Diversity Of Aquatic Insects Research Articles

Holocene environmental history of a small Mediterranean island in response to sea-level changes, climate and human impact

The aim of this study is to investigate human-climate-environment interactions in a small Mediterranean island. Comparison between palynological and palaeoentomological data from the Greco pond (Cavallo Island, southern Corsica) reveals that the island was first covered by a more-or-less open Erica arborea pasture-woodland from ca. 7000 to 6100cal.yrB.P. Grazing animals from 7000 to 6200cal.yrB.P., followed by a spreading of Ficus carica (marked by the bark beetle Hypoborus ficus) from ca. 6100 to 5750cal.yrB.P., suggest that human activities could be implicated in the E. arborea forest opening. From ca. 5500cal.yrB.P., a regional expansion of Q. ilex was recorded, but an open landscape with thermophilous and drought-tolerant plants locally took place from ca. 4700cal.yrB.P. onward. Pastoral and agricultural biomarkers (pollen, NPP and insect) together with archaeological evidence indicate that human activities were involved in the installation of a lasting open vegetation. Simultaneously, the effects of the Holocene relative sea-level rise on the coastal wetland are recorded: (1) freshwater conditions prevailed in the Greco pond since 7000cal.yrB.P. at least, (2) the first evidence of salt marsh development dates back to ca. 4500cal.yrB.P., (3) a strong increase of salinity with marine intrusions were recorded at ca. 3700cal.yrB.P. while a decline in aquatic insect diversity occurred and (4) a phase of sand dune formation was recorded from ca. 2000cal.yrB.P. onward. Our results suggest that if large-scale climatic trend such as the Holocene relative sea-level rise could affect coastal ecosystem, effects of human activities could play the leading role in vegetation and terrestrial beetle assemblage changes in a small island context.

<p class="Body" align="left"><strong>Re-habitation and changes in the genetic diversity of aquatic insects in a newly restored shoal type habitat created as the result of a nature restoration project in the central basin of the Chikuma-gawa River</strong></p>

The channels of almost all rivers in Japan have been fixed through the construction of artificial riverbanks to control flooding. In addition, to prevent flooding, maintenance works including the removal of gravel from the channels must be conducted regularly. As a result, the level of most riverbeds within river channels has been lowered, and riverbanks have become far steeper. These large changes to riverside environments have significantly altered the type of habitats available to plants, causing the level of vegetation growth on the riverside to increase. To improve such flood control methods, a new excavation project has commenced in the central area of the Chikuma-gawa River basin, under the auspices of the newly commissioned “Government Nature Restoration Project”. As part of this project, a large shallow environment approximately 1 km in length along the river’s course was newly created. We have attempted to evaluate the impact of this project and the subsequent environmental response, focusing on two dominant benthos, Stenopsyche marmorata and Isonychia japonica, particularly the dynamics of their genetic structure and diversity. Following the excavation of riverbanks and channels, the population density reached the same levels as at the control site, in a relatively short period of time. This is because the research site was limited to a small area within the large-scale river basin, with robust habitats located both upstream and downstream. The two target species in this study represent typical dominant species in the central basin of this river, and occur at high density. In other words, they could be transferred smoothly from the surrounding robust habitats, especially by the flow from upstream.

Diversity of Aquatic Insects in Karamana River, Southern Western Ghats, India

Diversity of Aquatic Insects in Karamana River, Southern Western Ghats, India

NightLife: A cheap, robust, LED based light trap for collecting aquatic insects in remote areas.

