxon among the hemimetabolous insects in aquatic and semi-aquatic ecosystems. Species may be found in almost every freshwater environment and have very specific habitat requirements, making them excellent bioindicator organisms for water quality. However, a correct determination by morphology is challenging in many species groups due to high morphological variability and polymorphisms within, but low variability between species. Furthermore, it is very difficult or even impossible to identify the immature life stages or females of some species, e.g., of the corixid genus Sigara. In this study we tested the effectiveness of a DNA barcode library to discriminate species of the Gerromorpha and Nepomorpha of Germany. We analyzed about 700 specimens of 67 species, with 63 species sampled in Germany, covering more than 90% of all recorded species. Our library included various morphological similar taxa, e.g., species within the genera Sigara and Notonecta as well as water striders of the genus Gerris. Fifty-five species (82%) were unambiguously assigned to a single Barcode Index Number (BIN) by their barcode sequences, whereas BIN sharing was observed for 10 species. Furthermore, we found monophyletic lineages for 52 analyzed species. Our data revealed interspecific K2P distances with below 2.2% for 18 species. Intraspecific distances above 2.2% were shown for 11 species. We found evidence for hybridization between various corixid species (Sigara, Callicorixa), but our molecular data also revealed exceptionally high intraspecific distances as a consequence of distinct mitochondrial lineages for Cymatia coleoptrata and the pygmy backswimmer Plea minutissima. Our study clearly demonstrates the usefulness of DNA barcodes for the identification of the aquatic Heteroptera of Germany and adjacent regions. In this context, our data set represents an essential baseline for a reference library for bioassessment studies of freshwater habitats using modern high-throughput technologies in the near future. The existing data also opens new questions regarding the causes of observed low inter- and high intraspecific genetic variation and furthermore highlight the necessity of taxonomic revisions for various taxa, combining both molecular and morphological data.

An initial survey of aquatic and semi-aquatic Heteroptera (Insecta) from the Cardamom Mountains and adjacent uplands of southwestern Cambodia, with descriptions of four new species

Previous collections of aquatic Heteroptera from Cambodia have been limited, and the biota of the country has remained essentially undocumented until the past several years. Recent surveys of aquatic Heteroptera in the Cardamom Mountains and adjacent Kirirom and Bokor plateaus of southwestern Cambodia, coupled with previous literature records, demonstrate that 11 families, 35 genera, and 68 species of water bugs occur in this area. These collections include 13 genus records and 37 species records newly listed for the country of Cambodia. The following four new species are described based on these recent surveys: Amemboa cambodiana n. sp. (Gerridae); Microvelia penglyi n. sp., Microvelia setifera n. sp. and Microvelia bokor n. sp. (all Veliidae). Based on an updated checklist provided herein, the aquatic Heteroptera biota of Cambodia as currently known consists of 78 species, and has an endemism rate of 7.7%, although these numbers should be considered provisional pending further sampling.