Inland waters cover less than 1% of our planet's surface, yet provide habitat to approximately one hundred thousand aquatic insect species, i.e. those with at least one aquatic lifestage (Balian et al. 2008, Dijkstra et al. 2014). Considering the taxonomic deficit in these groups this figure is likely a significant underestimate of the true aquatic insect diversity (Dijkstra et al. 2014). The majority of aquatic insect diversity is comprised of true flies (Diptera), followed by caddisflies (Trichoptera), beetles (Coleoptera), dragonflies (Odonata), stoneflies (Plecoptera) and mayflies (Ephemeroptera) (Balian et al. 2008, Dijkstra et al. 2014). The ecology of these groups has been the focus of significant study due to their role as bioindicators of water quality, as many species are sensitive to pollution and sudden changes in their environment (Rosenberg and Resh 1993). In addition many aquatic dipteran species are vectors of disease (e.g. Currie and Adler 2008, Rueda 2008). Aquatic insects are surveyed using a variety of methods including light trapping (e.g. Collier et al. 1997) which attracts emergent adults, and often mayfly subadults, using mercury vapour (MV) bulbs or actinic fluorescent tubes. Light trapping can be either active: attended light sheets, or passive: a combination of a light with a trap (Hardwick 1968, Hienton 1974). Passive traps allow samples from multiple sites to be collected in parallel by an individual in the field, with the number of sampling sites limited by the size and weight of each trap. Current Lights Mercury vapour (MV) bulbs work by passing an arc of electric current through ionised mercury vapour; as a result these bulbs require a relatively high current to maintain the arc and thus are limited to use with either mains power or a petrol / diesel powered generator. Remote areas therefore cannot be sampled without significant effort. In addition MV bulbs are excessively bright for attracting aquatic insects, and tend to draw large numbers of night flying lepidoptera and other non-target species. MV bulbs are also delicate, easily damaged in transport and liable to break if exposed to rain during operation due to thermal fracture of the glass, and their high operating temperature is a waste of power. Actinic fluorescent tubes also use mercury, but their method of operation requires a smaller current draw. While an improvement over MV bulbs, the current draw of fluorescent tubes does still require sizeable batteries if they are to be used in remote locations. For example a single 4W flourescent tube requires a 6v 12Ah battery weighing up to 2kg for an approximate 12hr run time. Fluorescent tubes are also delicate and liable to damage under field conditions. Both MV bulbs and actinic fluorescent tubes contain mercury, which if released in the field can be hazardous for the environment. An ideal aquatic insect light trap would have these properties: Be able to run from small, standard, [potentially] rechargeable batteries. Use low power light sources, at frequencies targeted for insect vision. Be robust enough for field use without special packing or travel arrangements. Be capable of autonomous operation. Light Emitting Diodes Light Emitting Diodes (LEDs) are semiconductor devices that are used in a wide range of scientific, home and commercial lighting solutions due to the following properties: low power / high-efficiency (compared to incandescent / fluorescent) narrow spectral emissions (i.e. specific colours) long-life low-operating temperature durable (enclosed in a solid epoxy case rather than hollow glass) small size and weight These same properties also lend themselves to the use of LEDs in insect collection.

Diversity of Aquatic Insects of Taean Area in South Korea, with Notes on Species-Specific Distribution1a

Diversity of Aquatic Insects of Taean Area in South Korea, with Notes on Species-Specific Distribution1a

β-diversity decline of aquatic insects at the microhabitat scale associated with agricultural land use

Several studies report the decline of β diversity caused by agricultural impacts in river ecosystems. However, the susceptible scale of β diversity to agricultural impacts and the indirect effects on β diversity within hierarchically nested ecosystems are unclear. We first tested the hypothesis that β diversity between microhabitats is significantly influenced by agricultural land use. We also examined the indirect effects of agricultural land use on α and β diversities at the microhabitat scale. Twelve microhabitat samples (25 cm2) were collected at 27 reaches within Kitamihorobetsu River, Japan. All reaches were classified into three agricultural intensities based on pasture area (low, middle, and high), and their hierarchical diversities (microhabitat, reach, and catchment) were calculated using additive partitioning. Indirect effects were demonstrated by structural equation modelling using indirect and direct environmental gradients. The α and β diversities at the microhabitat scale decreased significantly with agricultural intensity. Increasing pasture cover within catchments showed a negative correlation with habitat heterogeneity and water quality (habitat homogenization and water degradation) and a positive correlation with sand cover on streambeds (sedimentation of fine particles). The α diversity decreased with sedimentation of fine particles, and the β diversity decreased with habitat homogenization and water degradation. Our findings suggest that species diversity of aquatic insects at the microhabitat scale would be susceptible to agricultural land use. Furthermore, we emphasize that the diversity index used to evaluate restoration projects should be carefully selected because influential abiotic factors were different between α and β diversities.

Controls on metal exposure to aquatic organisms in urban streams.

Streams in urban ecosystems receive metal inputs primarily from stormwater runoff and wastewater effluent. The relative contribution of these metal sources to stream impairment is difficult to discern based on simple water characteristics and biological surveys. Stream impairment in these systems is often indicated by reduced abundance and diversity of aquatic insects, which tend to be more sensitive to chronic metal exposures. Metal species and controls on metal species in both the waterborne and dietborne exposure pathways to aquatic organisms are reviewed here. In addition, ecological changes that can control dietborne species are discussed. A main focus is on how organic matter from different anthropogenic sources may control both aqueous metal speciation as well as interaction with various inorganic or microbiological surfaces in streams. Most of the reviewed research focuses on Cu, Zn or Pb as those are the primary metals of concern in developed systems and Cu and Pb have unique and strong interactions with organic matter. Recommendations for further research are described in the context of exposure species, dynamics of exposure, stoichiometry, or advanced analytical tools, and regulatory implications are discussed.

Predator-prey body size relationship in temporary wetlands: effect of predatory insects on prey size spectra and survival

The effect of predators on prey size structure in aquatic communities has been well studied in lentic permanent habits, but less attention has been placed on temporary environments. The biota of seasonal Andean wetlands in Patagonia is basically formed by crustaceans, insects and pond-breeding amphibians. The dominant predators in these wetlands are macroinvertebrates, mostly aquatic insects. The main objectives of this study were to examine the seasonal and interannual variation in the body size of prey and predators in two temporary wetlands located in northwest Patagonia, during two consecutive hydroperiods and to evaluate the effect of different insect predators over different prey sizes and different ontogenetic stages of invertebrate and vertebrate prey. Prey size structure and predator size structure were affected by the wetland type and the sampling months and predator body size was not correlated with prey size structure. The experiments showed that small prey were the most impacted by predaceous insects and all predators showed size-limited predation. Although aquatic insects significantly reduced the number of prey in the predation experiments, they did not significantly affect the body size structure of prey in nature. In this sense, the diversity of aquatic insects with different predatory strategies could maintain the heterogeneity in prey size structure in the wetlands studied.

Diversity of Aquatic Insects in the Organic and Conventional Rice Fields in Khon Kaen Thailand

Diversity of Aquatic Insects in the Organic and Conventional Rice Fields in Khon Kaen Thailand

Diversity and Community Structure of Aquatic Insects in a Fresh Water Lentic System of Purba Medinipur District, W.B., India

Diversity and Community Structure of Aquatic Insects in a Fresh Water Lentic System of Purba Medinipur District, W.B., India

A comparative study of the aquatic insect diversity of two ponds locatedin Cachar District, Assam, India

Ponds play a vital role in the conservation of aquatic biodiversity at the local level apart from other lakes and rivers. A comparative study was carried out on the aquatic insect diversity of two different ponds, one in an urban area (urban pond, UP) and another in a rural area (Jalinga pond, JP). Two seasonal collections (postmonsoon and winter) were made to check the pollution status of the two ponds based on the aquatic insect community and physicochemical properties of water. Consequently, 29 species, 17 families, and 5 orders of aquatic insects from UP and 17 species, 8 families, and 3 orders from JP were recorded. Aphelonecta sp., Cloeon sp., and Micronecta sp. were the eudominant species recorded. According to the Shannon (H') index, UP was more diverse than JP. Family level biotic indices and scores further proved the better water quality of UP than of JP. Hence, it can be said that urban ponds have an important role to play in biodiversity conservation.

Abundance of aquatic insects in relation to physico-chemical parameters of two highly polluted Rivers Sitalakkhya and the Buriganga

Diversity of aquatic insects in relation to the physicochemical parameters of the river Buriganga and Shitalakhya were studied from January to December 2013. A total of 9,891 individuals of aquatic insects representing 22 families under 6 orders were collected and identified. Higher number of insects were recorded from the river Shitalakhya (5,493) than the river Buriganga (4,398). Representatives of the family Culicidae were found to be dominant in the river Buriganga (23.28%) than Shitalakhya (20.70%). Specimens under the order Ephemeroptera and Trichoptera were found only in the river Shitalakhya. The highest diversity of Shannon Weiner Index (2.98), Evenness (0.98) and Taxa Richness (0.98) were recorded in the river Shitalakhya than the river Buriganga. This indicated the less pollution and presence of higher diversity of aquatic insects in the Shitalakhya river. The highest temperature, pH, EC, TDS, COD was observed in Buriganga in dry season and highest DO was observed in Shitalakhya in monsoon. From the present investigation it may be concluded here that the river Buriganga was more polluted than the river Shitalakhya.Bangladesh J. Zool. 43(1): 63-72, 2015

Relationships between land cover, riparian vegetation, stream characteristics, and aquatic insects in cloud forest streams, Mexico

Cloud forest streams are diverse ecosystems that provide valuable services (i.e., drinking water), but are threatened by anthropogenic activities on the watershed. We assessed the relationships between forest cover in the catchment, riparian vegetation, water chemistry, channel geomorphology, and the diversity of aquatic insects (taxonomic and functional diversity) in streams running through cloud forest in the upper part of La Antigua watershed, Mexico. Variables and aquatic insect assemblages were sampled during the dry and rainy seasons, in six streams draining different land covers, including forest, pasture, and agriculture. Aquatic insect assemblages were related to forest cover and riparian vegetation, as well as to various physical and chemical parameters of streams. Certain insect genera (Suragina and Anacroneuria) were indicators of little forest cover and forested streams, respectively. Functional Feeding Groups were related to physical and chemical parameters. Seasonality was also found to influence both the physical and chemical characteristics of streams and insect assemblages. Our findings reveal that cloud forest streams in La Antigua watershed are diverse and their insect assemblages are affected by land cover both in the watershed and the riparian zone, and by the associated changes in the stream physical and chemical characteristics.

Biodiversity dynamics of chironomid midges in high‐altitude lakes of the Alps over the past two millennia

Abstract Climate change is one of the key drivers of changes in the biodiversity of the planet. There is, however, a general lack of long‐term data sets showing trends in taxonomic diversity of aquatic insects in high mountain environments particularly vulnerable to climate change. Using palaeolimnological techniques, we explored the changes in subfossil chironomid assemblages from three remote water bodies in the Eastern Alps, with the main focus on taxonomic turnover over different intervals of the late Holocene. Major changes in the assemblages coincided with shifts between different climate regimes and were mainly associated with the taxonomic shifts indicating the crossing ecological thresholds related to the ice‐cover duration in alpine lakes. Patterns of assemblage turnover through the past 2000 years differ between the study sites. Nevertheless, despite site‐specific differences in the physical setting and taxonomic composition, the study sites reveal substantial chironomid assemblage turnover (>1.0 SD) since AD 1850. The highest chironomid turnover (0.87 SD) over the last 30 years (AD 1980–2010), more than three times greater (0.26 SD) than in the previous 30 years, is observed in the lake situated at the highest elevation among the study lakes. Applying non‐linear structural equation modelling, we found that cold‐season (October–May) temperatures and therefore lake ice phenology are among the most important environment variables affecting the chironomid assemblages. The results of this study suggest that further climate warming will increase the risk of ecological alterations in remote Alpine freshwaters, including major shifts in chironomid fauna.

An Investigation into the Physico-chemical Factors Affecting the Abundance and Diversity of Aquatic Insects in Organically Manured Aquadams and Their Utilization by Oreochromis mossambicus (Perciformes: Cichlidae).

The interaction between the fish Oreochromis mossambicus (Percifomes: Cichlidae) and aquatic insects after application of chicken, cow, and pig manure was studied in 7,000-liter plastic aquadams. Principal component analysis showed that most of the variation in water quality after application of manure was accounted for by potassium, nitrogen, dissolved oxygen, phosphate, and alkalinity. Canonical correspondence analysis showed that Gyrinidae, Elminidae, Hydrophilidae, Hydraenidae, and Athericidae were associated with high nutrient levels (nitrogen, phosphorus, and potassium) characteristic of the chicken manure. However, the most abundant aquatic insects Gerridae, Notonectidae, and Culicidae were close to the centre of the ordination and not defined by any nutrient gradient. The Shannon-Wiener diversity was highest in the aquadams treated with chicken manure. The most frequently occurring aquatic insects in the diet of O. mossambicus were culicid mosquitoes in all the treatments. However, in the laboratory, Chironomidae were the most preferred because they lacked refuge. Notonectidae and Gerridae were not recorded in the diet of O. mossambicus despite their abundance. This may be because of their anti-predation strategies. Laboratory experiments showed that Notonectidae, Gyrinidae, and Gerridae fed on Chironomidae and Culicidae. This implies that aquatic predatory insects competed for food with O. mossambicus.

Abundance and diversity of aquatic insects in two water bodies of Chittagong university campus

Abundance and diversity of aquatic insects was studied in two water bodies, (a pond and a lake) of Chittagong University campus during October 2009 to September 2010. A total of 4406 insects belonging to 32 genera, under 20 families and 6 orders were recorded. In both the water bodies, the representatives of the orders Hemiptera and Odonata were the most abundant groups. During the study period highest abundance of the total insects was recorded in November 2009 and the lowest in July 2010. Abundance of insects was comparatively higher in the pond habitat than in the lake. The Quotient of Similarity (QS) of the insects between the two water bodies was found to be the highest in October 2009 and lowest in July 2010. Species diversity, species richness and species evenness values of the lake were higher than that of the pond. Hydrophilus sp. and Sphaerodema sp. were the most dominant insects in the pond, while Chironomous sp. and Gerris sp. in the lake.Bangladesh J. Zool. 42(1): 19-33, 2014

Aquatic insect diversity of a protected area, Keibul Lamjao National Park in Manipur, North East India

Keibul Lamjao National Park, only home of Brow-Antler Deer, (Rucervus eldii eldii) is the unique floating park of the world. It is a part of the Loktak Lake, Manipur (Ramsar site). The lake gets major share of water from seven feeder rivers. In this paper an attempt has been made to study aquatic insect diversity of the five sites of the national park area which will indicate the health of the unique but deteriorating ecosystem and at the same time reduce aquatic insect data deficiency of the area. The study recorded 3 orders, 12 families and 23 species of aquatic insects. Besides inventorying the aquatic insect taxa, their relationships with several environmental variables including heavy metals were also investigated. The low Shannon Weiner Diversity Index values of aquatic insects (Shannon H' less than 1 in all the sites) indicated perturbed condition of the water of the National Park area. The study revealed very low dissolved oxygen (DO) in all the sites. All the three heavy metals in most of the sites were found beyond the desirable level of BIS (IS 10500: 1991). Different biological monitoring scores and Canonical correspondence analysis (CCA) have been used for discussion and interpretation. This study found that although protected areas are meant for protecting biodiversity, management of outside protected area particularly catchment area should be given priority for minimizing land use disturbance, altered hydrology and other related factors.

Diversity and Distribution of Aquatic Insects in Streams of the Mae Klong Watershed, Western Thailand

The distribution and diversity of aquatic insects and water quality variables were studied among three streams of the Mae Klong Watershed. In each stream, two sites were sampled. Aquatic insects and water quality variables were randomly sampled seven times in February, May, September, and December 2010 and in January, April, and May 2011. Overall, 11,153 individuals belonging to 64 families and nine orders were examined. Among the aquatic insects collected from the three streams, the order Trichoptera was most diverse in number of individuals, followed by Ephemeroptera, Hemiptera, Odonata, Coleoptera, Diptera, Plecoptera, Megaloptera, and Lepidoptera. The highest Shannon index of diversity of 2.934 and 3.2 was recorded in Huai Kayeng stream and the lowest was in Huai Pakkok stream (2.68 and 2.62). The high diversity of insect fauna in streams is an indication of larger microhabitat diversity and better water quality conditions prevailing in the streams. The evenness value was recorded as high in most sites. The high species diversity and evenness in almost all sites indicated good water quality.

Morphological taxonomy, DNA barcoding, and species diversity in southern Rocky Mountain headwater streams

Elevation gradients allow scientists to observe changes in fauna over a range of abiotic conditions. A variety of trends in aquatic insect diversity patterns across elevation have been reported. However, many of these studies are confounded because they include streams at lower elevations, which are often larger in size and more polluted than their higher-elevation counterparts. Moreover, such studies always relied solely on morphological delineation of taxa, thereby potentially overlooking cryptic diversity. We reduced these limitations by sampling only minimally impacted wadeable streams across an elevation gradient and by combining morphological taxonomy with deoxyribonucleic acid (DNA) barcoding to identify taxa. We collected numerically abundant Ephemeroptera, Plecoptera, and Trichoptera (EPT) from single streams at ∼200-m elevation intervals across >1000-m transects in 3 watersheds draining the eastern slope of the Colorado Rocky Mountains. Based on morphology alone, we identified 49 numerically abundant EPT morphospecies across 26 sites. Using DNA barcoding, we found 69 distinct lineages that probably represent distinct species. EPT species richness was highest at mid-elevations, and rates of turnover along elevation transects showed no consistent elevation trend or trend among ecological zones defined by vegetation. β-diversity across sites at comparable elevations in different watersheds showed a negative trend with increasing elevation that was marginally significant for DNA barcode taxa (p = 0.051) but not for morphospecies. Furthermore, significant (p < 0.05) differences in taxon richness, turnover, and lateral β-diversity values generated by DNA barcoding underscore the ability of molecular tools to quantify patterns in aquatic insect diversity across elevations.

Diversity of mosquitoes and the aquatic insects associated with their oviposition sites along the Pacific coast of Mexico.

BackgroundThe abundance, richness and diversity of mosquitoes and aquatic insects associated with their oviposition sites were surveyed along eight states of the Pacific coast of Mexico. Diversity was estimated using the Shannon index (H’), similarity measures and cluster analysis.MethodsOviposition sites were sampled during 2–3 months per year, over a three year period. Field collected larvae and pupae were reared and identified to species following adult emergence. Aquatic insects present at oviposition sites were also collected, counted and identified to species or genus.ResultsIn total, 15 genera and 74 species of mosquitoes were identified: Anopheles pseudopunctipennis, An. albimanus and Aedes aegypti were the most abundant and widely-distributed species, representing 47% of total mosquito individuals sampled. New species records for certain states are reported. Anopheline diversity was lowest in Sinaloa state (H’ = 0.54) and highest in Chiapas (H’ = 1.61) and Michoacán (H’ = 1.56), whereas culicid diversity was lowest in Michoacán (H’ = 1.93), Colima (H’ = 1.95), Sinaloa (H’ = 1.99) and Jalisco (H’ = 2.01) and highest in Chiapas (H’ = 2.66). In total, 10 orders, 57 families, 166 genera and 247 species of aquatic insects were identified in samples. Aquatic insect diversity was highest in Chiapas, Oaxaca and Michoacán (H’ = 3.60-3.75). Mosquito larval/pupal abundance was not correlated with that of predatory Coleoptera and Hemiptera.ConclusionThis represents the first update on the diversity and geographic distribution of the mosquitoes and aquatic insects of Mexico in over five decades. This information has been cataloged in Mexico’s National Biodiversity Information System (SNIB-CONABIO) for public inspection.